1/* 2** 2001 September 15 3** 4** The author disclaims copyright to this source code. In place of 5** a legal notice, here is a blessing: 6** 7** May you do good and not evil. 8** May you find forgiveness for yourself and forgive others. 9** May you share freely, never taking more than you give. 10** 11************************************************************************* 12** This header file defines the interface that the SQLite library 13** presents to client programs. If a C-function, structure, datatype, 14** or constant definition does not appear in this file, then it is 15** not a published API of SQLite, is subject to change without 16** notice, and should not be referenced by programs that use SQLite. 17** 18** Some of the definitions that are in this file are marked as 19** "experimental". Experimental interfaces are normally new 20** features recently added to SQLite. We do not anticipate changes 21** to experimental interfaces but reserve the right to make minor changes 22** if experience from use "in the wild" suggest such changes are prudent. 23** 24** The official C-language API documentation for SQLite is derived 25** from comments in this file. This file is the authoritative source 26** on how SQLite interfaces are supposed to operate. 27** 28** The name of this file under configuration management is "sqlite.h.in". 29** The makefile makes some minor changes to this file (such as inserting 30** the version number) and changes its name to "sqlite3.h" as 31** part of the build process. 32*/ 33#ifndef SQLITE3_H 34#define SQLITE3_H 35#include <stdarg.h> /* Needed for the definition of va_list */ 36 37/* 38** Make sure we can call this stuff from C++. 39*/ 40#ifdef __cplusplus 41extern "C" { 42#endif 43 44 45/* 46** Provide the ability to override linkage features of the interface. 47*/ 48#ifndef SQLITE_EXTERN 49# define SQLITE_EXTERN extern 50#endif 51#ifndef SQLITE_API 52# define SQLITE_API 53#endif 54#ifndef SQLITE_CDECL 55# define SQLITE_CDECL 56#endif 57#ifndef SQLITE_APICALL 58# define SQLITE_APICALL 59#endif 60#ifndef SQLITE_STDCALL 61# define SQLITE_STDCALL SQLITE_APICALL 62#endif 63#ifndef SQLITE_CALLBACK 64# define SQLITE_CALLBACK 65#endif 66#ifndef SQLITE_SYSAPI 67# define SQLITE_SYSAPI 68#endif 69 70/* 71** These no-op macros are used in front of interfaces to mark those 72** interfaces as either deprecated or experimental. New applications 73** should not use deprecated interfaces - they are supported for backwards 74** compatibility only. Application writers should be aware that 75** experimental interfaces are subject to change in point releases. 76** 77** These macros used to resolve to various kinds of compiler magic that 78** would generate warning messages when they were used. But that 79** compiler magic ended up generating such a flurry of bug reports 80** that we have taken it all out and gone back to using simple 81** noop macros. 82*/ 83#define SQLITE_DEPRECATED 84#define SQLITE_EXPERIMENTAL 85 86/* 87** Ensure these symbols were not defined by some previous header file. 88*/ 89#ifdef SQLITE_VERSION 90# undef SQLITE_VERSION 91#endif 92#ifdef SQLITE_VERSION_NUMBER 93# undef SQLITE_VERSION_NUMBER 94#endif 95 96/* 97** CAPI3REF: Compile-Time Library Version Numbers 98** 99** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 100** evaluates to a string literal that is the SQLite version in the 101** format "X.Y.Z" where X is the major version number (always 3 for 102** SQLite3) and Y is the minor version number and Z is the release number.)^ 103** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 104** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 105** numbers used in [SQLITE_VERSION].)^ 106** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 107** be larger than the release from which it is derived. Either Y will 108** be held constant and Z will be incremented or else Y will be incremented 109** and Z will be reset to zero. 110** 111** Since [version 3.6.18] ([dateof:3.6.18]), 112** SQLite source code has been stored in the 113** <a href="http://www.fossil-scm.org/">Fossil configuration management 114** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 115** a string which identifies a particular check-in of SQLite 116** within its configuration management system. ^The SQLITE_SOURCE_ID 117** string contains the date and time of the check-in (UTC) and a SHA1 118** or SHA3-256 hash of the entire source tree. 119** 120** See also: [sqlite3_libversion()], 121** [sqlite3_libversion_number()], [sqlite3_sourceid()], 122** [sqlite_version()] and [sqlite_source_id()]. 123*/ 124#define SQLITE_VERSION "3.19.4" 125#define SQLITE_VERSION_NUMBER 3019004 126#define SQLITE_SOURCE_ID "2017-08-18 19:28:12 605907e73adb4533b12d22be8422f17a8dc125b5c37bb391756a11fc3a8c4d10" 127 128/* 129** CAPI3REF: Run-Time Library Version Numbers 130** KEYWORDS: sqlite3_version sqlite3_sourceid 131** 132** These interfaces provide the same information as the [SQLITE_VERSION], 133** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 134** but are associated with the library instead of the header file. ^(Cautious 135** programmers might include assert() statements in their application to 136** verify that values returned by these interfaces match the macros in 137** the header, and thus ensure that the application is 138** compiled with matching library and header files. 139** 140** <blockquote><pre> 141** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 142** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 143** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 144** </pre></blockquote>)^ 145** 146** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 147** macro. ^The sqlite3_libversion() function returns a pointer to the 148** to the sqlite3_version[] string constant. The sqlite3_libversion() 149** function is provided for use in DLLs since DLL users usually do not have 150** direct access to string constants within the DLL. ^The 151** sqlite3_libversion_number() function returns an integer equal to 152** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 153** a pointer to a string constant whose value is the same as the 154** [SQLITE_SOURCE_ID] C preprocessor macro. 155** 156** See also: [sqlite_version()] and [sqlite_source_id()]. 157*/ 158SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 159SQLITE_API const char *sqlite3_libversion(void); 160SQLITE_API const char *sqlite3_sourceid(void); 161SQLITE_API int sqlite3_libversion_number(void); 162 163/* 164** CAPI3REF: Run-Time Library Compilation Options Diagnostics 165** 166** ^The sqlite3_compileoption_used() function returns 0 or 1 167** indicating whether the specified option was defined at 168** compile time. ^The SQLITE_ prefix may be omitted from the 169** option name passed to sqlite3_compileoption_used(). 170** 171** ^The sqlite3_compileoption_get() function allows iterating 172** over the list of options that were defined at compile time by 173** returning the N-th compile time option string. ^If N is out of range, 174** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 175** prefix is omitted from any strings returned by 176** sqlite3_compileoption_get(). 177** 178** ^Support for the diagnostic functions sqlite3_compileoption_used() 179** and sqlite3_compileoption_get() may be omitted by specifying the 180** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 181** 182** See also: SQL functions [sqlite_compileoption_used()] and 183** [sqlite_compileoption_get()] and the [compile_options pragma]. 184*/ 185#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 186SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 187SQLITE_API const char *sqlite3_compileoption_get(int N); 188#endif 189 190/* 191** CAPI3REF: Test To See If The Library Is Threadsafe 192** 193** ^The sqlite3_threadsafe() function returns zero if and only if 194** SQLite was compiled with mutexing code omitted due to the 195** [SQLITE_THREADSAFE] compile-time option being set to 0. 196** 197** SQLite can be compiled with or without mutexes. When 198** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 199** are enabled and SQLite is threadsafe. When the 200** [SQLITE_THREADSAFE] macro is 0, 201** the mutexes are omitted. Without the mutexes, it is not safe 202** to use SQLite concurrently from more than one thread. 203** 204** Enabling mutexes incurs a measurable performance penalty. 205** So if speed is of utmost importance, it makes sense to disable 206** the mutexes. But for maximum safety, mutexes should be enabled. 207** ^The default behavior is for mutexes to be enabled. 208** 209** This interface can be used by an application to make sure that the 210** version of SQLite that it is linking against was compiled with 211** the desired setting of the [SQLITE_THREADSAFE] macro. 212** 213** This interface only reports on the compile-time mutex setting 214** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 215** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 216** can be fully or partially disabled using a call to [sqlite3_config()] 217** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 218** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 219** sqlite3_threadsafe() function shows only the compile-time setting of 220** thread safety, not any run-time changes to that setting made by 221** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 222** is unchanged by calls to sqlite3_config().)^ 223** 224** See the [threading mode] documentation for additional information. 225*/ 226SQLITE_API int sqlite3_threadsafe(void); 227 228/* 229** CAPI3REF: Database Connection Handle 230** KEYWORDS: {database connection} {database connections} 231** 232** Each open SQLite database is represented by a pointer to an instance of 233** the opaque structure named "sqlite3". It is useful to think of an sqlite3 234** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 235** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 236** and [sqlite3_close_v2()] are its destructors. There are many other 237** interfaces (such as 238** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 239** [sqlite3_busy_timeout()] to name but three) that are methods on an 240** sqlite3 object. 241*/ 242typedef struct sqlite3 sqlite3; 243 244/* 245** CAPI3REF: 64-Bit Integer Types 246** KEYWORDS: sqlite_int64 sqlite_uint64 247** 248** Because there is no cross-platform way to specify 64-bit integer types 249** SQLite includes typedefs for 64-bit signed and unsigned integers. 250** 251** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 252** The sqlite_int64 and sqlite_uint64 types are supported for backwards 253** compatibility only. 254** 255** ^The sqlite3_int64 and sqlite_int64 types can store integer values 256** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 257** sqlite3_uint64 and sqlite_uint64 types can store integer values 258** between 0 and +18446744073709551615 inclusive. 259*/ 260#ifdef SQLITE_INT64_TYPE 261 typedef SQLITE_INT64_TYPE sqlite_int64; 262# ifdef SQLITE_UINT64_TYPE 263 typedef SQLITE_UINT64_TYPE sqlite_uint64; 264# else 265 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 266# endif 267#elif defined(_MSC_VER) || defined(__BORLANDC__) 268 typedef __int64 sqlite_int64; 269 typedef unsigned __int64 sqlite_uint64; 270#else 271 typedef long long int sqlite_int64; 272 typedef unsigned long long int sqlite_uint64; 273#endif 274typedef sqlite_int64 sqlite3_int64; 275typedef sqlite_uint64 sqlite3_uint64; 276 277/* 278** If compiling for a processor that lacks floating point support, 279** substitute integer for floating-point. 280*/ 281#ifdef SQLITE_OMIT_FLOATING_POINT 282# define double sqlite3_int64 283#endif 284 285/* 286** CAPI3REF: Closing A Database Connection 287** DESTRUCTOR: sqlite3 288** 289** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 290** for the [sqlite3] object. 291** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 292** the [sqlite3] object is successfully destroyed and all associated 293** resources are deallocated. 294** 295** ^If the database connection is associated with unfinalized prepared 296** statements or unfinished sqlite3_backup objects then sqlite3_close() 297** will leave the database connection open and return [SQLITE_BUSY]. 298** ^If sqlite3_close_v2() is called with unfinalized prepared statements 299** and/or unfinished sqlite3_backups, then the database connection becomes 300** an unusable "zombie" which will automatically be deallocated when the 301** last prepared statement is finalized or the last sqlite3_backup is 302** finished. The sqlite3_close_v2() interface is intended for use with 303** host languages that are garbage collected, and where the order in which 304** destructors are called is arbitrary. 305** 306** Applications should [sqlite3_finalize | finalize] all [prepared statements], 307** [sqlite3_blob_close | close] all [BLOB handles], and 308** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 309** with the [sqlite3] object prior to attempting to close the object. ^If 310** sqlite3_close_v2() is called on a [database connection] that still has 311** outstanding [prepared statements], [BLOB handles], and/or 312** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 313** of resources is deferred until all [prepared statements], [BLOB handles], 314** and [sqlite3_backup] objects are also destroyed. 315** 316** ^If an [sqlite3] object is destroyed while a transaction is open, 317** the transaction is automatically rolled back. 318** 319** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 320** must be either a NULL 321** pointer or an [sqlite3] object pointer obtained 322** from [sqlite3_open()], [sqlite3_open16()], or 323** [sqlite3_open_v2()], and not previously closed. 324** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 325** argument is a harmless no-op. 326*/ 327SQLITE_API int sqlite3_close(sqlite3*); 328SQLITE_API int sqlite3_close_v2(sqlite3*); 329 330/* 331** The type for a callback function. 332** This is legacy and deprecated. It is included for historical 333** compatibility and is not documented. 334*/ 335typedef int (*sqlite3_callback)(void*,int,char**, char**); 336 337/* 338** CAPI3REF: One-Step Query Execution Interface 339** METHOD: sqlite3 340** 341** The sqlite3_exec() interface is a convenience wrapper around 342** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 343** that allows an application to run multiple statements of SQL 344** without having to use a lot of C code. 345** 346** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 347** semicolon-separate SQL statements passed into its 2nd argument, 348** in the context of the [database connection] passed in as its 1st 349** argument. ^If the callback function of the 3rd argument to 350** sqlite3_exec() is not NULL, then it is invoked for each result row 351** coming out of the evaluated SQL statements. ^The 4th argument to 352** sqlite3_exec() is relayed through to the 1st argument of each 353** callback invocation. ^If the callback pointer to sqlite3_exec() 354** is NULL, then no callback is ever invoked and result rows are 355** ignored. 356** 357** ^If an error occurs while evaluating the SQL statements passed into 358** sqlite3_exec(), then execution of the current statement stops and 359** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 360** is not NULL then any error message is written into memory obtained 361** from [sqlite3_malloc()] and passed back through the 5th parameter. 362** To avoid memory leaks, the application should invoke [sqlite3_free()] 363** on error message strings returned through the 5th parameter of 364** sqlite3_exec() after the error message string is no longer needed. 365** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 366** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 367** NULL before returning. 368** 369** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 370** routine returns SQLITE_ABORT without invoking the callback again and 371** without running any subsequent SQL statements. 372** 373** ^The 2nd argument to the sqlite3_exec() callback function is the 374** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 375** callback is an array of pointers to strings obtained as if from 376** [sqlite3_column_text()], one for each column. ^If an element of a 377** result row is NULL then the corresponding string pointer for the 378** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 379** sqlite3_exec() callback is an array of pointers to strings where each 380** entry represents the name of corresponding result column as obtained 381** from [sqlite3_column_name()]. 382** 383** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 384** to an empty string, or a pointer that contains only whitespace and/or 385** SQL comments, then no SQL statements are evaluated and the database 386** is not changed. 387** 388** Restrictions: 389** 390** <ul> 391** <li> The application must ensure that the 1st parameter to sqlite3_exec() 392** is a valid and open [database connection]. 393** <li> The application must not close the [database connection] specified by 394** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 395** <li> The application must not modify the SQL statement text passed into 396** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 397** </ul> 398*/ 399SQLITE_API int sqlite3_exec( 400 sqlite3*, /* An open database */ 401 const char *sql, /* SQL to be evaluated */ 402 int (*callback)(void*,int,char**,char**), /* Callback function */ 403 void *, /* 1st argument to callback */ 404 char **errmsg /* Error msg written here */ 405); 406 407/* 408** CAPI3REF: Result Codes 409** KEYWORDS: {result code definitions} 410** 411** Many SQLite functions return an integer result code from the set shown 412** here in order to indicate success or failure. 413** 414** New error codes may be added in future versions of SQLite. 415** 416** See also: [extended result code definitions] 417*/ 418#define SQLITE_OK 0 /* Successful result */ 419/* beginning-of-error-codes */ 420#define SQLITE_ERROR 1 /* SQL error or missing database */ 421#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 422#define SQLITE_PERM 3 /* Access permission denied */ 423#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 424#define SQLITE_BUSY 5 /* The database file is locked */ 425#define SQLITE_LOCKED 6 /* A table in the database is locked */ 426#define SQLITE_NOMEM 7 /* A malloc() failed */ 427#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 428#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 429#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 430#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 431#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 432#define SQLITE_FULL 13 /* Insertion failed because database is full */ 433#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 434#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 435#define SQLITE_EMPTY 16 /* Database is empty */ 436#define SQLITE_SCHEMA 17 /* The database schema changed */ 437#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 438#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 439#define SQLITE_MISMATCH 20 /* Data type mismatch */ 440#define SQLITE_MISUSE 21 /* Library used incorrectly */ 441#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 442#define SQLITE_AUTH 23 /* Authorization denied */ 443#define SQLITE_FORMAT 24 /* Auxiliary database format error */ 444#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 445#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 446#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 447#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 448#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 449#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 450/* end-of-error-codes */ 451 452/* 453** CAPI3REF: Extended Result Codes 454** KEYWORDS: {extended result code definitions} 455** 456** In its default configuration, SQLite API routines return one of 30 integer 457** [result codes]. However, experience has shown that many of 458** these result codes are too coarse-grained. They do not provide as 459** much information about problems as programmers might like. In an effort to 460** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 461** and later) include 462** support for additional result codes that provide more detailed information 463** about errors. These [extended result codes] are enabled or disabled 464** on a per database connection basis using the 465** [sqlite3_extended_result_codes()] API. Or, the extended code for 466** the most recent error can be obtained using 467** [sqlite3_extended_errcode()]. 468*/ 469#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 470#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 471#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 472#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 473#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 474#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 475#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 476#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 477#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 478#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 479#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 480#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 481#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 482#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 483#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 484#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 485#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 486#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 487#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 488#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 489#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 490#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 491#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 492#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 493#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 494#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 495#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 496#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 497#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 498#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 499#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 500#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 501#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 502#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 503#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 504#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 505#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 506#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 507#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 508#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 509#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 510#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 511#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 512#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 513#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 514#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 515#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 516#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 517#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 518#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 519#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 520#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 521#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 522#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 523#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 524#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 525#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 526#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 527#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 528 529/* 530** CAPI3REF: Flags For File Open Operations 531** 532** These bit values are intended for use in the 533** 3rd parameter to the [sqlite3_open_v2()] interface and 534** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 535*/ 536#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 537#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 538#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 539#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 540#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 541#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 542#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 543#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 544#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 545#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 546#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 547#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 548#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 549#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 550#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 551#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 552#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 553#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 554#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 555#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 556 557/* Reserved: 0x00F00000 */ 558 559/* 560** CAPI3REF: Device Characteristics 561** 562** The xDeviceCharacteristics method of the [sqlite3_io_methods] 563** object returns an integer which is a vector of these 564** bit values expressing I/O characteristics of the mass storage 565** device that holds the file that the [sqlite3_io_methods] 566** refers to. 567** 568** The SQLITE_IOCAP_ATOMIC property means that all writes of 569** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 570** mean that writes of blocks that are nnn bytes in size and 571** are aligned to an address which is an integer multiple of 572** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 573** that when data is appended to a file, the data is appended 574** first then the size of the file is extended, never the other 575** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 576** information is written to disk in the same order as calls 577** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 578** after reboot following a crash or power loss, the only bytes in a 579** file that were written at the application level might have changed 580** and that adjacent bytes, even bytes within the same sector are 581** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 582** flag indicates that a file cannot be deleted when open. The 583** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 584** read-only media and cannot be changed even by processes with 585** elevated privileges. 586** 587** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 588** filesystem supports doing multiple write operations atomically when those 589** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 590** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 591*/ 592#define SQLITE_IOCAP_ATOMIC 0x00000001 593#define SQLITE_IOCAP_ATOMIC512 0x00000002 594#define SQLITE_IOCAP_ATOMIC1K 0x00000004 595#define SQLITE_IOCAP_ATOMIC2K 0x00000008 596#define SQLITE_IOCAP_ATOMIC4K 0x00000010 597#define SQLITE_IOCAP_ATOMIC8K 0x00000020 598#define SQLITE_IOCAP_ATOMIC16K 0x00000040 599#define SQLITE_IOCAP_ATOMIC32K 0x00000080 600#define SQLITE_IOCAP_ATOMIC64K 0x00000100 601#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 602#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 603#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 604#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 605#define SQLITE_IOCAP_IMMUTABLE 0x00002000 606#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 607 608/* 609** CAPI3REF: File Locking Levels 610** 611** SQLite uses one of these integer values as the second 612** argument to calls it makes to the xLock() and xUnlock() methods 613** of an [sqlite3_io_methods] object. 614*/ 615#define SQLITE_LOCK_NONE 0 616#define SQLITE_LOCK_SHARED 1 617#define SQLITE_LOCK_RESERVED 2 618#define SQLITE_LOCK_PENDING 3 619#define SQLITE_LOCK_EXCLUSIVE 4 620 621/* 622** CAPI3REF: Synchronization Type Flags 623** 624** When SQLite invokes the xSync() method of an 625** [sqlite3_io_methods] object it uses a combination of 626** these integer values as the second argument. 627** 628** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 629** sync operation only needs to flush data to mass storage. Inode 630** information need not be flushed. If the lower four bits of the flag 631** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 632** If the lower four bits equal SQLITE_SYNC_FULL, that means 633** to use Mac OS X style fullsync instead of fsync(). 634** 635** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 636** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 637** settings. The [synchronous pragma] determines when calls to the 638** xSync VFS method occur and applies uniformly across all platforms. 639** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 640** energetic or rigorous or forceful the sync operations are and 641** only make a difference on Mac OSX for the default SQLite code. 642** (Third-party VFS implementations might also make the distinction 643** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 644** operating systems natively supported by SQLite, only Mac OSX 645** cares about the difference.) 646*/ 647#define SQLITE_SYNC_NORMAL 0x00002 648#define SQLITE_SYNC_FULL 0x00003 649#define SQLITE_SYNC_DATAONLY 0x00010 650 651/* 652** CAPI3REF: OS Interface Open File Handle 653** 654** An [sqlite3_file] object represents an open file in the 655** [sqlite3_vfs | OS interface layer]. Individual OS interface 656** implementations will 657** want to subclass this object by appending additional fields 658** for their own use. The pMethods entry is a pointer to an 659** [sqlite3_io_methods] object that defines methods for performing 660** I/O operations on the open file. 661*/ 662typedef struct sqlite3_file sqlite3_file; 663struct sqlite3_file { 664 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 665}; 666 667/* 668** CAPI3REF: OS Interface File Virtual Methods Object 669** 670** Every file opened by the [sqlite3_vfs.xOpen] method populates an 671** [sqlite3_file] object (or, more commonly, a subclass of the 672** [sqlite3_file] object) with a pointer to an instance of this object. 673** This object defines the methods used to perform various operations 674** against the open file represented by the [sqlite3_file] object. 675** 676** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 677** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 678** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 679** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 680** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 681** to NULL. 682** 683** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 684** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 685** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 686** flag may be ORed in to indicate that only the data of the file 687** and not its inode needs to be synced. 688** 689** The integer values to xLock() and xUnlock() are one of 690** <ul> 691** <li> [SQLITE_LOCK_NONE], 692** <li> [SQLITE_LOCK_SHARED], 693** <li> [SQLITE_LOCK_RESERVED], 694** <li> [SQLITE_LOCK_PENDING], or 695** <li> [SQLITE_LOCK_EXCLUSIVE]. 696** </ul> 697** xLock() increases the lock. xUnlock() decreases the lock. 698** The xCheckReservedLock() method checks whether any database connection, 699** either in this process or in some other process, is holding a RESERVED, 700** PENDING, or EXCLUSIVE lock on the file. It returns true 701** if such a lock exists and false otherwise. 702** 703** The xFileControl() method is a generic interface that allows custom 704** VFS implementations to directly control an open file using the 705** [sqlite3_file_control()] interface. The second "op" argument is an 706** integer opcode. The third argument is a generic pointer intended to 707** point to a structure that may contain arguments or space in which to 708** write return values. Potential uses for xFileControl() might be 709** functions to enable blocking locks with timeouts, to change the 710** locking strategy (for example to use dot-file locks), to inquire 711** about the status of a lock, or to break stale locks. The SQLite 712** core reserves all opcodes less than 100 for its own use. 713** A [file control opcodes | list of opcodes] less than 100 is available. 714** Applications that define a custom xFileControl method should use opcodes 715** greater than 100 to avoid conflicts. VFS implementations should 716** return [SQLITE_NOTFOUND] for file control opcodes that they do not 717** recognize. 718** 719** The xSectorSize() method returns the sector size of the 720** device that underlies the file. The sector size is the 721** minimum write that can be performed without disturbing 722** other bytes in the file. The xDeviceCharacteristics() 723** method returns a bit vector describing behaviors of the 724** underlying device: 725** 726** <ul> 727** <li> [SQLITE_IOCAP_ATOMIC] 728** <li> [SQLITE_IOCAP_ATOMIC512] 729** <li> [SQLITE_IOCAP_ATOMIC1K] 730** <li> [SQLITE_IOCAP_ATOMIC2K] 731** <li> [SQLITE_IOCAP_ATOMIC4K] 732** <li> [SQLITE_IOCAP_ATOMIC8K] 733** <li> [SQLITE_IOCAP_ATOMIC16K] 734** <li> [SQLITE_IOCAP_ATOMIC32K] 735** <li> [SQLITE_IOCAP_ATOMIC64K] 736** <li> [SQLITE_IOCAP_SAFE_APPEND] 737** <li> [SQLITE_IOCAP_SEQUENTIAL] 738** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 739** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 740** <li> [SQLITE_IOCAP_IMMUTABLE] 741** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 742** </ul> 743** 744** The SQLITE_IOCAP_ATOMIC property means that all writes of 745** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 746** mean that writes of blocks that are nnn bytes in size and 747** are aligned to an address which is an integer multiple of 748** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 749** that when data is appended to a file, the data is appended 750** first then the size of the file is extended, never the other 751** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 752** information is written to disk in the same order as calls 753** to xWrite(). 754** 755** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 756** in the unread portions of the buffer with zeros. A VFS that 757** fails to zero-fill short reads might seem to work. However, 758** failure to zero-fill short reads will eventually lead to 759** database corruption. 760*/ 761typedef struct sqlite3_io_methods sqlite3_io_methods; 762struct sqlite3_io_methods { 763 int iVersion; 764 int (*xClose)(sqlite3_file*); 765 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 766 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 767 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 768 int (*xSync)(sqlite3_file*, int flags); 769 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 770 int (*xLock)(sqlite3_file*, int); 771 int (*xUnlock)(sqlite3_file*, int); 772 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 773 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 774 int (*xSectorSize)(sqlite3_file*); 775 int (*xDeviceCharacteristics)(sqlite3_file*); 776 /* Methods above are valid for version 1 */ 777 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 778 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 779 void (*xShmBarrier)(sqlite3_file*); 780 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 781 /* Methods above are valid for version 2 */ 782 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 783 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 784 /* Methods above are valid for version 3 */ 785 /* Additional methods may be added in future releases */ 786}; 787 788/* 789** CAPI3REF: Standard File Control Opcodes 790** KEYWORDS: {file control opcodes} {file control opcode} 791** 792** These integer constants are opcodes for the xFileControl method 793** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 794** interface. 795** 796** <ul> 797** <li>[[SQLITE_FCNTL_LOCKSTATE]] 798** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 799** opcode causes the xFileControl method to write the current state of 800** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 801** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 802** into an integer that the pArg argument points to. This capability 803** is used during testing and is only available when the SQLITE_TEST 804** compile-time option is used. 805** 806** <li>[[SQLITE_FCNTL_SIZE_HINT]] 807** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 808** layer a hint of how large the database file will grow to be during the 809** current transaction. This hint is not guaranteed to be accurate but it 810** is often close. The underlying VFS might choose to preallocate database 811** file space based on this hint in order to help writes to the database 812** file run faster. 813** 814** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 815** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 816** extends and truncates the database file in chunks of a size specified 817** by the user. The fourth argument to [sqlite3_file_control()] should 818** point to an integer (type int) containing the new chunk-size to use 819** for the nominated database. Allocating database file space in large 820** chunks (say 1MB at a time), may reduce file-system fragmentation and 821** improve performance on some systems. 822** 823** <li>[[SQLITE_FCNTL_FILE_POINTER]] 824** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 825** to the [sqlite3_file] object associated with a particular database 826** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 827** 828** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 829** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 830** to the [sqlite3_file] object associated with the journal file (either 831** the [rollback journal] or the [write-ahead log]) for a particular database 832** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 833** 834** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 835** No longer in use. 836** 837** <li>[[SQLITE_FCNTL_SYNC]] 838** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 839** sent to the VFS immediately before the xSync method is invoked on a 840** database file descriptor. Or, if the xSync method is not invoked 841** because the user has configured SQLite with 842** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 843** of the xSync method. In most cases, the pointer argument passed with 844** this file-control is NULL. However, if the database file is being synced 845** as part of a multi-database commit, the argument points to a nul-terminated 846** string containing the transactions master-journal file name. VFSes that 847** do not need this signal should silently ignore this opcode. Applications 848** should not call [sqlite3_file_control()] with this opcode as doing so may 849** disrupt the operation of the specialized VFSes that do require it. 850** 851** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 852** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 853** and sent to the VFS after a transaction has been committed immediately 854** but before the database is unlocked. VFSes that do not need this signal 855** should silently ignore this opcode. Applications should not call 856** [sqlite3_file_control()] with this opcode as doing so may disrupt the 857** operation of the specialized VFSes that do require it. 858** 859** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 860** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 861** retry counts and intervals for certain disk I/O operations for the 862** windows [VFS] in order to provide robustness in the presence of 863** anti-virus programs. By default, the windows VFS will retry file read, 864** file write, and file delete operations up to 10 times, with a delay 865** of 25 milliseconds before the first retry and with the delay increasing 866** by an additional 25 milliseconds with each subsequent retry. This 867** opcode allows these two values (10 retries and 25 milliseconds of delay) 868** to be adjusted. The values are changed for all database connections 869** within the same process. The argument is a pointer to an array of two 870** integers where the first integer is the new retry count and the second 871** integer is the delay. If either integer is negative, then the setting 872** is not changed but instead the prior value of that setting is written 873** into the array entry, allowing the current retry settings to be 874** interrogated. The zDbName parameter is ignored. 875** 876** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 877** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 878** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 879** write ahead log and shared memory files used for transaction control 880** are automatically deleted when the latest connection to the database 881** closes. Setting persistent WAL mode causes those files to persist after 882** close. Persisting the files is useful when other processes that do not 883** have write permission on the directory containing the database file want 884** to read the database file, as the WAL and shared memory files must exist 885** in order for the database to be readable. The fourth parameter to 886** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 887** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 888** WAL mode. If the integer is -1, then it is overwritten with the current 889** WAL persistence setting. 890** 891** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 892** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 893** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 894** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 895** xDeviceCharacteristics methods. The fourth parameter to 896** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 897** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 898** mode. If the integer is -1, then it is overwritten with the current 899** zero-damage mode setting. 900** 901** <li>[[SQLITE_FCNTL_OVERWRITE]] 902** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 903** a write transaction to indicate that, unless it is rolled back for some 904** reason, the entire database file will be overwritten by the current 905** transaction. This is used by VACUUM operations. 906** 907** <li>[[SQLITE_FCNTL_VFSNAME]] 908** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 909** all [VFSes] in the VFS stack. The names are of all VFS shims and the 910** final bottom-level VFS are written into memory obtained from 911** [sqlite3_malloc()] and the result is stored in the char* variable 912** that the fourth parameter of [sqlite3_file_control()] points to. 913** The caller is responsible for freeing the memory when done. As with 914** all file-control actions, there is no guarantee that this will actually 915** do anything. Callers should initialize the char* variable to a NULL 916** pointer in case this file-control is not implemented. This file-control 917** is intended for diagnostic use only. 918** 919** <li>[[SQLITE_FCNTL_VFS_POINTER]] 920** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 921** [VFSes] currently in use. ^(The argument X in 922** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 923** of type "[sqlite3_vfs] **". This opcodes will set *X 924** to a pointer to the top-level VFS.)^ 925** ^When there are multiple VFS shims in the stack, this opcode finds the 926** upper-most shim only. 927** 928** <li>[[SQLITE_FCNTL_PRAGMA]] 929** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 930** file control is sent to the open [sqlite3_file] object corresponding 931** to the database file to which the pragma statement refers. ^The argument 932** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 933** pointers to strings (char**) in which the second element of the array 934** is the name of the pragma and the third element is the argument to the 935** pragma or NULL if the pragma has no argument. ^The handler for an 936** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 937** of the char** argument point to a string obtained from [sqlite3_mprintf()] 938** or the equivalent and that string will become the result of the pragma or 939** the error message if the pragma fails. ^If the 940** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 941** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 942** file control returns [SQLITE_OK], then the parser assumes that the 943** VFS has handled the PRAGMA itself and the parser generates a no-op 944** prepared statement if result string is NULL, or that returns a copy 945** of the result string if the string is non-NULL. 946** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 947** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 948** that the VFS encountered an error while handling the [PRAGMA] and the 949** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 950** file control occurs at the beginning of pragma statement analysis and so 951** it is able to override built-in [PRAGMA] statements. 952** 953** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 954** ^The [SQLITE_FCNTL_BUSYHANDLER] 955** file-control may be invoked by SQLite on the database file handle 956** shortly after it is opened in order to provide a custom VFS with access 957** to the connections busy-handler callback. The argument is of type (void **) 958** - an array of two (void *) values. The first (void *) actually points 959** to a function of type (int (*)(void *)). In order to invoke the connections 960** busy-handler, this function should be invoked with the second (void *) in 961** the array as the only argument. If it returns non-zero, then the operation 962** should be retried. If it returns zero, the custom VFS should abandon the 963** current operation. 964** 965** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 966** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 967** to have SQLite generate a 968** temporary filename using the same algorithm that is followed to generate 969** temporary filenames for TEMP tables and other internal uses. The 970** argument should be a char** which will be filled with the filename 971** written into memory obtained from [sqlite3_malloc()]. The caller should 972** invoke [sqlite3_free()] on the result to avoid a memory leak. 973** 974** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 975** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 976** maximum number of bytes that will be used for memory-mapped I/O. 977** The argument is a pointer to a value of type sqlite3_int64 that 978** is an advisory maximum number of bytes in the file to memory map. The 979** pointer is overwritten with the old value. The limit is not changed if 980** the value originally pointed to is negative, and so the current limit 981** can be queried by passing in a pointer to a negative number. This 982** file-control is used internally to implement [PRAGMA mmap_size]. 983** 984** <li>[[SQLITE_FCNTL_TRACE]] 985** The [SQLITE_FCNTL_TRACE] file control provides advisory information 986** to the VFS about what the higher layers of the SQLite stack are doing. 987** This file control is used by some VFS activity tracing [shims]. 988** The argument is a zero-terminated string. Higher layers in the 989** SQLite stack may generate instances of this file control if 990** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 991** 992** <li>[[SQLITE_FCNTL_HAS_MOVED]] 993** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 994** pointer to an integer and it writes a boolean into that integer depending 995** on whether or not the file has been renamed, moved, or deleted since it 996** was first opened. 997** 998** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 999** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1000** underlying native file handle associated with a file handle. This file 1001** control interprets its argument as a pointer to a native file handle and 1002** writes the resulting value there. 1003** 1004** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1005** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1006** opcode causes the xFileControl method to swap the file handle with the one 1007** pointed to by the pArg argument. This capability is used during testing 1008** and only needs to be supported when SQLITE_TEST is defined. 1009** 1010** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1011** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1012** be advantageous to block on the next WAL lock if the lock is not immediately 1013** available. The WAL subsystem issues this signal during rare 1014** circumstances in order to fix a problem with priority inversion. 1015** Applications should <em>not</em> use this file-control. 1016** 1017** <li>[[SQLITE_FCNTL_ZIPVFS]] 1018** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1019** VFS should return SQLITE_NOTFOUND for this opcode. 1020** 1021** <li>[[SQLITE_FCNTL_RBU]] 1022** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1023** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1024** this opcode. 1025** 1026** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1027** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1028** the file descriptor is placed in "batch write mode", which 1029** means all subsequent write operations will be deferred and done 1030** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1031** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1032** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1033** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1034** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1035** no VFS interface calls on the same [sqlite3_file] file descriptor 1036** except for calls to the xWrite method and the xFileControl method 1037** with [SQLITE_FCNTL_SIZE_HINT]. 1038** 1039** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1040** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1041** operations since the previous successful call to 1042** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1043** This file control returns [SQLITE_OK] if and only if the writes were 1044** all performed successfully and have been committed to persistent storage. 1045** ^Regardless of whether or not it is successful, this file control takes 1046** the file descriptor out of batch write mode so that all subsequent 1047** write operations are independent. 1048** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1049** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1050** 1051** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1052** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1053** operations since the previous successful call to 1054** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1055** ^This file control takes the file descriptor out of batch write mode 1056** so that all subsequent write operations are independent. 1057** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1058** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1059** </ul> 1060*/ 1061#define SQLITE_FCNTL_LOCKSTATE 1 1062#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1063#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1064#define SQLITE_FCNTL_LAST_ERRNO 4 1065#define SQLITE_FCNTL_SIZE_HINT 5 1066#define SQLITE_FCNTL_CHUNK_SIZE 6 1067#define SQLITE_FCNTL_FILE_POINTER 7 1068#define SQLITE_FCNTL_SYNC_OMITTED 8 1069#define SQLITE_FCNTL_WIN32_AV_RETRY 9 1070#define SQLITE_FCNTL_PERSIST_WAL 10 1071#define SQLITE_FCNTL_OVERWRITE 11 1072#define SQLITE_FCNTL_VFSNAME 12 1073#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1074#define SQLITE_FCNTL_PRAGMA 14 1075#define SQLITE_FCNTL_BUSYHANDLER 15 1076#define SQLITE_FCNTL_TEMPFILENAME 16 1077#define SQLITE_FCNTL_MMAP_SIZE 18 1078#define SQLITE_FCNTL_TRACE 19 1079#define SQLITE_FCNTL_HAS_MOVED 20 1080#define SQLITE_FCNTL_SYNC 21 1081#define SQLITE_FCNTL_COMMIT_PHASETWO 22 1082#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1083#define SQLITE_FCNTL_WAL_BLOCK 24 1084#define SQLITE_FCNTL_ZIPVFS 25 1085#define SQLITE_FCNTL_RBU 26 1086#define SQLITE_FCNTL_VFS_POINTER 27 1087#define SQLITE_FCNTL_JOURNAL_POINTER 28 1088#define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1089#define SQLITE_FCNTL_PDB 30 1090#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1091#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1092#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1093 1094/* deprecated names */ 1095#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1096#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1097#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1098 1099 1100/* 1101** CAPI3REF: Mutex Handle 1102** 1103** The mutex module within SQLite defines [sqlite3_mutex] to be an 1104** abstract type for a mutex object. The SQLite core never looks 1105** at the internal representation of an [sqlite3_mutex]. It only 1106** deals with pointers to the [sqlite3_mutex] object. 1107** 1108** Mutexes are created using [sqlite3_mutex_alloc()]. 1109*/ 1110typedef struct sqlite3_mutex sqlite3_mutex; 1111 1112/* 1113** CAPI3REF: Loadable Extension Thunk 1114** 1115** A pointer to the opaque sqlite3_api_routines structure is passed as 1116** the third parameter to entry points of [loadable extensions]. This 1117** structure must be typedefed in order to work around compiler warnings 1118** on some platforms. 1119*/ 1120typedef struct sqlite3_api_routines sqlite3_api_routines; 1121 1122/* 1123** CAPI3REF: OS Interface Object 1124** 1125** An instance of the sqlite3_vfs object defines the interface between 1126** the SQLite core and the underlying operating system. The "vfs" 1127** in the name of the object stands for "virtual file system". See 1128** the [VFS | VFS documentation] for further information. 1129** 1130** The value of the iVersion field is initially 1 but may be larger in 1131** future versions of SQLite. Additional fields may be appended to this 1132** object when the iVersion value is increased. Note that the structure 1133** of the sqlite3_vfs object changes in the transaction between 1134** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 1135** modified. 1136** 1137** The szOsFile field is the size of the subclassed [sqlite3_file] 1138** structure used by this VFS. mxPathname is the maximum length of 1139** a pathname in this VFS. 1140** 1141** Registered sqlite3_vfs objects are kept on a linked list formed by 1142** the pNext pointer. The [sqlite3_vfs_register()] 1143** and [sqlite3_vfs_unregister()] interfaces manage this list 1144** in a thread-safe way. The [sqlite3_vfs_find()] interface 1145** searches the list. Neither the application code nor the VFS 1146** implementation should use the pNext pointer. 1147** 1148** The pNext field is the only field in the sqlite3_vfs 1149** structure that SQLite will ever modify. SQLite will only access 1150** or modify this field while holding a particular static mutex. 1151** The application should never modify anything within the sqlite3_vfs 1152** object once the object has been registered. 1153** 1154** The zName field holds the name of the VFS module. The name must 1155** be unique across all VFS modules. 1156** 1157** [[sqlite3_vfs.xOpen]] 1158** ^SQLite guarantees that the zFilename parameter to xOpen 1159** is either a NULL pointer or string obtained 1160** from xFullPathname() with an optional suffix added. 1161** ^If a suffix is added to the zFilename parameter, it will 1162** consist of a single "-" character followed by no more than 1163** 11 alphanumeric and/or "-" characters. 1164** ^SQLite further guarantees that 1165** the string will be valid and unchanged until xClose() is 1166** called. Because of the previous sentence, 1167** the [sqlite3_file] can safely store a pointer to the 1168** filename if it needs to remember the filename for some reason. 1169** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1170** must invent its own temporary name for the file. ^Whenever the 1171** xFilename parameter is NULL it will also be the case that the 1172** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1173** 1174** The flags argument to xOpen() includes all bits set in 1175** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1176** or [sqlite3_open16()] is used, then flags includes at least 1177** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1178** If xOpen() opens a file read-only then it sets *pOutFlags to 1179** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1180** 1181** ^(SQLite will also add one of the following flags to the xOpen() 1182** call, depending on the object being opened: 1183** 1184** <ul> 1185** <li> [SQLITE_OPEN_MAIN_DB] 1186** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1187** <li> [SQLITE_OPEN_TEMP_DB] 1188** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1189** <li> [SQLITE_OPEN_TRANSIENT_DB] 1190** <li> [SQLITE_OPEN_SUBJOURNAL] 1191** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1192** <li> [SQLITE_OPEN_WAL] 1193** </ul>)^ 1194** 1195** The file I/O implementation can use the object type flags to 1196** change the way it deals with files. For example, an application 1197** that does not care about crash recovery or rollback might make 1198** the open of a journal file a no-op. Writes to this journal would 1199** also be no-ops, and any attempt to read the journal would return 1200** SQLITE_IOERR. Or the implementation might recognize that a database 1201** file will be doing page-aligned sector reads and writes in a random 1202** order and set up its I/O subsystem accordingly. 1203** 1204** SQLite might also add one of the following flags to the xOpen method: 1205** 1206** <ul> 1207** <li> [SQLITE_OPEN_DELETEONCLOSE] 1208** <li> [SQLITE_OPEN_EXCLUSIVE] 1209** </ul> 1210** 1211** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1212** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1213** will be set for TEMP databases and their journals, transient 1214** databases, and subjournals. 1215** 1216** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1217** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1218** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1219** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1220** SQLITE_OPEN_CREATE, is used to indicate that file should always 1221** be created, and that it is an error if it already exists. 1222** It is <i>not</i> used to indicate the file should be opened 1223** for exclusive access. 1224** 1225** ^At least szOsFile bytes of memory are allocated by SQLite 1226** to hold the [sqlite3_file] structure passed as the third 1227** argument to xOpen. The xOpen method does not have to 1228** allocate the structure; it should just fill it in. Note that 1229** the xOpen method must set the sqlite3_file.pMethods to either 1230** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1231** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1232** element will be valid after xOpen returns regardless of the success 1233** or failure of the xOpen call. 1234** 1235** [[sqlite3_vfs.xAccess]] 1236** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1237** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1238** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1239** to test whether a file is at least readable. The file can be a 1240** directory. 1241** 1242** ^SQLite will always allocate at least mxPathname+1 bytes for the 1243** output buffer xFullPathname. The exact size of the output buffer 1244** is also passed as a parameter to both methods. If the output buffer 1245** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1246** handled as a fatal error by SQLite, vfs implementations should endeavor 1247** to prevent this by setting mxPathname to a sufficiently large value. 1248** 1249** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1250** interfaces are not strictly a part of the filesystem, but they are 1251** included in the VFS structure for completeness. 1252** The xRandomness() function attempts to return nBytes bytes 1253** of good-quality randomness into zOut. The return value is 1254** the actual number of bytes of randomness obtained. 1255** The xSleep() method causes the calling thread to sleep for at 1256** least the number of microseconds given. ^The xCurrentTime() 1257** method returns a Julian Day Number for the current date and time as 1258** a floating point value. 1259** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1260** Day Number multiplied by 86400000 (the number of milliseconds in 1261** a 24-hour day). 1262** ^SQLite will use the xCurrentTimeInt64() method to get the current 1263** date and time if that method is available (if iVersion is 2 or 1264** greater and the function pointer is not NULL) and will fall back 1265** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1266** 1267** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1268** are not used by the SQLite core. These optional interfaces are provided 1269** by some VFSes to facilitate testing of the VFS code. By overriding 1270** system calls with functions under its control, a test program can 1271** simulate faults and error conditions that would otherwise be difficult 1272** or impossible to induce. The set of system calls that can be overridden 1273** varies from one VFS to another, and from one version of the same VFS to the 1274** next. Applications that use these interfaces must be prepared for any 1275** or all of these interfaces to be NULL or for their behavior to change 1276** from one release to the next. Applications must not attempt to access 1277** any of these methods if the iVersion of the VFS is less than 3. 1278*/ 1279typedef struct sqlite3_vfs sqlite3_vfs; 1280typedef void (*sqlite3_syscall_ptr)(void); 1281struct sqlite3_vfs { 1282 int iVersion; /* Structure version number (currently 3) */ 1283 int szOsFile; /* Size of subclassed sqlite3_file */ 1284 int mxPathname; /* Maximum file pathname length */ 1285 sqlite3_vfs *pNext; /* Next registered VFS */ 1286 const char *zName; /* Name of this virtual file system */ 1287 void *pAppData; /* Pointer to application-specific data */ 1288 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1289 int flags, int *pOutFlags); 1290 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1291 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1292 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1293 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1294 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1295 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1296 void (*xDlClose)(sqlite3_vfs*, void*); 1297 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1298 int (*xSleep)(sqlite3_vfs*, int microseconds); 1299 int (*xCurrentTime)(sqlite3_vfs*, double*); 1300 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1301 /* 1302 ** The methods above are in version 1 of the sqlite_vfs object 1303 ** definition. Those that follow are added in version 2 or later 1304 */ 1305 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1306 /* 1307 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1308 ** Those below are for version 3 and greater. 1309 */ 1310 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1311 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1312 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1313 /* 1314 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1315 ** New fields may be appended in future versions. The iVersion 1316 ** value will increment whenever this happens. 1317 */ 1318}; 1319 1320/* 1321** CAPI3REF: Flags for the xAccess VFS method 1322** 1323** These integer constants can be used as the third parameter to 1324** the xAccess method of an [sqlite3_vfs] object. They determine 1325** what kind of permissions the xAccess method is looking for. 1326** With SQLITE_ACCESS_EXISTS, the xAccess method 1327** simply checks whether the file exists. 1328** With SQLITE_ACCESS_READWRITE, the xAccess method 1329** checks whether the named directory is both readable and writable 1330** (in other words, if files can be added, removed, and renamed within 1331** the directory). 1332** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1333** [temp_store_directory pragma], though this could change in a future 1334** release of SQLite. 1335** With SQLITE_ACCESS_READ, the xAccess method 1336** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1337** currently unused, though it might be used in a future release of 1338** SQLite. 1339*/ 1340#define SQLITE_ACCESS_EXISTS 0 1341#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1342#define SQLITE_ACCESS_READ 2 /* Unused */ 1343 1344/* 1345** CAPI3REF: Flags for the xShmLock VFS method 1346** 1347** These integer constants define the various locking operations 1348** allowed by the xShmLock method of [sqlite3_io_methods]. The 1349** following are the only legal combinations of flags to the 1350** xShmLock method: 1351** 1352** <ul> 1353** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1354** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1355** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1356** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1357** </ul> 1358** 1359** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1360** was given on the corresponding lock. 1361** 1362** The xShmLock method can transition between unlocked and SHARED or 1363** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1364** and EXCLUSIVE. 1365*/ 1366#define SQLITE_SHM_UNLOCK 1 1367#define SQLITE_SHM_LOCK 2 1368#define SQLITE_SHM_SHARED 4 1369#define SQLITE_SHM_EXCLUSIVE 8 1370 1371/* 1372** CAPI3REF: Maximum xShmLock index 1373** 1374** The xShmLock method on [sqlite3_io_methods] may use values 1375** between 0 and this upper bound as its "offset" argument. 1376** The SQLite core will never attempt to acquire or release a 1377** lock outside of this range 1378*/ 1379#define SQLITE_SHM_NLOCK 8 1380 1381 1382/* 1383** CAPI3REF: Initialize The SQLite Library 1384** 1385** ^The sqlite3_initialize() routine initializes the 1386** SQLite library. ^The sqlite3_shutdown() routine 1387** deallocates any resources that were allocated by sqlite3_initialize(). 1388** These routines are designed to aid in process initialization and 1389** shutdown on embedded systems. Workstation applications using 1390** SQLite normally do not need to invoke either of these routines. 1391** 1392** A call to sqlite3_initialize() is an "effective" call if it is 1393** the first time sqlite3_initialize() is invoked during the lifetime of 1394** the process, or if it is the first time sqlite3_initialize() is invoked 1395** following a call to sqlite3_shutdown(). ^(Only an effective call 1396** of sqlite3_initialize() does any initialization. All other calls 1397** are harmless no-ops.)^ 1398** 1399** A call to sqlite3_shutdown() is an "effective" call if it is the first 1400** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1401** an effective call to sqlite3_shutdown() does any deinitialization. 1402** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1403** 1404** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1405** is not. The sqlite3_shutdown() interface must only be called from a 1406** single thread. All open [database connections] must be closed and all 1407** other SQLite resources must be deallocated prior to invoking 1408** sqlite3_shutdown(). 1409** 1410** Among other things, ^sqlite3_initialize() will invoke 1411** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1412** will invoke sqlite3_os_end(). 1413** 1414** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1415** ^If for some reason, sqlite3_initialize() is unable to initialize 1416** the library (perhaps it is unable to allocate a needed resource such 1417** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1418** 1419** ^The sqlite3_initialize() routine is called internally by many other 1420** SQLite interfaces so that an application usually does not need to 1421** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1422** calls sqlite3_initialize() so the SQLite library will be automatically 1423** initialized when [sqlite3_open()] is called if it has not be initialized 1424** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1425** compile-time option, then the automatic calls to sqlite3_initialize() 1426** are omitted and the application must call sqlite3_initialize() directly 1427** prior to using any other SQLite interface. For maximum portability, 1428** it is recommended that applications always invoke sqlite3_initialize() 1429** directly prior to using any other SQLite interface. Future releases 1430** of SQLite may require this. In other words, the behavior exhibited 1431** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1432** default behavior in some future release of SQLite. 1433** 1434** The sqlite3_os_init() routine does operating-system specific 1435** initialization of the SQLite library. The sqlite3_os_end() 1436** routine undoes the effect of sqlite3_os_init(). Typical tasks 1437** performed by these routines include allocation or deallocation 1438** of static resources, initialization of global variables, 1439** setting up a default [sqlite3_vfs] module, or setting up 1440** a default configuration using [sqlite3_config()]. 1441** 1442** The application should never invoke either sqlite3_os_init() 1443** or sqlite3_os_end() directly. The application should only invoke 1444** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1445** interface is called automatically by sqlite3_initialize() and 1446** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1447** implementations for sqlite3_os_init() and sqlite3_os_end() 1448** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1449** When [custom builds | built for other platforms] 1450** (using the [SQLITE_OS_OTHER=1] compile-time 1451** option) the application must supply a suitable implementation for 1452** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1453** implementation of sqlite3_os_init() or sqlite3_os_end() 1454** must return [SQLITE_OK] on success and some other [error code] upon 1455** failure. 1456*/ 1457SQLITE_API int sqlite3_initialize(void); 1458SQLITE_API int sqlite3_shutdown(void); 1459SQLITE_API int sqlite3_os_init(void); 1460SQLITE_API int sqlite3_os_end(void); 1461 1462/* 1463** CAPI3REF: Configuring The SQLite Library 1464** 1465** The sqlite3_config() interface is used to make global configuration 1466** changes to SQLite in order to tune SQLite to the specific needs of 1467** the application. The default configuration is recommended for most 1468** applications and so this routine is usually not necessary. It is 1469** provided to support rare applications with unusual needs. 1470** 1471** <b>The sqlite3_config() interface is not threadsafe. The application 1472** must ensure that no other SQLite interfaces are invoked by other 1473** threads while sqlite3_config() is running.</b> 1474** 1475** The sqlite3_config() interface 1476** may only be invoked prior to library initialization using 1477** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1478** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1479** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1480** Note, however, that ^sqlite3_config() can be called as part of the 1481** implementation of an application-defined [sqlite3_os_init()]. 1482** 1483** The first argument to sqlite3_config() is an integer 1484** [configuration option] that determines 1485** what property of SQLite is to be configured. Subsequent arguments 1486** vary depending on the [configuration option] 1487** in the first argument. 1488** 1489** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1490** ^If the option is unknown or SQLite is unable to set the option 1491** then this routine returns a non-zero [error code]. 1492*/ 1493SQLITE_API int sqlite3_config(int, ...); 1494 1495/* 1496** CAPI3REF: Configure database connections 1497** METHOD: sqlite3 1498** 1499** The sqlite3_db_config() interface is used to make configuration 1500** changes to a [database connection]. The interface is similar to 1501** [sqlite3_config()] except that the changes apply to a single 1502** [database connection] (specified in the first argument). 1503** 1504** The second argument to sqlite3_db_config(D,V,...) is the 1505** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1506** that indicates what aspect of the [database connection] is being configured. 1507** Subsequent arguments vary depending on the configuration verb. 1508** 1509** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1510** the call is considered successful. 1511*/ 1512SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1513 1514/* 1515** CAPI3REF: Memory Allocation Routines 1516** 1517** An instance of this object defines the interface between SQLite 1518** and low-level memory allocation routines. 1519** 1520** This object is used in only one place in the SQLite interface. 1521** A pointer to an instance of this object is the argument to 1522** [sqlite3_config()] when the configuration option is 1523** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1524** By creating an instance of this object 1525** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1526** during configuration, an application can specify an alternative 1527** memory allocation subsystem for SQLite to use for all of its 1528** dynamic memory needs. 1529** 1530** Note that SQLite comes with several [built-in memory allocators] 1531** that are perfectly adequate for the overwhelming majority of applications 1532** and that this object is only useful to a tiny minority of applications 1533** with specialized memory allocation requirements. This object is 1534** also used during testing of SQLite in order to specify an alternative 1535** memory allocator that simulates memory out-of-memory conditions in 1536** order to verify that SQLite recovers gracefully from such 1537** conditions. 1538** 1539** The xMalloc, xRealloc, and xFree methods must work like the 1540** malloc(), realloc() and free() functions from the standard C library. 1541** ^SQLite guarantees that the second argument to 1542** xRealloc is always a value returned by a prior call to xRoundup. 1543** 1544** xSize should return the allocated size of a memory allocation 1545** previously obtained from xMalloc or xRealloc. The allocated size 1546** is always at least as big as the requested size but may be larger. 1547** 1548** The xRoundup method returns what would be the allocated size of 1549** a memory allocation given a particular requested size. Most memory 1550** allocators round up memory allocations at least to the next multiple 1551** of 8. Some allocators round up to a larger multiple or to a power of 2. 1552** Every memory allocation request coming in through [sqlite3_malloc()] 1553** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1554** that causes the corresponding memory allocation to fail. 1555** 1556** The xInit method initializes the memory allocator. For example, 1557** it might allocate any require mutexes or initialize internal data 1558** structures. The xShutdown method is invoked (indirectly) by 1559** [sqlite3_shutdown()] and should deallocate any resources acquired 1560** by xInit. The pAppData pointer is used as the only parameter to 1561** xInit and xShutdown. 1562** 1563** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1564** the xInit method, so the xInit method need not be threadsafe. The 1565** xShutdown method is only called from [sqlite3_shutdown()] so it does 1566** not need to be threadsafe either. For all other methods, SQLite 1567** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1568** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1569** it is by default) and so the methods are automatically serialized. 1570** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1571** methods must be threadsafe or else make their own arrangements for 1572** serialization. 1573** 1574** SQLite will never invoke xInit() more than once without an intervening 1575** call to xShutdown(). 1576*/ 1577typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1578struct sqlite3_mem_methods { 1579 void *(*xMalloc)(int); /* Memory allocation function */ 1580 void (*xFree)(void*); /* Free a prior allocation */ 1581 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1582 int (*xSize)(void*); /* Return the size of an allocation */ 1583 int (*xRoundup)(int); /* Round up request size to allocation size */ 1584 int (*xInit)(void*); /* Initialize the memory allocator */ 1585 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1586 void *pAppData; /* Argument to xInit() and xShutdown() */ 1587}; 1588 1589/* 1590** CAPI3REF: Configuration Options 1591** KEYWORDS: {configuration option} 1592** 1593** These constants are the available integer configuration options that 1594** can be passed as the first argument to the [sqlite3_config()] interface. 1595** 1596** New configuration options may be added in future releases of SQLite. 1597** Existing configuration options might be discontinued. Applications 1598** should check the return code from [sqlite3_config()] to make sure that 1599** the call worked. The [sqlite3_config()] interface will return a 1600** non-zero [error code] if a discontinued or unsupported configuration option 1601** is invoked. 1602** 1603** <dl> 1604** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1605** <dd>There are no arguments to this option. ^This option sets the 1606** [threading mode] to Single-thread. In other words, it disables 1607** all mutexing and puts SQLite into a mode where it can only be used 1608** by a single thread. ^If SQLite is compiled with 1609** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1610** it is not possible to change the [threading mode] from its default 1611** value of Single-thread and so [sqlite3_config()] will return 1612** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1613** configuration option.</dd> 1614** 1615** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1616** <dd>There are no arguments to this option. ^This option sets the 1617** [threading mode] to Multi-thread. In other words, it disables 1618** mutexing on [database connection] and [prepared statement] objects. 1619** The application is responsible for serializing access to 1620** [database connections] and [prepared statements]. But other mutexes 1621** are enabled so that SQLite will be safe to use in a multi-threaded 1622** environment as long as no two threads attempt to use the same 1623** [database connection] at the same time. ^If SQLite is compiled with 1624** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1625** it is not possible to set the Multi-thread [threading mode] and 1626** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1627** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1628** 1629** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1630** <dd>There are no arguments to this option. ^This option sets the 1631** [threading mode] to Serialized. In other words, this option enables 1632** all mutexes including the recursive 1633** mutexes on [database connection] and [prepared statement] objects. 1634** In this mode (which is the default when SQLite is compiled with 1635** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1636** to [database connections] and [prepared statements] so that the 1637** application is free to use the same [database connection] or the 1638** same [prepared statement] in different threads at the same time. 1639** ^If SQLite is compiled with 1640** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1641** it is not possible to set the Serialized [threading mode] and 1642** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1643** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1644** 1645** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1646** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1647** a pointer to an instance of the [sqlite3_mem_methods] structure. 1648** The argument specifies 1649** alternative low-level memory allocation routines to be used in place of 1650** the memory allocation routines built into SQLite.)^ ^SQLite makes 1651** its own private copy of the content of the [sqlite3_mem_methods] structure 1652** before the [sqlite3_config()] call returns.</dd> 1653** 1654** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1655** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1656** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1657** The [sqlite3_mem_methods] 1658** structure is filled with the currently defined memory allocation routines.)^ 1659** This option can be used to overload the default memory allocation 1660** routines with a wrapper that simulations memory allocation failure or 1661** tracks memory usage, for example. </dd> 1662** 1663** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1664** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1665** interpreted as a boolean, which enables or disables the collection of 1666** memory allocation statistics. ^(When memory allocation statistics are 1667** disabled, the following SQLite interfaces become non-operational: 1668** <ul> 1669** <li> [sqlite3_memory_used()] 1670** <li> [sqlite3_memory_highwater()] 1671** <li> [sqlite3_soft_heap_limit64()] 1672** <li> [sqlite3_status64()] 1673** </ul>)^ 1674** ^Memory allocation statistics are enabled by default unless SQLite is 1675** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1676** allocation statistics are disabled by default. 1677** </dd> 1678** 1679** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1680** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer 1681** that SQLite can use for scratch memory. ^(There are three arguments 1682** to SQLITE_CONFIG_SCRATCH: A pointer an 8-byte 1683** aligned memory buffer from which the scratch allocations will be 1684** drawn, the size of each scratch allocation (sz), 1685** and the maximum number of scratch allocations (N).)^ 1686** The first argument must be a pointer to an 8-byte aligned buffer 1687** of at least sz*N bytes of memory. 1688** ^SQLite will not use more than one scratch buffers per thread. 1689** ^SQLite will never request a scratch buffer that is more than 6 1690** times the database page size. 1691** ^If SQLite needs needs additional 1692** scratch memory beyond what is provided by this configuration option, then 1693** [sqlite3_malloc()] will be used to obtain the memory needed.<p> 1694** ^When the application provides any amount of scratch memory using 1695** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large 1696** [sqlite3_malloc|heap allocations]. 1697** This can help [Robson proof|prevent memory allocation failures] due to heap 1698** fragmentation in low-memory embedded systems. 1699** </dd> 1700** 1701** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1702** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1703** that SQLite can use for the database page cache with the default page 1704** cache implementation. 1705** This configuration option is a no-op if an application-define page 1706** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1707** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1708** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1709** and the number of cache lines (N). 1710** The sz argument should be the size of the largest database page 1711** (a power of two between 512 and 65536) plus some extra bytes for each 1712** page header. ^The number of extra bytes needed by the page header 1713** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1714** ^It is harmless, apart from the wasted memory, 1715** for the sz parameter to be larger than necessary. The pMem 1716** argument must be either a NULL pointer or a pointer to an 8-byte 1717** aligned block of memory of at least sz*N bytes, otherwise 1718** subsequent behavior is undefined. 1719** ^When pMem is not NULL, SQLite will strive to use the memory provided 1720** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1721** a page cache line is larger than sz bytes or if all of the pMem buffer 1722** is exhausted. 1723** ^If pMem is NULL and N is non-zero, then each database connection 1724** does an initial bulk allocation for page cache memory 1725** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1726** of -1024*N bytes if N is negative, . ^If additional 1727** page cache memory is needed beyond what is provided by the initial 1728** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1729** additional cache line. </dd> 1730** 1731** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1732** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1733** that SQLite will use for all of its dynamic memory allocation needs 1734** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and 1735** [SQLITE_CONFIG_PAGECACHE]. 1736** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1737** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1738** [SQLITE_ERROR] if invoked otherwise. 1739** ^There are three arguments to SQLITE_CONFIG_HEAP: 1740** An 8-byte aligned pointer to the memory, 1741** the number of bytes in the memory buffer, and the minimum allocation size. 1742** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1743** to using its default memory allocator (the system malloc() implementation), 1744** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1745** memory pointer is not NULL then the alternative memory 1746** allocator is engaged to handle all of SQLites memory allocation needs. 1747** The first pointer (the memory pointer) must be aligned to an 8-byte 1748** boundary or subsequent behavior of SQLite will be undefined. 1749** The minimum allocation size is capped at 2**12. Reasonable values 1750** for the minimum allocation size are 2**5 through 2**8.</dd> 1751** 1752** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1753** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1754** pointer to an instance of the [sqlite3_mutex_methods] structure. 1755** The argument specifies alternative low-level mutex routines to be used 1756** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1757** the content of the [sqlite3_mutex_methods] structure before the call to 1758** [sqlite3_config()] returns. ^If SQLite is compiled with 1759** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1760** the entire mutexing subsystem is omitted from the build and hence calls to 1761** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1762** return [SQLITE_ERROR].</dd> 1763** 1764** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1765** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1766** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1767** [sqlite3_mutex_methods] 1768** structure is filled with the currently defined mutex routines.)^ 1769** This option can be used to overload the default mutex allocation 1770** routines with a wrapper used to track mutex usage for performance 1771** profiling or testing, for example. ^If SQLite is compiled with 1772** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1773** the entire mutexing subsystem is omitted from the build and hence calls to 1774** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1775** return [SQLITE_ERROR].</dd> 1776** 1777** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1778** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1779** the default size of lookaside memory on each [database connection]. 1780** The first argument is the 1781** size of each lookaside buffer slot and the second is the number of 1782** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1783** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1784** option to [sqlite3_db_config()] can be used to change the lookaside 1785** configuration on individual connections.)^ </dd> 1786** 1787** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1788** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1789** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1790** the interface to a custom page cache implementation.)^ 1791** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1792** 1793** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1794** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1795** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1796** the current page cache implementation into that object.)^ </dd> 1797** 1798** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1799** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1800** global [error log]. 1801** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1802** function with a call signature of void(*)(void*,int,const char*), 1803** and a pointer to void. ^If the function pointer is not NULL, it is 1804** invoked by [sqlite3_log()] to process each logging event. ^If the 1805** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1806** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1807** passed through as the first parameter to the application-defined logger 1808** function whenever that function is invoked. ^The second parameter to 1809** the logger function is a copy of the first parameter to the corresponding 1810** [sqlite3_log()] call and is intended to be a [result code] or an 1811** [extended result code]. ^The third parameter passed to the logger is 1812** log message after formatting via [sqlite3_snprintf()]. 1813** The SQLite logging interface is not reentrant; the logger function 1814** supplied by the application must not invoke any SQLite interface. 1815** In a multi-threaded application, the application-defined logger 1816** function must be threadsafe. </dd> 1817** 1818** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1819** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1820** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1821** then URI handling is globally disabled.)^ ^If URI handling is globally 1822** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1823** [sqlite3_open16()] or 1824** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1825** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1826** connection is opened. ^If it is globally disabled, filenames are 1827** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1828** database connection is opened. ^(By default, URI handling is globally 1829** disabled. The default value may be changed by compiling with the 1830** [SQLITE_USE_URI] symbol defined.)^ 1831** 1832** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1833** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1834** argument which is interpreted as a boolean in order to enable or disable 1835** the use of covering indices for full table scans in the query optimizer. 1836** ^The default setting is determined 1837** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1838** if that compile-time option is omitted. 1839** The ability to disable the use of covering indices for full table scans 1840** is because some incorrectly coded legacy applications might malfunction 1841** when the optimization is enabled. Providing the ability to 1842** disable the optimization allows the older, buggy application code to work 1843** without change even with newer versions of SQLite. 1844** 1845** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1846** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1847** <dd> These options are obsolete and should not be used by new code. 1848** They are retained for backwards compatibility but are now no-ops. 1849** </dd> 1850** 1851** [[SQLITE_CONFIG_SQLLOG]] 1852** <dt>SQLITE_CONFIG_SQLLOG 1853** <dd>This option is only available if sqlite is compiled with the 1854** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1855** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1856** The second should be of type (void*). The callback is invoked by the library 1857** in three separate circumstances, identified by the value passed as the 1858** fourth parameter. If the fourth parameter is 0, then the database connection 1859** passed as the second argument has just been opened. The third argument 1860** points to a buffer containing the name of the main database file. If the 1861** fourth parameter is 1, then the SQL statement that the third parameter 1862** points to has just been executed. Or, if the fourth parameter is 2, then 1863** the connection being passed as the second parameter is being closed. The 1864** third parameter is passed NULL In this case. An example of using this 1865** configuration option can be seen in the "test_sqllog.c" source file in 1866** the canonical SQLite source tree.</dd> 1867** 1868** [[SQLITE_CONFIG_MMAP_SIZE]] 1869** <dt>SQLITE_CONFIG_MMAP_SIZE 1870** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1871** that are the default mmap size limit (the default setting for 1872** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1873** ^The default setting can be overridden by each database connection using 1874** either the [PRAGMA mmap_size] command, or by using the 1875** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1876** will be silently truncated if necessary so that it does not exceed the 1877** compile-time maximum mmap size set by the 1878** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1879** ^If either argument to this option is negative, then that argument is 1880** changed to its compile-time default. 1881** 1882** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1883** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1884** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1885** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1886** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1887** that specifies the maximum size of the created heap. 1888** 1889** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1890** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1891** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1892** is a pointer to an integer and writes into that integer the number of extra 1893** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1894** The amount of extra space required can change depending on the compiler, 1895** target platform, and SQLite version. 1896** 1897** [[SQLITE_CONFIG_PMASZ]] 1898** <dt>SQLITE_CONFIG_PMASZ 1899** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1900** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1901** sorter to that integer. The default minimum PMA Size is set by the 1902** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1903** to help with sort operations when multithreaded sorting 1904** is enabled (using the [PRAGMA threads] command) and the amount of content 1905** to be sorted exceeds the page size times the minimum of the 1906** [PRAGMA cache_size] setting and this value. 1907** 1908** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1909** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1910** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1911** becomes the [statement journal] spill-to-disk threshold. 1912** [Statement journals] are held in memory until their size (in bytes) 1913** exceeds this threshold, at which point they are written to disk. 1914** Or if the threshold is -1, statement journals are always held 1915** exclusively in memory. 1916** Since many statement journals never become large, setting the spill 1917** threshold to a value such as 64KiB can greatly reduce the amount of 1918** I/O required to support statement rollback. 1919** The default value for this setting is controlled by the 1920** [SQLITE_STMTJRNL_SPILL] compile-time option. 1921** </dl> 1922*/ 1923#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1924#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1925#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1926#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1927#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1928#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1929#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1930#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1931#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1932#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1933#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1934/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1935#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1936#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1937#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1938#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1939#define SQLITE_CONFIG_URI 17 /* int */ 1940#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1941#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1942#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1943#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1944#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1945#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1946#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 1947#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 1948#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 1949 1950/* 1951** CAPI3REF: Database Connection Configuration Options 1952** 1953** These constants are the available integer configuration options that 1954** can be passed as the second argument to the [sqlite3_db_config()] interface. 1955** 1956** New configuration options may be added in future releases of SQLite. 1957** Existing configuration options might be discontinued. Applications 1958** should check the return code from [sqlite3_db_config()] to make sure that 1959** the call worked. ^The [sqlite3_db_config()] interface will return a 1960** non-zero [error code] if a discontinued or unsupported configuration option 1961** is invoked. 1962** 1963** <dl> 1964** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1965** <dd> ^This option takes three additional arguments that determine the 1966** [lookaside memory allocator] configuration for the [database connection]. 1967** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1968** pointer to a memory buffer to use for lookaside memory. 1969** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1970** may be NULL in which case SQLite will allocate the 1971** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1972** size of each lookaside buffer slot. ^The third argument is the number of 1973** slots. The size of the buffer in the first argument must be greater than 1974** or equal to the product of the second and third arguments. The buffer 1975** must be aligned to an 8-byte boundary. ^If the second argument to 1976** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1977** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1978** configuration for a database connection can only be changed when that 1979** connection is not currently using lookaside memory, or in other words 1980** when the "current value" returned by 1981** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1982** Any attempt to change the lookaside memory configuration when lookaside 1983** memory is in use leaves the configuration unchanged and returns 1984** [SQLITE_BUSY].)^</dd> 1985** 1986** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1987** <dd> ^This option is used to enable or disable the enforcement of 1988** [foreign key constraints]. There should be two additional arguments. 1989** The first argument is an integer which is 0 to disable FK enforcement, 1990** positive to enable FK enforcement or negative to leave FK enforcement 1991** unchanged. The second parameter is a pointer to an integer into which 1992** is written 0 or 1 to indicate whether FK enforcement is off or on 1993** following this call. The second parameter may be a NULL pointer, in 1994** which case the FK enforcement setting is not reported back. </dd> 1995** 1996** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1997** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1998** There should be two additional arguments. 1999** The first argument is an integer which is 0 to disable triggers, 2000** positive to enable triggers or negative to leave the setting unchanged. 2001** The second parameter is a pointer to an integer into which 2002** is written 0 or 1 to indicate whether triggers are disabled or enabled 2003** following this call. The second parameter may be a NULL pointer, in 2004** which case the trigger setting is not reported back. </dd> 2005** 2006** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2007** <dd> ^This option is used to enable or disable the two-argument 2008** version of the [fts3_tokenizer()] function which is part of the 2009** [FTS3] full-text search engine extension. 2010** There should be two additional arguments. 2011** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2012** positive to enable fts3_tokenizer() or negative to leave the setting 2013** unchanged. 2014** The second parameter is a pointer to an integer into which 2015** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2016** following this call. The second parameter may be a NULL pointer, in 2017** which case the new setting is not reported back. </dd> 2018** 2019** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2020** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2021** interface independently of the [load_extension()] SQL function. 2022** The [sqlite3_enable_load_extension()] API enables or disables both the 2023** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2024** There should be two additional arguments. 2025** When the first argument to this interface is 1, then only the C-API is 2026** enabled and the SQL function remains disabled. If the first argument to 2027** this interface is 0, then both the C-API and the SQL function are disabled. 2028** If the first argument is -1, then no changes are made to state of either the 2029** C-API or the SQL function. 2030** The second parameter is a pointer to an integer into which 2031** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2032** is disabled or enabled following this call. The second parameter may 2033** be a NULL pointer, in which case the new setting is not reported back. 2034** </dd> 2035** 2036** <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2037** <dd> ^This option is used to change the name of the "main" database 2038** schema. ^The sole argument is a pointer to a constant UTF8 string 2039** which will become the new schema name in place of "main". ^SQLite 2040** does not make a copy of the new main schema name string, so the application 2041** must ensure that the argument passed into this DBCONFIG option is unchanged 2042** until after the database connection closes. 2043** </dd> 2044** 2045** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2046** <dd> Usually, when a database in wal mode is closed or detached from a 2047** database handle, SQLite checks if this will mean that there are now no 2048** connections at all to the database. If so, it performs a checkpoint 2049** operation before closing the connection. This option may be used to 2050** override this behaviour. The first parameter passed to this operation 2051** is an integer - non-zero to disable checkpoints-on-close, or zero (the 2052** default) to enable them. The second parameter is a pointer to an integer 2053** into which is written 0 or 1 to indicate whether checkpoints-on-close 2054** have been disabled - 0 if they are not disabled, 1 if they are. 2055** </dd> 2056** 2057** </dl> 2058*/ 2059#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2060#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2061#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2062#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2063#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2064#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2065#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2066 2067 2068/* 2069** CAPI3REF: Enable Or Disable Extended Result Codes 2070** METHOD: sqlite3 2071** 2072** ^The sqlite3_extended_result_codes() routine enables or disables the 2073** [extended result codes] feature of SQLite. ^The extended result 2074** codes are disabled by default for historical compatibility. 2075*/ 2076SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2077 2078/* 2079** CAPI3REF: Last Insert Rowid 2080** METHOD: sqlite3 2081** 2082** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2083** has a unique 64-bit signed 2084** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2085** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2086** names are not also used by explicitly declared columns. ^If 2087** the table has a column of type [INTEGER PRIMARY KEY] then that column 2088** is another alias for the rowid. 2089** 2090** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2091** the most recent successful [INSERT] into a rowid table or [virtual table] 2092** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2093** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2094** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2095** zero. 2096** 2097** As well as being set automatically as rows are inserted into database 2098** tables, the value returned by this function may be set explicitly by 2099** [sqlite3_set_last_insert_rowid()] 2100** 2101** Some virtual table implementations may INSERT rows into rowid tables as 2102** part of committing a transaction (e.g. to flush data accumulated in memory 2103** to disk). In this case subsequent calls to this function return the rowid 2104** associated with these internal INSERT operations, which leads to 2105** unintuitive results. Virtual table implementations that do write to rowid 2106** tables in this way can avoid this problem by restoring the original 2107** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2108** control to the user. 2109** 2110** ^(If an [INSERT] occurs within a trigger then this routine will 2111** return the [rowid] of the inserted row as long as the trigger is 2112** running. Once the trigger program ends, the value returned 2113** by this routine reverts to what it was before the trigger was fired.)^ 2114** 2115** ^An [INSERT] that fails due to a constraint violation is not a 2116** successful [INSERT] and does not change the value returned by this 2117** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2118** and INSERT OR ABORT make no changes to the return value of this 2119** routine when their insertion fails. ^(When INSERT OR REPLACE 2120** encounters a constraint violation, it does not fail. The 2121** INSERT continues to completion after deleting rows that caused 2122** the constraint problem so INSERT OR REPLACE will always change 2123** the return value of this interface.)^ 2124** 2125** ^For the purposes of this routine, an [INSERT] is considered to 2126** be successful even if it is subsequently rolled back. 2127** 2128** This function is accessible to SQL statements via the 2129** [last_insert_rowid() SQL function]. 2130** 2131** If a separate thread performs a new [INSERT] on the same 2132** database connection while the [sqlite3_last_insert_rowid()] 2133** function is running and thus changes the last insert [rowid], 2134** then the value returned by [sqlite3_last_insert_rowid()] is 2135** unpredictable and might not equal either the old or the new 2136** last insert [rowid]. 2137*/ 2138SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2139 2140/* 2141** CAPI3REF: Set the Last Insert Rowid value. 2142** METHOD: sqlite3 2143** 2144** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2145** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2146** without inserting a row into the database. 2147*/ 2148SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2149 2150/* 2151** CAPI3REF: Count The Number Of Rows Modified 2152** METHOD: sqlite3 2153** 2154** ^This function returns the number of rows modified, inserted or 2155** deleted by the most recently completed INSERT, UPDATE or DELETE 2156** statement on the database connection specified by the only parameter. 2157** ^Executing any other type of SQL statement does not modify the value 2158** returned by this function. 2159** 2160** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2161** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2162** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2163** 2164** Changes to a view that are intercepted by 2165** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2166** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2167** DELETE statement run on a view is always zero. Only changes made to real 2168** tables are counted. 2169** 2170** Things are more complicated if the sqlite3_changes() function is 2171** executed while a trigger program is running. This may happen if the 2172** program uses the [changes() SQL function], or if some other callback 2173** function invokes sqlite3_changes() directly. Essentially: 2174** 2175** <ul> 2176** <li> ^(Before entering a trigger program the value returned by 2177** sqlite3_changes() function is saved. After the trigger program 2178** has finished, the original value is restored.)^ 2179** 2180** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2181** statement sets the value returned by sqlite3_changes() 2182** upon completion as normal. Of course, this value will not include 2183** any changes performed by sub-triggers, as the sqlite3_changes() 2184** value will be saved and restored after each sub-trigger has run.)^ 2185** </ul> 2186** 2187** ^This means that if the changes() SQL function (or similar) is used 2188** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2189** returns the value as set when the calling statement began executing. 2190** ^If it is used by the second or subsequent such statement within a trigger 2191** program, the value returned reflects the number of rows modified by the 2192** previous INSERT, UPDATE or DELETE statement within the same trigger. 2193** 2194** See also the [sqlite3_total_changes()] interface, the 2195** [count_changes pragma], and the [changes() SQL function]. 2196** 2197** If a separate thread makes changes on the same database connection 2198** while [sqlite3_changes()] is running then the value returned 2199** is unpredictable and not meaningful. 2200*/ 2201SQLITE_API int sqlite3_changes(sqlite3*); 2202 2203/* 2204** CAPI3REF: Total Number Of Rows Modified 2205** METHOD: sqlite3 2206** 2207** ^This function returns the total number of rows inserted, modified or 2208** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2209** since the database connection was opened, including those executed as 2210** part of trigger programs. ^Executing any other type of SQL statement 2211** does not affect the value returned by sqlite3_total_changes(). 2212** 2213** ^Changes made as part of [foreign key actions] are included in the 2214** count, but those made as part of REPLACE constraint resolution are 2215** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2216** are not counted. 2217** 2218** See also the [sqlite3_changes()] interface, the 2219** [count_changes pragma], and the [total_changes() SQL function]. 2220** 2221** If a separate thread makes changes on the same database connection 2222** while [sqlite3_total_changes()] is running then the value 2223** returned is unpredictable and not meaningful. 2224*/ 2225SQLITE_API int sqlite3_total_changes(sqlite3*); 2226 2227/* 2228** CAPI3REF: Interrupt A Long-Running Query 2229** METHOD: sqlite3 2230** 2231** ^This function causes any pending database operation to abort and 2232** return at its earliest opportunity. This routine is typically 2233** called in response to a user action such as pressing "Cancel" 2234** or Ctrl-C where the user wants a long query operation to halt 2235** immediately. 2236** 2237** ^It is safe to call this routine from a thread different from the 2238** thread that is currently running the database operation. But it 2239** is not safe to call this routine with a [database connection] that 2240** is closed or might close before sqlite3_interrupt() returns. 2241** 2242** ^If an SQL operation is very nearly finished at the time when 2243** sqlite3_interrupt() is called, then it might not have an opportunity 2244** to be interrupted and might continue to completion. 2245** 2246** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2247** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2248** that is inside an explicit transaction, then the entire transaction 2249** will be rolled back automatically. 2250** 2251** ^The sqlite3_interrupt(D) call is in effect until all currently running 2252** SQL statements on [database connection] D complete. ^Any new SQL statements 2253** that are started after the sqlite3_interrupt() call and before the 2254** running statements reaches zero are interrupted as if they had been 2255** running prior to the sqlite3_interrupt() call. ^New SQL statements 2256** that are started after the running statement count reaches zero are 2257** not effected by the sqlite3_interrupt(). 2258** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2259** SQL statements is a no-op and has no effect on SQL statements 2260** that are started after the sqlite3_interrupt() call returns. 2261*/ 2262SQLITE_API void sqlite3_interrupt(sqlite3*); 2263 2264/* 2265** CAPI3REF: Determine If An SQL Statement Is Complete 2266** 2267** These routines are useful during command-line input to determine if the 2268** currently entered text seems to form a complete SQL statement or 2269** if additional input is needed before sending the text into 2270** SQLite for parsing. ^These routines return 1 if the input string 2271** appears to be a complete SQL statement. ^A statement is judged to be 2272** complete if it ends with a semicolon token and is not a prefix of a 2273** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2274** string literals or quoted identifier names or comments are not 2275** independent tokens (they are part of the token in which they are 2276** embedded) and thus do not count as a statement terminator. ^Whitespace 2277** and comments that follow the final semicolon are ignored. 2278** 2279** ^These routines return 0 if the statement is incomplete. ^If a 2280** memory allocation fails, then SQLITE_NOMEM is returned. 2281** 2282** ^These routines do not parse the SQL statements thus 2283** will not detect syntactically incorrect SQL. 2284** 2285** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2286** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2287** automatically by sqlite3_complete16(). If that initialization fails, 2288** then the return value from sqlite3_complete16() will be non-zero 2289** regardless of whether or not the input SQL is complete.)^ 2290** 2291** The input to [sqlite3_complete()] must be a zero-terminated 2292** UTF-8 string. 2293** 2294** The input to [sqlite3_complete16()] must be a zero-terminated 2295** UTF-16 string in native byte order. 2296*/ 2297SQLITE_API int sqlite3_complete(const char *sql); 2298SQLITE_API int sqlite3_complete16(const void *sql); 2299 2300/* 2301** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2302** KEYWORDS: {busy-handler callback} {busy handler} 2303** METHOD: sqlite3 2304** 2305** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2306** that might be invoked with argument P whenever 2307** an attempt is made to access a database table associated with 2308** [database connection] D when another thread 2309** or process has the table locked. 2310** The sqlite3_busy_handler() interface is used to implement 2311** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2312** 2313** ^If the busy callback is NULL, then [SQLITE_BUSY] 2314** is returned immediately upon encountering the lock. ^If the busy callback 2315** is not NULL, then the callback might be invoked with two arguments. 2316** 2317** ^The first argument to the busy handler is a copy of the void* pointer which 2318** is the third argument to sqlite3_busy_handler(). ^The second argument to 2319** the busy handler callback is the number of times that the busy handler has 2320** been invoked previously for the same locking event. ^If the 2321** busy callback returns 0, then no additional attempts are made to 2322** access the database and [SQLITE_BUSY] is returned 2323** to the application. 2324** ^If the callback returns non-zero, then another attempt 2325** is made to access the database and the cycle repeats. 2326** 2327** The presence of a busy handler does not guarantee that it will be invoked 2328** when there is lock contention. ^If SQLite determines that invoking the busy 2329** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2330** to the application instead of invoking the 2331** busy handler. 2332** Consider a scenario where one process is holding a read lock that 2333** it is trying to promote to a reserved lock and 2334** a second process is holding a reserved lock that it is trying 2335** to promote to an exclusive lock. The first process cannot proceed 2336** because it is blocked by the second and the second process cannot 2337** proceed because it is blocked by the first. If both processes 2338** invoke the busy handlers, neither will make any progress. Therefore, 2339** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2340** will induce the first process to release its read lock and allow 2341** the second process to proceed. 2342** 2343** ^The default busy callback is NULL. 2344** 2345** ^(There can only be a single busy handler defined for each 2346** [database connection]. Setting a new busy handler clears any 2347** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2348** or evaluating [PRAGMA busy_timeout=N] will change the 2349** busy handler and thus clear any previously set busy handler. 2350** 2351** The busy callback should not take any actions which modify the 2352** database connection that invoked the busy handler. In other words, 2353** the busy handler is not reentrant. Any such actions 2354** result in undefined behavior. 2355** 2356** A busy handler must not close the database connection 2357** or [prepared statement] that invoked the busy handler. 2358*/ 2359SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2360 2361/* 2362** CAPI3REF: Set A Busy Timeout 2363** METHOD: sqlite3 2364** 2365** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2366** for a specified amount of time when a table is locked. ^The handler 2367** will sleep multiple times until at least "ms" milliseconds of sleeping 2368** have accumulated. ^After at least "ms" milliseconds of sleeping, 2369** the handler returns 0 which causes [sqlite3_step()] to return 2370** [SQLITE_BUSY]. 2371** 2372** ^Calling this routine with an argument less than or equal to zero 2373** turns off all busy handlers. 2374** 2375** ^(There can only be a single busy handler for a particular 2376** [database connection] at any given moment. If another busy handler 2377** was defined (using [sqlite3_busy_handler()]) prior to calling 2378** this routine, that other busy handler is cleared.)^ 2379** 2380** See also: [PRAGMA busy_timeout] 2381*/ 2382SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2383 2384/* 2385** CAPI3REF: Convenience Routines For Running Queries 2386** METHOD: sqlite3 2387** 2388** This is a legacy interface that is preserved for backwards compatibility. 2389** Use of this interface is not recommended. 2390** 2391** Definition: A <b>result table</b> is memory data structure created by the 2392** [sqlite3_get_table()] interface. A result table records the 2393** complete query results from one or more queries. 2394** 2395** The table conceptually has a number of rows and columns. But 2396** these numbers are not part of the result table itself. These 2397** numbers are obtained separately. Let N be the number of rows 2398** and M be the number of columns. 2399** 2400** A result table is an array of pointers to zero-terminated UTF-8 strings. 2401** There are (N+1)*M elements in the array. The first M pointers point 2402** to zero-terminated strings that contain the names of the columns. 2403** The remaining entries all point to query results. NULL values result 2404** in NULL pointers. All other values are in their UTF-8 zero-terminated 2405** string representation as returned by [sqlite3_column_text()]. 2406** 2407** A result table might consist of one or more memory allocations. 2408** It is not safe to pass a result table directly to [sqlite3_free()]. 2409** A result table should be deallocated using [sqlite3_free_table()]. 2410** 2411** ^(As an example of the result table format, suppose a query result 2412** is as follows: 2413** 2414** <blockquote><pre> 2415** Name | Age 2416** ----------------------- 2417** Alice | 43 2418** Bob | 28 2419** Cindy | 21 2420** </pre></blockquote> 2421** 2422** There are two column (M==2) and three rows (N==3). Thus the 2423** result table has 8 entries. Suppose the result table is stored 2424** in an array names azResult. Then azResult holds this content: 2425** 2426** <blockquote><pre> 2427** azResult[0] = "Name"; 2428** azResult[1] = "Age"; 2429** azResult[2] = "Alice"; 2430** azResult[3] = "43"; 2431** azResult[4] = "Bob"; 2432** azResult[5] = "28"; 2433** azResult[6] = "Cindy"; 2434** azResult[7] = "21"; 2435** </pre></blockquote>)^ 2436** 2437** ^The sqlite3_get_table() function evaluates one or more 2438** semicolon-separated SQL statements in the zero-terminated UTF-8 2439** string of its 2nd parameter and returns a result table to the 2440** pointer given in its 3rd parameter. 2441** 2442** After the application has finished with the result from sqlite3_get_table(), 2443** it must pass the result table pointer to sqlite3_free_table() in order to 2444** release the memory that was malloced. Because of the way the 2445** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2446** function must not try to call [sqlite3_free()] directly. Only 2447** [sqlite3_free_table()] is able to release the memory properly and safely. 2448** 2449** The sqlite3_get_table() interface is implemented as a wrapper around 2450** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2451** to any internal data structures of SQLite. It uses only the public 2452** interface defined here. As a consequence, errors that occur in the 2453** wrapper layer outside of the internal [sqlite3_exec()] call are not 2454** reflected in subsequent calls to [sqlite3_errcode()] or 2455** [sqlite3_errmsg()]. 2456*/ 2457SQLITE_API int sqlite3_get_table( 2458 sqlite3 *db, /* An open database */ 2459 const char *zSql, /* SQL to be evaluated */ 2460 char ***pazResult, /* Results of the query */ 2461 int *pnRow, /* Number of result rows written here */ 2462 int *pnColumn, /* Number of result columns written here */ 2463 char **pzErrmsg /* Error msg written here */ 2464); 2465SQLITE_API void sqlite3_free_table(char **result); 2466 2467/* 2468** CAPI3REF: Formatted String Printing Functions 2469** 2470** These routines are work-alikes of the "printf()" family of functions 2471** from the standard C library. 2472** These routines understand most of the common K&R formatting options, 2473** plus some additional non-standard formats, detailed below. 2474** Note that some of the more obscure formatting options from recent 2475** C-library standards are omitted from this implementation. 2476** 2477** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2478** results into memory obtained from [sqlite3_malloc()]. 2479** The strings returned by these two routines should be 2480** released by [sqlite3_free()]. ^Both routines return a 2481** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2482** memory to hold the resulting string. 2483** 2484** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2485** the standard C library. The result is written into the 2486** buffer supplied as the second parameter whose size is given by 2487** the first parameter. Note that the order of the 2488** first two parameters is reversed from snprintf().)^ This is an 2489** historical accident that cannot be fixed without breaking 2490** backwards compatibility. ^(Note also that sqlite3_snprintf() 2491** returns a pointer to its buffer instead of the number of 2492** characters actually written into the buffer.)^ We admit that 2493** the number of characters written would be a more useful return 2494** value but we cannot change the implementation of sqlite3_snprintf() 2495** now without breaking compatibility. 2496** 2497** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2498** guarantees that the buffer is always zero-terminated. ^The first 2499** parameter "n" is the total size of the buffer, including space for 2500** the zero terminator. So the longest string that can be completely 2501** written will be n-1 characters. 2502** 2503** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2504** 2505** These routines all implement some additional formatting 2506** options that are useful for constructing SQL statements. 2507** All of the usual printf() formatting options apply. In addition, there 2508** is are "%q", "%Q", "%w" and "%z" options. 2509** 2510** ^(The %q option works like %s in that it substitutes a nul-terminated 2511** string from the argument list. But %q also doubles every '\'' character. 2512** %q is designed for use inside a string literal.)^ By doubling each '\'' 2513** character it escapes that character and allows it to be inserted into 2514** the string. 2515** 2516** For example, assume the string variable zText contains text as follows: 2517** 2518** <blockquote><pre> 2519** char *zText = "It's a happy day!"; 2520** </pre></blockquote> 2521** 2522** One can use this text in an SQL statement as follows: 2523** 2524** <blockquote><pre> 2525** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2526** sqlite3_exec(db, zSQL, 0, 0, 0); 2527** sqlite3_free(zSQL); 2528** </pre></blockquote> 2529** 2530** Because the %q format string is used, the '\'' character in zText 2531** is escaped and the SQL generated is as follows: 2532** 2533** <blockquote><pre> 2534** INSERT INTO table1 VALUES('It''s a happy day!') 2535** </pre></blockquote> 2536** 2537** This is correct. Had we used %s instead of %q, the generated SQL 2538** would have looked like this: 2539** 2540** <blockquote><pre> 2541** INSERT INTO table1 VALUES('It's a happy day!'); 2542** </pre></blockquote> 2543** 2544** This second example is an SQL syntax error. As a general rule you should 2545** always use %q instead of %s when inserting text into a string literal. 2546** 2547** ^(The %Q option works like %q except it also adds single quotes around 2548** the outside of the total string. Additionally, if the parameter in the 2549** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2550** single quotes).)^ So, for example, one could say: 2551** 2552** <blockquote><pre> 2553** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2554** sqlite3_exec(db, zSQL, 0, 0, 0); 2555** sqlite3_free(zSQL); 2556** </pre></blockquote> 2557** 2558** The code above will render a correct SQL statement in the zSQL 2559** variable even if the zText variable is a NULL pointer. 2560** 2561** ^(The "%w" formatting option is like "%q" except that it expects to 2562** be contained within double-quotes instead of single quotes, and it 2563** escapes the double-quote character instead of the single-quote 2564** character.)^ The "%w" formatting option is intended for safely inserting 2565** table and column names into a constructed SQL statement. 2566** 2567** ^(The "%z" formatting option works like "%s" but with the 2568** addition that after the string has been read and copied into 2569** the result, [sqlite3_free()] is called on the input string.)^ 2570*/ 2571SQLITE_API char *sqlite3_mprintf(const char*,...); 2572SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2573SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2574SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2575 2576/* 2577** CAPI3REF: Memory Allocation Subsystem 2578** 2579** The SQLite core uses these three routines for all of its own 2580** internal memory allocation needs. "Core" in the previous sentence 2581** does not include operating-system specific VFS implementation. The 2582** Windows VFS uses native malloc() and free() for some operations. 2583** 2584** ^The sqlite3_malloc() routine returns a pointer to a block 2585** of memory at least N bytes in length, where N is the parameter. 2586** ^If sqlite3_malloc() is unable to obtain sufficient free 2587** memory, it returns a NULL pointer. ^If the parameter N to 2588** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2589** a NULL pointer. 2590** 2591** ^The sqlite3_malloc64(N) routine works just like 2592** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2593** of a signed 32-bit integer. 2594** 2595** ^Calling sqlite3_free() with a pointer previously returned 2596** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2597** that it might be reused. ^The sqlite3_free() routine is 2598** a no-op if is called with a NULL pointer. Passing a NULL pointer 2599** to sqlite3_free() is harmless. After being freed, memory 2600** should neither be read nor written. Even reading previously freed 2601** memory might result in a segmentation fault or other severe error. 2602** Memory corruption, a segmentation fault, or other severe error 2603** might result if sqlite3_free() is called with a non-NULL pointer that 2604** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2605** 2606** ^The sqlite3_realloc(X,N) interface attempts to resize a 2607** prior memory allocation X to be at least N bytes. 2608** ^If the X parameter to sqlite3_realloc(X,N) 2609** is a NULL pointer then its behavior is identical to calling 2610** sqlite3_malloc(N). 2611** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2612** negative then the behavior is exactly the same as calling 2613** sqlite3_free(X). 2614** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2615** of at least N bytes in size or NULL if insufficient memory is available. 2616** ^If M is the size of the prior allocation, then min(N,M) bytes 2617** of the prior allocation are copied into the beginning of buffer returned 2618** by sqlite3_realloc(X,N) and the prior allocation is freed. 2619** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2620** prior allocation is not freed. 2621** 2622** ^The sqlite3_realloc64(X,N) interfaces works the same as 2623** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2624** of a 32-bit signed integer. 2625** 2626** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2627** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2628** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2629** ^The value returned by sqlite3_msize(X) might be larger than the number 2630** of bytes requested when X was allocated. ^If X is a NULL pointer then 2631** sqlite3_msize(X) returns zero. If X points to something that is not 2632** the beginning of memory allocation, or if it points to a formerly 2633** valid memory allocation that has now been freed, then the behavior 2634** of sqlite3_msize(X) is undefined and possibly harmful. 2635** 2636** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2637** sqlite3_malloc64(), and sqlite3_realloc64() 2638** is always aligned to at least an 8 byte boundary, or to a 2639** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2640** option is used. 2641** 2642** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2643** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2644** implementation of these routines to be omitted. That capability 2645** is no longer provided. Only built-in memory allocators can be used. 2646** 2647** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2648** the system malloc() and free() directly when converting 2649** filenames between the UTF-8 encoding used by SQLite 2650** and whatever filename encoding is used by the particular Windows 2651** installation. Memory allocation errors were detected, but 2652** they were reported back as [SQLITE_CANTOPEN] or 2653** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2654** 2655** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2656** must be either NULL or else pointers obtained from a prior 2657** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2658** not yet been released. 2659** 2660** The application must not read or write any part of 2661** a block of memory after it has been released using 2662** [sqlite3_free()] or [sqlite3_realloc()]. 2663*/ 2664SQLITE_API void *sqlite3_malloc(int); 2665SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 2666SQLITE_API void *sqlite3_realloc(void*, int); 2667SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 2668SQLITE_API void sqlite3_free(void*); 2669SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 2670 2671/* 2672** CAPI3REF: Memory Allocator Statistics 2673** 2674** SQLite provides these two interfaces for reporting on the status 2675** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2676** routines, which form the built-in memory allocation subsystem. 2677** 2678** ^The [sqlite3_memory_used()] routine returns the number of bytes 2679** of memory currently outstanding (malloced but not freed). 2680** ^The [sqlite3_memory_highwater()] routine returns the maximum 2681** value of [sqlite3_memory_used()] since the high-water mark 2682** was last reset. ^The values returned by [sqlite3_memory_used()] and 2683** [sqlite3_memory_highwater()] include any overhead 2684** added by SQLite in its implementation of [sqlite3_malloc()], 2685** but not overhead added by the any underlying system library 2686** routines that [sqlite3_malloc()] may call. 2687** 2688** ^The memory high-water mark is reset to the current value of 2689** [sqlite3_memory_used()] if and only if the parameter to 2690** [sqlite3_memory_highwater()] is true. ^The value returned 2691** by [sqlite3_memory_highwater(1)] is the high-water mark 2692** prior to the reset. 2693*/ 2694SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2695SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2696 2697/* 2698** CAPI3REF: Pseudo-Random Number Generator 2699** 2700** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2701** select random [ROWID | ROWIDs] when inserting new records into a table that 2702** already uses the largest possible [ROWID]. The PRNG is also used for 2703** the build-in random() and randomblob() SQL functions. This interface allows 2704** applications to access the same PRNG for other purposes. 2705** 2706** ^A call to this routine stores N bytes of randomness into buffer P. 2707** ^The P parameter can be a NULL pointer. 2708** 2709** ^If this routine has not been previously called or if the previous 2710** call had N less than one or a NULL pointer for P, then the PRNG is 2711** seeded using randomness obtained from the xRandomness method of 2712** the default [sqlite3_vfs] object. 2713** ^If the previous call to this routine had an N of 1 or more and a 2714** non-NULL P then the pseudo-randomness is generated 2715** internally and without recourse to the [sqlite3_vfs] xRandomness 2716** method. 2717*/ 2718SQLITE_API void sqlite3_randomness(int N, void *P); 2719 2720/* 2721** CAPI3REF: Compile-Time Authorization Callbacks 2722** METHOD: sqlite3 2723** KEYWORDS: {authorizer callback} 2724** 2725** ^This routine registers an authorizer callback with a particular 2726** [database connection], supplied in the first argument. 2727** ^The authorizer callback is invoked as SQL statements are being compiled 2728** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2729** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2730** points during the compilation process, as logic is being created 2731** to perform various actions, the authorizer callback is invoked to 2732** see if those actions are allowed. ^The authorizer callback should 2733** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2734** specific action but allow the SQL statement to continue to be 2735** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2736** rejected with an error. ^If the authorizer callback returns 2737** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2738** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2739** the authorizer will fail with an error message. 2740** 2741** When the callback returns [SQLITE_OK], that means the operation 2742** requested is ok. ^When the callback returns [SQLITE_DENY], the 2743** [sqlite3_prepare_v2()] or equivalent call that triggered the 2744** authorizer will fail with an error message explaining that 2745** access is denied. 2746** 2747** ^The first parameter to the authorizer callback is a copy of the third 2748** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2749** to the callback is an integer [SQLITE_COPY | action code] that specifies 2750** the particular action to be authorized. ^The third through sixth parameters 2751** to the callback are either NULL pointers or zero-terminated strings 2752** that contain additional details about the action to be authorized. 2753** Applications must always be prepared to encounter a NULL pointer in any 2754** of the third through the sixth parameters of the authorization callback. 2755** 2756** ^If the action code is [SQLITE_READ] 2757** and the callback returns [SQLITE_IGNORE] then the 2758** [prepared statement] statement is constructed to substitute 2759** a NULL value in place of the table column that would have 2760** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2761** return can be used to deny an untrusted user access to individual 2762** columns of a table. 2763** ^When a table is referenced by a [SELECT] but no column values are 2764** extracted from that table (for example in a query like 2765** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 2766** is invoked once for that table with a column name that is an empty string. 2767** ^If the action code is [SQLITE_DELETE] and the callback returns 2768** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2769** [truncate optimization] is disabled and all rows are deleted individually. 2770** 2771** An authorizer is used when [sqlite3_prepare | preparing] 2772** SQL statements from an untrusted source, to ensure that the SQL statements 2773** do not try to access data they are not allowed to see, or that they do not 2774** try to execute malicious statements that damage the database. For 2775** example, an application may allow a user to enter arbitrary 2776** SQL queries for evaluation by a database. But the application does 2777** not want the user to be able to make arbitrary changes to the 2778** database. An authorizer could then be put in place while the 2779** user-entered SQL is being [sqlite3_prepare | prepared] that 2780** disallows everything except [SELECT] statements. 2781** 2782** Applications that need to process SQL from untrusted sources 2783** might also consider lowering resource limits using [sqlite3_limit()] 2784** and limiting database size using the [max_page_count] [PRAGMA] 2785** in addition to using an authorizer. 2786** 2787** ^(Only a single authorizer can be in place on a database connection 2788** at a time. Each call to sqlite3_set_authorizer overrides the 2789** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2790** The authorizer is disabled by default. 2791** 2792** The authorizer callback must not do anything that will modify 2793** the database connection that invoked the authorizer callback. 2794** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2795** database connections for the meaning of "modify" in this paragraph. 2796** 2797** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2798** statement might be re-prepared during [sqlite3_step()] due to a 2799** schema change. Hence, the application should ensure that the 2800** correct authorizer callback remains in place during the [sqlite3_step()]. 2801** 2802** ^Note that the authorizer callback is invoked only during 2803** [sqlite3_prepare()] or its variants. Authorization is not 2804** performed during statement evaluation in [sqlite3_step()], unless 2805** as stated in the previous paragraph, sqlite3_step() invokes 2806** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2807*/ 2808SQLITE_API int sqlite3_set_authorizer( 2809 sqlite3*, 2810 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2811 void *pUserData 2812); 2813 2814/* 2815** CAPI3REF: Authorizer Return Codes 2816** 2817** The [sqlite3_set_authorizer | authorizer callback function] must 2818** return either [SQLITE_OK] or one of these two constants in order 2819** to signal SQLite whether or not the action is permitted. See the 2820** [sqlite3_set_authorizer | authorizer documentation] for additional 2821** information. 2822** 2823** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2824** returned from the [sqlite3_vtab_on_conflict()] interface. 2825*/ 2826#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2827#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2828 2829/* 2830** CAPI3REF: Authorizer Action Codes 2831** 2832** The [sqlite3_set_authorizer()] interface registers a callback function 2833** that is invoked to authorize certain SQL statement actions. The 2834** second parameter to the callback is an integer code that specifies 2835** what action is being authorized. These are the integer action codes that 2836** the authorizer callback may be passed. 2837** 2838** These action code values signify what kind of operation is to be 2839** authorized. The 3rd and 4th parameters to the authorization 2840** callback function will be parameters or NULL depending on which of these 2841** codes is used as the second parameter. ^(The 5th parameter to the 2842** authorizer callback is the name of the database ("main", "temp", 2843** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2844** is the name of the inner-most trigger or view that is responsible for 2845** the access attempt or NULL if this access attempt is directly from 2846** top-level SQL code. 2847*/ 2848/******************************************* 3rd ************ 4th ***********/ 2849#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2850#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2851#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2852#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2853#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2854#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2855#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2856#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2857#define SQLITE_DELETE 9 /* Table Name NULL */ 2858#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2859#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2860#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2861#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2862#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2863#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2864#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2865#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2866#define SQLITE_INSERT 18 /* Table Name NULL */ 2867#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2868#define SQLITE_READ 20 /* Table Name Column Name */ 2869#define SQLITE_SELECT 21 /* NULL NULL */ 2870#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2871#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2872#define SQLITE_ATTACH 24 /* Filename NULL */ 2873#define SQLITE_DETACH 25 /* Database Name NULL */ 2874#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2875#define SQLITE_REINDEX 27 /* Index Name NULL */ 2876#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2877#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2878#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2879#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2880#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2881#define SQLITE_COPY 0 /* No longer used */ 2882#define SQLITE_RECURSIVE 33 /* NULL NULL */ 2883 2884/* 2885** CAPI3REF: Tracing And Profiling Functions 2886** METHOD: sqlite3 2887** 2888** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 2889** instead of the routines described here. 2890** 2891** These routines register callback functions that can be used for 2892** tracing and profiling the execution of SQL statements. 2893** 2894** ^The callback function registered by sqlite3_trace() is invoked at 2895** various times when an SQL statement is being run by [sqlite3_step()]. 2896** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2897** SQL statement text as the statement first begins executing. 2898** ^(Additional sqlite3_trace() callbacks might occur 2899** as each triggered subprogram is entered. The callbacks for triggers 2900** contain a UTF-8 SQL comment that identifies the trigger.)^ 2901** 2902** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2903** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2904** 2905** ^The callback function registered by sqlite3_profile() is invoked 2906** as each SQL statement finishes. ^The profile callback contains 2907** the original statement text and an estimate of wall-clock time 2908** of how long that statement took to run. ^The profile callback 2909** time is in units of nanoseconds, however the current implementation 2910** is only capable of millisecond resolution so the six least significant 2911** digits in the time are meaningless. Future versions of SQLite 2912** might provide greater resolution on the profiler callback. The 2913** sqlite3_profile() function is considered experimental and is 2914** subject to change in future versions of SQLite. 2915*/ 2916SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 2917 void(*xTrace)(void*,const char*), void*); 2918SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 2919 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2920 2921/* 2922** CAPI3REF: SQL Trace Event Codes 2923** KEYWORDS: SQLITE_TRACE 2924** 2925** These constants identify classes of events that can be monitored 2926** using the [sqlite3_trace_v2()] tracing logic. The third argument 2927** to [sqlite3_trace_v2()] is an OR-ed combination of one or more of 2928** the following constants. ^The first argument to the trace callback 2929** is one of the following constants. 2930** 2931** New tracing constants may be added in future releases. 2932** 2933** ^A trace callback has four arguments: xCallback(T,C,P,X). 2934** ^The T argument is one of the integer type codes above. 2935** ^The C argument is a copy of the context pointer passed in as the 2936** fourth argument to [sqlite3_trace_v2()]. 2937** The P and X arguments are pointers whose meanings depend on T. 2938** 2939** <dl> 2940** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 2941** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 2942** first begins running and possibly at other times during the 2943** execution of the prepared statement, such as at the start of each 2944** trigger subprogram. ^The P argument is a pointer to the 2945** [prepared statement]. ^The X argument is a pointer to a string which 2946** is the unexpanded SQL text of the prepared statement or an SQL comment 2947** that indicates the invocation of a trigger. ^The callback can compute 2948** the same text that would have been returned by the legacy [sqlite3_trace()] 2949** interface by using the X argument when X begins with "--" and invoking 2950** [sqlite3_expanded_sql(P)] otherwise. 2951** 2952** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 2953** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 2954** information as is provided by the [sqlite3_profile()] callback. 2955** ^The P argument is a pointer to the [prepared statement] and the 2956** X argument points to a 64-bit integer which is the estimated of 2957** the number of nanosecond that the prepared statement took to run. 2958** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 2959** 2960** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 2961** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 2962** statement generates a single row of result. 2963** ^The P argument is a pointer to the [prepared statement] and the 2964** X argument is unused. 2965** 2966** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 2967** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 2968** connection closes. 2969** ^The P argument is a pointer to the [database connection] object 2970** and the X argument is unused. 2971** </dl> 2972*/ 2973#define SQLITE_TRACE_STMT 0x01 2974#define SQLITE_TRACE_PROFILE 0x02 2975#define SQLITE_TRACE_ROW 0x04 2976#define SQLITE_TRACE_CLOSE 0x08 2977 2978/* 2979** CAPI3REF: SQL Trace Hook 2980** METHOD: sqlite3 2981** 2982** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 2983** function X against [database connection] D, using property mask M 2984** and context pointer P. ^If the X callback is 2985** NULL or if the M mask is zero, then tracing is disabled. The 2986** M argument should be the bitwise OR-ed combination of 2987** zero or more [SQLITE_TRACE] constants. 2988** 2989** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 2990** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 2991** 2992** ^The X callback is invoked whenever any of the events identified by 2993** mask M occur. ^The integer return value from the callback is currently 2994** ignored, though this may change in future releases. Callback 2995** implementations should return zero to ensure future compatibility. 2996** 2997** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 2998** ^The T argument is one of the [SQLITE_TRACE] 2999** constants to indicate why the callback was invoked. 3000** ^The C argument is a copy of the context pointer. 3001** The P and X arguments are pointers whose meanings depend on T. 3002** 3003** The sqlite3_trace_v2() interface is intended to replace the legacy 3004** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3005** are deprecated. 3006*/ 3007SQLITE_API int sqlite3_trace_v2( 3008 sqlite3*, 3009 unsigned uMask, 3010 int(*xCallback)(unsigned,void*,void*,void*), 3011 void *pCtx 3012); 3013 3014/* 3015** CAPI3REF: Query Progress Callbacks 3016** METHOD: sqlite3 3017** 3018** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3019** function X to be invoked periodically during long running calls to 3020** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3021** database connection D. An example use for this 3022** interface is to keep a GUI updated during a large query. 3023** 3024** ^The parameter P is passed through as the only parameter to the 3025** callback function X. ^The parameter N is the approximate number of 3026** [virtual machine instructions] that are evaluated between successive 3027** invocations of the callback X. ^If N is less than one then the progress 3028** handler is disabled. 3029** 3030** ^Only a single progress handler may be defined at one time per 3031** [database connection]; setting a new progress handler cancels the 3032** old one. ^Setting parameter X to NULL disables the progress handler. 3033** ^The progress handler is also disabled by setting N to a value less 3034** than 1. 3035** 3036** ^If the progress callback returns non-zero, the operation is 3037** interrupted. This feature can be used to implement a 3038** "Cancel" button on a GUI progress dialog box. 3039** 3040** The progress handler callback must not do anything that will modify 3041** the database connection that invoked the progress handler. 3042** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3043** database connections for the meaning of "modify" in this paragraph. 3044** 3045*/ 3046SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3047 3048/* 3049** CAPI3REF: Opening A New Database Connection 3050** CONSTRUCTOR: sqlite3 3051** 3052** ^These routines open an SQLite database file as specified by the 3053** filename argument. ^The filename argument is interpreted as UTF-8 for 3054** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3055** order for sqlite3_open16(). ^(A [database connection] handle is usually 3056** returned in *ppDb, even if an error occurs. The only exception is that 3057** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3058** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3059** object.)^ ^(If the database is opened (and/or created) successfully, then 3060** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3061** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3062** an English language description of the error following a failure of any 3063** of the sqlite3_open() routines. 3064** 3065** ^The default encoding will be UTF-8 for databases created using 3066** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3067** created using sqlite3_open16() will be UTF-16 in the native byte order. 3068** 3069** Whether or not an error occurs when it is opened, resources 3070** associated with the [database connection] handle should be released by 3071** passing it to [sqlite3_close()] when it is no longer required. 3072** 3073** The sqlite3_open_v2() interface works like sqlite3_open() 3074** except that it accepts two additional parameters for additional control 3075** over the new database connection. ^(The flags parameter to 3076** sqlite3_open_v2() can take one of 3077** the following three values, optionally combined with the 3078** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 3079** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 3080** 3081** <dl> 3082** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3083** <dd>The database is opened in read-only mode. If the database does not 3084** already exist, an error is returned.</dd>)^ 3085** 3086** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3087** <dd>The database is opened for reading and writing if possible, or reading 3088** only if the file is write protected by the operating system. In either 3089** case the database must already exist, otherwise an error is returned.</dd>)^ 3090** 3091** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3092** <dd>The database is opened for reading and writing, and is created if 3093** it does not already exist. This is the behavior that is always used for 3094** sqlite3_open() and sqlite3_open16().</dd>)^ 3095** </dl> 3096** 3097** If the 3rd parameter to sqlite3_open_v2() is not one of the 3098** combinations shown above optionally combined with other 3099** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3100** then the behavior is undefined. 3101** 3102** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 3103** opens in the multi-thread [threading mode] as long as the single-thread 3104** mode has not been set at compile-time or start-time. ^If the 3105** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 3106** in the serialized [threading mode] unless single-thread was 3107** previously selected at compile-time or start-time. 3108** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 3109** eligible to use [shared cache mode], regardless of whether or not shared 3110** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 3111** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 3112** participate in [shared cache mode] even if it is enabled. 3113** 3114** ^The fourth parameter to sqlite3_open_v2() is the name of the 3115** [sqlite3_vfs] object that defines the operating system interface that 3116** the new database connection should use. ^If the fourth parameter is 3117** a NULL pointer then the default [sqlite3_vfs] object is used. 3118** 3119** ^If the filename is ":memory:", then a private, temporary in-memory database 3120** is created for the connection. ^This in-memory database will vanish when 3121** the database connection is closed. Future versions of SQLite might 3122** make use of additional special filenames that begin with the ":" character. 3123** It is recommended that when a database filename actually does begin with 3124** a ":" character you should prefix the filename with a pathname such as 3125** "./" to avoid ambiguity. 3126** 3127** ^If the filename is an empty string, then a private, temporary 3128** on-disk database will be created. ^This private database will be 3129** automatically deleted as soon as the database connection is closed. 3130** 3131** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3132** 3133** ^If [URI filename] interpretation is enabled, and the filename argument 3134** begins with "file:", then the filename is interpreted as a URI. ^URI 3135** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3136** set in the fourth argument to sqlite3_open_v2(), or if it has 3137** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3138** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3139** As of SQLite version 3.7.7, URI filename interpretation is turned off 3140** by default, but future releases of SQLite might enable URI filename 3141** interpretation by default. See "[URI filenames]" for additional 3142** information. 3143** 3144** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3145** authority, then it must be either an empty string or the string 3146** "localhost". ^If the authority is not an empty string or "localhost", an 3147** error is returned to the caller. ^The fragment component of a URI, if 3148** present, is ignored. 3149** 3150** ^SQLite uses the path component of the URI as the name of the disk file 3151** which contains the database. ^If the path begins with a '/' character, 3152** then it is interpreted as an absolute path. ^If the path does not begin 3153** with a '/' (meaning that the authority section is omitted from the URI) 3154** then the path is interpreted as a relative path. 3155** ^(On windows, the first component of an absolute path 3156** is a drive specification (e.g. "C:").)^ 3157** 3158** [[core URI query parameters]] 3159** The query component of a URI may contain parameters that are interpreted 3160** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3161** SQLite and its built-in [VFSes] interpret the 3162** following query parameters: 3163** 3164** <ul> 3165** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3166** a VFS object that provides the operating system interface that should 3167** be used to access the database file on disk. ^If this option is set to 3168** an empty string the default VFS object is used. ^Specifying an unknown 3169** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3170** present, then the VFS specified by the option takes precedence over 3171** the value passed as the fourth parameter to sqlite3_open_v2(). 3172** 3173** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3174** "rwc", or "memory". Attempting to set it to any other value is 3175** an error)^. 3176** ^If "ro" is specified, then the database is opened for read-only 3177** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3178** third argument to sqlite3_open_v2(). ^If the mode option is set to 3179** "rw", then the database is opened for read-write (but not create) 3180** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3181** been set. ^Value "rwc" is equivalent to setting both 3182** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3183** set to "memory" then a pure [in-memory database] that never reads 3184** or writes from disk is used. ^It is an error to specify a value for 3185** the mode parameter that is less restrictive than that specified by 3186** the flags passed in the third parameter to sqlite3_open_v2(). 3187** 3188** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3189** "private". ^Setting it to "shared" is equivalent to setting the 3190** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3191** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3192** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3193** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3194** a URI filename, its value overrides any behavior requested by setting 3195** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3196** 3197** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3198** [powersafe overwrite] property does or does not apply to the 3199** storage media on which the database file resides. 3200** 3201** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3202** which if set disables file locking in rollback journal modes. This 3203** is useful for accessing a database on a filesystem that does not 3204** support locking. Caution: Database corruption might result if two 3205** or more processes write to the same database and any one of those 3206** processes uses nolock=1. 3207** 3208** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3209** parameter that indicates that the database file is stored on 3210** read-only media. ^When immutable is set, SQLite assumes that the 3211** database file cannot be changed, even by a process with higher 3212** privilege, and so the database is opened read-only and all locking 3213** and change detection is disabled. Caution: Setting the immutable 3214** property on a database file that does in fact change can result 3215** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3216** See also: [SQLITE_IOCAP_IMMUTABLE]. 3217** 3218** </ul> 3219** 3220** ^Specifying an unknown parameter in the query component of a URI is not an 3221** error. Future versions of SQLite might understand additional query 3222** parameters. See "[query parameters with special meaning to SQLite]" for 3223** additional information. 3224** 3225** [[URI filename examples]] <h3>URI filename examples</h3> 3226** 3227** <table border="1" align=center cellpadding=5> 3228** <tr><th> URI filenames <th> Results 3229** <tr><td> file:data.db <td> 3230** Open the file "data.db" in the current directory. 3231** <tr><td> file:/home/fred/data.db<br> 3232** file:///home/fred/data.db <br> 3233** file://localhost/home/fred/data.db <br> <td> 3234** Open the database file "/home/fred/data.db". 3235** <tr><td> file://darkstar/home/fred/data.db <td> 3236** An error. "darkstar" is not a recognized authority. 3237** <tr><td style="white-space:nowrap"> 3238** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3239** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3240** C:. Note that the %20 escaping in this example is not strictly 3241** necessary - space characters can be used literally 3242** in URI filenames. 3243** <tr><td> file:data.db?mode=ro&cache=private <td> 3244** Open file "data.db" in the current directory for read-only access. 3245** Regardless of whether or not shared-cache mode is enabled by 3246** default, use a private cache. 3247** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3248** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3249** that uses dot-files in place of posix advisory locking. 3250** <tr><td> file:data.db?mode=readonly <td> 3251** An error. "readonly" is not a valid option for the "mode" parameter. 3252** </table> 3253** 3254** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3255** query components of a URI. A hexadecimal escape sequence consists of a 3256** percent sign - "%" - followed by exactly two hexadecimal digits 3257** specifying an octet value. ^Before the path or query components of a 3258** URI filename are interpreted, they are encoded using UTF-8 and all 3259** hexadecimal escape sequences replaced by a single byte containing the 3260** corresponding octet. If this process generates an invalid UTF-8 encoding, 3261** the results are undefined. 3262** 3263** <b>Note to Windows users:</b> The encoding used for the filename argument 3264** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3265** codepage is currently defined. Filenames containing international 3266** characters must be converted to UTF-8 prior to passing them into 3267** sqlite3_open() or sqlite3_open_v2(). 3268** 3269** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3270** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3271** features that require the use of temporary files may fail. 3272** 3273** See also: [sqlite3_temp_directory] 3274*/ 3275SQLITE_API int sqlite3_open( 3276 const char *filename, /* Database filename (UTF-8) */ 3277 sqlite3 **ppDb /* OUT: SQLite db handle */ 3278); 3279SQLITE_API int sqlite3_open16( 3280 const void *filename, /* Database filename (UTF-16) */ 3281 sqlite3 **ppDb /* OUT: SQLite db handle */ 3282); 3283SQLITE_API int sqlite3_open_v2( 3284 const char *filename, /* Database filename (UTF-8) */ 3285 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3286 int flags, /* Flags */ 3287 const char *zVfs /* Name of VFS module to use */ 3288); 3289 3290/* 3291** CAPI3REF: Obtain Values For URI Parameters 3292** 3293** These are utility routines, useful to VFS implementations, that check 3294** to see if a database file was a URI that contained a specific query 3295** parameter, and if so obtains the value of that query parameter. 3296** 3297** If F is the database filename pointer passed into the xOpen() method of 3298** a VFS implementation when the flags parameter to xOpen() has one or 3299** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3300** P is the name of the query parameter, then 3301** sqlite3_uri_parameter(F,P) returns the value of the P 3302** parameter if it exists or a NULL pointer if P does not appear as a 3303** query parameter on F. If P is a query parameter of F 3304** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3305** a pointer to an empty string. 3306** 3307** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3308** parameter and returns true (1) or false (0) according to the value 3309** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3310** value of query parameter P is one of "yes", "true", or "on" in any 3311** case or if the value begins with a non-zero number. The 3312** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3313** query parameter P is one of "no", "false", or "off" in any case or 3314** if the value begins with a numeric zero. If P is not a query 3315** parameter on F or if the value of P is does not match any of the 3316** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3317** 3318** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3319** 64-bit signed integer and returns that integer, or D if P does not 3320** exist. If the value of P is something other than an integer, then 3321** zero is returned. 3322** 3323** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3324** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3325** is not a database file pathname pointer that SQLite passed into the xOpen 3326** VFS method, then the behavior of this routine is undefined and probably 3327** undesirable. 3328*/ 3329SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3330SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3331SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3332 3333 3334/* 3335** CAPI3REF: Error Codes And Messages 3336** METHOD: sqlite3 3337** 3338** ^If the most recent sqlite3_* API call associated with 3339** [database connection] D failed, then the sqlite3_errcode(D) interface 3340** returns the numeric [result code] or [extended result code] for that 3341** API call. 3342** If the most recent API call was successful, 3343** then the return value from sqlite3_errcode() is undefined. 3344** ^The sqlite3_extended_errcode() 3345** interface is the same except that it always returns the 3346** [extended result code] even when extended result codes are 3347** disabled. 3348** 3349** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3350** text that describes the error, as either UTF-8 or UTF-16 respectively. 3351** ^(Memory to hold the error message string is managed internally. 3352** The application does not need to worry about freeing the result. 3353** However, the error string might be overwritten or deallocated by 3354** subsequent calls to other SQLite interface functions.)^ 3355** 3356** ^The sqlite3_errstr() interface returns the English-language text 3357** that describes the [result code], as UTF-8. 3358** ^(Memory to hold the error message string is managed internally 3359** and must not be freed by the application)^. 3360** 3361** When the serialized [threading mode] is in use, it might be the 3362** case that a second error occurs on a separate thread in between 3363** the time of the first error and the call to these interfaces. 3364** When that happens, the second error will be reported since these 3365** interfaces always report the most recent result. To avoid 3366** this, each thread can obtain exclusive use of the [database connection] D 3367** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3368** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3369** all calls to the interfaces listed here are completed. 3370** 3371** If an interface fails with SQLITE_MISUSE, that means the interface 3372** was invoked incorrectly by the application. In that case, the 3373** error code and message may or may not be set. 3374*/ 3375SQLITE_API int sqlite3_errcode(sqlite3 *db); 3376SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3377SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3378SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3379SQLITE_API const char *sqlite3_errstr(int); 3380 3381/* 3382** CAPI3REF: Prepared Statement Object 3383** KEYWORDS: {prepared statement} {prepared statements} 3384** 3385** An instance of this object represents a single SQL statement that 3386** has been compiled into binary form and is ready to be evaluated. 3387** 3388** Think of each SQL statement as a separate computer program. The 3389** original SQL text is source code. A prepared statement object 3390** is the compiled object code. All SQL must be converted into a 3391** prepared statement before it can be run. 3392** 3393** The life-cycle of a prepared statement object usually goes like this: 3394** 3395** <ol> 3396** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3397** <li> Bind values to [parameters] using the sqlite3_bind_*() 3398** interfaces. 3399** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3400** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3401** to step 2. Do this zero or more times. 3402** <li> Destroy the object using [sqlite3_finalize()]. 3403** </ol> 3404*/ 3405typedef struct sqlite3_stmt sqlite3_stmt; 3406 3407/* 3408** CAPI3REF: Run-time Limits 3409** METHOD: sqlite3 3410** 3411** ^(This interface allows the size of various constructs to be limited 3412** on a connection by connection basis. The first parameter is the 3413** [database connection] whose limit is to be set or queried. The 3414** second parameter is one of the [limit categories] that define a 3415** class of constructs to be size limited. The third parameter is the 3416** new limit for that construct.)^ 3417** 3418** ^If the new limit is a negative number, the limit is unchanged. 3419** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3420** [limits | hard upper bound] 3421** set at compile-time by a C preprocessor macro called 3422** [limits | SQLITE_MAX_<i>NAME</i>]. 3423** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3424** ^Attempts to increase a limit above its hard upper bound are 3425** silently truncated to the hard upper bound. 3426** 3427** ^Regardless of whether or not the limit was changed, the 3428** [sqlite3_limit()] interface returns the prior value of the limit. 3429** ^Hence, to find the current value of a limit without changing it, 3430** simply invoke this interface with the third parameter set to -1. 3431** 3432** Run-time limits are intended for use in applications that manage 3433** both their own internal database and also databases that are controlled 3434** by untrusted external sources. An example application might be a 3435** web browser that has its own databases for storing history and 3436** separate databases controlled by JavaScript applications downloaded 3437** off the Internet. The internal databases can be given the 3438** large, default limits. Databases managed by external sources can 3439** be given much smaller limits designed to prevent a denial of service 3440** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3441** interface to further control untrusted SQL. The size of the database 3442** created by an untrusted script can be contained using the 3443** [max_page_count] [PRAGMA]. 3444** 3445** New run-time limit categories may be added in future releases. 3446*/ 3447SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 3448 3449/* 3450** CAPI3REF: Run-Time Limit Categories 3451** KEYWORDS: {limit category} {*limit categories} 3452** 3453** These constants define various performance limits 3454** that can be lowered at run-time using [sqlite3_limit()]. 3455** The synopsis of the meanings of the various limits is shown below. 3456** Additional information is available at [limits | Limits in SQLite]. 3457** 3458** <dl> 3459** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3460** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3461** 3462** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3463** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3464** 3465** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3466** <dd>The maximum number of columns in a table definition or in the 3467** result set of a [SELECT] or the maximum number of columns in an index 3468** or in an ORDER BY or GROUP BY clause.</dd>)^ 3469** 3470** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3471** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3472** 3473** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3474** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3475** 3476** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3477** <dd>The maximum number of instructions in a virtual machine program 3478** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3479** the equivalent tries to allocate space for more than this many opcodes 3480** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3481** 3482** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3483** <dd>The maximum number of arguments on a function.</dd>)^ 3484** 3485** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3486** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3487** 3488** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3489** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3490** <dd>The maximum length of the pattern argument to the [LIKE] or 3491** [GLOB] operators.</dd>)^ 3492** 3493** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3494** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3495** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3496** 3497** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3498** <dd>The maximum depth of recursion for triggers.</dd>)^ 3499** 3500** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3501** <dd>The maximum number of auxiliary worker threads that a single 3502** [prepared statement] may start.</dd>)^ 3503** </dl> 3504*/ 3505#define SQLITE_LIMIT_LENGTH 0 3506#define SQLITE_LIMIT_SQL_LENGTH 1 3507#define SQLITE_LIMIT_COLUMN 2 3508#define SQLITE_LIMIT_EXPR_DEPTH 3 3509#define SQLITE_LIMIT_COMPOUND_SELECT 4 3510#define SQLITE_LIMIT_VDBE_OP 5 3511#define SQLITE_LIMIT_FUNCTION_ARG 6 3512#define SQLITE_LIMIT_ATTACHED 7 3513#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3514#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3515#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3516#define SQLITE_LIMIT_WORKER_THREADS 11 3517 3518 3519/* 3520** CAPI3REF: Compiling An SQL Statement 3521** KEYWORDS: {SQL statement compiler} 3522** METHOD: sqlite3 3523** CONSTRUCTOR: sqlite3_stmt 3524** 3525** To execute an SQL query, it must first be compiled into a byte-code 3526** program using one of these routines. 3527** 3528** The first argument, "db", is a [database connection] obtained from a 3529** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3530** [sqlite3_open16()]. The database connection must not have been closed. 3531** 3532** The second argument, "zSql", is the statement to be compiled, encoded 3533** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 3534** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 3535** use UTF-16. 3536** 3537** ^If the nByte argument is negative, then zSql is read up to the 3538** first zero terminator. ^If nByte is positive, then it is the 3539** number of bytes read from zSql. ^If nByte is zero, then no prepared 3540** statement is generated. 3541** If the caller knows that the supplied string is nul-terminated, then 3542** there is a small performance advantage to passing an nByte parameter that 3543** is the number of bytes in the input string <i>including</i> 3544** the nul-terminator. 3545** 3546** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3547** past the end of the first SQL statement in zSql. These routines only 3548** compile the first statement in zSql, so *pzTail is left pointing to 3549** what remains uncompiled. 3550** 3551** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3552** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3553** to NULL. ^If the input text contains no SQL (if the input is an empty 3554** string or a comment) then *ppStmt is set to NULL. 3555** The calling procedure is responsible for deleting the compiled 3556** SQL statement using [sqlite3_finalize()] after it has finished with it. 3557** ppStmt may not be NULL. 3558** 3559** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3560** otherwise an [error code] is returned. 3561** 3562** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 3563** recommended for all new programs. The two older interfaces are retained 3564** for backwards compatibility, but their use is discouraged. 3565** ^In the "v2" interfaces, the prepared statement 3566** that is returned (the [sqlite3_stmt] object) contains a copy of the 3567** original SQL text. This causes the [sqlite3_step()] interface to 3568** behave differently in three ways: 3569** 3570** <ol> 3571** <li> 3572** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3573** always used to do, [sqlite3_step()] will automatically recompile the SQL 3574** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3575** retries will occur before sqlite3_step() gives up and returns an error. 3576** </li> 3577** 3578** <li> 3579** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3580** [error codes] or [extended error codes]. ^The legacy behavior was that 3581** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3582** and the application would have to make a second call to [sqlite3_reset()] 3583** in order to find the underlying cause of the problem. With the "v2" prepare 3584** interfaces, the underlying reason for the error is returned immediately. 3585** </li> 3586** 3587** <li> 3588** ^If the specific value bound to [parameter | host parameter] in the 3589** WHERE clause might influence the choice of query plan for a statement, 3590** then the statement will be automatically recompiled, as if there had been 3591** a schema change, on the first [sqlite3_step()] call following any change 3592** to the [sqlite3_bind_text | bindings] of that [parameter]. 3593** ^The specific value of WHERE-clause [parameter] might influence the 3594** choice of query plan if the parameter is the left-hand side of a [LIKE] 3595** or [GLOB] operator or if the parameter is compared to an indexed column 3596** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3597** </li> 3598** </ol> 3599*/ 3600SQLITE_API int sqlite3_prepare( 3601 sqlite3 *db, /* Database handle */ 3602 const char *zSql, /* SQL statement, UTF-8 encoded */ 3603 int nByte, /* Maximum length of zSql in bytes. */ 3604 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3605 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3606); 3607SQLITE_API int sqlite3_prepare_v2( 3608 sqlite3 *db, /* Database handle */ 3609 const char *zSql, /* SQL statement, UTF-8 encoded */ 3610 int nByte, /* Maximum length of zSql in bytes. */ 3611 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3612 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3613); 3614SQLITE_API int sqlite3_prepare16( 3615 sqlite3 *db, /* Database handle */ 3616 const void *zSql, /* SQL statement, UTF-16 encoded */ 3617 int nByte, /* Maximum length of zSql in bytes. */ 3618 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3619 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3620); 3621SQLITE_API int sqlite3_prepare16_v2( 3622 sqlite3 *db, /* Database handle */ 3623 const void *zSql, /* SQL statement, UTF-16 encoded */ 3624 int nByte, /* Maximum length of zSql in bytes. */ 3625 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3626 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3627); 3628 3629/* 3630** CAPI3REF: Retrieving Statement SQL 3631** METHOD: sqlite3_stmt 3632** 3633** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 3634** SQL text used to create [prepared statement] P if P was 3635** created by either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3636** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 3637** string containing the SQL text of prepared statement P with 3638** [bound parameters] expanded. 3639** 3640** ^(For example, if a prepared statement is created using the SQL 3641** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 3642** and parameter :xyz is unbound, then sqlite3_sql() will return 3643** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 3644** will return "SELECT 2345,NULL".)^ 3645** 3646** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 3647** is available to hold the result, or if the result would exceed the 3648** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 3649** 3650** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 3651** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 3652** option causes sqlite3_expanded_sql() to always return NULL. 3653** 3654** ^The string returned by sqlite3_sql(P) is managed by SQLite and is 3655** automatically freed when the prepared statement is finalized. 3656** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 3657** is obtained from [sqlite3_malloc()] and must be free by the application 3658** by passing it to [sqlite3_free()]. 3659*/ 3660SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 3661SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 3662 3663/* 3664** CAPI3REF: Determine If An SQL Statement Writes The Database 3665** METHOD: sqlite3_stmt 3666** 3667** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3668** and only if the [prepared statement] X makes no direct changes to 3669** the content of the database file. 3670** 3671** Note that [application-defined SQL functions] or 3672** [virtual tables] might change the database indirectly as a side effect. 3673** ^(For example, if an application defines a function "eval()" that 3674** calls [sqlite3_exec()], then the following SQL statement would 3675** change the database file through side-effects: 3676** 3677** <blockquote><pre> 3678** SELECT eval('DELETE FROM t1') FROM t2; 3679** </pre></blockquote> 3680** 3681** But because the [SELECT] statement does not change the database file 3682** directly, sqlite3_stmt_readonly() would still return true.)^ 3683** 3684** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3685** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3686** since the statements themselves do not actually modify the database but 3687** rather they control the timing of when other statements modify the 3688** database. ^The [ATTACH] and [DETACH] statements also cause 3689** sqlite3_stmt_readonly() to return true since, while those statements 3690** change the configuration of a database connection, they do not make 3691** changes to the content of the database files on disk. 3692** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 3693** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 3694** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 3695** sqlite3_stmt_readonly() returns false for those commands. 3696*/ 3697SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3698 3699/* 3700** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3701** METHOD: sqlite3_stmt 3702** 3703** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3704** [prepared statement] S has been stepped at least once using 3705** [sqlite3_step(S)] but has neither run to completion (returned 3706** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3707** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3708** interface returns false if S is a NULL pointer. If S is not a 3709** NULL pointer and is not a pointer to a valid [prepared statement] 3710** object, then the behavior is undefined and probably undesirable. 3711** 3712** This interface can be used in combination [sqlite3_next_stmt()] 3713** to locate all prepared statements associated with a database 3714** connection that are in need of being reset. This can be used, 3715** for example, in diagnostic routines to search for prepared 3716** statements that are holding a transaction open. 3717*/ 3718SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 3719 3720/* 3721** CAPI3REF: Dynamically Typed Value Object 3722** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3723** 3724** SQLite uses the sqlite3_value object to represent all values 3725** that can be stored in a database table. SQLite uses dynamic typing 3726** for the values it stores. ^Values stored in sqlite3_value objects 3727** can be integers, floating point values, strings, BLOBs, or NULL. 3728** 3729** An sqlite3_value object may be either "protected" or "unprotected". 3730** Some interfaces require a protected sqlite3_value. Other interfaces 3731** will accept either a protected or an unprotected sqlite3_value. 3732** Every interface that accepts sqlite3_value arguments specifies 3733** whether or not it requires a protected sqlite3_value. The 3734** [sqlite3_value_dup()] interface can be used to construct a new 3735** protected sqlite3_value from an unprotected sqlite3_value. 3736** 3737** The terms "protected" and "unprotected" refer to whether or not 3738** a mutex is held. An internal mutex is held for a protected 3739** sqlite3_value object but no mutex is held for an unprotected 3740** sqlite3_value object. If SQLite is compiled to be single-threaded 3741** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3742** or if SQLite is run in one of reduced mutex modes 3743** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3744** then there is no distinction between protected and unprotected 3745** sqlite3_value objects and they can be used interchangeably. However, 3746** for maximum code portability it is recommended that applications 3747** still make the distinction between protected and unprotected 3748** sqlite3_value objects even when not strictly required. 3749** 3750** ^The sqlite3_value objects that are passed as parameters into the 3751** implementation of [application-defined SQL functions] are protected. 3752** ^The sqlite3_value object returned by 3753** [sqlite3_column_value()] is unprotected. 3754** Unprotected sqlite3_value objects may only be used with 3755** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3756** The [sqlite3_value_blob | sqlite3_value_type()] family of 3757** interfaces require protected sqlite3_value objects. 3758*/ 3759typedef struct sqlite3_value sqlite3_value; 3760 3761/* 3762** CAPI3REF: SQL Function Context Object 3763** 3764** The context in which an SQL function executes is stored in an 3765** sqlite3_context object. ^A pointer to an sqlite3_context object 3766** is always first parameter to [application-defined SQL functions]. 3767** The application-defined SQL function implementation will pass this 3768** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3769** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3770** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3771** and/or [sqlite3_set_auxdata()]. 3772*/ 3773typedef struct sqlite3_context sqlite3_context; 3774 3775/* 3776** CAPI3REF: Binding Values To Prepared Statements 3777** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3778** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3779** METHOD: sqlite3_stmt 3780** 3781** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3782** literals may be replaced by a [parameter] that matches one of following 3783** templates: 3784** 3785** <ul> 3786** <li> ? 3787** <li> ?NNN 3788** <li> :VVV 3789** <li> @VVV 3790** <li> $VVV 3791** </ul> 3792** 3793** In the templates above, NNN represents an integer literal, 3794** and VVV represents an alphanumeric identifier.)^ ^The values of these 3795** parameters (also called "host parameter names" or "SQL parameters") 3796** can be set using the sqlite3_bind_*() routines defined here. 3797** 3798** ^The first argument to the sqlite3_bind_*() routines is always 3799** a pointer to the [sqlite3_stmt] object returned from 3800** [sqlite3_prepare_v2()] or its variants. 3801** 3802** ^The second argument is the index of the SQL parameter to be set. 3803** ^The leftmost SQL parameter has an index of 1. ^When the same named 3804** SQL parameter is used more than once, second and subsequent 3805** occurrences have the same index as the first occurrence. 3806** ^The index for named parameters can be looked up using the 3807** [sqlite3_bind_parameter_index()] API if desired. ^The index 3808** for "?NNN" parameters is the value of NNN. 3809** ^The NNN value must be between 1 and the [sqlite3_limit()] 3810** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3811** 3812** ^The third argument is the value to bind to the parameter. 3813** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3814** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3815** is ignored and the end result is the same as sqlite3_bind_null(). 3816** 3817** ^(In those routines that have a fourth argument, its value is the 3818** number of bytes in the parameter. To be clear: the value is the 3819** number of <u>bytes</u> in the value, not the number of characters.)^ 3820** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3821** is negative, then the length of the string is 3822** the number of bytes up to the first zero terminator. 3823** If the fourth parameter to sqlite3_bind_blob() is negative, then 3824** the behavior is undefined. 3825** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3826** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3827** that parameter must be the byte offset 3828** where the NUL terminator would occur assuming the string were NUL 3829** terminated. If any NUL characters occur at byte offsets less than 3830** the value of the fourth parameter then the resulting string value will 3831** contain embedded NULs. The result of expressions involving strings 3832** with embedded NULs is undefined. 3833** 3834** ^The fifth argument to the BLOB and string binding interfaces 3835** is a destructor used to dispose of the BLOB or 3836** string after SQLite has finished with it. ^The destructor is called 3837** to dispose of the BLOB or string even if the call to bind API fails. 3838** ^If the fifth argument is 3839** the special value [SQLITE_STATIC], then SQLite assumes that the 3840** information is in static, unmanaged space and does not need to be freed. 3841** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3842** SQLite makes its own private copy of the data immediately, before 3843** the sqlite3_bind_*() routine returns. 3844** 3845** ^The sixth argument to sqlite3_bind_text64() must be one of 3846** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 3847** to specify the encoding of the text in the third parameter. If 3848** the sixth argument to sqlite3_bind_text64() is not one of the 3849** allowed values shown above, or if the text encoding is different 3850** from the encoding specified by the sixth parameter, then the behavior 3851** is undefined. 3852** 3853** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3854** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3855** (just an integer to hold its size) while it is being processed. 3856** Zeroblobs are intended to serve as placeholders for BLOBs whose 3857** content is later written using 3858** [sqlite3_blob_open | incremental BLOB I/O] routines. 3859** ^A negative value for the zeroblob results in a zero-length BLOB. 3860** 3861** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3862** for the [prepared statement] or with a prepared statement for which 3863** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3864** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3865** routine is passed a [prepared statement] that has been finalized, the 3866** result is undefined and probably harmful. 3867** 3868** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3869** ^Unbound parameters are interpreted as NULL. 3870** 3871** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3872** [error code] if anything goes wrong. 3873** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 3874** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 3875** [SQLITE_MAX_LENGTH]. 3876** ^[SQLITE_RANGE] is returned if the parameter 3877** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3878** 3879** See also: [sqlite3_bind_parameter_count()], 3880** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3881*/ 3882SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3883SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 3884 void(*)(void*)); 3885SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 3886SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 3887SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3888SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 3889SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 3890SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3891SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 3892 void(*)(void*), unsigned char encoding); 3893SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3894SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3895SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 3896 3897/* 3898** CAPI3REF: Number Of SQL Parameters 3899** METHOD: sqlite3_stmt 3900** 3901** ^This routine can be used to find the number of [SQL parameters] 3902** in a [prepared statement]. SQL parameters are tokens of the 3903** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3904** placeholders for values that are [sqlite3_bind_blob | bound] 3905** to the parameters at a later time. 3906** 3907** ^(This routine actually returns the index of the largest (rightmost) 3908** parameter. For all forms except ?NNN, this will correspond to the 3909** number of unique parameters. If parameters of the ?NNN form are used, 3910** there may be gaps in the list.)^ 3911** 3912** See also: [sqlite3_bind_blob|sqlite3_bind()], 3913** [sqlite3_bind_parameter_name()], and 3914** [sqlite3_bind_parameter_index()]. 3915*/ 3916SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 3917 3918/* 3919** CAPI3REF: Name Of A Host Parameter 3920** METHOD: sqlite3_stmt 3921** 3922** ^The sqlite3_bind_parameter_name(P,N) interface returns 3923** the name of the N-th [SQL parameter] in the [prepared statement] P. 3924** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3925** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3926** respectively. 3927** In other words, the initial ":" or "$" or "@" or "?" 3928** is included as part of the name.)^ 3929** ^Parameters of the form "?" without a following integer have no name 3930** and are referred to as "nameless" or "anonymous parameters". 3931** 3932** ^The first host parameter has an index of 1, not 0. 3933** 3934** ^If the value N is out of range or if the N-th parameter is 3935** nameless, then NULL is returned. ^The returned string is 3936** always in UTF-8 encoding even if the named parameter was 3937** originally specified as UTF-16 in [sqlite3_prepare16()] or 3938** [sqlite3_prepare16_v2()]. 3939** 3940** See also: [sqlite3_bind_blob|sqlite3_bind()], 3941** [sqlite3_bind_parameter_count()], and 3942** [sqlite3_bind_parameter_index()]. 3943*/ 3944SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3945 3946/* 3947** CAPI3REF: Index Of A Parameter With A Given Name 3948** METHOD: sqlite3_stmt 3949** 3950** ^Return the index of an SQL parameter given its name. ^The 3951** index value returned is suitable for use as the second 3952** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3953** is returned if no matching parameter is found. ^The parameter 3954** name must be given in UTF-8 even if the original statement 3955** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3956** 3957** See also: [sqlite3_bind_blob|sqlite3_bind()], 3958** [sqlite3_bind_parameter_count()], and 3959** [sqlite3_bind_parameter_name()]. 3960*/ 3961SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3962 3963/* 3964** CAPI3REF: Reset All Bindings On A Prepared Statement 3965** METHOD: sqlite3_stmt 3966** 3967** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3968** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3969** ^Use this routine to reset all host parameters to NULL. 3970*/ 3971SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 3972 3973/* 3974** CAPI3REF: Number Of Columns In A Result Set 3975** METHOD: sqlite3_stmt 3976** 3977** ^Return the number of columns in the result set returned by the 3978** [prepared statement]. ^If this routine returns 0, that means the 3979** [prepared statement] returns no data (for example an [UPDATE]). 3980** ^However, just because this routine returns a positive number does not 3981** mean that one or more rows of data will be returned. ^A SELECT statement 3982** will always have a positive sqlite3_column_count() but depending on the 3983** WHERE clause constraints and the table content, it might return no rows. 3984** 3985** See also: [sqlite3_data_count()] 3986*/ 3987SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 3988 3989/* 3990** CAPI3REF: Column Names In A Result Set 3991** METHOD: sqlite3_stmt 3992** 3993** ^These routines return the name assigned to a particular column 3994** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3995** interface returns a pointer to a zero-terminated UTF-8 string 3996** and sqlite3_column_name16() returns a pointer to a zero-terminated 3997** UTF-16 string. ^The first parameter is the [prepared statement] 3998** that implements the [SELECT] statement. ^The second parameter is the 3999** column number. ^The leftmost column is number 0. 4000** 4001** ^The returned string pointer is valid until either the [prepared statement] 4002** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4003** reprepared by the first call to [sqlite3_step()] for a particular run 4004** or until the next call to 4005** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4006** 4007** ^If sqlite3_malloc() fails during the processing of either routine 4008** (for example during a conversion from UTF-8 to UTF-16) then a 4009** NULL pointer is returned. 4010** 4011** ^The name of a result column is the value of the "AS" clause for 4012** that column, if there is an AS clause. If there is no AS clause 4013** then the name of the column is unspecified and may change from 4014** one release of SQLite to the next. 4015*/ 4016SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 4017SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4018 4019/* 4020** CAPI3REF: Source Of Data In A Query Result 4021** METHOD: sqlite3_stmt 4022** 4023** ^These routines provide a means to determine the database, table, and 4024** table column that is the origin of a particular result column in 4025** [SELECT] statement. 4026** ^The name of the database or table or column can be returned as 4027** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4028** the database name, the _table_ routines return the table name, and 4029** the origin_ routines return the column name. 4030** ^The returned string is valid until the [prepared statement] is destroyed 4031** using [sqlite3_finalize()] or until the statement is automatically 4032** reprepared by the first call to [sqlite3_step()] for a particular run 4033** or until the same information is requested 4034** again in a different encoding. 4035** 4036** ^The names returned are the original un-aliased names of the 4037** database, table, and column. 4038** 4039** ^The first argument to these interfaces is a [prepared statement]. 4040** ^These functions return information about the Nth result column returned by 4041** the statement, where N is the second function argument. 4042** ^The left-most column is column 0 for these routines. 4043** 4044** ^If the Nth column returned by the statement is an expression or 4045** subquery and is not a column value, then all of these functions return 4046** NULL. ^These routine might also return NULL if a memory allocation error 4047** occurs. ^Otherwise, they return the name of the attached database, table, 4048** or column that query result column was extracted from. 4049** 4050** ^As with all other SQLite APIs, those whose names end with "16" return 4051** UTF-16 encoded strings and the other functions return UTF-8. 4052** 4053** ^These APIs are only available if the library was compiled with the 4054** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4055** 4056** If two or more threads call one or more of these routines against the same 4057** prepared statement and column at the same time then the results are 4058** undefined. 4059** 4060** If two or more threads call one or more 4061** [sqlite3_column_database_name | column metadata interfaces] 4062** for the same [prepared statement] and result column 4063** at the same time then the results are undefined. 4064*/ 4065SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4066SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4067SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4068SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4069SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4070SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4071 4072/* 4073** CAPI3REF: Declared Datatype Of A Query Result 4074** METHOD: sqlite3_stmt 4075** 4076** ^(The first parameter is a [prepared statement]. 4077** If this statement is a [SELECT] statement and the Nth column of the 4078** returned result set of that [SELECT] is a table column (not an 4079** expression or subquery) then the declared type of the table 4080** column is returned.)^ ^If the Nth column of the result set is an 4081** expression or subquery, then a NULL pointer is returned. 4082** ^The returned string is always UTF-8 encoded. 4083** 4084** ^(For example, given the database schema: 4085** 4086** CREATE TABLE t1(c1 VARIANT); 4087** 4088** and the following statement to be compiled: 4089** 4090** SELECT c1 + 1, c1 FROM t1; 4091** 4092** this routine would return the string "VARIANT" for the second result 4093** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4094** 4095** ^SQLite uses dynamic run-time typing. ^So just because a column 4096** is declared to contain a particular type does not mean that the 4097** data stored in that column is of the declared type. SQLite is 4098** strongly typed, but the typing is dynamic not static. ^Type 4099** is associated with individual values, not with the containers 4100** used to hold those values. 4101*/ 4102SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4103SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4104 4105/* 4106** CAPI3REF: Evaluate An SQL Statement 4107** METHOD: sqlite3_stmt 4108** 4109** After a [prepared statement] has been prepared using either 4110** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 4111** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4112** must be called one or more times to evaluate the statement. 4113** 4114** The details of the behavior of the sqlite3_step() interface depend 4115** on whether the statement was prepared using the newer "v2" interface 4116** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 4117** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4118** new "v2" interface is recommended for new applications but the legacy 4119** interface will continue to be supported. 4120** 4121** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4122** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4123** ^With the "v2" interface, any of the other [result codes] or 4124** [extended result codes] might be returned as well. 4125** 4126** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4127** database locks it needs to do its job. ^If the statement is a [COMMIT] 4128** or occurs outside of an explicit transaction, then you can retry the 4129** statement. If the statement is not a [COMMIT] and occurs within an 4130** explicit transaction then you should rollback the transaction before 4131** continuing. 4132** 4133** ^[SQLITE_DONE] means that the statement has finished executing 4134** successfully. sqlite3_step() should not be called again on this virtual 4135** machine without first calling [sqlite3_reset()] to reset the virtual 4136** machine back to its initial state. 4137** 4138** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4139** is returned each time a new row of data is ready for processing by the 4140** caller. The values may be accessed using the [column access functions]. 4141** sqlite3_step() is called again to retrieve the next row of data. 4142** 4143** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4144** violation) has occurred. sqlite3_step() should not be called again on 4145** the VM. More information may be found by calling [sqlite3_errmsg()]. 4146** ^With the legacy interface, a more specific error code (for example, 4147** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4148** can be obtained by calling [sqlite3_reset()] on the 4149** [prepared statement]. ^In the "v2" interface, 4150** the more specific error code is returned directly by sqlite3_step(). 4151** 4152** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4153** Perhaps it was called on a [prepared statement] that has 4154** already been [sqlite3_finalize | finalized] or on one that had 4155** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4156** be the case that the same database connection is being used by two or 4157** more threads at the same moment in time. 4158** 4159** For all versions of SQLite up to and including 3.6.23.1, a call to 4160** [sqlite3_reset()] was required after sqlite3_step() returned anything 4161** other than [SQLITE_ROW] before any subsequent invocation of 4162** sqlite3_step(). Failure to reset the prepared statement using 4163** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4164** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4165** sqlite3_step() began 4166** calling [sqlite3_reset()] automatically in this circumstance rather 4167** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4168** break because any application that ever receives an SQLITE_MISUSE error 4169** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4170** can be used to restore the legacy behavior. 4171** 4172** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4173** API always returns a generic error code, [SQLITE_ERROR], following any 4174** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4175** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4176** specific [error codes] that better describes the error. 4177** We admit that this is a goofy design. The problem has been fixed 4178** with the "v2" interface. If you prepare all of your SQL statements 4179** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 4180** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4181** then the more specific [error codes] are returned directly 4182** by sqlite3_step(). The use of the "v2" interface is recommended. 4183*/ 4184SQLITE_API int sqlite3_step(sqlite3_stmt*); 4185 4186/* 4187** CAPI3REF: Number of columns in a result set 4188** METHOD: sqlite3_stmt 4189** 4190** ^The sqlite3_data_count(P) interface returns the number of columns in the 4191** current row of the result set of [prepared statement] P. 4192** ^If prepared statement P does not have results ready to return 4193** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 4194** interfaces) then sqlite3_data_count(P) returns 0. 4195** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4196** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4197** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4198** will return non-zero if previous call to [sqlite3_step](P) returned 4199** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4200** where it always returns zero since each step of that multi-step 4201** pragma returns 0 columns of data. 4202** 4203** See also: [sqlite3_column_count()] 4204*/ 4205SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 4206 4207/* 4208** CAPI3REF: Fundamental Datatypes 4209** KEYWORDS: SQLITE_TEXT 4210** 4211** ^(Every value in SQLite has one of five fundamental datatypes: 4212** 4213** <ul> 4214** <li> 64-bit signed integer 4215** <li> 64-bit IEEE floating point number 4216** <li> string 4217** <li> BLOB 4218** <li> NULL 4219** </ul>)^ 4220** 4221** These constants are codes for each of those types. 4222** 4223** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4224** for a completely different meaning. Software that links against both 4225** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4226** SQLITE_TEXT. 4227*/ 4228#define SQLITE_INTEGER 1 4229#define SQLITE_FLOAT 2 4230#define SQLITE_BLOB 4 4231#define SQLITE_NULL 5 4232#ifdef SQLITE_TEXT 4233# undef SQLITE_TEXT 4234#else 4235# define SQLITE_TEXT 3 4236#endif 4237#define SQLITE3_TEXT 3 4238 4239/* 4240** CAPI3REF: Result Values From A Query 4241** KEYWORDS: {column access functions} 4242** METHOD: sqlite3_stmt 4243** 4244** ^These routines return information about a single column of the current 4245** result row of a query. ^In every case the first argument is a pointer 4246** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4247** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4248** and the second argument is the index of the column for which information 4249** should be returned. ^The leftmost column of the result set has the index 0. 4250** ^The number of columns in the result can be determined using 4251** [sqlite3_column_count()]. 4252** 4253** If the SQL statement does not currently point to a valid row, or if the 4254** column index is out of range, the result is undefined. 4255** These routines may only be called when the most recent call to 4256** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4257** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4258** If any of these routines are called after [sqlite3_reset()] or 4259** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4260** something other than [SQLITE_ROW], the results are undefined. 4261** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4262** are called from a different thread while any of these routines 4263** are pending, then the results are undefined. 4264** 4265** ^The sqlite3_column_type() routine returns the 4266** [SQLITE_INTEGER | datatype code] for the initial data type 4267** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4268** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 4269** returned by sqlite3_column_type() is only meaningful if no type 4270** conversions have occurred as described below. After a type conversion, 4271** the value returned by sqlite3_column_type() is undefined. Future 4272** versions of SQLite may change the behavior of sqlite3_column_type() 4273** following a type conversion. 4274** 4275** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4276** routine returns the number of bytes in that BLOB or string. 4277** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4278** the string to UTF-8 and then returns the number of bytes. 4279** ^If the result is a numeric value then sqlite3_column_bytes() uses 4280** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4281** the number of bytes in that string. 4282** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4283** 4284** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4285** routine returns the number of bytes in that BLOB or string. 4286** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4287** the string to UTF-16 and then returns the number of bytes. 4288** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4289** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4290** the number of bytes in that string. 4291** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4292** 4293** ^The values returned by [sqlite3_column_bytes()] and 4294** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4295** of the string. ^For clarity: the values returned by 4296** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4297** bytes in the string, not the number of characters. 4298** 4299** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4300** even empty strings, are always zero-terminated. ^The return 4301** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4302** 4303** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4304** [unprotected sqlite3_value] object. In a multithreaded environment, 4305** an unprotected sqlite3_value object may only be used safely with 4306** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4307** If the [unprotected sqlite3_value] object returned by 4308** [sqlite3_column_value()] is used in any other way, including calls 4309** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4310** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4311** 4312** These routines attempt to convert the value where appropriate. ^For 4313** example, if the internal representation is FLOAT and a text result 4314** is requested, [sqlite3_snprintf()] is used internally to perform the 4315** conversion automatically. ^(The following table details the conversions 4316** that are applied: 4317** 4318** <blockquote> 4319** <table border="1"> 4320** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4321** 4322** <tr><td> NULL <td> INTEGER <td> Result is 0 4323** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4324** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4325** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4326** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4327** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4328** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4329** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4330** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4331** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4332** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4333** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4334** <tr><td> TEXT <td> BLOB <td> No change 4335** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4336** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4337** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4338** </table> 4339** </blockquote>)^ 4340** 4341** Note that when type conversions occur, pointers returned by prior 4342** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4343** sqlite3_column_text16() may be invalidated. 4344** Type conversions and pointer invalidations might occur 4345** in the following cases: 4346** 4347** <ul> 4348** <li> The initial content is a BLOB and sqlite3_column_text() or 4349** sqlite3_column_text16() is called. A zero-terminator might 4350** need to be added to the string.</li> 4351** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4352** sqlite3_column_text16() is called. The content must be converted 4353** to UTF-16.</li> 4354** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4355** sqlite3_column_text() is called. The content must be converted 4356** to UTF-8.</li> 4357** </ul> 4358** 4359** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4360** not invalidate a prior pointer, though of course the content of the buffer 4361** that the prior pointer references will have been modified. Other kinds 4362** of conversion are done in place when it is possible, but sometimes they 4363** are not possible and in those cases prior pointers are invalidated. 4364** 4365** The safest policy is to invoke these routines 4366** in one of the following ways: 4367** 4368** <ul> 4369** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4370** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4371** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4372** </ul> 4373** 4374** In other words, you should call sqlite3_column_text(), 4375** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4376** into the desired format, then invoke sqlite3_column_bytes() or 4377** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4378** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4379** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4380** with calls to sqlite3_column_bytes(). 4381** 4382** ^The pointers returned are valid until a type conversion occurs as 4383** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4384** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4385** and BLOBs is freed automatically. Do <em>not</em> pass the pointers returned 4386** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4387** [sqlite3_free()]. 4388** 4389** ^(If a memory allocation error occurs during the evaluation of any 4390** of these routines, a default value is returned. The default value 4391** is either the integer 0, the floating point number 0.0, or a NULL 4392** pointer. Subsequent calls to [sqlite3_errcode()] will return 4393** [SQLITE_NOMEM].)^ 4394*/ 4395SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4396SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4397SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4398SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 4399SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 4400SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4401SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4402SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4403SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 4404SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4405 4406/* 4407** CAPI3REF: Destroy A Prepared Statement Object 4408** DESTRUCTOR: sqlite3_stmt 4409** 4410** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4411** ^If the most recent evaluation of the statement encountered no errors 4412** or if the statement is never been evaluated, then sqlite3_finalize() returns 4413** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4414** sqlite3_finalize(S) returns the appropriate [error code] or 4415** [extended error code]. 4416** 4417** ^The sqlite3_finalize(S) routine can be called at any point during 4418** the life cycle of [prepared statement] S: 4419** before statement S is ever evaluated, after 4420** one or more calls to [sqlite3_reset()], or after any call 4421** to [sqlite3_step()] regardless of whether or not the statement has 4422** completed execution. 4423** 4424** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4425** 4426** The application must finalize every [prepared statement] in order to avoid 4427** resource leaks. It is a grievous error for the application to try to use 4428** a prepared statement after it has been finalized. Any use of a prepared 4429** statement after it has been finalized can result in undefined and 4430** undesirable behavior such as segfaults and heap corruption. 4431*/ 4432SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 4433 4434/* 4435** CAPI3REF: Reset A Prepared Statement Object 4436** METHOD: sqlite3_stmt 4437** 4438** The sqlite3_reset() function is called to reset a [prepared statement] 4439** object back to its initial state, ready to be re-executed. 4440** ^Any SQL statement variables that had values bound to them using 4441** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4442** Use [sqlite3_clear_bindings()] to reset the bindings. 4443** 4444** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4445** back to the beginning of its program. 4446** 4447** ^If the most recent call to [sqlite3_step(S)] for the 4448** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4449** or if [sqlite3_step(S)] has never before been called on S, 4450** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4451** 4452** ^If the most recent call to [sqlite3_step(S)] for the 4453** [prepared statement] S indicated an error, then 4454** [sqlite3_reset(S)] returns an appropriate [error code]. 4455** 4456** ^The [sqlite3_reset(S)] interface does not change the values 4457** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4458*/ 4459SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 4460 4461/* 4462** CAPI3REF: Create Or Redefine SQL Functions 4463** KEYWORDS: {function creation routines} 4464** KEYWORDS: {application-defined SQL function} 4465** KEYWORDS: {application-defined SQL functions} 4466** METHOD: sqlite3 4467** 4468** ^These functions (collectively known as "function creation routines") 4469** are used to add SQL functions or aggregates or to redefine the behavior 4470** of existing SQL functions or aggregates. The only differences between 4471** these routines are the text encoding expected for 4472** the second parameter (the name of the function being created) 4473** and the presence or absence of a destructor callback for 4474** the application data pointer. 4475** 4476** ^The first parameter is the [database connection] to which the SQL 4477** function is to be added. ^If an application uses more than one database 4478** connection then application-defined SQL functions must be added 4479** to each database connection separately. 4480** 4481** ^The second parameter is the name of the SQL function to be created or 4482** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4483** representation, exclusive of the zero-terminator. ^Note that the name 4484** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4485** ^Any attempt to create a function with a longer name 4486** will result in [SQLITE_MISUSE] being returned. 4487** 4488** ^The third parameter (nArg) 4489** is the number of arguments that the SQL function or 4490** aggregate takes. ^If this parameter is -1, then the SQL function or 4491** aggregate may take any number of arguments between 0 and the limit 4492** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4493** parameter is less than -1 or greater than 127 then the behavior is 4494** undefined. 4495** 4496** ^The fourth parameter, eTextRep, specifies what 4497** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4498** its parameters. The application should set this parameter to 4499** [SQLITE_UTF16LE] if the function implementation invokes 4500** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4501** implementation invokes [sqlite3_value_text16be()] on an input, or 4502** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4503** otherwise. ^The same SQL function may be registered multiple times using 4504** different preferred text encodings, with different implementations for 4505** each encoding. 4506** ^When multiple implementations of the same function are available, SQLite 4507** will pick the one that involves the least amount of data conversion. 4508** 4509** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4510** to signal that the function will always return the same result given 4511** the same inputs within a single SQL statement. Most SQL functions are 4512** deterministic. The built-in [random()] SQL function is an example of a 4513** function that is not deterministic. The SQLite query planner is able to 4514** perform additional optimizations on deterministic functions, so use 4515** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4516** 4517** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4518** function can gain access to this pointer using [sqlite3_user_data()].)^ 4519** 4520** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4521** pointers to C-language functions that implement the SQL function or 4522** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4523** callback only; NULL pointers must be passed as the xStep and xFinal 4524** parameters. ^An aggregate SQL function requires an implementation of xStep 4525** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4526** SQL function or aggregate, pass NULL pointers for all three function 4527** callbacks. 4528** 4529** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4530** then it is destructor for the application data pointer. 4531** The destructor is invoked when the function is deleted, either by being 4532** overloaded or when the database connection closes.)^ 4533** ^The destructor is also invoked if the call to 4534** sqlite3_create_function_v2() fails. 4535** ^When the destructor callback of the tenth parameter is invoked, it 4536** is passed a single argument which is a copy of the application data 4537** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4538** 4539** ^It is permitted to register multiple implementations of the same 4540** functions with the same name but with either differing numbers of 4541** arguments or differing preferred text encodings. ^SQLite will use 4542** the implementation that most closely matches the way in which the 4543** SQL function is used. ^A function implementation with a non-negative 4544** nArg parameter is a better match than a function implementation with 4545** a negative nArg. ^A function where the preferred text encoding 4546** matches the database encoding is a better 4547** match than a function where the encoding is different. 4548** ^A function where the encoding difference is between UTF16le and UTF16be 4549** is a closer match than a function where the encoding difference is 4550** between UTF8 and UTF16. 4551** 4552** ^Built-in functions may be overloaded by new application-defined functions. 4553** 4554** ^An application-defined function is permitted to call other 4555** SQLite interfaces. However, such calls must not 4556** close the database connection nor finalize or reset the prepared 4557** statement in which the function is running. 4558*/ 4559SQLITE_API int sqlite3_create_function( 4560 sqlite3 *db, 4561 const char *zFunctionName, 4562 int nArg, 4563 int eTextRep, 4564 void *pApp, 4565 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4566 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4567 void (*xFinal)(sqlite3_context*) 4568); 4569SQLITE_API int sqlite3_create_function16( 4570 sqlite3 *db, 4571 const void *zFunctionName, 4572 int nArg, 4573 int eTextRep, 4574 void *pApp, 4575 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4576 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4577 void (*xFinal)(sqlite3_context*) 4578); 4579SQLITE_API int sqlite3_create_function_v2( 4580 sqlite3 *db, 4581 const char *zFunctionName, 4582 int nArg, 4583 int eTextRep, 4584 void *pApp, 4585 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4586 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4587 void (*xFinal)(sqlite3_context*), 4588 void(*xDestroy)(void*) 4589); 4590 4591/* 4592** CAPI3REF: Text Encodings 4593** 4594** These constant define integer codes that represent the various 4595** text encodings supported by SQLite. 4596*/ 4597#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4598#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4599#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4600#define SQLITE_UTF16 4 /* Use native byte order */ 4601#define SQLITE_ANY 5 /* Deprecated */ 4602#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4603 4604/* 4605** CAPI3REF: Function Flags 4606** 4607** These constants may be ORed together with the 4608** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4609** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4610** [sqlite3_create_function_v2()]. 4611*/ 4612#define SQLITE_DETERMINISTIC 0x800 4613 4614/* 4615** CAPI3REF: Deprecated Functions 4616** DEPRECATED 4617** 4618** These functions are [deprecated]. In order to maintain 4619** backwards compatibility with older code, these functions continue 4620** to be supported. However, new applications should avoid 4621** the use of these functions. To encourage programmers to avoid 4622** these functions, we will not explain what they do. 4623*/ 4624#ifndef SQLITE_OMIT_DEPRECATED 4625SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4626SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4627SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4628SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 4629SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4630SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4631 void*,sqlite3_int64); 4632#endif 4633 4634/* 4635** CAPI3REF: Obtaining SQL Values 4636** METHOD: sqlite3_value 4637** 4638** The C-language implementation of SQL functions and aggregates uses 4639** this set of interface routines to access the parameter values on 4640** the function or aggregate. 4641** 4642** The xFunc (for scalar functions) or xStep (for aggregates) parameters 4643** to [sqlite3_create_function()] and [sqlite3_create_function16()] 4644** define callbacks that implement the SQL functions and aggregates. 4645** The 3rd parameter to these callbacks is an array of pointers to 4646** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 4647** each parameter to the SQL function. These routines are used to 4648** extract values from the [sqlite3_value] objects. 4649** 4650** These routines work only with [protected sqlite3_value] objects. 4651** Any attempt to use these routines on an [unprotected sqlite3_value] 4652** object results in undefined behavior. 4653** 4654** ^These routines work just like the corresponding [column access functions] 4655** except that these routines take a single [protected sqlite3_value] object 4656** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4657** 4658** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4659** in the native byte-order of the host machine. ^The 4660** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4661** extract UTF-16 strings as big-endian and little-endian respectively. 4662** 4663** ^(The sqlite3_value_numeric_type() interface attempts to apply 4664** numeric affinity to the value. This means that an attempt is 4665** made to convert the value to an integer or floating point. If 4666** such a conversion is possible without loss of information (in other 4667** words, if the value is a string that looks like a number) 4668** then the conversion is performed. Otherwise no conversion occurs. 4669** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4670** 4671** Please pay particular attention to the fact that the pointer returned 4672** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4673** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4674** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4675** or [sqlite3_value_text16()]. 4676** 4677** These routines must be called from the same thread as 4678** the SQL function that supplied the [sqlite3_value*] parameters. 4679*/ 4680SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 4681SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 4682SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 4683SQLITE_API double sqlite3_value_double(sqlite3_value*); 4684SQLITE_API int sqlite3_value_int(sqlite3_value*); 4685SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4686SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 4687SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 4688SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 4689SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 4690SQLITE_API int sqlite3_value_type(sqlite3_value*); 4691SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 4692 4693/* 4694** CAPI3REF: Finding The Subtype Of SQL Values 4695** METHOD: sqlite3_value 4696** 4697** The sqlite3_value_subtype(V) function returns the subtype for 4698** an [application-defined SQL function] argument V. The subtype 4699** information can be used to pass a limited amount of context from 4700** one SQL function to another. Use the [sqlite3_result_subtype()] 4701** routine to set the subtype for the return value of an SQL function. 4702** 4703** SQLite makes no use of subtype itself. It merely passes the subtype 4704** from the result of one [application-defined SQL function] into the 4705** input of another. 4706*/ 4707SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 4708 4709/* 4710** CAPI3REF: Copy And Free SQL Values 4711** METHOD: sqlite3_value 4712** 4713** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 4714** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 4715** is a [protected sqlite3_value] object even if the input is not. 4716** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 4717** memory allocation fails. 4718** 4719** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 4720** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 4721** then sqlite3_value_free(V) is a harmless no-op. 4722*/ 4723SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 4724SQLITE_API void sqlite3_value_free(sqlite3_value*); 4725 4726/* 4727** CAPI3REF: Obtain Aggregate Function Context 4728** METHOD: sqlite3_context 4729** 4730** Implementations of aggregate SQL functions use this 4731** routine to allocate memory for storing their state. 4732** 4733** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4734** for a particular aggregate function, SQLite 4735** allocates N of memory, zeroes out that memory, and returns a pointer 4736** to the new memory. ^On second and subsequent calls to 4737** sqlite3_aggregate_context() for the same aggregate function instance, 4738** the same buffer is returned. Sqlite3_aggregate_context() is normally 4739** called once for each invocation of the xStep callback and then one 4740** last time when the xFinal callback is invoked. ^(When no rows match 4741** an aggregate query, the xStep() callback of the aggregate function 4742** implementation is never called and xFinal() is called exactly once. 4743** In those cases, sqlite3_aggregate_context() might be called for the 4744** first time from within xFinal().)^ 4745** 4746** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4747** when first called if N is less than or equal to zero or if a memory 4748** allocate error occurs. 4749** 4750** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4751** determined by the N parameter on first successful call. Changing the 4752** value of N in subsequent call to sqlite3_aggregate_context() within 4753** the same aggregate function instance will not resize the memory 4754** allocation.)^ Within the xFinal callback, it is customary to set 4755** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4756** pointless memory allocations occur. 4757** 4758** ^SQLite automatically frees the memory allocated by 4759** sqlite3_aggregate_context() when the aggregate query concludes. 4760** 4761** The first parameter must be a copy of the 4762** [sqlite3_context | SQL function context] that is the first parameter 4763** to the xStep or xFinal callback routine that implements the aggregate 4764** function. 4765** 4766** This routine must be called from the same thread in which 4767** the aggregate SQL function is running. 4768*/ 4769SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4770 4771/* 4772** CAPI3REF: User Data For Functions 4773** METHOD: sqlite3_context 4774** 4775** ^The sqlite3_user_data() interface returns a copy of 4776** the pointer that was the pUserData parameter (the 5th parameter) 4777** of the [sqlite3_create_function()] 4778** and [sqlite3_create_function16()] routines that originally 4779** registered the application defined function. 4780** 4781** This routine must be called from the same thread in which 4782** the application-defined function is running. 4783*/ 4784SQLITE_API void *sqlite3_user_data(sqlite3_context*); 4785 4786/* 4787** CAPI3REF: Database Connection For Functions 4788** METHOD: sqlite3_context 4789** 4790** ^The sqlite3_context_db_handle() interface returns a copy of 4791** the pointer to the [database connection] (the 1st parameter) 4792** of the [sqlite3_create_function()] 4793** and [sqlite3_create_function16()] routines that originally 4794** registered the application defined function. 4795*/ 4796SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 4797 4798/* 4799** CAPI3REF: Function Auxiliary Data 4800** METHOD: sqlite3_context 4801** 4802** These functions may be used by (non-aggregate) SQL functions to 4803** associate metadata with argument values. If the same value is passed to 4804** multiple invocations of the same SQL function during query execution, under 4805** some circumstances the associated metadata may be preserved. An example 4806** of where this might be useful is in a regular-expression matching 4807** function. The compiled version of the regular expression can be stored as 4808** metadata associated with the pattern string. 4809** Then as long as the pattern string remains the same, 4810** the compiled regular expression can be reused on multiple 4811** invocations of the same function. 4812** 4813** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 4814** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 4815** value to the application-defined function. ^N is zero for the left-most 4816** function argument. ^If there is no metadata 4817** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 4818** returns a NULL pointer. 4819** 4820** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 4821** argument of the application-defined function. ^Subsequent 4822** calls to sqlite3_get_auxdata(C,N) return P from the most recent 4823** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 4824** NULL if the metadata has been discarded. 4825** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 4826** SQLite will invoke the destructor function X with parameter P exactly 4827** once, when the metadata is discarded. 4828** SQLite is free to discard the metadata at any time, including: <ul> 4829** <li> ^(when the corresponding function parameter changes)^, or 4830** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 4831** SQL statement)^, or 4832** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 4833** parameter)^, or 4834** <li> ^(during the original sqlite3_set_auxdata() call when a memory 4835** allocation error occurs.)^ </ul> 4836** 4837** Note the last bullet in particular. The destructor X in 4838** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 4839** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 4840** should be called near the end of the function implementation and the 4841** function implementation should not make any use of P after 4842** sqlite3_set_auxdata() has been called. 4843** 4844** ^(In practice, metadata is preserved between function calls for 4845** function parameters that are compile-time constants, including literal 4846** values and [parameters] and expressions composed from the same.)^ 4847** 4848** The value of the N parameter to these interfaces should be non-negative. 4849** Future enhancements may make use of negative N values to define new 4850** kinds of function caching behavior. 4851** 4852** These routines must be called from the same thread in which 4853** the SQL function is running. 4854*/ 4855SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 4856SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4857 4858 4859/* 4860** CAPI3REF: Constants Defining Special Destructor Behavior 4861** 4862** These are special values for the destructor that is passed in as the 4863** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4864** argument is SQLITE_STATIC, it means that the content pointer is constant 4865** and will never change. It does not need to be destroyed. ^The 4866** SQLITE_TRANSIENT value means that the content will likely change in 4867** the near future and that SQLite should make its own private copy of 4868** the content before returning. 4869** 4870** The typedef is necessary to work around problems in certain 4871** C++ compilers. 4872*/ 4873typedef void (*sqlite3_destructor_type)(void*); 4874#define SQLITE_STATIC ((sqlite3_destructor_type)0) 4875#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4876 4877/* 4878** CAPI3REF: Setting The Result Of An SQL Function 4879** METHOD: sqlite3_context 4880** 4881** These routines are used by the xFunc or xFinal callbacks that 4882** implement SQL functions and aggregates. See 4883** [sqlite3_create_function()] and [sqlite3_create_function16()] 4884** for additional information. 4885** 4886** These functions work very much like the [parameter binding] family of 4887** functions used to bind values to host parameters in prepared statements. 4888** Refer to the [SQL parameter] documentation for additional information. 4889** 4890** ^The sqlite3_result_blob() interface sets the result from 4891** an application-defined function to be the BLOB whose content is pointed 4892** to by the second parameter and which is N bytes long where N is the 4893** third parameter. 4894** 4895** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 4896** interfaces set the result of the application-defined function to be 4897** a BLOB containing all zero bytes and N bytes in size. 4898** 4899** ^The sqlite3_result_double() interface sets the result from 4900** an application-defined function to be a floating point value specified 4901** by its 2nd argument. 4902** 4903** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4904** cause the implemented SQL function to throw an exception. 4905** ^SQLite uses the string pointed to by the 4906** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4907** as the text of an error message. ^SQLite interprets the error 4908** message string from sqlite3_result_error() as UTF-8. ^SQLite 4909** interprets the string from sqlite3_result_error16() as UTF-16 in native 4910** byte order. ^If the third parameter to sqlite3_result_error() 4911** or sqlite3_result_error16() is negative then SQLite takes as the error 4912** message all text up through the first zero character. 4913** ^If the third parameter to sqlite3_result_error() or 4914** sqlite3_result_error16() is non-negative then SQLite takes that many 4915** bytes (not characters) from the 2nd parameter as the error message. 4916** ^The sqlite3_result_error() and sqlite3_result_error16() 4917** routines make a private copy of the error message text before 4918** they return. Hence, the calling function can deallocate or 4919** modify the text after they return without harm. 4920** ^The sqlite3_result_error_code() function changes the error code 4921** returned by SQLite as a result of an error in a function. ^By default, 4922** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4923** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4924** 4925** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4926** error indicating that a string or BLOB is too long to represent. 4927** 4928** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4929** error indicating that a memory allocation failed. 4930** 4931** ^The sqlite3_result_int() interface sets the return value 4932** of the application-defined function to be the 32-bit signed integer 4933** value given in the 2nd argument. 4934** ^The sqlite3_result_int64() interface sets the return value 4935** of the application-defined function to be the 64-bit signed integer 4936** value given in the 2nd argument. 4937** 4938** ^The sqlite3_result_null() interface sets the return value 4939** of the application-defined function to be NULL. 4940** 4941** ^The sqlite3_result_text(), sqlite3_result_text16(), 4942** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4943** set the return value of the application-defined function to be 4944** a text string which is represented as UTF-8, UTF-16 native byte order, 4945** UTF-16 little endian, or UTF-16 big endian, respectively. 4946** ^The sqlite3_result_text64() interface sets the return value of an 4947** application-defined function to be a text string in an encoding 4948** specified by the fifth (and last) parameter, which must be one 4949** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 4950** ^SQLite takes the text result from the application from 4951** the 2nd parameter of the sqlite3_result_text* interfaces. 4952** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4953** is negative, then SQLite takes result text from the 2nd parameter 4954** through the first zero character. 4955** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4956** is non-negative, then as many bytes (not characters) of the text 4957** pointed to by the 2nd parameter are taken as the application-defined 4958** function result. If the 3rd parameter is non-negative, then it 4959** must be the byte offset into the string where the NUL terminator would 4960** appear if the string where NUL terminated. If any NUL characters occur 4961** in the string at a byte offset that is less than the value of the 3rd 4962** parameter, then the resulting string will contain embedded NULs and the 4963** result of expressions operating on strings with embedded NULs is undefined. 4964** ^If the 4th parameter to the sqlite3_result_text* interfaces 4965** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4966** function as the destructor on the text or BLOB result when it has 4967** finished using that result. 4968** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4969** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4970** assumes that the text or BLOB result is in constant space and does not 4971** copy the content of the parameter nor call a destructor on the content 4972** when it has finished using that result. 4973** ^If the 4th parameter to the sqlite3_result_text* interfaces 4974** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4975** then SQLite makes a copy of the result into space obtained from 4976** from [sqlite3_malloc()] before it returns. 4977** 4978** ^The sqlite3_result_value() interface sets the result of 4979** the application-defined function to be a copy of the 4980** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4981** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4982** so that the [sqlite3_value] specified in the parameter may change or 4983** be deallocated after sqlite3_result_value() returns without harm. 4984** ^A [protected sqlite3_value] object may always be used where an 4985** [unprotected sqlite3_value] object is required, so either 4986** kind of [sqlite3_value] object can be used with this interface. 4987** 4988** If these routines are called from within the different thread 4989** than the one containing the application-defined function that received 4990** the [sqlite3_context] pointer, the results are undefined. 4991*/ 4992SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4993SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 4994 sqlite3_uint64,void(*)(void*)); 4995SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 4996SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 4997SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 4998SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 4999SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 5000SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 5001SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 5002SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5003SQLITE_API void sqlite3_result_null(sqlite3_context*); 5004SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5005SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5006 void(*)(void*), unsigned char encoding); 5007SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5008SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5009SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5010SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5011SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 5012SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5013 5014 5015/* 5016** CAPI3REF: Setting The Subtype Of An SQL Function 5017** METHOD: sqlite3_context 5018** 5019** The sqlite3_result_subtype(C,T) function causes the subtype of 5020** the result from the [application-defined SQL function] with 5021** [sqlite3_context] C to be the value T. Only the lower 8 bits 5022** of the subtype T are preserved in current versions of SQLite; 5023** higher order bits are discarded. 5024** The number of subtype bytes preserved by SQLite might increase 5025** in future releases of SQLite. 5026*/ 5027SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5028 5029/* 5030** CAPI3REF: Define New Collating Sequences 5031** METHOD: sqlite3 5032** 5033** ^These functions add, remove, or modify a [collation] associated 5034** with the [database connection] specified as the first argument. 5035** 5036** ^The name of the collation is a UTF-8 string 5037** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5038** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5039** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5040** considered to be the same name. 5041** 5042** ^(The third argument (eTextRep) must be one of the constants: 5043** <ul> 5044** <li> [SQLITE_UTF8], 5045** <li> [SQLITE_UTF16LE], 5046** <li> [SQLITE_UTF16BE], 5047** <li> [SQLITE_UTF16], or 5048** <li> [SQLITE_UTF16_ALIGNED]. 5049** </ul>)^ 5050** ^The eTextRep argument determines the encoding of strings passed 5051** to the collating function callback, xCallback. 5052** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5053** force strings to be UTF16 with native byte order. 5054** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5055** on an even byte address. 5056** 5057** ^The fourth argument, pArg, is an application data pointer that is passed 5058** through as the first argument to the collating function callback. 5059** 5060** ^The fifth argument, xCallback, is a pointer to the collating function. 5061** ^Multiple collating functions can be registered using the same name but 5062** with different eTextRep parameters and SQLite will use whichever 5063** function requires the least amount of data transformation. 5064** ^If the xCallback argument is NULL then the collating function is 5065** deleted. ^When all collating functions having the same name are deleted, 5066** that collation is no longer usable. 5067** 5068** ^The collating function callback is invoked with a copy of the pArg 5069** application data pointer and with two strings in the encoding specified 5070** by the eTextRep argument. The collating function must return an 5071** integer that is negative, zero, or positive 5072** if the first string is less than, equal to, or greater than the second, 5073** respectively. A collating function must always return the same answer 5074** given the same inputs. If two or more collating functions are registered 5075** to the same collation name (using different eTextRep values) then all 5076** must give an equivalent answer when invoked with equivalent strings. 5077** The collating function must obey the following properties for all 5078** strings A, B, and C: 5079** 5080** <ol> 5081** <li> If A==B then B==A. 5082** <li> If A==B and B==C then A==C. 5083** <li> If A<B THEN B>A. 5084** <li> If A<B and B<C then A<C. 5085** </ol> 5086** 5087** If a collating function fails any of the above constraints and that 5088** collating function is registered and used, then the behavior of SQLite 5089** is undefined. 5090** 5091** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5092** with the addition that the xDestroy callback is invoked on pArg when 5093** the collating function is deleted. 5094** ^Collating functions are deleted when they are overridden by later 5095** calls to the collation creation functions or when the 5096** [database connection] is closed using [sqlite3_close()]. 5097** 5098** ^The xDestroy callback is <u>not</u> called if the 5099** sqlite3_create_collation_v2() function fails. Applications that invoke 5100** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5101** check the return code and dispose of the application data pointer 5102** themselves rather than expecting SQLite to deal with it for them. 5103** This is different from every other SQLite interface. The inconsistency 5104** is unfortunate but cannot be changed without breaking backwards 5105** compatibility. 5106** 5107** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5108*/ 5109SQLITE_API int sqlite3_create_collation( 5110 sqlite3*, 5111 const char *zName, 5112 int eTextRep, 5113 void *pArg, 5114 int(*xCompare)(void*,int,const void*,int,const void*) 5115); 5116SQLITE_API int sqlite3_create_collation_v2( 5117 sqlite3*, 5118 const char *zName, 5119 int eTextRep, 5120 void *pArg, 5121 int(*xCompare)(void*,int,const void*,int,const void*), 5122 void(*xDestroy)(void*) 5123); 5124SQLITE_API int sqlite3_create_collation16( 5125 sqlite3*, 5126 const void *zName, 5127 int eTextRep, 5128 void *pArg, 5129 int(*xCompare)(void*,int,const void*,int,const void*) 5130); 5131 5132/* 5133** CAPI3REF: Collation Needed Callbacks 5134** METHOD: sqlite3 5135** 5136** ^To avoid having to register all collation sequences before a database 5137** can be used, a single callback function may be registered with the 5138** [database connection] to be invoked whenever an undefined collation 5139** sequence is required. 5140** 5141** ^If the function is registered using the sqlite3_collation_needed() API, 5142** then it is passed the names of undefined collation sequences as strings 5143** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5144** the names are passed as UTF-16 in machine native byte order. 5145** ^A call to either function replaces the existing collation-needed callback. 5146** 5147** ^(When the callback is invoked, the first argument passed is a copy 5148** of the second argument to sqlite3_collation_needed() or 5149** sqlite3_collation_needed16(). The second argument is the database 5150** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5151** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5152** sequence function required. The fourth parameter is the name of the 5153** required collation sequence.)^ 5154** 5155** The callback function should register the desired collation using 5156** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5157** [sqlite3_create_collation_v2()]. 5158*/ 5159SQLITE_API int sqlite3_collation_needed( 5160 sqlite3*, 5161 void*, 5162 void(*)(void*,sqlite3*,int eTextRep,const char*) 5163); 5164SQLITE_API int sqlite3_collation_needed16( 5165 sqlite3*, 5166 void*, 5167 void(*)(void*,sqlite3*,int eTextRep,const void*) 5168); 5169 5170#ifdef SQLITE_HAS_CODEC 5171/* 5172** Specify the key for an encrypted database. This routine should be 5173** called right after sqlite3_open(). 5174** 5175** The code to implement this API is not available in the public release 5176** of SQLite. 5177*/ 5178SQLITE_API int sqlite3_key( 5179 sqlite3 *db, /* Database to be rekeyed */ 5180 const void *pKey, int nKey /* The key */ 5181); 5182SQLITE_API int sqlite3_key_v2( 5183 sqlite3 *db, /* Database to be rekeyed */ 5184 const char *zDbName, /* Name of the database */ 5185 const void *pKey, int nKey /* The key */ 5186); 5187 5188/* 5189** Change the key on an open database. If the current database is not 5190** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5191** database is decrypted. 5192** 5193** The code to implement this API is not available in the public release 5194** of SQLite. 5195*/ 5196SQLITE_API int sqlite3_rekey( 5197 sqlite3 *db, /* Database to be rekeyed */ 5198 const void *pKey, int nKey /* The new key */ 5199); 5200SQLITE_API int sqlite3_rekey_v2( 5201 sqlite3 *db, /* Database to be rekeyed */ 5202 const char *zDbName, /* Name of the database */ 5203 const void *pKey, int nKey /* The new key */ 5204); 5205 5206/* 5207** Specify the activation key for a SEE database. Unless 5208** activated, none of the SEE routines will work. 5209*/ 5210SQLITE_API void sqlite3_activate_see( 5211 const char *zPassPhrase /* Activation phrase */ 5212); 5213#endif 5214 5215#ifdef SQLITE_ENABLE_CEROD 5216/* 5217** Specify the activation key for a CEROD database. Unless 5218** activated, none of the CEROD routines will work. 5219*/ 5220SQLITE_API void sqlite3_activate_cerod( 5221 const char *zPassPhrase /* Activation phrase */ 5222); 5223#endif 5224 5225/* 5226** CAPI3REF: Suspend Execution For A Short Time 5227** 5228** The sqlite3_sleep() function causes the current thread to suspend execution 5229** for at least a number of milliseconds specified in its parameter. 5230** 5231** If the operating system does not support sleep requests with 5232** millisecond time resolution, then the time will be rounded up to 5233** the nearest second. The number of milliseconds of sleep actually 5234** requested from the operating system is returned. 5235** 5236** ^SQLite implements this interface by calling the xSleep() 5237** method of the default [sqlite3_vfs] object. If the xSleep() method 5238** of the default VFS is not implemented correctly, or not implemented at 5239** all, then the behavior of sqlite3_sleep() may deviate from the description 5240** in the previous paragraphs. 5241*/ 5242SQLITE_API int sqlite3_sleep(int); 5243 5244/* 5245** CAPI3REF: Name Of The Folder Holding Temporary Files 5246** 5247** ^(If this global variable is made to point to a string which is 5248** the name of a folder (a.k.a. directory), then all temporary files 5249** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5250** will be placed in that directory.)^ ^If this variable 5251** is a NULL pointer, then SQLite performs a search for an appropriate 5252** temporary file directory. 5253** 5254** Applications are strongly discouraged from using this global variable. 5255** It is required to set a temporary folder on Windows Runtime (WinRT). 5256** But for all other platforms, it is highly recommended that applications 5257** neither read nor write this variable. This global variable is a relic 5258** that exists for backwards compatibility of legacy applications and should 5259** be avoided in new projects. 5260** 5261** It is not safe to read or modify this variable in more than one 5262** thread at a time. It is not safe to read or modify this variable 5263** if a [database connection] is being used at the same time in a separate 5264** thread. 5265** It is intended that this variable be set once 5266** as part of process initialization and before any SQLite interface 5267** routines have been called and that this variable remain unchanged 5268** thereafter. 5269** 5270** ^The [temp_store_directory pragma] may modify this variable and cause 5271** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5272** the [temp_store_directory pragma] always assumes that any string 5273** that this variable points to is held in memory obtained from 5274** [sqlite3_malloc] and the pragma may attempt to free that memory 5275** using [sqlite3_free]. 5276** Hence, if this variable is modified directly, either it should be 5277** made NULL or made to point to memory obtained from [sqlite3_malloc] 5278** or else the use of the [temp_store_directory pragma] should be avoided. 5279** Except when requested by the [temp_store_directory pragma], SQLite 5280** does not free the memory that sqlite3_temp_directory points to. If 5281** the application wants that memory to be freed, it must do 5282** so itself, taking care to only do so after all [database connection] 5283** objects have been destroyed. 5284** 5285** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5286** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5287** features that require the use of temporary files may fail. Here is an 5288** example of how to do this using C++ with the Windows Runtime: 5289** 5290** <blockquote><pre> 5291** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5292** TemporaryFolder->Path->Data(); 5293** char zPathBuf[MAX_PATH + 1]; 5294** memset(zPathBuf, 0, sizeof(zPathBuf)); 5295** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5296** NULL, NULL); 5297** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5298** </pre></blockquote> 5299*/ 5300SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 5301 5302/* 5303** CAPI3REF: Name Of The Folder Holding Database Files 5304** 5305** ^(If this global variable is made to point to a string which is 5306** the name of a folder (a.k.a. directory), then all database files 5307** specified with a relative pathname and created or accessed by 5308** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5309** to be relative to that directory.)^ ^If this variable is a NULL 5310** pointer, then SQLite assumes that all database files specified 5311** with a relative pathname are relative to the current directory 5312** for the process. Only the windows VFS makes use of this global 5313** variable; it is ignored by the unix VFS. 5314** 5315** Changing the value of this variable while a database connection is 5316** open can result in a corrupt database. 5317** 5318** It is not safe to read or modify this variable in more than one 5319** thread at a time. It is not safe to read or modify this variable 5320** if a [database connection] is being used at the same time in a separate 5321** thread. 5322** It is intended that this variable be set once 5323** as part of process initialization and before any SQLite interface 5324** routines have been called and that this variable remain unchanged 5325** thereafter. 5326** 5327** ^The [data_store_directory pragma] may modify this variable and cause 5328** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5329** the [data_store_directory pragma] always assumes that any string 5330** that this variable points to is held in memory obtained from 5331** [sqlite3_malloc] and the pragma may attempt to free that memory 5332** using [sqlite3_free]. 5333** Hence, if this variable is modified directly, either it should be 5334** made NULL or made to point to memory obtained from [sqlite3_malloc] 5335** or else the use of the [data_store_directory pragma] should be avoided. 5336*/ 5337SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 5338 5339/* 5340** CAPI3REF: Test For Auto-Commit Mode 5341** KEYWORDS: {autocommit mode} 5342** METHOD: sqlite3 5343** 5344** ^The sqlite3_get_autocommit() interface returns non-zero or 5345** zero if the given database connection is or is not in autocommit mode, 5346** respectively. ^Autocommit mode is on by default. 5347** ^Autocommit mode is disabled by a [BEGIN] statement. 5348** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5349** 5350** If certain kinds of errors occur on a statement within a multi-statement 5351** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5352** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5353** transaction might be rolled back automatically. The only way to 5354** find out whether SQLite automatically rolled back the transaction after 5355** an error is to use this function. 5356** 5357** If another thread changes the autocommit status of the database 5358** connection while this routine is running, then the return value 5359** is undefined. 5360*/ 5361SQLITE_API int sqlite3_get_autocommit(sqlite3*); 5362 5363/* 5364** CAPI3REF: Find The Database Handle Of A Prepared Statement 5365** METHOD: sqlite3_stmt 5366** 5367** ^The sqlite3_db_handle interface returns the [database connection] handle 5368** to which a [prepared statement] belongs. ^The [database connection] 5369** returned by sqlite3_db_handle is the same [database connection] 5370** that was the first argument 5371** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5372** create the statement in the first place. 5373*/ 5374SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 5375 5376/* 5377** CAPI3REF: Return The Filename For A Database Connection 5378** METHOD: sqlite3 5379** 5380** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5381** associated with database N of connection D. ^The main database file 5382** has the name "main". If there is no attached database N on the database 5383** connection D, or if database N is a temporary or in-memory database, then 5384** a NULL pointer is returned. 5385** 5386** ^The filename returned by this function is the output of the 5387** xFullPathname method of the [VFS]. ^In other words, the filename 5388** will be an absolute pathname, even if the filename used 5389** to open the database originally was a URI or relative pathname. 5390*/ 5391SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5392 5393/* 5394** CAPI3REF: Determine if a database is read-only 5395** METHOD: sqlite3 5396** 5397** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5398** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5399** the name of a database on connection D. 5400*/ 5401SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5402 5403/* 5404** CAPI3REF: Find the next prepared statement 5405** METHOD: sqlite3 5406** 5407** ^This interface returns a pointer to the next [prepared statement] after 5408** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5409** then this interface returns a pointer to the first prepared statement 5410** associated with the database connection pDb. ^If no prepared statement 5411** satisfies the conditions of this routine, it returns NULL. 5412** 5413** The [database connection] pointer D in a call to 5414** [sqlite3_next_stmt(D,S)] must refer to an open database 5415** connection and in particular must not be a NULL pointer. 5416*/ 5417SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5418 5419/* 5420** CAPI3REF: Commit And Rollback Notification Callbacks 5421** METHOD: sqlite3 5422** 5423** ^The sqlite3_commit_hook() interface registers a callback 5424** function to be invoked whenever a transaction is [COMMIT | committed]. 5425** ^Any callback set by a previous call to sqlite3_commit_hook() 5426** for the same database connection is overridden. 5427** ^The sqlite3_rollback_hook() interface registers a callback 5428** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5429** ^Any callback set by a previous call to sqlite3_rollback_hook() 5430** for the same database connection is overridden. 5431** ^The pArg argument is passed through to the callback. 5432** ^If the callback on a commit hook function returns non-zero, 5433** then the commit is converted into a rollback. 5434** 5435** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5436** return the P argument from the previous call of the same function 5437** on the same [database connection] D, or NULL for 5438** the first call for each function on D. 5439** 5440** The commit and rollback hook callbacks are not reentrant. 5441** The callback implementation must not do anything that will modify 5442** the database connection that invoked the callback. Any actions 5443** to modify the database connection must be deferred until after the 5444** completion of the [sqlite3_step()] call that triggered the commit 5445** or rollback hook in the first place. 5446** Note that running any other SQL statements, including SELECT statements, 5447** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5448** the database connections for the meaning of "modify" in this paragraph. 5449** 5450** ^Registering a NULL function disables the callback. 5451** 5452** ^When the commit hook callback routine returns zero, the [COMMIT] 5453** operation is allowed to continue normally. ^If the commit hook 5454** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5455** ^The rollback hook is invoked on a rollback that results from a commit 5456** hook returning non-zero, just as it would be with any other rollback. 5457** 5458** ^For the purposes of this API, a transaction is said to have been 5459** rolled back if an explicit "ROLLBACK" statement is executed, or 5460** an error or constraint causes an implicit rollback to occur. 5461** ^The rollback callback is not invoked if a transaction is 5462** automatically rolled back because the database connection is closed. 5463** 5464** See also the [sqlite3_update_hook()] interface. 5465*/ 5466SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5467SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5468 5469/* 5470** CAPI3REF: Data Change Notification Callbacks 5471** METHOD: sqlite3 5472** 5473** ^The sqlite3_update_hook() interface registers a callback function 5474** with the [database connection] identified by the first argument 5475** to be invoked whenever a row is updated, inserted or deleted in 5476** a [rowid table]. 5477** ^Any callback set by a previous call to this function 5478** for the same database connection is overridden. 5479** 5480** ^The second argument is a pointer to the function to invoke when a 5481** row is updated, inserted or deleted in a rowid table. 5482** ^The first argument to the callback is a copy of the third argument 5483** to sqlite3_update_hook(). 5484** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5485** or [SQLITE_UPDATE], depending on the operation that caused the callback 5486** to be invoked. 5487** ^The third and fourth arguments to the callback contain pointers to the 5488** database and table name containing the affected row. 5489** ^The final callback parameter is the [rowid] of the row. 5490** ^In the case of an update, this is the [rowid] after the update takes place. 5491** 5492** ^(The update hook is not invoked when internal system tables are 5493** modified (i.e. sqlite_master and sqlite_sequence).)^ 5494** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5495** 5496** ^In the current implementation, the update hook 5497** is not invoked when conflicting rows are deleted because of an 5498** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5499** invoked when rows are deleted using the [truncate optimization]. 5500** The exceptions defined in this paragraph might change in a future 5501** release of SQLite. 5502** 5503** The update hook implementation must not do anything that will modify 5504** the database connection that invoked the update hook. Any actions 5505** to modify the database connection must be deferred until after the 5506** completion of the [sqlite3_step()] call that triggered the update hook. 5507** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5508** database connections for the meaning of "modify" in this paragraph. 5509** 5510** ^The sqlite3_update_hook(D,C,P) function 5511** returns the P argument from the previous call 5512** on the same [database connection] D, or NULL for 5513** the first call on D. 5514** 5515** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 5516** and [sqlite3_preupdate_hook()] interfaces. 5517*/ 5518SQLITE_API void *sqlite3_update_hook( 5519 sqlite3*, 5520 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5521 void* 5522); 5523 5524/* 5525** CAPI3REF: Enable Or Disable Shared Pager Cache 5526** 5527** ^(This routine enables or disables the sharing of the database cache 5528** and schema data structures between [database connection | connections] 5529** to the same database. Sharing is enabled if the argument is true 5530** and disabled if the argument is false.)^ 5531** 5532** ^Cache sharing is enabled and disabled for an entire process. 5533** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 5534** In prior versions of SQLite, 5535** sharing was enabled or disabled for each thread separately. 5536** 5537** ^(The cache sharing mode set by this interface effects all subsequent 5538** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5539** Existing database connections continue use the sharing mode 5540** that was in effect at the time they were opened.)^ 5541** 5542** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5543** successfully. An [error code] is returned otherwise.)^ 5544** 5545** ^Shared cache is disabled by default. But this might change in 5546** future releases of SQLite. Applications that care about shared 5547** cache setting should set it explicitly. 5548** 5549** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5550** and will always return SQLITE_MISUSE. On those systems, 5551** shared cache mode should be enabled per-database connection via 5552** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5553** 5554** This interface is threadsafe on processors where writing a 5555** 32-bit integer is atomic. 5556** 5557** See Also: [SQLite Shared-Cache Mode] 5558*/ 5559SQLITE_API int sqlite3_enable_shared_cache(int); 5560 5561/* 5562** CAPI3REF: Attempt To Free Heap Memory 5563** 5564** ^The sqlite3_release_memory() interface attempts to free N bytes 5565** of heap memory by deallocating non-essential memory allocations 5566** held by the database library. Memory used to cache database 5567** pages to improve performance is an example of non-essential memory. 5568** ^sqlite3_release_memory() returns the number of bytes actually freed, 5569** which might be more or less than the amount requested. 5570** ^The sqlite3_release_memory() routine is a no-op returning zero 5571** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5572** 5573** See also: [sqlite3_db_release_memory()] 5574*/ 5575SQLITE_API int sqlite3_release_memory(int); 5576 5577/* 5578** CAPI3REF: Free Memory Used By A Database Connection 5579** METHOD: sqlite3 5580** 5581** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5582** memory as possible from database connection D. Unlike the 5583** [sqlite3_release_memory()] interface, this interface is in effect even 5584** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5585** omitted. 5586** 5587** See also: [sqlite3_release_memory()] 5588*/ 5589SQLITE_API int sqlite3_db_release_memory(sqlite3*); 5590 5591/* 5592** CAPI3REF: Impose A Limit On Heap Size 5593** 5594** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5595** soft limit on the amount of heap memory that may be allocated by SQLite. 5596** ^SQLite strives to keep heap memory utilization below the soft heap 5597** limit by reducing the number of pages held in the page cache 5598** as heap memory usages approaches the limit. 5599** ^The soft heap limit is "soft" because even though SQLite strives to stay 5600** below the limit, it will exceed the limit rather than generate 5601** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5602** is advisory only. 5603** 5604** ^The return value from sqlite3_soft_heap_limit64() is the size of 5605** the soft heap limit prior to the call, or negative in the case of an 5606** error. ^If the argument N is negative 5607** then no change is made to the soft heap limit. Hence, the current 5608** size of the soft heap limit can be determined by invoking 5609** sqlite3_soft_heap_limit64() with a negative argument. 5610** 5611** ^If the argument N is zero then the soft heap limit is disabled. 5612** 5613** ^(The soft heap limit is not enforced in the current implementation 5614** if one or more of following conditions are true: 5615** 5616** <ul> 5617** <li> The soft heap limit is set to zero. 5618** <li> Memory accounting is disabled using a combination of the 5619** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5620** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5621** <li> An alternative page cache implementation is specified using 5622** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5623** <li> The page cache allocates from its own memory pool supplied 5624** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5625** from the heap. 5626** </ul>)^ 5627** 5628** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]), 5629** the soft heap limit is enforced 5630** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5631** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5632** the soft heap limit is enforced on every memory allocation. Without 5633** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5634** when memory is allocated by the page cache. Testing suggests that because 5635** the page cache is the predominate memory user in SQLite, most 5636** applications will achieve adequate soft heap limit enforcement without 5637** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5638** 5639** The circumstances under which SQLite will enforce the soft heap limit may 5640** changes in future releases of SQLite. 5641*/ 5642SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 5643 5644/* 5645** CAPI3REF: Deprecated Soft Heap Limit Interface 5646** DEPRECATED 5647** 5648** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5649** interface. This routine is provided for historical compatibility 5650** only. All new applications should use the 5651** [sqlite3_soft_heap_limit64()] interface rather than this one. 5652*/ 5653SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 5654 5655 5656/* 5657** CAPI3REF: Extract Metadata About A Column Of A Table 5658** METHOD: sqlite3 5659** 5660** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 5661** information about column C of table T in database D 5662** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 5663** interface returns SQLITE_OK and fills in the non-NULL pointers in 5664** the final five arguments with appropriate values if the specified 5665** column exists. ^The sqlite3_table_column_metadata() interface returns 5666** SQLITE_ERROR and if the specified column does not exist. 5667** ^If the column-name parameter to sqlite3_table_column_metadata() is a 5668** NULL pointer, then this routine simply checks for the existence of the 5669** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 5670** does not. 5671** 5672** ^The column is identified by the second, third and fourth parameters to 5673** this function. ^(The second parameter is either the name of the database 5674** (i.e. "main", "temp", or an attached database) containing the specified 5675** table or NULL.)^ ^If it is NULL, then all attached databases are searched 5676** for the table using the same algorithm used by the database engine to 5677** resolve unqualified table references. 5678** 5679** ^The third and fourth parameters to this function are the table and column 5680** name of the desired column, respectively. 5681** 5682** ^Metadata is returned by writing to the memory locations passed as the 5th 5683** and subsequent parameters to this function. ^Any of these arguments may be 5684** NULL, in which case the corresponding element of metadata is omitted. 5685** 5686** ^(<blockquote> 5687** <table border="1"> 5688** <tr><th> Parameter <th> Output<br>Type <th> Description 5689** 5690** <tr><td> 5th <td> const char* <td> Data type 5691** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5692** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5693** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5694** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5695** </table> 5696** </blockquote>)^ 5697** 5698** ^The memory pointed to by the character pointers returned for the 5699** declaration type and collation sequence is valid until the next 5700** call to any SQLite API function. 5701** 5702** ^If the specified table is actually a view, an [error code] is returned. 5703** 5704** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 5705** is not a [WITHOUT ROWID] table and an 5706** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5707** parameters are set for the explicitly declared column. ^(If there is no 5708** [INTEGER PRIMARY KEY] column, then the outputs 5709** for the [rowid] are set as follows: 5710** 5711** <pre> 5712** data type: "INTEGER" 5713** collation sequence: "BINARY" 5714** not null: 0 5715** primary key: 1 5716** auto increment: 0 5717** </pre>)^ 5718** 5719** ^This function causes all database schemas to be read from disk and 5720** parsed, if that has not already been done, and returns an error if 5721** any errors are encountered while loading the schema. 5722*/ 5723SQLITE_API int sqlite3_table_column_metadata( 5724 sqlite3 *db, /* Connection handle */ 5725 const char *zDbName, /* Database name or NULL */ 5726 const char *zTableName, /* Table name */ 5727 const char *zColumnName, /* Column name */ 5728 char const **pzDataType, /* OUTPUT: Declared data type */ 5729 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5730 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5731 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5732 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5733); 5734 5735/* 5736** CAPI3REF: Load An Extension 5737** METHOD: sqlite3 5738** 5739** ^This interface loads an SQLite extension library from the named file. 5740** 5741** ^The sqlite3_load_extension() interface attempts to load an 5742** [SQLite extension] library contained in the file zFile. If 5743** the file cannot be loaded directly, attempts are made to load 5744** with various operating-system specific extensions added. 5745** So for example, if "samplelib" cannot be loaded, then names like 5746** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5747** be tried also. 5748** 5749** ^The entry point is zProc. 5750** ^(zProc may be 0, in which case SQLite will try to come up with an 5751** entry point name on its own. It first tries "sqlite3_extension_init". 5752** If that does not work, it constructs a name "sqlite3_X_init" where the 5753** X is consists of the lower-case equivalent of all ASCII alphabetic 5754** characters in the filename from the last "/" to the first following 5755** "." and omitting any initial "lib".)^ 5756** ^The sqlite3_load_extension() interface returns 5757** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5758** ^If an error occurs and pzErrMsg is not 0, then the 5759** [sqlite3_load_extension()] interface shall attempt to 5760** fill *pzErrMsg with error message text stored in memory 5761** obtained from [sqlite3_malloc()]. The calling function 5762** should free this memory by calling [sqlite3_free()]. 5763** 5764** ^Extension loading must be enabled using 5765** [sqlite3_enable_load_extension()] or 5766** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 5767** prior to calling this API, 5768** otherwise an error will be returned. 5769** 5770** <b>Security warning:</b> It is recommended that the 5771** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 5772** interface. The use of the [sqlite3_enable_load_extension()] interface 5773** should be avoided. This will keep the SQL function [load_extension()] 5774** disabled and prevent SQL injections from giving attackers 5775** access to extension loading capabilities. 5776** 5777** See also the [load_extension() SQL function]. 5778*/ 5779SQLITE_API int sqlite3_load_extension( 5780 sqlite3 *db, /* Load the extension into this database connection */ 5781 const char *zFile, /* Name of the shared library containing extension */ 5782 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5783 char **pzErrMsg /* Put error message here if not 0 */ 5784); 5785 5786/* 5787** CAPI3REF: Enable Or Disable Extension Loading 5788** METHOD: sqlite3 5789** 5790** ^So as not to open security holes in older applications that are 5791** unprepared to deal with [extension loading], and as a means of disabling 5792** [extension loading] while evaluating user-entered SQL, the following API 5793** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5794** 5795** ^Extension loading is off by default. 5796** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5797** to turn extension loading on and call it with onoff==0 to turn 5798** it back off again. 5799** 5800** ^This interface enables or disables both the C-API 5801** [sqlite3_load_extension()] and the SQL function [load_extension()]. 5802** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 5803** to enable or disable only the C-API.)^ 5804** 5805** <b>Security warning:</b> It is recommended that extension loading 5806** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 5807** rather than this interface, so the [load_extension()] SQL function 5808** remains disabled. This will prevent SQL injections from giving attackers 5809** access to extension loading capabilities. 5810*/ 5811SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5812 5813/* 5814** CAPI3REF: Automatically Load Statically Linked Extensions 5815** 5816** ^This interface causes the xEntryPoint() function to be invoked for 5817** each new [database connection] that is created. The idea here is that 5818** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5819** that is to be automatically loaded into all new database connections. 5820** 5821** ^(Even though the function prototype shows that xEntryPoint() takes 5822** no arguments and returns void, SQLite invokes xEntryPoint() with three 5823** arguments and expects an integer result as if the signature of the 5824** entry point where as follows: 5825** 5826** <blockquote><pre> 5827** int xEntryPoint( 5828** sqlite3 *db, 5829** const char **pzErrMsg, 5830** const struct sqlite3_api_routines *pThunk 5831** ); 5832** </pre></blockquote>)^ 5833** 5834** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5835** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5836** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5837** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5838** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5839** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5840** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5841** 5842** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5843** on the list of automatic extensions is a harmless no-op. ^No entry point 5844** will be called more than once for each database connection that is opened. 5845** 5846** See also: [sqlite3_reset_auto_extension()] 5847** and [sqlite3_cancel_auto_extension()] 5848*/ 5849SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 5850 5851/* 5852** CAPI3REF: Cancel Automatic Extension Loading 5853** 5854** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 5855** initialization routine X that was registered using a prior call to 5856** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 5857** routine returns 1 if initialization routine X was successfully 5858** unregistered and it returns 0 if X was not on the list of initialization 5859** routines. 5860*/ 5861SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 5862 5863/* 5864** CAPI3REF: Reset Automatic Extension Loading 5865** 5866** ^This interface disables all automatic extensions previously 5867** registered using [sqlite3_auto_extension()]. 5868*/ 5869SQLITE_API void sqlite3_reset_auto_extension(void); 5870 5871/* 5872** The interface to the virtual-table mechanism is currently considered 5873** to be experimental. The interface might change in incompatible ways. 5874** If this is a problem for you, do not use the interface at this time. 5875** 5876** When the virtual-table mechanism stabilizes, we will declare the 5877** interface fixed, support it indefinitely, and remove this comment. 5878*/ 5879 5880/* 5881** Structures used by the virtual table interface 5882*/ 5883typedef struct sqlite3_vtab sqlite3_vtab; 5884typedef struct sqlite3_index_info sqlite3_index_info; 5885typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5886typedef struct sqlite3_module sqlite3_module; 5887 5888/* 5889** CAPI3REF: Virtual Table Object 5890** KEYWORDS: sqlite3_module {virtual table module} 5891** 5892** This structure, sometimes called a "virtual table module", 5893** defines the implementation of a [virtual tables]. 5894** This structure consists mostly of methods for the module. 5895** 5896** ^A virtual table module is created by filling in a persistent 5897** instance of this structure and passing a pointer to that instance 5898** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5899** ^The registration remains valid until it is replaced by a different 5900** module or until the [database connection] closes. The content 5901** of this structure must not change while it is registered with 5902** any database connection. 5903*/ 5904struct sqlite3_module { 5905 int iVersion; 5906 int (*xCreate)(sqlite3*, void *pAux, 5907 int argc, const char *const*argv, 5908 sqlite3_vtab **ppVTab, char**); 5909 int (*xConnect)(sqlite3*, void *pAux, 5910 int argc, const char *const*argv, 5911 sqlite3_vtab **ppVTab, char**); 5912 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5913 int (*xDisconnect)(sqlite3_vtab *pVTab); 5914 int (*xDestroy)(sqlite3_vtab *pVTab); 5915 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5916 int (*xClose)(sqlite3_vtab_cursor*); 5917 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5918 int argc, sqlite3_value **argv); 5919 int (*xNext)(sqlite3_vtab_cursor*); 5920 int (*xEof)(sqlite3_vtab_cursor*); 5921 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5922 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5923 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5924 int (*xBegin)(sqlite3_vtab *pVTab); 5925 int (*xSync)(sqlite3_vtab *pVTab); 5926 int (*xCommit)(sqlite3_vtab *pVTab); 5927 int (*xRollback)(sqlite3_vtab *pVTab); 5928 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5929 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5930 void **ppArg); 5931 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5932 /* The methods above are in version 1 of the sqlite_module object. Those 5933 ** below are for version 2 and greater. */ 5934 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5935 int (*xRelease)(sqlite3_vtab *pVTab, int); 5936 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5937}; 5938 5939/* 5940** CAPI3REF: Virtual Table Indexing Information 5941** KEYWORDS: sqlite3_index_info 5942** 5943** The sqlite3_index_info structure and its substructures is used as part 5944** of the [virtual table] interface to 5945** pass information into and receive the reply from the [xBestIndex] 5946** method of a [virtual table module]. The fields under **Inputs** are the 5947** inputs to xBestIndex and are read-only. xBestIndex inserts its 5948** results into the **Outputs** fields. 5949** 5950** ^(The aConstraint[] array records WHERE clause constraints of the form: 5951** 5952** <blockquote>column OP expr</blockquote> 5953** 5954** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5955** stored in aConstraint[].op using one of the 5956** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5957** ^(The index of the column is stored in 5958** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5959** expr on the right-hand side can be evaluated (and thus the constraint 5960** is usable) and false if it cannot.)^ 5961** 5962** ^The optimizer automatically inverts terms of the form "expr OP column" 5963** and makes other simplifications to the WHERE clause in an attempt to 5964** get as many WHERE clause terms into the form shown above as possible. 5965** ^The aConstraint[] array only reports WHERE clause terms that are 5966** relevant to the particular virtual table being queried. 5967** 5968** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5969** ^Each term of aOrderBy records a column of the ORDER BY clause. 5970** 5971** The colUsed field indicates which columns of the virtual table may be 5972** required by the current scan. Virtual table columns are numbered from 5973** zero in the order in which they appear within the CREATE TABLE statement 5974** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 5975** the corresponding bit is set within the colUsed mask if the column may be 5976** required by SQLite. If the table has at least 64 columns and any column 5977** to the right of the first 63 is required, then bit 63 of colUsed is also 5978** set. In other words, column iCol may be required if the expression 5979** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 5980** non-zero. 5981** 5982** The [xBestIndex] method must fill aConstraintUsage[] with information 5983** about what parameters to pass to xFilter. ^If argvIndex>0 then 5984** the right-hand side of the corresponding aConstraint[] is evaluated 5985** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5986** is true, then the constraint is assumed to be fully handled by the 5987** virtual table and is not checked again by SQLite.)^ 5988** 5989** ^The idxNum and idxPtr values are recorded and passed into the 5990** [xFilter] method. 5991** ^[sqlite3_free()] is used to free idxPtr if and only if 5992** needToFreeIdxPtr is true. 5993** 5994** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5995** the correct order to satisfy the ORDER BY clause so that no separate 5996** sorting step is required. 5997** 5998** ^The estimatedCost value is an estimate of the cost of a particular 5999** strategy. A cost of N indicates that the cost of the strategy is similar 6000** to a linear scan of an SQLite table with N rows. A cost of log(N) 6001** indicates that the expense of the operation is similar to that of a 6002** binary search on a unique indexed field of an SQLite table with N rows. 6003** 6004** ^The estimatedRows value is an estimate of the number of rows that 6005** will be returned by the strategy. 6006** 6007** The xBestIndex method may optionally populate the idxFlags field with a 6008** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6009** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6010** assumes that the strategy may visit at most one row. 6011** 6012** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6013** SQLite also assumes that if a call to the xUpdate() method is made as 6014** part of the same statement to delete or update a virtual table row and the 6015** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6016** any database changes. In other words, if the xUpdate() returns 6017** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6018** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6019** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6020** the xUpdate method are automatically rolled back by SQLite. 6021** 6022** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6023** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6024** If a virtual table extension is 6025** used with an SQLite version earlier than 3.8.2, the results of attempting 6026** to read or write the estimatedRows field are undefined (but are likely 6027** to included crashing the application). The estimatedRows field should 6028** therefore only be used if [sqlite3_libversion_number()] returns a 6029** value greater than or equal to 3008002. Similarly, the idxFlags field 6030** was added for [version 3.9.0] ([dateof:3.9.0]). 6031** It may therefore only be used if 6032** sqlite3_libversion_number() returns a value greater than or equal to 6033** 3009000. 6034*/ 6035struct sqlite3_index_info { 6036 /* Inputs */ 6037 int nConstraint; /* Number of entries in aConstraint */ 6038 struct sqlite3_index_constraint { 6039 int iColumn; /* Column constrained. -1 for ROWID */ 6040 unsigned char op; /* Constraint operator */ 6041 unsigned char usable; /* True if this constraint is usable */ 6042 int iTermOffset; /* Used internally - xBestIndex should ignore */ 6043 } *aConstraint; /* Table of WHERE clause constraints */ 6044 int nOrderBy; /* Number of terms in the ORDER BY clause */ 6045 struct sqlite3_index_orderby { 6046 int iColumn; /* Column number */ 6047 unsigned char desc; /* True for DESC. False for ASC. */ 6048 } *aOrderBy; /* The ORDER BY clause */ 6049 /* Outputs */ 6050 struct sqlite3_index_constraint_usage { 6051 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 6052 unsigned char omit; /* Do not code a test for this constraint */ 6053 } *aConstraintUsage; 6054 int idxNum; /* Number used to identify the index */ 6055 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6056 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6057 int orderByConsumed; /* True if output is already ordered */ 6058 double estimatedCost; /* Estimated cost of using this index */ 6059 /* Fields below are only available in SQLite 3.8.2 and later */ 6060 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6061 /* Fields below are only available in SQLite 3.9.0 and later */ 6062 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6063 /* Fields below are only available in SQLite 3.10.0 and later */ 6064 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6065}; 6066 6067/* 6068** CAPI3REF: Virtual Table Scan Flags 6069*/ 6070#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6071 6072/* 6073** CAPI3REF: Virtual Table Constraint Operator Codes 6074** 6075** These macros defined the allowed values for the 6076** [sqlite3_index_info].aConstraint[].op field. Each value represents 6077** an operator that is part of a constraint term in the wHERE clause of 6078** a query that uses a [virtual table]. 6079*/ 6080#define SQLITE_INDEX_CONSTRAINT_EQ 2 6081#define SQLITE_INDEX_CONSTRAINT_GT 4 6082#define SQLITE_INDEX_CONSTRAINT_LE 8 6083#define SQLITE_INDEX_CONSTRAINT_LT 16 6084#define SQLITE_INDEX_CONSTRAINT_GE 32 6085#define SQLITE_INDEX_CONSTRAINT_MATCH 64 6086#define SQLITE_INDEX_CONSTRAINT_LIKE 65 6087#define SQLITE_INDEX_CONSTRAINT_GLOB 66 6088#define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6089 6090/* 6091** CAPI3REF: Register A Virtual Table Implementation 6092** METHOD: sqlite3 6093** 6094** ^These routines are used to register a new [virtual table module] name. 6095** ^Module names must be registered before 6096** creating a new [virtual table] using the module and before using a 6097** preexisting [virtual table] for the module. 6098** 6099** ^The module name is registered on the [database connection] specified 6100** by the first parameter. ^The name of the module is given by the 6101** second parameter. ^The third parameter is a pointer to 6102** the implementation of the [virtual table module]. ^The fourth 6103** parameter is an arbitrary client data pointer that is passed through 6104** into the [xCreate] and [xConnect] methods of the virtual table module 6105** when a new virtual table is be being created or reinitialized. 6106** 6107** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6108** is a pointer to a destructor for the pClientData. ^SQLite will 6109** invoke the destructor function (if it is not NULL) when SQLite 6110** no longer needs the pClientData pointer. ^The destructor will also 6111** be invoked if the call to sqlite3_create_module_v2() fails. 6112** ^The sqlite3_create_module() 6113** interface is equivalent to sqlite3_create_module_v2() with a NULL 6114** destructor. 6115*/ 6116SQLITE_API int sqlite3_create_module( 6117 sqlite3 *db, /* SQLite connection to register module with */ 6118 const char *zName, /* Name of the module */ 6119 const sqlite3_module *p, /* Methods for the module */ 6120 void *pClientData /* Client data for xCreate/xConnect */ 6121); 6122SQLITE_API int sqlite3_create_module_v2( 6123 sqlite3 *db, /* SQLite connection to register module with */ 6124 const char *zName, /* Name of the module */ 6125 const sqlite3_module *p, /* Methods for the module */ 6126 void *pClientData, /* Client data for xCreate/xConnect */ 6127 void(*xDestroy)(void*) /* Module destructor function */ 6128); 6129 6130/* 6131** CAPI3REF: Virtual Table Instance Object 6132** KEYWORDS: sqlite3_vtab 6133** 6134** Every [virtual table module] implementation uses a subclass 6135** of this object to describe a particular instance 6136** of the [virtual table]. Each subclass will 6137** be tailored to the specific needs of the module implementation. 6138** The purpose of this superclass is to define certain fields that are 6139** common to all module implementations. 6140** 6141** ^Virtual tables methods can set an error message by assigning a 6142** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6143** take care that any prior string is freed by a call to [sqlite3_free()] 6144** prior to assigning a new string to zErrMsg. ^After the error message 6145** is delivered up to the client application, the string will be automatically 6146** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6147*/ 6148struct sqlite3_vtab { 6149 const sqlite3_module *pModule; /* The module for this virtual table */ 6150 int nRef; /* Number of open cursors */ 6151 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6152 /* Virtual table implementations will typically add additional fields */ 6153}; 6154 6155/* 6156** CAPI3REF: Virtual Table Cursor Object 6157** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6158** 6159** Every [virtual table module] implementation uses a subclass of the 6160** following structure to describe cursors that point into the 6161** [virtual table] and are used 6162** to loop through the virtual table. Cursors are created using the 6163** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6164** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6165** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6166** of the module. Each module implementation will define 6167** the content of a cursor structure to suit its own needs. 6168** 6169** This superclass exists in order to define fields of the cursor that 6170** are common to all implementations. 6171*/ 6172struct sqlite3_vtab_cursor { 6173 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6174 /* Virtual table implementations will typically add additional fields */ 6175}; 6176 6177/* 6178** CAPI3REF: Declare The Schema Of A Virtual Table 6179** 6180** ^The [xCreate] and [xConnect] methods of a 6181** [virtual table module] call this interface 6182** to declare the format (the names and datatypes of the columns) of 6183** the virtual tables they implement. 6184*/ 6185SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6186 6187/* 6188** CAPI3REF: Overload A Function For A Virtual Table 6189** METHOD: sqlite3 6190** 6191** ^(Virtual tables can provide alternative implementations of functions 6192** using the [xFindFunction] method of the [virtual table module]. 6193** But global versions of those functions 6194** must exist in order to be overloaded.)^ 6195** 6196** ^(This API makes sure a global version of a function with a particular 6197** name and number of parameters exists. If no such function exists 6198** before this API is called, a new function is created.)^ ^The implementation 6199** of the new function always causes an exception to be thrown. So 6200** the new function is not good for anything by itself. Its only 6201** purpose is to be a placeholder function that can be overloaded 6202** by a [virtual table]. 6203*/ 6204SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6205 6206/* 6207** The interface to the virtual-table mechanism defined above (back up 6208** to a comment remarkably similar to this one) is currently considered 6209** to be experimental. The interface might change in incompatible ways. 6210** If this is a problem for you, do not use the interface at this time. 6211** 6212** When the virtual-table mechanism stabilizes, we will declare the 6213** interface fixed, support it indefinitely, and remove this comment. 6214*/ 6215 6216/* 6217** CAPI3REF: A Handle To An Open BLOB 6218** KEYWORDS: {BLOB handle} {BLOB handles} 6219** 6220** An instance of this object represents an open BLOB on which 6221** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6222** ^Objects of this type are created by [sqlite3_blob_open()] 6223** and destroyed by [sqlite3_blob_close()]. 6224** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6225** can be used to read or write small subsections of the BLOB. 6226** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6227*/ 6228typedef struct sqlite3_blob sqlite3_blob; 6229 6230/* 6231** CAPI3REF: Open A BLOB For Incremental I/O 6232** METHOD: sqlite3 6233** CONSTRUCTOR: sqlite3_blob 6234** 6235** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6236** in row iRow, column zColumn, table zTable in database zDb; 6237** in other words, the same BLOB that would be selected by: 6238** 6239** <pre> 6240** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 6241** </pre>)^ 6242** 6243** ^(Parameter zDb is not the filename that contains the database, but 6244** rather the symbolic name of the database. For attached databases, this is 6245** the name that appears after the AS keyword in the [ATTACH] statement. 6246** For the main database file, the database name is "main". For TEMP 6247** tables, the database name is "temp".)^ 6248** 6249** ^If the flags parameter is non-zero, then the BLOB is opened for read 6250** and write access. ^If the flags parameter is zero, the BLOB is opened for 6251** read-only access. 6252** 6253** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 6254** in *ppBlob. Otherwise an [error code] is returned and, unless the error 6255** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 6256** the API is not misused, it is always safe to call [sqlite3_blob_close()] 6257** on *ppBlob after this function it returns. 6258** 6259** This function fails with SQLITE_ERROR if any of the following are true: 6260** <ul> 6261** <li> ^(Database zDb does not exist)^, 6262** <li> ^(Table zTable does not exist within database zDb)^, 6263** <li> ^(Table zTable is a WITHOUT ROWID table)^, 6264** <li> ^(Column zColumn does not exist)^, 6265** <li> ^(Row iRow is not present in the table)^, 6266** <li> ^(The specified column of row iRow contains a value that is not 6267** a TEXT or BLOB value)^, 6268** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 6269** constraint and the blob is being opened for read/write access)^, 6270** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 6271** column zColumn is part of a [child key] definition and the blob is 6272** being opened for read/write access)^. 6273** </ul> 6274** 6275** ^Unless it returns SQLITE_MISUSE, this function sets the 6276** [database connection] error code and message accessible via 6277** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6278** 6279** A BLOB referenced by sqlite3_blob_open() may be read using the 6280** [sqlite3_blob_read()] interface and modified by using 6281** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 6282** different row of the same table using the [sqlite3_blob_reopen()] 6283** interface. However, the column, table, or database of a [BLOB handle] 6284** cannot be changed after the [BLOB handle] is opened. 6285** 6286** ^(If the row that a BLOB handle points to is modified by an 6287** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 6288** then the BLOB handle is marked as "expired". 6289** This is true if any column of the row is changed, even a column 6290** other than the one the BLOB handle is open on.)^ 6291** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 6292** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 6293** ^(Changes written into a BLOB prior to the BLOB expiring are not 6294** rolled back by the expiration of the BLOB. Such changes will eventually 6295** commit if the transaction continues to completion.)^ 6296** 6297** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 6298** the opened blob. ^The size of a blob may not be changed by this 6299** interface. Use the [UPDATE] SQL command to change the size of a 6300** blob. 6301** 6302** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 6303** and the built-in [zeroblob] SQL function may be used to create a 6304** zero-filled blob to read or write using the incremental-blob interface. 6305** 6306** To avoid a resource leak, every open [BLOB handle] should eventually 6307** be released by a call to [sqlite3_blob_close()]. 6308** 6309** See also: [sqlite3_blob_close()], 6310** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 6311** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 6312*/ 6313SQLITE_API int sqlite3_blob_open( 6314 sqlite3*, 6315 const char *zDb, 6316 const char *zTable, 6317 const char *zColumn, 6318 sqlite3_int64 iRow, 6319 int flags, 6320 sqlite3_blob **ppBlob 6321); 6322 6323/* 6324** CAPI3REF: Move a BLOB Handle to a New Row 6325** METHOD: sqlite3_blob 6326** 6327** ^This function is used to move an existing [BLOB handle] so that it points 6328** to a different row of the same database table. ^The new row is identified 6329** by the rowid value passed as the second argument. Only the row can be 6330** changed. ^The database, table and column on which the blob handle is open 6331** remain the same. Moving an existing [BLOB handle] to a new row is 6332** faster than closing the existing handle and opening a new one. 6333** 6334** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6335** it must exist and there must be either a blob or text value stored in 6336** the nominated column.)^ ^If the new row is not present in the table, or if 6337** it does not contain a blob or text value, or if another error occurs, an 6338** SQLite error code is returned and the blob handle is considered aborted. 6339** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6340** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6341** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6342** always returns zero. 6343** 6344** ^This function sets the database handle error code and message. 6345*/ 6346SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6347 6348/* 6349** CAPI3REF: Close A BLOB Handle 6350** DESTRUCTOR: sqlite3_blob 6351** 6352** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6353** unconditionally. Even if this routine returns an error code, the 6354** handle is still closed.)^ 6355** 6356** ^If the blob handle being closed was opened for read-write access, and if 6357** the database is in auto-commit mode and there are no other open read-write 6358** blob handles or active write statements, the current transaction is 6359** committed. ^If an error occurs while committing the transaction, an error 6360** code is returned and the transaction rolled back. 6361** 6362** Calling this function with an argument that is not a NULL pointer or an 6363** open blob handle results in undefined behaviour. ^Calling this routine 6364** with a null pointer (such as would be returned by a failed call to 6365** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6366** is passed a valid open blob handle, the values returned by the 6367** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6368*/ 6369SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 6370 6371/* 6372** CAPI3REF: Return The Size Of An Open BLOB 6373** METHOD: sqlite3_blob 6374** 6375** ^Returns the size in bytes of the BLOB accessible via the 6376** successfully opened [BLOB handle] in its only argument. ^The 6377** incremental blob I/O routines can only read or overwriting existing 6378** blob content; they cannot change the size of a blob. 6379** 6380** This routine only works on a [BLOB handle] which has been created 6381** by a prior successful call to [sqlite3_blob_open()] and which has not 6382** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6383** to this routine results in undefined and probably undesirable behavior. 6384*/ 6385SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 6386 6387/* 6388** CAPI3REF: Read Data From A BLOB Incrementally 6389** METHOD: sqlite3_blob 6390** 6391** ^(This function is used to read data from an open [BLOB handle] into a 6392** caller-supplied buffer. N bytes of data are copied into buffer Z 6393** from the open BLOB, starting at offset iOffset.)^ 6394** 6395** ^If offset iOffset is less than N bytes from the end of the BLOB, 6396** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6397** less than zero, [SQLITE_ERROR] is returned and no data is read. 6398** ^The size of the blob (and hence the maximum value of N+iOffset) 6399** can be determined using the [sqlite3_blob_bytes()] interface. 6400** 6401** ^An attempt to read from an expired [BLOB handle] fails with an 6402** error code of [SQLITE_ABORT]. 6403** 6404** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6405** Otherwise, an [error code] or an [extended error code] is returned.)^ 6406** 6407** This routine only works on a [BLOB handle] which has been created 6408** by a prior successful call to [sqlite3_blob_open()] and which has not 6409** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6410** to this routine results in undefined and probably undesirable behavior. 6411** 6412** See also: [sqlite3_blob_write()]. 6413*/ 6414SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6415 6416/* 6417** CAPI3REF: Write Data Into A BLOB Incrementally 6418** METHOD: sqlite3_blob 6419** 6420** ^(This function is used to write data into an open [BLOB handle] from a 6421** caller-supplied buffer. N bytes of data are copied from the buffer Z 6422** into the open BLOB, starting at offset iOffset.)^ 6423** 6424** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6425** Otherwise, an [error code] or an [extended error code] is returned.)^ 6426** ^Unless SQLITE_MISUSE is returned, this function sets the 6427** [database connection] error code and message accessible via 6428** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6429** 6430** ^If the [BLOB handle] passed as the first argument was not opened for 6431** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6432** this function returns [SQLITE_READONLY]. 6433** 6434** This function may only modify the contents of the BLOB; it is 6435** not possible to increase the size of a BLOB using this API. 6436** ^If offset iOffset is less than N bytes from the end of the BLOB, 6437** [SQLITE_ERROR] is returned and no data is written. The size of the 6438** BLOB (and hence the maximum value of N+iOffset) can be determined 6439** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 6440** than zero [SQLITE_ERROR] is returned and no data is written. 6441** 6442** ^An attempt to write to an expired [BLOB handle] fails with an 6443** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 6444** before the [BLOB handle] expired are not rolled back by the 6445** expiration of the handle, though of course those changes might 6446** have been overwritten by the statement that expired the BLOB handle 6447** or by other independent statements. 6448** 6449** This routine only works on a [BLOB handle] which has been created 6450** by a prior successful call to [sqlite3_blob_open()] and which has not 6451** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6452** to this routine results in undefined and probably undesirable behavior. 6453** 6454** See also: [sqlite3_blob_read()]. 6455*/ 6456SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 6457 6458/* 6459** CAPI3REF: Virtual File System Objects 6460** 6461** A virtual filesystem (VFS) is an [sqlite3_vfs] object 6462** that SQLite uses to interact 6463** with the underlying operating system. Most SQLite builds come with a 6464** single default VFS that is appropriate for the host computer. 6465** New VFSes can be registered and existing VFSes can be unregistered. 6466** The following interfaces are provided. 6467** 6468** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 6469** ^Names are case sensitive. 6470** ^Names are zero-terminated UTF-8 strings. 6471** ^If there is no match, a NULL pointer is returned. 6472** ^If zVfsName is NULL then the default VFS is returned. 6473** 6474** ^New VFSes are registered with sqlite3_vfs_register(). 6475** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6476** ^The same VFS can be registered multiple times without injury. 6477** ^To make an existing VFS into the default VFS, register it again 6478** with the makeDflt flag set. If two different VFSes with the 6479** same name are registered, the behavior is undefined. If a 6480** VFS is registered with a name that is NULL or an empty string, 6481** then the behavior is undefined. 6482** 6483** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6484** ^(If the default VFS is unregistered, another VFS is chosen as 6485** the default. The choice for the new VFS is arbitrary.)^ 6486*/ 6487SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 6488SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6489SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 6490 6491/* 6492** CAPI3REF: Mutexes 6493** 6494** The SQLite core uses these routines for thread 6495** synchronization. Though they are intended for internal 6496** use by SQLite, code that links against SQLite is 6497** permitted to use any of these routines. 6498** 6499** The SQLite source code contains multiple implementations 6500** of these mutex routines. An appropriate implementation 6501** is selected automatically at compile-time. The following 6502** implementations are available in the SQLite core: 6503** 6504** <ul> 6505** <li> SQLITE_MUTEX_PTHREADS 6506** <li> SQLITE_MUTEX_W32 6507** <li> SQLITE_MUTEX_NOOP 6508** </ul> 6509** 6510** The SQLITE_MUTEX_NOOP implementation is a set of routines 6511** that does no real locking and is appropriate for use in 6512** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6513** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6514** and Windows. 6515** 6516** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6517** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6518** implementation is included with the library. In this case the 6519** application must supply a custom mutex implementation using the 6520** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6521** before calling sqlite3_initialize() or any other public sqlite3_ 6522** function that calls sqlite3_initialize(). 6523** 6524** ^The sqlite3_mutex_alloc() routine allocates a new 6525** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6526** routine returns NULL if it is unable to allocate the requested 6527** mutex. The argument to sqlite3_mutex_alloc() must one of these 6528** integer constants: 6529** 6530** <ul> 6531** <li> SQLITE_MUTEX_FAST 6532** <li> SQLITE_MUTEX_RECURSIVE 6533** <li> SQLITE_MUTEX_STATIC_MASTER 6534** <li> SQLITE_MUTEX_STATIC_MEM 6535** <li> SQLITE_MUTEX_STATIC_OPEN 6536** <li> SQLITE_MUTEX_STATIC_PRNG 6537** <li> SQLITE_MUTEX_STATIC_LRU 6538** <li> SQLITE_MUTEX_STATIC_PMEM 6539** <li> SQLITE_MUTEX_STATIC_APP1 6540** <li> SQLITE_MUTEX_STATIC_APP2 6541** <li> SQLITE_MUTEX_STATIC_APP3 6542** <li> SQLITE_MUTEX_STATIC_VFS1 6543** <li> SQLITE_MUTEX_STATIC_VFS2 6544** <li> SQLITE_MUTEX_STATIC_VFS3 6545** </ul> 6546** 6547** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6548** cause sqlite3_mutex_alloc() to create 6549** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6550** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6551** The mutex implementation does not need to make a distinction 6552** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6553** not want to. SQLite will only request a recursive mutex in 6554** cases where it really needs one. If a faster non-recursive mutex 6555** implementation is available on the host platform, the mutex subsystem 6556** might return such a mutex in response to SQLITE_MUTEX_FAST. 6557** 6558** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6559** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6560** a pointer to a static preexisting mutex. ^Nine static mutexes are 6561** used by the current version of SQLite. Future versions of SQLite 6562** may add additional static mutexes. Static mutexes are for internal 6563** use by SQLite only. Applications that use SQLite mutexes should 6564** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6565** SQLITE_MUTEX_RECURSIVE. 6566** 6567** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6568** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6569** returns a different mutex on every call. ^For the static 6570** mutex types, the same mutex is returned on every call that has 6571** the same type number. 6572** 6573** ^The sqlite3_mutex_free() routine deallocates a previously 6574** allocated dynamic mutex. Attempting to deallocate a static 6575** mutex results in undefined behavior. 6576** 6577** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6578** to enter a mutex. ^If another thread is already within the mutex, 6579** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6580** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6581** upon successful entry. ^(Mutexes created using 6582** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6583** In such cases, the 6584** mutex must be exited an equal number of times before another thread 6585** can enter.)^ If the same thread tries to enter any mutex other 6586** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6587** 6588** ^(Some systems (for example, Windows 95) do not support the operation 6589** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6590** will always return SQLITE_BUSY. The SQLite core only ever uses 6591** sqlite3_mutex_try() as an optimization so this is acceptable 6592** behavior.)^ 6593** 6594** ^The sqlite3_mutex_leave() routine exits a mutex that was 6595** previously entered by the same thread. The behavior 6596** is undefined if the mutex is not currently entered by the 6597** calling thread or is not currently allocated. 6598** 6599** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6600** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6601** behave as no-ops. 6602** 6603** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6604*/ 6605SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 6606SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 6607SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 6608SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 6609SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 6610 6611/* 6612** CAPI3REF: Mutex Methods Object 6613** 6614** An instance of this structure defines the low-level routines 6615** used to allocate and use mutexes. 6616** 6617** Usually, the default mutex implementations provided by SQLite are 6618** sufficient, however the application has the option of substituting a custom 6619** implementation for specialized deployments or systems for which SQLite 6620** does not provide a suitable implementation. In this case, the application 6621** creates and populates an instance of this structure to pass 6622** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6623** Additionally, an instance of this structure can be used as an 6624** output variable when querying the system for the current mutex 6625** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6626** 6627** ^The xMutexInit method defined by this structure is invoked as 6628** part of system initialization by the sqlite3_initialize() function. 6629** ^The xMutexInit routine is called by SQLite exactly once for each 6630** effective call to [sqlite3_initialize()]. 6631** 6632** ^The xMutexEnd method defined by this structure is invoked as 6633** part of system shutdown by the sqlite3_shutdown() function. The 6634** implementation of this method is expected to release all outstanding 6635** resources obtained by the mutex methods implementation, especially 6636** those obtained by the xMutexInit method. ^The xMutexEnd() 6637** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6638** 6639** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6640** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6641** xMutexNotheld) implement the following interfaces (respectively): 6642** 6643** <ul> 6644** <li> [sqlite3_mutex_alloc()] </li> 6645** <li> [sqlite3_mutex_free()] </li> 6646** <li> [sqlite3_mutex_enter()] </li> 6647** <li> [sqlite3_mutex_try()] </li> 6648** <li> [sqlite3_mutex_leave()] </li> 6649** <li> [sqlite3_mutex_held()] </li> 6650** <li> [sqlite3_mutex_notheld()] </li> 6651** </ul>)^ 6652** 6653** The only difference is that the public sqlite3_XXX functions enumerated 6654** above silently ignore any invocations that pass a NULL pointer instead 6655** of a valid mutex handle. The implementations of the methods defined 6656** by this structure are not required to handle this case, the results 6657** of passing a NULL pointer instead of a valid mutex handle are undefined 6658** (i.e. it is acceptable to provide an implementation that segfaults if 6659** it is passed a NULL pointer). 6660** 6661** The xMutexInit() method must be threadsafe. It must be harmless to 6662** invoke xMutexInit() multiple times within the same process and without 6663** intervening calls to xMutexEnd(). Second and subsequent calls to 6664** xMutexInit() must be no-ops. 6665** 6666** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 6667** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 6668** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 6669** memory allocation for a fast or recursive mutex. 6670** 6671** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 6672** called, but only if the prior call to xMutexInit returned SQLITE_OK. 6673** If xMutexInit fails in any way, it is expected to clean up after itself 6674** prior to returning. 6675*/ 6676typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6677struct sqlite3_mutex_methods { 6678 int (*xMutexInit)(void); 6679 int (*xMutexEnd)(void); 6680 sqlite3_mutex *(*xMutexAlloc)(int); 6681 void (*xMutexFree)(sqlite3_mutex *); 6682 void (*xMutexEnter)(sqlite3_mutex *); 6683 int (*xMutexTry)(sqlite3_mutex *); 6684 void (*xMutexLeave)(sqlite3_mutex *); 6685 int (*xMutexHeld)(sqlite3_mutex *); 6686 int (*xMutexNotheld)(sqlite3_mutex *); 6687}; 6688 6689/* 6690** CAPI3REF: Mutex Verification Routines 6691** 6692** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 6693** are intended for use inside assert() statements. The SQLite core 6694** never uses these routines except inside an assert() and applications 6695** are advised to follow the lead of the core. The SQLite core only 6696** provides implementations for these routines when it is compiled 6697** with the SQLITE_DEBUG flag. External mutex implementations 6698** are only required to provide these routines if SQLITE_DEBUG is 6699** defined and if NDEBUG is not defined. 6700** 6701** These routines should return true if the mutex in their argument 6702** is held or not held, respectively, by the calling thread. 6703** 6704** The implementation is not required to provide versions of these 6705** routines that actually work. If the implementation does not provide working 6706** versions of these routines, it should at least provide stubs that always 6707** return true so that one does not get spurious assertion failures. 6708** 6709** If the argument to sqlite3_mutex_held() is a NULL pointer then 6710** the routine should return 1. This seems counter-intuitive since 6711** clearly the mutex cannot be held if it does not exist. But 6712** the reason the mutex does not exist is because the build is not 6713** using mutexes. And we do not want the assert() containing the 6714** call to sqlite3_mutex_held() to fail, so a non-zero return is 6715** the appropriate thing to do. The sqlite3_mutex_notheld() 6716** interface should also return 1 when given a NULL pointer. 6717*/ 6718#ifndef NDEBUG 6719SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 6720SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 6721#endif 6722 6723/* 6724** CAPI3REF: Mutex Types 6725** 6726** The [sqlite3_mutex_alloc()] interface takes a single argument 6727** which is one of these integer constants. 6728** 6729** The set of static mutexes may change from one SQLite release to the 6730** next. Applications that override the built-in mutex logic must be 6731** prepared to accommodate additional static mutexes. 6732*/ 6733#define SQLITE_MUTEX_FAST 0 6734#define SQLITE_MUTEX_RECURSIVE 1 6735#define SQLITE_MUTEX_STATIC_MASTER 2 6736#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6737#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6738#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6739#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 6740#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6741#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6742#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6743#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 6744#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 6745#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 6746#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 6747#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 6748#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 6749 6750/* 6751** CAPI3REF: Retrieve the mutex for a database connection 6752** METHOD: sqlite3 6753** 6754** ^This interface returns a pointer the [sqlite3_mutex] object that 6755** serializes access to the [database connection] given in the argument 6756** when the [threading mode] is Serialized. 6757** ^If the [threading mode] is Single-thread or Multi-thread then this 6758** routine returns a NULL pointer. 6759*/ 6760SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 6761 6762/* 6763** CAPI3REF: Low-Level Control Of Database Files 6764** METHOD: sqlite3 6765** 6766** ^The [sqlite3_file_control()] interface makes a direct call to the 6767** xFileControl method for the [sqlite3_io_methods] object associated 6768** with a particular database identified by the second argument. ^The 6769** name of the database is "main" for the main database or "temp" for the 6770** TEMP database, or the name that appears after the AS keyword for 6771** databases that are added using the [ATTACH] SQL command. 6772** ^A NULL pointer can be used in place of "main" to refer to the 6773** main database file. 6774** ^The third and fourth parameters to this routine 6775** are passed directly through to the second and third parameters of 6776** the xFileControl method. ^The return value of the xFileControl 6777** method becomes the return value of this routine. 6778** 6779** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 6780** a pointer to the underlying [sqlite3_file] object to be written into 6781** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 6782** case is a short-circuit path which does not actually invoke the 6783** underlying sqlite3_io_methods.xFileControl method. 6784** 6785** ^If the second parameter (zDbName) does not match the name of any 6786** open database file, then SQLITE_ERROR is returned. ^This error 6787** code is not remembered and will not be recalled by [sqlite3_errcode()] 6788** or [sqlite3_errmsg()]. The underlying xFileControl method might 6789** also return SQLITE_ERROR. There is no way to distinguish between 6790** an incorrect zDbName and an SQLITE_ERROR return from the underlying 6791** xFileControl method. 6792** 6793** See also: [SQLITE_FCNTL_LOCKSTATE] 6794*/ 6795SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 6796 6797/* 6798** CAPI3REF: Testing Interface 6799** 6800** ^The sqlite3_test_control() interface is used to read out internal 6801** state of SQLite and to inject faults into SQLite for testing 6802** purposes. ^The first parameter is an operation code that determines 6803** the number, meaning, and operation of all subsequent parameters. 6804** 6805** This interface is not for use by applications. It exists solely 6806** for verifying the correct operation of the SQLite library. Depending 6807** on how the SQLite library is compiled, this interface might not exist. 6808** 6809** The details of the operation codes, their meanings, the parameters 6810** they take, and what they do are all subject to change without notice. 6811** Unlike most of the SQLite API, this function is not guaranteed to 6812** operate consistently from one release to the next. 6813*/ 6814SQLITE_API int sqlite3_test_control(int op, ...); 6815 6816/* 6817** CAPI3REF: Testing Interface Operation Codes 6818** 6819** These constants are the valid operation code parameters used 6820** as the first argument to [sqlite3_test_control()]. 6821** 6822** These parameters and their meanings are subject to change 6823** without notice. These values are for testing purposes only. 6824** Applications should not use any of these parameters or the 6825** [sqlite3_test_control()] interface. 6826*/ 6827#define SQLITE_TESTCTRL_FIRST 5 6828#define SQLITE_TESTCTRL_PRNG_SAVE 5 6829#define SQLITE_TESTCTRL_PRNG_RESTORE 6 6830#define SQLITE_TESTCTRL_PRNG_RESET 7 6831#define SQLITE_TESTCTRL_BITVEC_TEST 8 6832#define SQLITE_TESTCTRL_FAULT_INSTALL 9 6833#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 6834#define SQLITE_TESTCTRL_PENDING_BYTE 11 6835#define SQLITE_TESTCTRL_ASSERT 12 6836#define SQLITE_TESTCTRL_ALWAYS 13 6837#define SQLITE_TESTCTRL_RESERVE 14 6838#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 6839#define SQLITE_TESTCTRL_ISKEYWORD 16 6840#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 6841#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 6842#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 6843#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 6844#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 6845#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 6846#define SQLITE_TESTCTRL_BYTEORDER 22 6847#define SQLITE_TESTCTRL_ISINIT 23 6848#define SQLITE_TESTCTRL_SORTER_MMAP 24 6849#define SQLITE_TESTCTRL_IMPOSTER 25 6850#define SQLITE_TESTCTRL_LAST 25 6851 6852/* 6853** CAPI3REF: SQLite Runtime Status 6854** 6855** ^These interfaces are used to retrieve runtime status information 6856** about the performance of SQLite, and optionally to reset various 6857** highwater marks. ^The first argument is an integer code for 6858** the specific parameter to measure. ^(Recognized integer codes 6859** are of the form [status parameters | SQLITE_STATUS_...].)^ 6860** ^The current value of the parameter is returned into *pCurrent. 6861** ^The highest recorded value is returned in *pHighwater. ^If the 6862** resetFlag is true, then the highest record value is reset after 6863** *pHighwater is written. ^(Some parameters do not record the highest 6864** value. For those parameters 6865** nothing is written into *pHighwater and the resetFlag is ignored.)^ 6866** ^(Other parameters record only the highwater mark and not the current 6867** value. For these latter parameters nothing is written into *pCurrent.)^ 6868** 6869** ^The sqlite3_status() and sqlite3_status64() routines return 6870** SQLITE_OK on success and a non-zero [error code] on failure. 6871** 6872** If either the current value or the highwater mark is too large to 6873** be represented by a 32-bit integer, then the values returned by 6874** sqlite3_status() are undefined. 6875** 6876** See also: [sqlite3_db_status()] 6877*/ 6878SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 6879SQLITE_API int sqlite3_status64( 6880 int op, 6881 sqlite3_int64 *pCurrent, 6882 sqlite3_int64 *pHighwater, 6883 int resetFlag 6884); 6885 6886 6887/* 6888** CAPI3REF: Status Parameters 6889** KEYWORDS: {status parameters} 6890** 6891** These integer constants designate various run-time status parameters 6892** that can be returned by [sqlite3_status()]. 6893** 6894** <dl> 6895** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 6896** <dd>This parameter is the current amount of memory checked out 6897** using [sqlite3_malloc()], either directly or indirectly. The 6898** figure includes calls made to [sqlite3_malloc()] by the application 6899** and internal memory usage by the SQLite library. Scratch memory 6900** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 6901** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 6902** this parameter. The amount returned is the sum of the allocation 6903** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 6904** 6905** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 6906** <dd>This parameter records the largest memory allocation request 6907** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 6908** internal equivalents). Only the value returned in the 6909** *pHighwater parameter to [sqlite3_status()] is of interest. 6910** The value written into the *pCurrent parameter is undefined.</dd>)^ 6911** 6912** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 6913** <dd>This parameter records the number of separate memory allocations 6914** currently checked out.</dd>)^ 6915** 6916** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 6917** <dd>This parameter returns the number of pages used out of the 6918** [pagecache memory allocator] that was configured using 6919** [SQLITE_CONFIG_PAGECACHE]. The 6920** value returned is in pages, not in bytes.</dd>)^ 6921** 6922** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 6923** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6924** <dd>This parameter returns the number of bytes of page cache 6925** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 6926** buffer and where forced to overflow to [sqlite3_malloc()]. The 6927** returned value includes allocations that overflowed because they 6928** where too large (they were larger than the "sz" parameter to 6929** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 6930** no space was left in the page cache.</dd>)^ 6931** 6932** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 6933** <dd>This parameter records the largest memory allocation request 6934** handed to [pagecache memory allocator]. Only the value returned in the 6935** *pHighwater parameter to [sqlite3_status()] is of interest. 6936** The value written into the *pCurrent parameter is undefined.</dd>)^ 6937** 6938** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 6939** <dd>This parameter returns the number of allocations used out of the 6940** [scratch memory allocator] configured using 6941** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6942** in bytes. Since a single thread may only have one scratch allocation 6943** outstanding at time, this parameter also reports the number of threads 6944** using scratch memory at the same time.</dd>)^ 6945** 6946** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6947** <dd>This parameter returns the number of bytes of scratch memory 6948** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 6949** buffer and where forced to overflow to [sqlite3_malloc()]. The values 6950** returned include overflows because the requested allocation was too 6951** larger (that is, because the requested allocation was larger than the 6952** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 6953** slots were available. 6954** </dd>)^ 6955** 6956** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6957** <dd>This parameter records the largest memory allocation request 6958** handed to [scratch memory allocator]. Only the value returned in the 6959** *pHighwater parameter to [sqlite3_status()] is of interest. 6960** The value written into the *pCurrent parameter is undefined.</dd>)^ 6961** 6962** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6963** <dd>The *pHighwater parameter records the deepest parser stack. 6964** The *pCurrent value is undefined. The *pHighwater value is only 6965** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6966** </dl> 6967** 6968** New status parameters may be added from time to time. 6969*/ 6970#define SQLITE_STATUS_MEMORY_USED 0 6971#define SQLITE_STATUS_PAGECACHE_USED 1 6972#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6973#define SQLITE_STATUS_SCRATCH_USED 3 6974#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6975#define SQLITE_STATUS_MALLOC_SIZE 5 6976#define SQLITE_STATUS_PARSER_STACK 6 6977#define SQLITE_STATUS_PAGECACHE_SIZE 7 6978#define SQLITE_STATUS_SCRATCH_SIZE 8 6979#define SQLITE_STATUS_MALLOC_COUNT 9 6980 6981/* 6982** CAPI3REF: Database Connection Status 6983** METHOD: sqlite3 6984** 6985** ^This interface is used to retrieve runtime status information 6986** about a single [database connection]. ^The first argument is the 6987** database connection object to be interrogated. ^The second argument 6988** is an integer constant, taken from the set of 6989** [SQLITE_DBSTATUS options], that 6990** determines the parameter to interrogate. The set of 6991** [SQLITE_DBSTATUS options] is likely 6992** to grow in future releases of SQLite. 6993** 6994** ^The current value of the requested parameter is written into *pCur 6995** and the highest instantaneous value is written into *pHiwtr. ^If 6996** the resetFlg is true, then the highest instantaneous value is 6997** reset back down to the current value. 6998** 6999** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 7000** non-zero [error code] on failure. 7001** 7002** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 7003*/ 7004SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 7005 7006/* 7007** CAPI3REF: Status Parameters for database connections 7008** KEYWORDS: {SQLITE_DBSTATUS options} 7009** 7010** These constants are the available integer "verbs" that can be passed as 7011** the second argument to the [sqlite3_db_status()] interface. 7012** 7013** New verbs may be added in future releases of SQLite. Existing verbs 7014** might be discontinued. Applications should check the return code from 7015** [sqlite3_db_status()] to make sure that the call worked. 7016** The [sqlite3_db_status()] interface will return a non-zero error code 7017** if a discontinued or unsupported verb is invoked. 7018** 7019** <dl> 7020** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 7021** <dd>This parameter returns the number of lookaside memory slots currently 7022** checked out.</dd>)^ 7023** 7024** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 7025** <dd>This parameter returns the number malloc attempts that were 7026** satisfied using lookaside memory. Only the high-water value is meaningful; 7027** the current value is always zero.)^ 7028** 7029** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 7030** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 7031** <dd>This parameter returns the number malloc attempts that might have 7032** been satisfied using lookaside memory but failed due to the amount of 7033** memory requested being larger than the lookaside slot size. 7034** Only the high-water value is meaningful; 7035** the current value is always zero.)^ 7036** 7037** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 7038** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 7039** <dd>This parameter returns the number malloc attempts that might have 7040** been satisfied using lookaside memory but failed due to all lookaside 7041** memory already being in use. 7042** Only the high-water value is meaningful; 7043** the current value is always zero.)^ 7044** 7045** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 7046** <dd>This parameter returns the approximate number of bytes of heap 7047** memory used by all pager caches associated with the database connection.)^ 7048** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 7049** 7050** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 7051** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 7052** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 7053** pager cache is shared between two or more connections the bytes of heap 7054** memory used by that pager cache is divided evenly between the attached 7055** connections.)^ In other words, if none of the pager caches associated 7056** with the database connection are shared, this request returns the same 7057** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 7058** shared, the value returned by this call will be smaller than that returned 7059** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 7060** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 7061** 7062** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 7063** <dd>This parameter returns the approximate number of bytes of heap 7064** memory used to store the schema for all databases associated 7065** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 7066** ^The full amount of memory used by the schemas is reported, even if the 7067** schema memory is shared with other database connections due to 7068** [shared cache mode] being enabled. 7069** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 7070** 7071** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 7072** <dd>This parameter returns the approximate number of bytes of heap 7073** and lookaside memory used by all prepared statements associated with 7074** the database connection.)^ 7075** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 7076** </dd> 7077** 7078** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 7079** <dd>This parameter returns the number of pager cache hits that have 7080** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 7081** is always 0. 7082** </dd> 7083** 7084** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 7085** <dd>This parameter returns the number of pager cache misses that have 7086** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 7087** is always 0. 7088** </dd> 7089** 7090** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 7091** <dd>This parameter returns the number of dirty cache entries that have 7092** been written to disk. Specifically, the number of pages written to the 7093** wal file in wal mode databases, or the number of pages written to the 7094** database file in rollback mode databases. Any pages written as part of 7095** transaction rollback or database recovery operations are not included. 7096** If an IO or other error occurs while writing a page to disk, the effect 7097** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 7098** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 7099** </dd> 7100** 7101** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 7102** <dd>This parameter returns zero for the current value if and only if 7103** all foreign key constraints (deferred or immediate) have been 7104** resolved.)^ ^The highwater mark is always 0. 7105** </dd> 7106** </dl> 7107*/ 7108#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 7109#define SQLITE_DBSTATUS_CACHE_USED 1 7110#define SQLITE_DBSTATUS_SCHEMA_USED 2 7111#define SQLITE_DBSTATUS_STMT_USED 3 7112#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 7113#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 7114#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 7115#define SQLITE_DBSTATUS_CACHE_HIT 7 7116#define SQLITE_DBSTATUS_CACHE_MISS 8 7117#define SQLITE_DBSTATUS_CACHE_WRITE 9 7118#define SQLITE_DBSTATUS_DEFERRED_FKS 10 7119#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 7120#define SQLITE_DBSTATUS_MAX 11 /* Largest defined DBSTATUS */ 7121 7122 7123/* 7124** CAPI3REF: Prepared Statement Status 7125** METHOD: sqlite3_stmt 7126** 7127** ^(Each prepared statement maintains various 7128** [SQLITE_STMTSTATUS counters] that measure the number 7129** of times it has performed specific operations.)^ These counters can 7130** be used to monitor the performance characteristics of the prepared 7131** statements. For example, if the number of table steps greatly exceeds 7132** the number of table searches or result rows, that would tend to indicate 7133** that the prepared statement is using a full table scan rather than 7134** an index. 7135** 7136** ^(This interface is used to retrieve and reset counter values from 7137** a [prepared statement]. The first argument is the prepared statement 7138** object to be interrogated. The second argument 7139** is an integer code for a specific [SQLITE_STMTSTATUS counter] 7140** to be interrogated.)^ 7141** ^The current value of the requested counter is returned. 7142** ^If the resetFlg is true, then the counter is reset to zero after this 7143** interface call returns. 7144** 7145** See also: [sqlite3_status()] and [sqlite3_db_status()]. 7146*/ 7147SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 7148 7149/* 7150** CAPI3REF: Status Parameters for prepared statements 7151** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 7152** 7153** These preprocessor macros define integer codes that name counter 7154** values associated with the [sqlite3_stmt_status()] interface. 7155** The meanings of the various counters are as follows: 7156** 7157** <dl> 7158** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 7159** <dd>^This is the number of times that SQLite has stepped forward in 7160** a table as part of a full table scan. Large numbers for this counter 7161** may indicate opportunities for performance improvement through 7162** careful use of indices.</dd> 7163** 7164** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 7165** <dd>^This is the number of sort operations that have occurred. 7166** A non-zero value in this counter may indicate an opportunity to 7167** improvement performance through careful use of indices.</dd> 7168** 7169** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 7170** <dd>^This is the number of rows inserted into transient indices that 7171** were created automatically in order to help joins run faster. 7172** A non-zero value in this counter may indicate an opportunity to 7173** improvement performance by adding permanent indices that do not 7174** need to be reinitialized each time the statement is run.</dd> 7175** 7176** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 7177** <dd>^This is the number of virtual machine operations executed 7178** by the prepared statement if that number is less than or equal 7179** to 2147483647. The number of virtual machine operations can be 7180** used as a proxy for the total work done by the prepared statement. 7181** If the number of virtual machine operations exceeds 2147483647 7182** then the value returned by this statement status code is undefined. 7183** </dd> 7184** </dl> 7185*/ 7186#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 7187#define SQLITE_STMTSTATUS_SORT 2 7188#define SQLITE_STMTSTATUS_AUTOINDEX 3 7189#define SQLITE_STMTSTATUS_VM_STEP 4 7190 7191/* 7192** CAPI3REF: Custom Page Cache Object 7193** 7194** The sqlite3_pcache type is opaque. It is implemented by 7195** the pluggable module. The SQLite core has no knowledge of 7196** its size or internal structure and never deals with the 7197** sqlite3_pcache object except by holding and passing pointers 7198** to the object. 7199** 7200** See [sqlite3_pcache_methods2] for additional information. 7201*/ 7202typedef struct sqlite3_pcache sqlite3_pcache; 7203 7204/* 7205** CAPI3REF: Custom Page Cache Object 7206** 7207** The sqlite3_pcache_page object represents a single page in the 7208** page cache. The page cache will allocate instances of this 7209** object. Various methods of the page cache use pointers to instances 7210** of this object as parameters or as their return value. 7211** 7212** See [sqlite3_pcache_methods2] for additional information. 7213*/ 7214typedef struct sqlite3_pcache_page sqlite3_pcache_page; 7215struct sqlite3_pcache_page { 7216 void *pBuf; /* The content of the page */ 7217 void *pExtra; /* Extra information associated with the page */ 7218}; 7219 7220/* 7221** CAPI3REF: Application Defined Page Cache. 7222** KEYWORDS: {page cache} 7223** 7224** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 7225** register an alternative page cache implementation by passing in an 7226** instance of the sqlite3_pcache_methods2 structure.)^ 7227** In many applications, most of the heap memory allocated by 7228** SQLite is used for the page cache. 7229** By implementing a 7230** custom page cache using this API, an application can better control 7231** the amount of memory consumed by SQLite, the way in which 7232** that memory is allocated and released, and the policies used to 7233** determine exactly which parts of a database file are cached and for 7234** how long. 7235** 7236** The alternative page cache mechanism is an 7237** extreme measure that is only needed by the most demanding applications. 7238** The built-in page cache is recommended for most uses. 7239** 7240** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 7241** internal buffer by SQLite within the call to [sqlite3_config]. Hence 7242** the application may discard the parameter after the call to 7243** [sqlite3_config()] returns.)^ 7244** 7245** [[the xInit() page cache method]] 7246** ^(The xInit() method is called once for each effective 7247** call to [sqlite3_initialize()])^ 7248** (usually only once during the lifetime of the process). ^(The xInit() 7249** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 7250** The intent of the xInit() method is to set up global data structures 7251** required by the custom page cache implementation. 7252** ^(If the xInit() method is NULL, then the 7253** built-in default page cache is used instead of the application defined 7254** page cache.)^ 7255** 7256** [[the xShutdown() page cache method]] 7257** ^The xShutdown() method is called by [sqlite3_shutdown()]. 7258** It can be used to clean up 7259** any outstanding resources before process shutdown, if required. 7260** ^The xShutdown() method may be NULL. 7261** 7262** ^SQLite automatically serializes calls to the xInit method, 7263** so the xInit method need not be threadsafe. ^The 7264** xShutdown method is only called from [sqlite3_shutdown()] so it does 7265** not need to be threadsafe either. All other methods must be threadsafe 7266** in multithreaded applications. 7267** 7268** ^SQLite will never invoke xInit() more than once without an intervening 7269** call to xShutdown(). 7270** 7271** [[the xCreate() page cache methods]] 7272** ^SQLite invokes the xCreate() method to construct a new cache instance. 7273** SQLite will typically create one cache instance for each open database file, 7274** though this is not guaranteed. ^The 7275** first parameter, szPage, is the size in bytes of the pages that must 7276** be allocated by the cache. ^szPage will always a power of two. ^The 7277** second parameter szExtra is a number of bytes of extra storage 7278** associated with each page cache entry. ^The szExtra parameter will 7279** a number less than 250. SQLite will use the 7280** extra szExtra bytes on each page to store metadata about the underlying 7281** database page on disk. The value passed into szExtra depends 7282** on the SQLite version, the target platform, and how SQLite was compiled. 7283** ^The third argument to xCreate(), bPurgeable, is true if the cache being 7284** created will be used to cache database pages of a file stored on disk, or 7285** false if it is used for an in-memory database. The cache implementation 7286** does not have to do anything special based with the value of bPurgeable; 7287** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 7288** never invoke xUnpin() except to deliberately delete a page. 7289** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 7290** false will always have the "discard" flag set to true. 7291** ^Hence, a cache created with bPurgeable false will 7292** never contain any unpinned pages. 7293** 7294** [[the xCachesize() page cache method]] 7295** ^(The xCachesize() method may be called at any time by SQLite to set the 7296** suggested maximum cache-size (number of pages stored by) the cache 7297** instance passed as the first argument. This is the value configured using 7298** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 7299** parameter, the implementation is not required to do anything with this 7300** value; it is advisory only. 7301** 7302** [[the xPagecount() page cache methods]] 7303** The xPagecount() method must return the number of pages currently 7304** stored in the cache, both pinned and unpinned. 7305** 7306** [[the xFetch() page cache methods]] 7307** The xFetch() method locates a page in the cache and returns a pointer to 7308** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 7309** The pBuf element of the returned sqlite3_pcache_page object will be a 7310** pointer to a buffer of szPage bytes used to store the content of a 7311** single database page. The pExtra element of sqlite3_pcache_page will be 7312** a pointer to the szExtra bytes of extra storage that SQLite has requested 7313** for each entry in the page cache. 7314** 7315** The page to be fetched is determined by the key. ^The minimum key value 7316** is 1. After it has been retrieved using xFetch, the page is considered 7317** to be "pinned". 7318** 7319** If the requested page is already in the page cache, then the page cache 7320** implementation must return a pointer to the page buffer with its content 7321** intact. If the requested page is not already in the cache, then the 7322** cache implementation should use the value of the createFlag 7323** parameter to help it determined what action to take: 7324** 7325** <table border=1 width=85% align=center> 7326** <tr><th> createFlag <th> Behavior when page is not already in cache 7327** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 7328** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 7329** Otherwise return NULL. 7330** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 7331** NULL if allocating a new page is effectively impossible. 7332** </table> 7333** 7334** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 7335** will only use a createFlag of 2 after a prior call with a createFlag of 1 7336** failed.)^ In between the to xFetch() calls, SQLite may 7337** attempt to unpin one or more cache pages by spilling the content of 7338** pinned pages to disk and synching the operating system disk cache. 7339** 7340** [[the xUnpin() page cache method]] 7341** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 7342** as its second argument. If the third parameter, discard, is non-zero, 7343** then the page must be evicted from the cache. 7344** ^If the discard parameter is 7345** zero, then the page may be discarded or retained at the discretion of 7346** page cache implementation. ^The page cache implementation 7347** may choose to evict unpinned pages at any time. 7348** 7349** The cache must not perform any reference counting. A single 7350** call to xUnpin() unpins the page regardless of the number of prior calls 7351** to xFetch(). 7352** 7353** [[the xRekey() page cache methods]] 7354** The xRekey() method is used to change the key value associated with the 7355** page passed as the second argument. If the cache 7356** previously contains an entry associated with newKey, it must be 7357** discarded. ^Any prior cache entry associated with newKey is guaranteed not 7358** to be pinned. 7359** 7360** When SQLite calls the xTruncate() method, the cache must discard all 7361** existing cache entries with page numbers (keys) greater than or equal 7362** to the value of the iLimit parameter passed to xTruncate(). If any 7363** of these pages are pinned, they are implicitly unpinned, meaning that 7364** they can be safely discarded. 7365** 7366** [[the xDestroy() page cache method]] 7367** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 7368** All resources associated with the specified cache should be freed. ^After 7369** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 7370** handle invalid, and will not use it with any other sqlite3_pcache_methods2 7371** functions. 7372** 7373** [[the xShrink() page cache method]] 7374** ^SQLite invokes the xShrink() method when it wants the page cache to 7375** free up as much of heap memory as possible. The page cache implementation 7376** is not obligated to free any memory, but well-behaved implementations should 7377** do their best. 7378*/ 7379typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 7380struct sqlite3_pcache_methods2 { 7381 int iVersion; 7382 void *pArg; 7383 int (*xInit)(void*); 7384 void (*xShutdown)(void*); 7385 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 7386 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7387 int (*xPagecount)(sqlite3_pcache*); 7388 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7389 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 7390 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 7391 unsigned oldKey, unsigned newKey); 7392 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7393 void (*xDestroy)(sqlite3_pcache*); 7394 void (*xShrink)(sqlite3_pcache*); 7395}; 7396 7397/* 7398** This is the obsolete pcache_methods object that has now been replaced 7399** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 7400** retained in the header file for backwards compatibility only. 7401*/ 7402typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 7403struct sqlite3_pcache_methods { 7404 void *pArg; 7405 int (*xInit)(void*); 7406 void (*xShutdown)(void*); 7407 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 7408 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7409 int (*xPagecount)(sqlite3_pcache*); 7410 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7411 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 7412 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 7413 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7414 void (*xDestroy)(sqlite3_pcache*); 7415}; 7416 7417 7418/* 7419** CAPI3REF: Online Backup Object 7420** 7421** The sqlite3_backup object records state information about an ongoing 7422** online backup operation. ^The sqlite3_backup object is created by 7423** a call to [sqlite3_backup_init()] and is destroyed by a call to 7424** [sqlite3_backup_finish()]. 7425** 7426** See Also: [Using the SQLite Online Backup API] 7427*/ 7428typedef struct sqlite3_backup sqlite3_backup; 7429 7430/* 7431** CAPI3REF: Online Backup API. 7432** 7433** The backup API copies the content of one database into another. 7434** It is useful either for creating backups of databases or 7435** for copying in-memory databases to or from persistent files. 7436** 7437** See Also: [Using the SQLite Online Backup API] 7438** 7439** ^SQLite holds a write transaction open on the destination database file 7440** for the duration of the backup operation. 7441** ^The source database is read-locked only while it is being read; 7442** it is not locked continuously for the entire backup operation. 7443** ^Thus, the backup may be performed on a live source database without 7444** preventing other database connections from 7445** reading or writing to the source database while the backup is underway. 7446** 7447** ^(To perform a backup operation: 7448** <ol> 7449** <li><b>sqlite3_backup_init()</b> is called once to initialize the 7450** backup, 7451** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 7452** the data between the two databases, and finally 7453** <li><b>sqlite3_backup_finish()</b> is called to release all resources 7454** associated with the backup operation. 7455** </ol>)^ 7456** There should be exactly one call to sqlite3_backup_finish() for each 7457** successful call to sqlite3_backup_init(). 7458** 7459** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 7460** 7461** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 7462** [database connection] associated with the destination database 7463** and the database name, respectively. 7464** ^The database name is "main" for the main database, "temp" for the 7465** temporary database, or the name specified after the AS keyword in 7466** an [ATTACH] statement for an attached database. 7467** ^The S and M arguments passed to 7468** sqlite3_backup_init(D,N,S,M) identify the [database connection] 7469** and database name of the source database, respectively. 7470** ^The source and destination [database connections] (parameters S and D) 7471** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 7472** an error. 7473** 7474** ^A call to sqlite3_backup_init() will fail, returning NULL, if 7475** there is already a read or read-write transaction open on the 7476** destination database. 7477** 7478** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 7479** returned and an error code and error message are stored in the 7480** destination [database connection] D. 7481** ^The error code and message for the failed call to sqlite3_backup_init() 7482** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 7483** [sqlite3_errmsg16()] functions. 7484** ^A successful call to sqlite3_backup_init() returns a pointer to an 7485** [sqlite3_backup] object. 7486** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 7487** sqlite3_backup_finish() functions to perform the specified backup 7488** operation. 7489** 7490** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 7491** 7492** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 7493** the source and destination databases specified by [sqlite3_backup] object B. 7494** ^If N is negative, all remaining source pages are copied. 7495** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 7496** are still more pages to be copied, then the function returns [SQLITE_OK]. 7497** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 7498** from source to destination, then it returns [SQLITE_DONE]. 7499** ^If an error occurs while running sqlite3_backup_step(B,N), 7500** then an [error code] is returned. ^As well as [SQLITE_OK] and 7501** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 7502** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 7503** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 7504** 7505** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 7506** <ol> 7507** <li> the destination database was opened read-only, or 7508** <li> the destination database is using write-ahead-log journaling 7509** and the destination and source page sizes differ, or 7510** <li> the destination database is an in-memory database and the 7511** destination and source page sizes differ. 7512** </ol>)^ 7513** 7514** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 7515** the [sqlite3_busy_handler | busy-handler function] 7516** is invoked (if one is specified). ^If the 7517** busy-handler returns non-zero before the lock is available, then 7518** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 7519** sqlite3_backup_step() can be retried later. ^If the source 7520** [database connection] 7521** is being used to write to the source database when sqlite3_backup_step() 7522** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 7523** case the call to sqlite3_backup_step() can be retried later on. ^(If 7524** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 7525** [SQLITE_READONLY] is returned, then 7526** there is no point in retrying the call to sqlite3_backup_step(). These 7527** errors are considered fatal.)^ The application must accept 7528** that the backup operation has failed and pass the backup operation handle 7529** to the sqlite3_backup_finish() to release associated resources. 7530** 7531** ^The first call to sqlite3_backup_step() obtains an exclusive lock 7532** on the destination file. ^The exclusive lock is not released until either 7533** sqlite3_backup_finish() is called or the backup operation is complete 7534** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 7535** sqlite3_backup_step() obtains a [shared lock] on the source database that 7536** lasts for the duration of the sqlite3_backup_step() call. 7537** ^Because the source database is not locked between calls to 7538** sqlite3_backup_step(), the source database may be modified mid-way 7539** through the backup process. ^If the source database is modified by an 7540** external process or via a database connection other than the one being 7541** used by the backup operation, then the backup will be automatically 7542** restarted by the next call to sqlite3_backup_step(). ^If the source 7543** database is modified by the using the same database connection as is used 7544** by the backup operation, then the backup database is automatically 7545** updated at the same time. 7546** 7547** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 7548** 7549** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 7550** application wishes to abandon the backup operation, the application 7551** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 7552** ^The sqlite3_backup_finish() interfaces releases all 7553** resources associated with the [sqlite3_backup] object. 7554** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 7555** active write-transaction on the destination database is rolled back. 7556** The [sqlite3_backup] object is invalid 7557** and may not be used following a call to sqlite3_backup_finish(). 7558** 7559** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 7560** sqlite3_backup_step() errors occurred, regardless or whether or not 7561** sqlite3_backup_step() completed. 7562** ^If an out-of-memory condition or IO error occurred during any prior 7563** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 7564** sqlite3_backup_finish() returns the corresponding [error code]. 7565** 7566** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 7567** is not a permanent error and does not affect the return value of 7568** sqlite3_backup_finish(). 7569** 7570** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 7571** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 7572** 7573** ^The sqlite3_backup_remaining() routine returns the number of pages still 7574** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 7575** ^The sqlite3_backup_pagecount() routine returns the total number of pages 7576** in the source database at the conclusion of the most recent 7577** sqlite3_backup_step(). 7578** ^(The values returned by these functions are only updated by 7579** sqlite3_backup_step(). If the source database is modified in a way that 7580** changes the size of the source database or the number of pages remaining, 7581** those changes are not reflected in the output of sqlite3_backup_pagecount() 7582** and sqlite3_backup_remaining() until after the next 7583** sqlite3_backup_step().)^ 7584** 7585** <b>Concurrent Usage of Database Handles</b> 7586** 7587** ^The source [database connection] may be used by the application for other 7588** purposes while a backup operation is underway or being initialized. 7589** ^If SQLite is compiled and configured to support threadsafe database 7590** connections, then the source database connection may be used concurrently 7591** from within other threads. 7592** 7593** However, the application must guarantee that the destination 7594** [database connection] is not passed to any other API (by any thread) after 7595** sqlite3_backup_init() is called and before the corresponding call to 7596** sqlite3_backup_finish(). SQLite does not currently check to see 7597** if the application incorrectly accesses the destination [database connection] 7598** and so no error code is reported, but the operations may malfunction 7599** nevertheless. Use of the destination database connection while a 7600** backup is in progress might also also cause a mutex deadlock. 7601** 7602** If running in [shared cache mode], the application must 7603** guarantee that the shared cache used by the destination database 7604** is not accessed while the backup is running. In practice this means 7605** that the application must guarantee that the disk file being 7606** backed up to is not accessed by any connection within the process, 7607** not just the specific connection that was passed to sqlite3_backup_init(). 7608** 7609** The [sqlite3_backup] object itself is partially threadsafe. Multiple 7610** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 7611** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 7612** APIs are not strictly speaking threadsafe. If they are invoked at the 7613** same time as another thread is invoking sqlite3_backup_step() it is 7614** possible that they return invalid values. 7615*/ 7616SQLITE_API sqlite3_backup *sqlite3_backup_init( 7617 sqlite3 *pDest, /* Destination database handle */ 7618 const char *zDestName, /* Destination database name */ 7619 sqlite3 *pSource, /* Source database handle */ 7620 const char *zSourceName /* Source database name */ 7621); 7622SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 7623SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 7624SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 7625SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 7626 7627/* 7628** CAPI3REF: Unlock Notification 7629** METHOD: sqlite3 7630** 7631** ^When running in shared-cache mode, a database operation may fail with 7632** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 7633** individual tables within the shared-cache cannot be obtained. See 7634** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 7635** ^This API may be used to register a callback that SQLite will invoke 7636** when the connection currently holding the required lock relinquishes it. 7637** ^This API is only available if the library was compiled with the 7638** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 7639** 7640** See Also: [Using the SQLite Unlock Notification Feature]. 7641** 7642** ^Shared-cache locks are released when a database connection concludes 7643** its current transaction, either by committing it or rolling it back. 7644** 7645** ^When a connection (known as the blocked connection) fails to obtain a 7646** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 7647** identity of the database connection (the blocking connection) that 7648** has locked the required resource is stored internally. ^After an 7649** application receives an SQLITE_LOCKED error, it may call the 7650** sqlite3_unlock_notify() method with the blocked connection handle as 7651** the first argument to register for a callback that will be invoked 7652** when the blocking connections current transaction is concluded. ^The 7653** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 7654** call that concludes the blocking connections transaction. 7655** 7656** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 7657** there is a chance that the blocking connection will have already 7658** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 7659** If this happens, then the specified callback is invoked immediately, 7660** from within the call to sqlite3_unlock_notify().)^ 7661** 7662** ^If the blocked connection is attempting to obtain a write-lock on a 7663** shared-cache table, and more than one other connection currently holds 7664** a read-lock on the same table, then SQLite arbitrarily selects one of 7665** the other connections to use as the blocking connection. 7666** 7667** ^(There may be at most one unlock-notify callback registered by a 7668** blocked connection. If sqlite3_unlock_notify() is called when the 7669** blocked connection already has a registered unlock-notify callback, 7670** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 7671** called with a NULL pointer as its second argument, then any existing 7672** unlock-notify callback is canceled. ^The blocked connections 7673** unlock-notify callback may also be canceled by closing the blocked 7674** connection using [sqlite3_close()]. 7675** 7676** The unlock-notify callback is not reentrant. If an application invokes 7677** any sqlite3_xxx API functions from within an unlock-notify callback, a 7678** crash or deadlock may be the result. 7679** 7680** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 7681** returns SQLITE_OK. 7682** 7683** <b>Callback Invocation Details</b> 7684** 7685** When an unlock-notify callback is registered, the application provides a 7686** single void* pointer that is passed to the callback when it is invoked. 7687** However, the signature of the callback function allows SQLite to pass 7688** it an array of void* context pointers. The first argument passed to 7689** an unlock-notify callback is a pointer to an array of void* pointers, 7690** and the second is the number of entries in the array. 7691** 7692** When a blocking connections transaction is concluded, there may be 7693** more than one blocked connection that has registered for an unlock-notify 7694** callback. ^If two or more such blocked connections have specified the 7695** same callback function, then instead of invoking the callback function 7696** multiple times, it is invoked once with the set of void* context pointers 7697** specified by the blocked connections bundled together into an array. 7698** This gives the application an opportunity to prioritize any actions 7699** related to the set of unblocked database connections. 7700** 7701** <b>Deadlock Detection</b> 7702** 7703** Assuming that after registering for an unlock-notify callback a 7704** database waits for the callback to be issued before taking any further 7705** action (a reasonable assumption), then using this API may cause the 7706** application to deadlock. For example, if connection X is waiting for 7707** connection Y's transaction to be concluded, and similarly connection 7708** Y is waiting on connection X's transaction, then neither connection 7709** will proceed and the system may remain deadlocked indefinitely. 7710** 7711** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 7712** detection. ^If a given call to sqlite3_unlock_notify() would put the 7713** system in a deadlocked state, then SQLITE_LOCKED is returned and no 7714** unlock-notify callback is registered. The system is said to be in 7715** a deadlocked state if connection A has registered for an unlock-notify 7716** callback on the conclusion of connection B's transaction, and connection 7717** B has itself registered for an unlock-notify callback when connection 7718** A's transaction is concluded. ^Indirect deadlock is also detected, so 7719** the system is also considered to be deadlocked if connection B has 7720** registered for an unlock-notify callback on the conclusion of connection 7721** C's transaction, where connection C is waiting on connection A. ^Any 7722** number of levels of indirection are allowed. 7723** 7724** <b>The "DROP TABLE" Exception</b> 7725** 7726** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 7727** always appropriate to call sqlite3_unlock_notify(). There is however, 7728** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 7729** SQLite checks if there are any currently executing SELECT statements 7730** that belong to the same connection. If there are, SQLITE_LOCKED is 7731** returned. In this case there is no "blocking connection", so invoking 7732** sqlite3_unlock_notify() results in the unlock-notify callback being 7733** invoked immediately. If the application then re-attempts the "DROP TABLE" 7734** or "DROP INDEX" query, an infinite loop might be the result. 7735** 7736** One way around this problem is to check the extended error code returned 7737** by an sqlite3_step() call. ^(If there is a blocking connection, then the 7738** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 7739** the special "DROP TABLE/INDEX" case, the extended error code is just 7740** SQLITE_LOCKED.)^ 7741*/ 7742SQLITE_API int sqlite3_unlock_notify( 7743 sqlite3 *pBlocked, /* Waiting connection */ 7744 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 7745 void *pNotifyArg /* Argument to pass to xNotify */ 7746); 7747 7748 7749/* 7750** CAPI3REF: String Comparison 7751** 7752** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 7753** and extensions to compare the contents of two buffers containing UTF-8 7754** strings in a case-independent fashion, using the same definition of "case 7755** independence" that SQLite uses internally when comparing identifiers. 7756*/ 7757SQLITE_API int sqlite3_stricmp(const char *, const char *); 7758SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 7759 7760/* 7761** CAPI3REF: String Globbing 7762* 7763** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 7764** string X matches the [GLOB] pattern P. 7765** ^The definition of [GLOB] pattern matching used in 7766** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 7767** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 7768** is case sensitive. 7769** 7770** Note that this routine returns zero on a match and non-zero if the strings 7771** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7772** 7773** See also: [sqlite3_strlike()]. 7774*/ 7775SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 7776 7777/* 7778** CAPI3REF: String LIKE Matching 7779* 7780** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 7781** string X matches the [LIKE] pattern P with escape character E. 7782** ^The definition of [LIKE] pattern matching used in 7783** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 7784** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 7785** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 7786** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 7787** insensitive - equivalent upper and lower case ASCII characters match 7788** one another. 7789** 7790** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 7791** only ASCII characters are case folded. 7792** 7793** Note that this routine returns zero on a match and non-zero if the strings 7794** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7795** 7796** See also: [sqlite3_strglob()]. 7797*/ 7798SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 7799 7800/* 7801** CAPI3REF: Error Logging Interface 7802** 7803** ^The [sqlite3_log()] interface writes a message into the [error log] 7804** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 7805** ^If logging is enabled, the zFormat string and subsequent arguments are 7806** used with [sqlite3_snprintf()] to generate the final output string. 7807** 7808** The sqlite3_log() interface is intended for use by extensions such as 7809** virtual tables, collating functions, and SQL functions. While there is 7810** nothing to prevent an application from calling sqlite3_log(), doing so 7811** is considered bad form. 7812** 7813** The zFormat string must not be NULL. 7814** 7815** To avoid deadlocks and other threading problems, the sqlite3_log() routine 7816** will not use dynamically allocated memory. The log message is stored in 7817** a fixed-length buffer on the stack. If the log message is longer than 7818** a few hundred characters, it will be truncated to the length of the 7819** buffer. 7820*/ 7821SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 7822 7823/* 7824** CAPI3REF: Write-Ahead Log Commit Hook 7825** METHOD: sqlite3 7826** 7827** ^The [sqlite3_wal_hook()] function is used to register a callback that 7828** is invoked each time data is committed to a database in wal mode. 7829** 7830** ^(The callback is invoked by SQLite after the commit has taken place and 7831** the associated write-lock on the database released)^, so the implementation 7832** may read, write or [checkpoint] the database as required. 7833** 7834** ^The first parameter passed to the callback function when it is invoked 7835** is a copy of the third parameter passed to sqlite3_wal_hook() when 7836** registering the callback. ^The second is a copy of the database handle. 7837** ^The third parameter is the name of the database that was written to - 7838** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 7839** is the number of pages currently in the write-ahead log file, 7840** including those that were just committed. 7841** 7842** The callback function should normally return [SQLITE_OK]. ^If an error 7843** code is returned, that error will propagate back up through the 7844** SQLite code base to cause the statement that provoked the callback 7845** to report an error, though the commit will have still occurred. If the 7846** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 7847** that does not correspond to any valid SQLite error code, the results 7848** are undefined. 7849** 7850** A single database handle may have at most a single write-ahead log callback 7851** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 7852** previously registered write-ahead log callback. ^Note that the 7853** [sqlite3_wal_autocheckpoint()] interface and the 7854** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 7855** overwrite any prior [sqlite3_wal_hook()] settings. 7856*/ 7857SQLITE_API void *sqlite3_wal_hook( 7858 sqlite3*, 7859 int(*)(void *,sqlite3*,const char*,int), 7860 void* 7861); 7862 7863/* 7864** CAPI3REF: Configure an auto-checkpoint 7865** METHOD: sqlite3 7866** 7867** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 7868** [sqlite3_wal_hook()] that causes any database on [database connection] D 7869** to automatically [checkpoint] 7870** after committing a transaction if there are N or 7871** more frames in the [write-ahead log] file. ^Passing zero or 7872** a negative value as the nFrame parameter disables automatic 7873** checkpoints entirely. 7874** 7875** ^The callback registered by this function replaces any existing callback 7876** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 7877** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 7878** configured by this function. 7879** 7880** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 7881** from SQL. 7882** 7883** ^Checkpoints initiated by this mechanism are 7884** [sqlite3_wal_checkpoint_v2|PASSIVE]. 7885** 7886** ^Every new [database connection] defaults to having the auto-checkpoint 7887** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 7888** pages. The use of this interface 7889** is only necessary if the default setting is found to be suboptimal 7890** for a particular application. 7891*/ 7892SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 7893 7894/* 7895** CAPI3REF: Checkpoint a database 7896** METHOD: sqlite3 7897** 7898** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 7899** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 7900** 7901** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 7902** [write-ahead log] for database X on [database connection] D to be 7903** transferred into the database file and for the write-ahead log to 7904** be reset. See the [checkpointing] documentation for addition 7905** information. 7906** 7907** This interface used to be the only way to cause a checkpoint to 7908** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 7909** interface was added. This interface is retained for backwards 7910** compatibility and as a convenience for applications that need to manually 7911** start a callback but which do not need the full power (and corresponding 7912** complication) of [sqlite3_wal_checkpoint_v2()]. 7913*/ 7914SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 7915 7916/* 7917** CAPI3REF: Checkpoint a database 7918** METHOD: sqlite3 7919** 7920** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 7921** operation on database X of [database connection] D in mode M. Status 7922** information is written back into integers pointed to by L and C.)^ 7923** ^(The M parameter must be a valid [checkpoint mode]:)^ 7924** 7925** <dl> 7926** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 7927** ^Checkpoint as many frames as possible without waiting for any database 7928** readers or writers to finish, then sync the database file if all frames 7929** in the log were checkpointed. ^The [busy-handler callback] 7930** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 7931** ^On the other hand, passive mode might leave the checkpoint unfinished 7932** if there are concurrent readers or writers. 7933** 7934** <dt>SQLITE_CHECKPOINT_FULL<dd> 7935** ^This mode blocks (it invokes the 7936** [sqlite3_busy_handler|busy-handler callback]) until there is no 7937** database writer and all readers are reading from the most recent database 7938** snapshot. ^It then checkpoints all frames in the log file and syncs the 7939** database file. ^This mode blocks new database writers while it is pending, 7940** but new database readers are allowed to continue unimpeded. 7941** 7942** <dt>SQLITE_CHECKPOINT_RESTART<dd> 7943** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 7944** that after checkpointing the log file it blocks (calls the 7945** [busy-handler callback]) 7946** until all readers are reading from the database file only. ^This ensures 7947** that the next writer will restart the log file from the beginning. 7948** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 7949** database writer attempts while it is pending, but does not impede readers. 7950** 7951** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 7952** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 7953** addition that it also truncates the log file to zero bytes just prior 7954** to a successful return. 7955** </dl> 7956** 7957** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 7958** the log file or to -1 if the checkpoint could not run because 7959** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 7960** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 7961** log file (including any that were already checkpointed before the function 7962** was called) or to -1 if the checkpoint could not run due to an error or 7963** because the database is not in WAL mode. ^Note that upon successful 7964** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 7965** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 7966** 7967** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 7968** any other process is running a checkpoint operation at the same time, the 7969** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 7970** busy-handler configured, it will not be invoked in this case. 7971** 7972** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 7973** exclusive "writer" lock on the database file. ^If the writer lock cannot be 7974** obtained immediately, and a busy-handler is configured, it is invoked and 7975** the writer lock retried until either the busy-handler returns 0 or the lock 7976** is successfully obtained. ^The busy-handler is also invoked while waiting for 7977** database readers as described above. ^If the busy-handler returns 0 before 7978** the writer lock is obtained or while waiting for database readers, the 7979** checkpoint operation proceeds from that point in the same way as 7980** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 7981** without blocking any further. ^SQLITE_BUSY is returned in this case. 7982** 7983** ^If parameter zDb is NULL or points to a zero length string, then the 7984** specified operation is attempted on all WAL databases [attached] to 7985** [database connection] db. In this case the 7986** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 7987** an SQLITE_BUSY error is encountered when processing one or more of the 7988** attached WAL databases, the operation is still attempted on any remaining 7989** attached databases and SQLITE_BUSY is returned at the end. ^If any other 7990** error occurs while processing an attached database, processing is abandoned 7991** and the error code is returned to the caller immediately. ^If no error 7992** (SQLITE_BUSY or otherwise) is encountered while processing the attached 7993** databases, SQLITE_OK is returned. 7994** 7995** ^If database zDb is the name of an attached database that is not in WAL 7996** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 7997** zDb is not NULL (or a zero length string) and is not the name of any 7998** attached database, SQLITE_ERROR is returned to the caller. 7999** 8000** ^Unless it returns SQLITE_MISUSE, 8001** the sqlite3_wal_checkpoint_v2() interface 8002** sets the error information that is queried by 8003** [sqlite3_errcode()] and [sqlite3_errmsg()]. 8004** 8005** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 8006** from SQL. 8007*/ 8008SQLITE_API int sqlite3_wal_checkpoint_v2( 8009 sqlite3 *db, /* Database handle */ 8010 const char *zDb, /* Name of attached database (or NULL) */ 8011 int eMode, /* SQLITE_CHECKPOINT_* value */ 8012 int *pnLog, /* OUT: Size of WAL log in frames */ 8013 int *pnCkpt /* OUT: Total number of frames checkpointed */ 8014); 8015 8016/* 8017** CAPI3REF: Checkpoint Mode Values 8018** KEYWORDS: {checkpoint mode} 8019** 8020** These constants define all valid values for the "checkpoint mode" passed 8021** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 8022** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 8023** meaning of each of these checkpoint modes. 8024*/ 8025#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 8026#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 8027#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 8028#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 8029 8030/* 8031** CAPI3REF: Virtual Table Interface Configuration 8032** 8033** This function may be called by either the [xConnect] or [xCreate] method 8034** of a [virtual table] implementation to configure 8035** various facets of the virtual table interface. 8036** 8037** If this interface is invoked outside the context of an xConnect or 8038** xCreate virtual table method then the behavior is undefined. 8039** 8040** At present, there is only one option that may be configured using 8041** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 8042** may be added in the future. 8043*/ 8044SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 8045 8046/* 8047** CAPI3REF: Virtual Table Configuration Options 8048** 8049** These macros define the various options to the 8050** [sqlite3_vtab_config()] interface that [virtual table] implementations 8051** can use to customize and optimize their behavior. 8052** 8053** <dl> 8054** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 8055** <dd>Calls of the form 8056** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 8057** where X is an integer. If X is zero, then the [virtual table] whose 8058** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 8059** support constraints. In this configuration (which is the default) if 8060** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 8061** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 8062** specified as part of the users SQL statement, regardless of the actual 8063** ON CONFLICT mode specified. 8064** 8065** If X is non-zero, then the virtual table implementation guarantees 8066** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 8067** any modifications to internal or persistent data structures have been made. 8068** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 8069** is able to roll back a statement or database transaction, and abandon 8070** or continue processing the current SQL statement as appropriate. 8071** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 8072** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 8073** had been ABORT. 8074** 8075** Virtual table implementations that are required to handle OR REPLACE 8076** must do so within the [xUpdate] method. If a call to the 8077** [sqlite3_vtab_on_conflict()] function indicates that the current ON 8078** CONFLICT policy is REPLACE, the virtual table implementation should 8079** silently replace the appropriate rows within the xUpdate callback and 8080** return SQLITE_OK. Or, if this is not possible, it may return 8081** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 8082** constraint handling. 8083** </dl> 8084*/ 8085#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 8086 8087/* 8088** CAPI3REF: Determine The Virtual Table Conflict Policy 8089** 8090** This function may only be called from within a call to the [xUpdate] method 8091** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 8092** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 8093** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 8094** of the SQL statement that triggered the call to the [xUpdate] method of the 8095** [virtual table]. 8096*/ 8097SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 8098 8099/* 8100** CAPI3REF: Conflict resolution modes 8101** KEYWORDS: {conflict resolution mode} 8102** 8103** These constants are returned by [sqlite3_vtab_on_conflict()] to 8104** inform a [virtual table] implementation what the [ON CONFLICT] mode 8105** is for the SQL statement being evaluated. 8106** 8107** Note that the [SQLITE_IGNORE] constant is also used as a potential 8108** return value from the [sqlite3_set_authorizer()] callback and that 8109** [SQLITE_ABORT] is also a [result code]. 8110*/ 8111#define SQLITE_ROLLBACK 1 8112/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 8113#define SQLITE_FAIL 3 8114/* #define SQLITE_ABORT 4 // Also an error code */ 8115#define SQLITE_REPLACE 5 8116 8117/* 8118** CAPI3REF: Prepared Statement Scan Status Opcodes 8119** KEYWORDS: {scanstatus options} 8120** 8121** The following constants can be used for the T parameter to the 8122** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 8123** different metric for sqlite3_stmt_scanstatus() to return. 8124** 8125** When the value returned to V is a string, space to hold that string is 8126** managed by the prepared statement S and will be automatically freed when 8127** S is finalized. 8128** 8129** <dl> 8130** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 8131** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 8132** set to the total number of times that the X-th loop has run.</dd> 8133** 8134** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 8135** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 8136** to the total number of rows examined by all iterations of the X-th loop.</dd> 8137** 8138** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 8139** <dd>^The "double" variable pointed to by the T parameter will be set to the 8140** query planner's estimate for the average number of rows output from each 8141** iteration of the X-th loop. If the query planner's estimates was accurate, 8142** then this value will approximate the quotient NVISIT/NLOOP and the 8143** product of this value for all prior loops with the same SELECTID will 8144** be the NLOOP value for the current loop. 8145** 8146** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 8147** <dd>^The "const char *" variable pointed to by the T parameter will be set 8148** to a zero-terminated UTF-8 string containing the name of the index or table 8149** used for the X-th loop. 8150** 8151** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 8152** <dd>^The "const char *" variable pointed to by the T parameter will be set 8153** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 8154** description for the X-th loop. 8155** 8156** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 8157** <dd>^The "int" variable pointed to by the T parameter will be set to the 8158** "select-id" for the X-th loop. The select-id identifies which query or 8159** subquery the loop is part of. The main query has a select-id of zero. 8160** The select-id is the same value as is output in the first column 8161** of an [EXPLAIN QUERY PLAN] query. 8162** </dl> 8163*/ 8164#define SQLITE_SCANSTAT_NLOOP 0 8165#define SQLITE_SCANSTAT_NVISIT 1 8166#define SQLITE_SCANSTAT_EST 2 8167#define SQLITE_SCANSTAT_NAME 3 8168#define SQLITE_SCANSTAT_EXPLAIN 4 8169#define SQLITE_SCANSTAT_SELECTID 5 8170 8171/* 8172** CAPI3REF: Prepared Statement Scan Status 8173** METHOD: sqlite3_stmt 8174** 8175** This interface returns information about the predicted and measured 8176** performance for pStmt. Advanced applications can use this 8177** interface to compare the predicted and the measured performance and 8178** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 8179** 8180** Since this interface is expected to be rarely used, it is only 8181** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 8182** compile-time option. 8183** 8184** The "iScanStatusOp" parameter determines which status information to return. 8185** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 8186** of this interface is undefined. 8187** ^The requested measurement is written into a variable pointed to by 8188** the "pOut" parameter. 8189** Parameter "idx" identifies the specific loop to retrieve statistics for. 8190** Loops are numbered starting from zero. ^If idx is out of range - less than 8191** zero or greater than or equal to the total number of loops used to implement 8192** the statement - a non-zero value is returned and the variable that pOut 8193** points to is unchanged. 8194** 8195** ^Statistics might not be available for all loops in all statements. ^In cases 8196** where there exist loops with no available statistics, this function behaves 8197** as if the loop did not exist - it returns non-zero and leave the variable 8198** that pOut points to unchanged. 8199** 8200** See also: [sqlite3_stmt_scanstatus_reset()] 8201*/ 8202SQLITE_API int sqlite3_stmt_scanstatus( 8203 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 8204 int idx, /* Index of loop to report on */ 8205 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 8206 void *pOut /* Result written here */ 8207); 8208 8209/* 8210** CAPI3REF: Zero Scan-Status Counters 8211** METHOD: sqlite3_stmt 8212** 8213** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 8214** 8215** This API is only available if the library is built with pre-processor 8216** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 8217*/ 8218SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 8219 8220/* 8221** CAPI3REF: Flush caches to disk mid-transaction 8222** 8223** ^If a write-transaction is open on [database connection] D when the 8224** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 8225** pages in the pager-cache that are not currently in use are written out 8226** to disk. A dirty page may be in use if a database cursor created by an 8227** active SQL statement is reading from it, or if it is page 1 of a database 8228** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 8229** interface flushes caches for all schemas - "main", "temp", and 8230** any [attached] databases. 8231** 8232** ^If this function needs to obtain extra database locks before dirty pages 8233** can be flushed to disk, it does so. ^If those locks cannot be obtained 8234** immediately and there is a busy-handler callback configured, it is invoked 8235** in the usual manner. ^If the required lock still cannot be obtained, then 8236** the database is skipped and an attempt made to flush any dirty pages 8237** belonging to the next (if any) database. ^If any databases are skipped 8238** because locks cannot be obtained, but no other error occurs, this 8239** function returns SQLITE_BUSY. 8240** 8241** ^If any other error occurs while flushing dirty pages to disk (for 8242** example an IO error or out-of-memory condition), then processing is 8243** abandoned and an SQLite [error code] is returned to the caller immediately. 8244** 8245** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 8246** 8247** ^This function does not set the database handle error code or message 8248** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 8249*/ 8250SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 8251 8252/* 8253** CAPI3REF: The pre-update hook. 8254** 8255** ^These interfaces are only available if SQLite is compiled using the 8256** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 8257** 8258** ^The [sqlite3_preupdate_hook()] interface registers a callback function 8259** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 8260** on a database table. 8261** ^At most one preupdate hook may be registered at a time on a single 8262** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 8263** the previous setting. 8264** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 8265** with a NULL pointer as the second parameter. 8266** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 8267** the first parameter to callbacks. 8268** 8269** ^The preupdate hook only fires for changes to real database tables; the 8270** preupdate hook is not invoked for changes to [virtual tables] or to 8271** system tables like sqlite_master or sqlite_stat1. 8272** 8273** ^The second parameter to the preupdate callback is a pointer to 8274** the [database connection] that registered the preupdate hook. 8275** ^The third parameter to the preupdate callback is one of the constants 8276** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 8277** kind of update operation that is about to occur. 8278** ^(The fourth parameter to the preupdate callback is the name of the 8279** database within the database connection that is being modified. This 8280** will be "main" for the main database or "temp" for TEMP tables or 8281** the name given after the AS keyword in the [ATTACH] statement for attached 8282** databases.)^ 8283** ^The fifth parameter to the preupdate callback is the name of the 8284** table that is being modified. 8285** 8286** For an UPDATE or DELETE operation on a [rowid table], the sixth 8287** parameter passed to the preupdate callback is the initial [rowid] of the 8288** row being modified or deleted. For an INSERT operation on a rowid table, 8289** or any operation on a WITHOUT ROWID table, the value of the sixth 8290** parameter is undefined. For an INSERT or UPDATE on a rowid table the 8291** seventh parameter is the final rowid value of the row being inserted 8292** or updated. The value of the seventh parameter passed to the callback 8293** function is not defined for operations on WITHOUT ROWID tables, or for 8294** INSERT operations on rowid tables. 8295** 8296** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 8297** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 8298** provide additional information about a preupdate event. These routines 8299** may only be called from within a preupdate callback. Invoking any of 8300** these routines from outside of a preupdate callback or with a 8301** [database connection] pointer that is different from the one supplied 8302** to the preupdate callback results in undefined and probably undesirable 8303** behavior. 8304** 8305** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 8306** in the row that is being inserted, updated, or deleted. 8307** 8308** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 8309** a [protected sqlite3_value] that contains the value of the Nth column of 8310** the table row before it is updated. The N parameter must be between 0 8311** and one less than the number of columns or the behavior will be 8312** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 8313** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 8314** behavior is undefined. The [sqlite3_value] that P points to 8315** will be destroyed when the preupdate callback returns. 8316** 8317** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 8318** a [protected sqlite3_value] that contains the value of the Nth column of 8319** the table row after it is updated. The N parameter must be between 0 8320** and one less than the number of columns or the behavior will be 8321** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 8322** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 8323** behavior is undefined. The [sqlite3_value] that P points to 8324** will be destroyed when the preupdate callback returns. 8325** 8326** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 8327** callback was invoked as a result of a direct insert, update, or delete 8328** operation; or 1 for inserts, updates, or deletes invoked by top-level 8329** triggers; or 2 for changes resulting from triggers called by top-level 8330** triggers; and so forth. 8331** 8332** See also: [sqlite3_update_hook()] 8333*/ 8334#if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 8335SQLITE_API void *sqlite3_preupdate_hook( 8336 sqlite3 *db, 8337 void(*xPreUpdate)( 8338 void *pCtx, /* Copy of third arg to preupdate_hook() */ 8339 sqlite3 *db, /* Database handle */ 8340 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 8341 char const *zDb, /* Database name */ 8342 char const *zName, /* Table name */ 8343 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 8344 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 8345 ), 8346 void* 8347); 8348SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 8349SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 8350SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 8351SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 8352#endif 8353 8354/* 8355** CAPI3REF: Low-level system error code 8356** 8357** ^Attempt to return the underlying operating system error code or error 8358** number that caused the most recent I/O error or failure to open a file. 8359** The return value is OS-dependent. For example, on unix systems, after 8360** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 8361** called to get back the underlying "errno" that caused the problem, such 8362** as ENOSPC, EAUTH, EISDIR, and so forth. 8363*/ 8364SQLITE_API int sqlite3_system_errno(sqlite3*); 8365 8366/* 8367** CAPI3REF: Database Snapshot 8368** KEYWORDS: {snapshot} {sqlite3_snapshot} 8369** EXPERIMENTAL 8370** 8371** An instance of the snapshot object records the state of a [WAL mode] 8372** database for some specific point in history. 8373** 8374** In [WAL mode], multiple [database connections] that are open on the 8375** same database file can each be reading a different historical version 8376** of the database file. When a [database connection] begins a read 8377** transaction, that connection sees an unchanging copy of the database 8378** as it existed for the point in time when the transaction first started. 8379** Subsequent changes to the database from other connections are not seen 8380** by the reader until a new read transaction is started. 8381** 8382** The sqlite3_snapshot object records state information about an historical 8383** version of the database file so that it is possible to later open a new read 8384** transaction that sees that historical version of the database rather than 8385** the most recent version. 8386** 8387** The constructor for this object is [sqlite3_snapshot_get()]. The 8388** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer 8389** to an historical snapshot (if possible). The destructor for 8390** sqlite3_snapshot objects is [sqlite3_snapshot_free()]. 8391*/ 8392typedef struct sqlite3_snapshot { 8393 unsigned char hidden[48]; 8394} sqlite3_snapshot; 8395 8396/* 8397** CAPI3REF: Record A Database Snapshot 8398** EXPERIMENTAL 8399** 8400** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 8401** new [sqlite3_snapshot] object that records the current state of 8402** schema S in database connection D. ^On success, the 8403** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 8404** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 8405** If there is not already a read-transaction open on schema S when 8406** this function is called, one is opened automatically. 8407** 8408** The following must be true for this function to succeed. If any of 8409** the following statements are false when sqlite3_snapshot_get() is 8410** called, SQLITE_ERROR is returned. The final value of *P is undefined 8411** in this case. 8412** 8413** <ul> 8414** <li> The database handle must be in [autocommit mode]. 8415** 8416** <li> Schema S of [database connection] D must be a [WAL mode] database. 8417** 8418** <li> There must not be a write transaction open on schema S of database 8419** connection D. 8420** 8421** <li> One or more transactions must have been written to the current wal 8422** file since it was created on disk (by any connection). This means 8423** that a snapshot cannot be taken on a wal mode database with no wal 8424** file immediately after it is first opened. At least one transaction 8425** must be written to it first. 8426** </ul> 8427** 8428** This function may also return SQLITE_NOMEM. If it is called with the 8429** database handle in autocommit mode but fails for some other reason, 8430** whether or not a read transaction is opened on schema S is undefined. 8431** 8432** The [sqlite3_snapshot] object returned from a successful call to 8433** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 8434** to avoid a memory leak. 8435** 8436** The [sqlite3_snapshot_get()] interface is only available when the 8437** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8438*/ 8439SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 8440 sqlite3 *db, 8441 const char *zSchema, 8442 sqlite3_snapshot **ppSnapshot 8443); 8444 8445/* 8446** CAPI3REF: Start a read transaction on an historical snapshot 8447** EXPERIMENTAL 8448** 8449** ^The [sqlite3_snapshot_open(D,S,P)] interface starts a 8450** read transaction for schema S of 8451** [database connection] D such that the read transaction 8452** refers to historical [snapshot] P, rather than the most 8453** recent change to the database. 8454** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success 8455** or an appropriate [error code] if it fails. 8456** 8457** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be 8458** the first operation following the [BEGIN] that takes the schema S 8459** out of [autocommit mode]. 8460** ^In other words, schema S must not currently be in 8461** a transaction for [sqlite3_snapshot_open(D,S,P)] to work, but the 8462** database connection D must be out of [autocommit mode]. 8463** ^A [snapshot] will fail to open if it has been overwritten by a 8464** [checkpoint]. 8465** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 8466** database connection D does not know that the database file for 8467** schema S is in [WAL mode]. A database connection might not know 8468** that the database file is in [WAL mode] if there has been no prior 8469** I/O on that database connection, or if the database entered [WAL mode] 8470** after the most recent I/O on the database connection.)^ 8471** (Hint: Run "[PRAGMA application_id]" against a newly opened 8472** database connection in order to make it ready to use snapshots.) 8473** 8474** The [sqlite3_snapshot_open()] interface is only available when the 8475** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8476*/ 8477SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 8478 sqlite3 *db, 8479 const char *zSchema, 8480 sqlite3_snapshot *pSnapshot 8481); 8482 8483/* 8484** CAPI3REF: Destroy a snapshot 8485** EXPERIMENTAL 8486** 8487** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 8488** The application must eventually free every [sqlite3_snapshot] object 8489** using this routine to avoid a memory leak. 8490** 8491** The [sqlite3_snapshot_free()] interface is only available when the 8492** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8493*/ 8494SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 8495 8496/* 8497** CAPI3REF: Compare the ages of two snapshot handles. 8498** EXPERIMENTAL 8499** 8500** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 8501** of two valid snapshot handles. 8502** 8503** If the two snapshot handles are not associated with the same database 8504** file, the result of the comparison is undefined. 8505** 8506** Additionally, the result of the comparison is only valid if both of the 8507** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 8508** last time the wal file was deleted. The wal file is deleted when the 8509** database is changed back to rollback mode or when the number of database 8510** clients drops to zero. If either snapshot handle was obtained before the 8511** wal file was last deleted, the value returned by this function 8512** is undefined. 8513** 8514** Otherwise, this API returns a negative value if P1 refers to an older 8515** snapshot than P2, zero if the two handles refer to the same database 8516** snapshot, and a positive value if P1 is a newer snapshot than P2. 8517*/ 8518SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 8519 sqlite3_snapshot *p1, 8520 sqlite3_snapshot *p2 8521); 8522 8523/* 8524** CAPI3REF: Recover snapshots from a wal file 8525** EXPERIMENTAL 8526** 8527** If all connections disconnect from a database file but do not perform 8528** a checkpoint, the existing wal file is opened along with the database 8529** file the next time the database is opened. At this point it is only 8530** possible to successfully call sqlite3_snapshot_open() to open the most 8531** recent snapshot of the database (the one at the head of the wal file), 8532** even though the wal file may contain other valid snapshots for which 8533** clients have sqlite3_snapshot handles. 8534** 8535** This function attempts to scan the wal file associated with database zDb 8536** of database handle db and make all valid snapshots available to 8537** sqlite3_snapshot_open(). It is an error if there is already a read 8538** transaction open on the database, or if the database is not a wal mode 8539** database. 8540** 8541** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 8542*/ 8543SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 8544 8545/* 8546** Undo the hack that converts floating point types to integer for 8547** builds on processors without floating point support. 8548*/ 8549#ifdef SQLITE_OMIT_FLOATING_POINT 8550# undef double 8551#endif 8552 8553#ifdef __cplusplus 8554} /* End of the 'extern "C"' block */ 8555#endif 8556#endif /* SQLITE3_H */ 8557 8558/******** Begin file sqlite3rtree.h *********/ 8559/* 8560** 2010 August 30 8561** 8562** The author disclaims copyright to this source code. In place of 8563** a legal notice, here is a blessing: 8564** 8565** May you do good and not evil. 8566** May you find forgiveness for yourself and forgive others. 8567** May you share freely, never taking more than you give. 8568** 8569************************************************************************* 8570*/ 8571 8572#ifndef _SQLITE3RTREE_H_ 8573#define _SQLITE3RTREE_H_ 8574 8575 8576#ifdef __cplusplus 8577extern "C" { 8578#endif 8579 8580typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 8581typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 8582 8583/* The double-precision datatype used by RTree depends on the 8584** SQLITE_RTREE_INT_ONLY compile-time option. 8585*/ 8586#ifdef SQLITE_RTREE_INT_ONLY 8587 typedef sqlite3_int64 sqlite3_rtree_dbl; 8588#else 8589 typedef double sqlite3_rtree_dbl; 8590#endif 8591 8592/* 8593** Register a geometry callback named zGeom that can be used as part of an 8594** R-Tree geometry query as follows: 8595** 8596** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 8597*/ 8598SQLITE_API int sqlite3_rtree_geometry_callback( 8599 sqlite3 *db, 8600 const char *zGeom, 8601 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 8602 void *pContext 8603); 8604 8605 8606/* 8607** A pointer to a structure of the following type is passed as the first 8608** argument to callbacks registered using rtree_geometry_callback(). 8609*/ 8610struct sqlite3_rtree_geometry { 8611 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 8612 int nParam; /* Size of array aParam[] */ 8613 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 8614 void *pUser; /* Callback implementation user data */ 8615 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 8616}; 8617 8618/* 8619** Register a 2nd-generation geometry callback named zScore that can be 8620** used as part of an R-Tree geometry query as follows: 8621** 8622** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 8623*/ 8624SQLITE_API int sqlite3_rtree_query_callback( 8625 sqlite3 *db, 8626 const char *zQueryFunc, 8627 int (*xQueryFunc)(sqlite3_rtree_query_info*), 8628 void *pContext, 8629 void (*xDestructor)(void*) 8630); 8631 8632 8633/* 8634** A pointer to a structure of the following type is passed as the 8635** argument to scored geometry callback registered using 8636** sqlite3_rtree_query_callback(). 8637** 8638** Note that the first 5 fields of this structure are identical to 8639** sqlite3_rtree_geometry. This structure is a subclass of 8640** sqlite3_rtree_geometry. 8641*/ 8642struct sqlite3_rtree_query_info { 8643 void *pContext; /* pContext from when function registered */ 8644 int nParam; /* Number of function parameters */ 8645 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 8646 void *pUser; /* callback can use this, if desired */ 8647 void (*xDelUser)(void*); /* function to free pUser */ 8648 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 8649 unsigned int *anQueue; /* Number of pending entries in the queue */ 8650 int nCoord; /* Number of coordinates */ 8651 int iLevel; /* Level of current node or entry */ 8652 int mxLevel; /* The largest iLevel value in the tree */ 8653 sqlite3_int64 iRowid; /* Rowid for current entry */ 8654 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 8655 int eParentWithin; /* Visibility of parent node */ 8656 int eWithin; /* OUT: Visiblity */ 8657 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 8658 /* The following fields are only available in 3.8.11 and later */ 8659 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 8660}; 8661 8662/* 8663** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 8664*/ 8665#define NOT_WITHIN 0 /* Object completely outside of query region */ 8666#define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 8667#define FULLY_WITHIN 2 /* Object fully contained within query region */ 8668 8669 8670#ifdef __cplusplus 8671} /* end of the 'extern "C"' block */ 8672#endif 8673 8674#endif /* ifndef _SQLITE3RTREE_H_ */ 8675 8676/******** End of sqlite3rtree.h *********/ 8677/******** Begin file sqlite3session.h *********/ 8678 8679#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 8680#define __SQLITESESSION_H_ 1 8681 8682/* 8683** Make sure we can call this stuff from C++. 8684*/ 8685#ifdef __cplusplus 8686extern "C" { 8687#endif 8688 8689 8690/* 8691** CAPI3REF: Session Object Handle 8692*/ 8693typedef struct sqlite3_session sqlite3_session; 8694 8695/* 8696** CAPI3REF: Changeset Iterator Handle 8697*/ 8698typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 8699 8700/* 8701** CAPI3REF: Create A New Session Object 8702** 8703** Create a new session object attached to database handle db. If successful, 8704** a pointer to the new object is written to *ppSession and SQLITE_OK is 8705** returned. If an error occurs, *ppSession is set to NULL and an SQLite 8706** error code (e.g. SQLITE_NOMEM) is returned. 8707** 8708** It is possible to create multiple session objects attached to a single 8709** database handle. 8710** 8711** Session objects created using this function should be deleted using the 8712** [sqlite3session_delete()] function before the database handle that they 8713** are attached to is itself closed. If the database handle is closed before 8714** the session object is deleted, then the results of calling any session 8715** module function, including [sqlite3session_delete()] on the session object 8716** are undefined. 8717** 8718** Because the session module uses the [sqlite3_preupdate_hook()] API, it 8719** is not possible for an application to register a pre-update hook on a 8720** database handle that has one or more session objects attached. Nor is 8721** it possible to create a session object attached to a database handle for 8722** which a pre-update hook is already defined. The results of attempting 8723** either of these things are undefined. 8724** 8725** The session object will be used to create changesets for tables in 8726** database zDb, where zDb is either "main", or "temp", or the name of an 8727** attached database. It is not an error if database zDb is not attached 8728** to the database when the session object is created. 8729*/ 8730SQLITE_API int sqlite3session_create( 8731 sqlite3 *db, /* Database handle */ 8732 const char *zDb, /* Name of db (e.g. "main") */ 8733 sqlite3_session **ppSession /* OUT: New session object */ 8734); 8735 8736/* 8737** CAPI3REF: Delete A Session Object 8738** 8739** Delete a session object previously allocated using 8740** [sqlite3session_create()]. Once a session object has been deleted, the 8741** results of attempting to use pSession with any other session module 8742** function are undefined. 8743** 8744** Session objects must be deleted before the database handle to which they 8745** are attached is closed. Refer to the documentation for 8746** [sqlite3session_create()] for details. 8747*/ 8748SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 8749 8750 8751/* 8752** CAPI3REF: Enable Or Disable A Session Object 8753** 8754** Enable or disable the recording of changes by a session object. When 8755** enabled, a session object records changes made to the database. When 8756** disabled - it does not. A newly created session object is enabled. 8757** Refer to the documentation for [sqlite3session_changeset()] for further 8758** details regarding how enabling and disabling a session object affects 8759** the eventual changesets. 8760** 8761** Passing zero to this function disables the session. Passing a value 8762** greater than zero enables it. Passing a value less than zero is a 8763** no-op, and may be used to query the current state of the session. 8764** 8765** The return value indicates the final state of the session object: 0 if 8766** the session is disabled, or 1 if it is enabled. 8767*/ 8768SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 8769 8770/* 8771** CAPI3REF: Set Or Clear the Indirect Change Flag 8772** 8773** Each change recorded by a session object is marked as either direct or 8774** indirect. A change is marked as indirect if either: 8775** 8776** <ul> 8777** <li> The session object "indirect" flag is set when the change is 8778** made, or 8779** <li> The change is made by an SQL trigger or foreign key action 8780** instead of directly as a result of a users SQL statement. 8781** </ul> 8782** 8783** If a single row is affected by more than one operation within a session, 8784** then the change is considered indirect if all operations meet the criteria 8785** for an indirect change above, or direct otherwise. 8786** 8787** This function is used to set, clear or query the session object indirect 8788** flag. If the second argument passed to this function is zero, then the 8789** indirect flag is cleared. If it is greater than zero, the indirect flag 8790** is set. Passing a value less than zero does not modify the current value 8791** of the indirect flag, and may be used to query the current state of the 8792** indirect flag for the specified session object. 8793** 8794** The return value indicates the final state of the indirect flag: 0 if 8795** it is clear, or 1 if it is set. 8796*/ 8797SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 8798 8799/* 8800** CAPI3REF: Attach A Table To A Session Object 8801** 8802** If argument zTab is not NULL, then it is the name of a table to attach 8803** to the session object passed as the first argument. All subsequent changes 8804** made to the table while the session object is enabled will be recorded. See 8805** documentation for [sqlite3session_changeset()] for further details. 8806** 8807** Or, if argument zTab is NULL, then changes are recorded for all tables 8808** in the database. If additional tables are added to the database (by 8809** executing "CREATE TABLE" statements) after this call is made, changes for 8810** the new tables are also recorded. 8811** 8812** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 8813** defined as part of their CREATE TABLE statement. It does not matter if the 8814** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 8815** KEY may consist of a single column, or may be a composite key. 8816** 8817** It is not an error if the named table does not exist in the database. Nor 8818** is it an error if the named table does not have a PRIMARY KEY. However, 8819** no changes will be recorded in either of these scenarios. 8820** 8821** Changes are not recorded for individual rows that have NULL values stored 8822** in one or more of their PRIMARY KEY columns. 8823** 8824** SQLITE_OK is returned if the call completes without error. Or, if an error 8825** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 8826*/ 8827SQLITE_API int sqlite3session_attach( 8828 sqlite3_session *pSession, /* Session object */ 8829 const char *zTab /* Table name */ 8830); 8831 8832/* 8833** CAPI3REF: Set a table filter on a Session Object. 8834** 8835** The second argument (xFilter) is the "filter callback". For changes to rows 8836** in tables that are not attached to the Session object, the filter is called 8837** to determine whether changes to the table's rows should be tracked or not. 8838** If xFilter returns 0, changes is not tracked. Note that once a table is 8839** attached, xFilter will not be called again. 8840*/ 8841SQLITE_API void sqlite3session_table_filter( 8842 sqlite3_session *pSession, /* Session object */ 8843 int(*xFilter)( 8844 void *pCtx, /* Copy of third arg to _filter_table() */ 8845 const char *zTab /* Table name */ 8846 ), 8847 void *pCtx /* First argument passed to xFilter */ 8848); 8849 8850/* 8851** CAPI3REF: Generate A Changeset From A Session Object 8852** 8853** Obtain a changeset containing changes to the tables attached to the 8854** session object passed as the first argument. If successful, 8855** set *ppChangeset to point to a buffer containing the changeset 8856** and *pnChangeset to the size of the changeset in bytes before returning 8857** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 8858** zero and return an SQLite error code. 8859** 8860** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 8861** each representing a change to a single row of an attached table. An INSERT 8862** change contains the values of each field of a new database row. A DELETE 8863** contains the original values of each field of a deleted database row. An 8864** UPDATE change contains the original values of each field of an updated 8865** database row along with the updated values for each updated non-primary-key 8866** column. It is not possible for an UPDATE change to represent a change that 8867** modifies the values of primary key columns. If such a change is made, it 8868** is represented in a changeset as a DELETE followed by an INSERT. 8869** 8870** Changes are not recorded for rows that have NULL values stored in one or 8871** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 8872** no corresponding change is present in the changesets returned by this 8873** function. If an existing row with one or more NULL values stored in 8874** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 8875** only an INSERT is appears in the changeset. Similarly, if an existing row 8876** with non-NULL PRIMARY KEY values is updated so that one or more of its 8877** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 8878** DELETE change only. 8879** 8880** The contents of a changeset may be traversed using an iterator created 8881** using the [sqlite3changeset_start()] API. A changeset may be applied to 8882** a database with a compatible schema using the [sqlite3changeset_apply()] 8883** API. 8884** 8885** Within a changeset generated by this function, all changes related to a 8886** single table are grouped together. In other words, when iterating through 8887** a changeset or when applying a changeset to a database, all changes related 8888** to a single table are processed before moving on to the next table. Tables 8889** are sorted in the same order in which they were attached (or auto-attached) 8890** to the sqlite3_session object. The order in which the changes related to 8891** a single table are stored is undefined. 8892** 8893** Following a successful call to this function, it is the responsibility of 8894** the caller to eventually free the buffer that *ppChangeset points to using 8895** [sqlite3_free()]. 8896** 8897** <h3>Changeset Generation</h3> 8898** 8899** Once a table has been attached to a session object, the session object 8900** records the primary key values of all new rows inserted into the table. 8901** It also records the original primary key and other column values of any 8902** deleted or updated rows. For each unique primary key value, data is only 8903** recorded once - the first time a row with said primary key is inserted, 8904** updated or deleted in the lifetime of the session. 8905** 8906** There is one exception to the previous paragraph: when a row is inserted, 8907** updated or deleted, if one or more of its primary key columns contain a 8908** NULL value, no record of the change is made. 8909** 8910** The session object therefore accumulates two types of records - those 8911** that consist of primary key values only (created when the user inserts 8912** a new record) and those that consist of the primary key values and the 8913** original values of other table columns (created when the users deletes 8914** or updates a record). 8915** 8916** When this function is called, the requested changeset is created using 8917** both the accumulated records and the current contents of the database 8918** file. Specifically: 8919** 8920** <ul> 8921** <li> For each record generated by an insert, the database is queried 8922** for a row with a matching primary key. If one is found, an INSERT 8923** change is added to the changeset. If no such row is found, no change 8924** is added to the changeset. 8925** 8926** <li> For each record generated by an update or delete, the database is 8927** queried for a row with a matching primary key. If such a row is 8928** found and one or more of the non-primary key fields have been 8929** modified from their original values, an UPDATE change is added to 8930** the changeset. Or, if no such row is found in the table, a DELETE 8931** change is added to the changeset. If there is a row with a matching 8932** primary key in the database, but all fields contain their original 8933** values, no change is added to the changeset. 8934** </ul> 8935** 8936** This means, amongst other things, that if a row is inserted and then later 8937** deleted while a session object is active, neither the insert nor the delete 8938** will be present in the changeset. Or if a row is deleted and then later a 8939** row with the same primary key values inserted while a session object is 8940** active, the resulting changeset will contain an UPDATE change instead of 8941** a DELETE and an INSERT. 8942** 8943** When a session object is disabled (see the [sqlite3session_enable()] API), 8944** it does not accumulate records when rows are inserted, updated or deleted. 8945** This may appear to have some counter-intuitive effects if a single row 8946** is written to more than once during a session. For example, if a row 8947** is inserted while a session object is enabled, then later deleted while 8948** the same session object is disabled, no INSERT record will appear in the 8949** changeset, even though the delete took place while the session was disabled. 8950** Or, if one field of a row is updated while a session is disabled, and 8951** another field of the same row is updated while the session is enabled, the 8952** resulting changeset will contain an UPDATE change that updates both fields. 8953*/ 8954SQLITE_API int sqlite3session_changeset( 8955 sqlite3_session *pSession, /* Session object */ 8956 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 8957 void **ppChangeset /* OUT: Buffer containing changeset */ 8958); 8959 8960/* 8961** CAPI3REF: Load The Difference Between Tables Into A Session 8962** 8963** If it is not already attached to the session object passed as the first 8964** argument, this function attaches table zTbl in the same manner as the 8965** [sqlite3session_attach()] function. If zTbl does not exist, or if it 8966** does not have a primary key, this function is a no-op (but does not return 8967** an error). 8968** 8969** Argument zFromDb must be the name of a database ("main", "temp" etc.) 8970** attached to the same database handle as the session object that contains 8971** a table compatible with the table attached to the session by this function. 8972** A table is considered compatible if it: 8973** 8974** <ul> 8975** <li> Has the same name, 8976** <li> Has the same set of columns declared in the same order, and 8977** <li> Has the same PRIMARY KEY definition. 8978** </ul> 8979** 8980** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 8981** are compatible but do not have any PRIMARY KEY columns, it is not an error 8982** but no changes are added to the session object. As with other session 8983** APIs, tables without PRIMARY KEYs are simply ignored. 8984** 8985** This function adds a set of changes to the session object that could be 8986** used to update the table in database zFrom (call this the "from-table") 8987** so that its content is the same as the table attached to the session 8988** object (call this the "to-table"). Specifically: 8989** 8990** <ul> 8991** <li> For each row (primary key) that exists in the to-table but not in 8992** the from-table, an INSERT record is added to the session object. 8993** 8994** <li> For each row (primary key) that exists in the to-table but not in 8995** the from-table, a DELETE record is added to the session object. 8996** 8997** <li> For each row (primary key) that exists in both tables, but features 8998** different non-PK values in each, an UPDATE record is added to the 8999** session. 9000** </ul> 9001** 9002** To clarify, if this function is called and then a changeset constructed 9003** using [sqlite3session_changeset()], then after applying that changeset to 9004** database zFrom the contents of the two compatible tables would be 9005** identical. 9006** 9007** It an error if database zFrom does not exist or does not contain the 9008** required compatible table. 9009** 9010** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite 9011** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 9012** may be set to point to a buffer containing an English language error 9013** message. It is the responsibility of the caller to free this buffer using 9014** sqlite3_free(). 9015*/ 9016SQLITE_API int sqlite3session_diff( 9017 sqlite3_session *pSession, 9018 const char *zFromDb, 9019 const char *zTbl, 9020 char **pzErrMsg 9021); 9022 9023 9024/* 9025** CAPI3REF: Generate A Patchset From A Session Object 9026** 9027** The differences between a patchset and a changeset are that: 9028** 9029** <ul> 9030** <li> DELETE records consist of the primary key fields only. The 9031** original values of other fields are omitted. 9032** <li> The original values of any modified fields are omitted from 9033** UPDATE records. 9034** </ul> 9035** 9036** A patchset blob may be used with up to date versions of all 9037** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 9038** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 9039** attempting to use a patchset blob with old versions of the 9040** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 9041** 9042** Because the non-primary key "old.*" fields are omitted, no 9043** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 9044** is passed to the sqlite3changeset_apply() API. Other conflict types work 9045** in the same way as for changesets. 9046** 9047** Changes within a patchset are ordered in the same way as for changesets 9048** generated by the sqlite3session_changeset() function (i.e. all changes for 9049** a single table are grouped together, tables appear in the order in which 9050** they were attached to the session object). 9051*/ 9052SQLITE_API int sqlite3session_patchset( 9053 sqlite3_session *pSession, /* Session object */ 9054 int *pnPatchset, /* OUT: Size of buffer at *ppChangeset */ 9055 void **ppPatchset /* OUT: Buffer containing changeset */ 9056); 9057 9058/* 9059** CAPI3REF: Test if a changeset has recorded any changes. 9060** 9061** Return non-zero if no changes to attached tables have been recorded by 9062** the session object passed as the first argument. Otherwise, if one or 9063** more changes have been recorded, return zero. 9064** 9065** Even if this function returns zero, it is possible that calling 9066** [sqlite3session_changeset()] on the session handle may still return a 9067** changeset that contains no changes. This can happen when a row in 9068** an attached table is modified and then later on the original values 9069** are restored. However, if this function returns non-zero, then it is 9070** guaranteed that a call to sqlite3session_changeset() will return a 9071** changeset containing zero changes. 9072*/ 9073SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 9074 9075/* 9076** CAPI3REF: Create An Iterator To Traverse A Changeset 9077** 9078** Create an iterator used to iterate through the contents of a changeset. 9079** If successful, *pp is set to point to the iterator handle and SQLITE_OK 9080** is returned. Otherwise, if an error occurs, *pp is set to zero and an 9081** SQLite error code is returned. 9082** 9083** The following functions can be used to advance and query a changeset 9084** iterator created by this function: 9085** 9086** <ul> 9087** <li> [sqlite3changeset_next()] 9088** <li> [sqlite3changeset_op()] 9089** <li> [sqlite3changeset_new()] 9090** <li> [sqlite3changeset_old()] 9091** </ul> 9092** 9093** It is the responsibility of the caller to eventually destroy the iterator 9094** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 9095** changeset (pChangeset) must remain valid until after the iterator is 9096** destroyed. 9097** 9098** Assuming the changeset blob was created by one of the 9099** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 9100** [sqlite3changeset_invert()] functions, all changes within the changeset 9101** that apply to a single table are grouped together. This means that when 9102** an application iterates through a changeset using an iterator created by 9103** this function, all changes that relate to a single table are visited 9104** consecutively. There is no chance that the iterator will visit a change 9105** the applies to table X, then one for table Y, and then later on visit 9106** another change for table X. 9107*/ 9108SQLITE_API int sqlite3changeset_start( 9109 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 9110 int nChangeset, /* Size of changeset blob in bytes */ 9111 void *pChangeset /* Pointer to blob containing changeset */ 9112); 9113 9114 9115/* 9116** CAPI3REF: Advance A Changeset Iterator 9117** 9118** This function may only be used with iterators created by function 9119** [sqlite3changeset_start()]. If it is called on an iterator passed to 9120** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 9121** is returned and the call has no effect. 9122** 9123** Immediately after an iterator is created by sqlite3changeset_start(), it 9124** does not point to any change in the changeset. Assuming the changeset 9125** is not empty, the first call to this function advances the iterator to 9126** point to the first change in the changeset. Each subsequent call advances 9127** the iterator to point to the next change in the changeset (if any). If 9128** no error occurs and the iterator points to a valid change after a call 9129** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 9130** Otherwise, if all changes in the changeset have already been visited, 9131** SQLITE_DONE is returned. 9132** 9133** If an error occurs, an SQLite error code is returned. Possible error 9134** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 9135** SQLITE_NOMEM. 9136*/ 9137SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 9138 9139/* 9140** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 9141** 9142** The pIter argument passed to this function may either be an iterator 9143** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9144** created by [sqlite3changeset_start()]. In the latter case, the most recent 9145** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 9146** is not the case, this function returns [SQLITE_MISUSE]. 9147** 9148** If argument pzTab is not NULL, then *pzTab is set to point to a 9149** nul-terminated utf-8 encoded string containing the name of the table 9150** affected by the current change. The buffer remains valid until either 9151** sqlite3changeset_next() is called on the iterator or until the 9152** conflict-handler function returns. If pnCol is not NULL, then *pnCol is 9153** set to the number of columns in the table affected by the change. If 9154** pbIncorrect is not NULL, then *pbIndirect is set to true (1) if the change 9155** is an indirect change, or false (0) otherwise. See the documentation for 9156** [sqlite3session_indirect()] for a description of direct and indirect 9157** changes. Finally, if pOp is not NULL, then *pOp is set to one of 9158** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the 9159** type of change that the iterator currently points to. 9160** 9161** If no error occurs, SQLITE_OK is returned. If an error does occur, an 9162** SQLite error code is returned. The values of the output variables may not 9163** be trusted in this case. 9164*/ 9165SQLITE_API int sqlite3changeset_op( 9166 sqlite3_changeset_iter *pIter, /* Iterator object */ 9167 const char **pzTab, /* OUT: Pointer to table name */ 9168 int *pnCol, /* OUT: Number of columns in table */ 9169 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 9170 int *pbIndirect /* OUT: True for an 'indirect' change */ 9171); 9172 9173/* 9174** CAPI3REF: Obtain The Primary Key Definition Of A Table 9175** 9176** For each modified table, a changeset includes the following: 9177** 9178** <ul> 9179** <li> The number of columns in the table, and 9180** <li> Which of those columns make up the tables PRIMARY KEY. 9181** </ul> 9182** 9183** This function is used to find which columns comprise the PRIMARY KEY of 9184** the table modified by the change that iterator pIter currently points to. 9185** If successful, *pabPK is set to point to an array of nCol entries, where 9186** nCol is the number of columns in the table. Elements of *pabPK are set to 9187** 0x01 if the corresponding column is part of the tables primary key, or 9188** 0x00 if it is not. 9189** 9190** If argument pnCol is not NULL, then *pnCol is set to the number of columns 9191** in the table. 9192** 9193** If this function is called when the iterator does not point to a valid 9194** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 9195** SQLITE_OK is returned and the output variables populated as described 9196** above. 9197*/ 9198SQLITE_API int sqlite3changeset_pk( 9199 sqlite3_changeset_iter *pIter, /* Iterator object */ 9200 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 9201 int *pnCol /* OUT: Number of entries in output array */ 9202); 9203 9204/* 9205** CAPI3REF: Obtain old.* Values From A Changeset Iterator 9206** 9207** The pIter argument passed to this function may either be an iterator 9208** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9209** created by [sqlite3changeset_start()]. In the latter case, the most recent 9210** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 9211** Furthermore, it may only be called if the type of change that the iterator 9212** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 9213** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 9214** 9215** Argument iVal must be greater than or equal to 0, and less than the number 9216** of columns in the table affected by the current change. Otherwise, 9217** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9218** 9219** If successful, this function sets *ppValue to point to a protected 9220** sqlite3_value object containing the iVal'th value from the vector of 9221** original row values stored as part of the UPDATE or DELETE change and 9222** returns SQLITE_OK. The name of the function comes from the fact that this 9223** is similar to the "old.*" columns available to update or delete triggers. 9224** 9225** If some other error occurs (e.g. an OOM condition), an SQLite error code 9226** is returned and *ppValue is set to NULL. 9227*/ 9228SQLITE_API int sqlite3changeset_old( 9229 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9230 int iVal, /* Column number */ 9231 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 9232); 9233 9234/* 9235** CAPI3REF: Obtain new.* Values From A Changeset Iterator 9236** 9237** The pIter argument passed to this function may either be an iterator 9238** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9239** created by [sqlite3changeset_start()]. In the latter case, the most recent 9240** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 9241** Furthermore, it may only be called if the type of change that the iterator 9242** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 9243** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 9244** 9245** Argument iVal must be greater than or equal to 0, and less than the number 9246** of columns in the table affected by the current change. Otherwise, 9247** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9248** 9249** If successful, this function sets *ppValue to point to a protected 9250** sqlite3_value object containing the iVal'th value from the vector of 9251** new row values stored as part of the UPDATE or INSERT change and 9252** returns SQLITE_OK. If the change is an UPDATE and does not include 9253** a new value for the requested column, *ppValue is set to NULL and 9254** SQLITE_OK returned. The name of the function comes from the fact that 9255** this is similar to the "new.*" columns available to update or delete 9256** triggers. 9257** 9258** If some other error occurs (e.g. an OOM condition), an SQLite error code 9259** is returned and *ppValue is set to NULL. 9260*/ 9261SQLITE_API int sqlite3changeset_new( 9262 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9263 int iVal, /* Column number */ 9264 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 9265); 9266 9267/* 9268** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 9269** 9270** This function should only be used with iterator objects passed to a 9271** conflict-handler callback by [sqlite3changeset_apply()] with either 9272** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 9273** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 9274** is set to NULL. 9275** 9276** Argument iVal must be greater than or equal to 0, and less than the number 9277** of columns in the table affected by the current change. Otherwise, 9278** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9279** 9280** If successful, this function sets *ppValue to point to a protected 9281** sqlite3_value object containing the iVal'th value from the 9282** "conflicting row" associated with the current conflict-handler callback 9283** and returns SQLITE_OK. 9284** 9285** If some other error occurs (e.g. an OOM condition), an SQLite error code 9286** is returned and *ppValue is set to NULL. 9287*/ 9288SQLITE_API int sqlite3changeset_conflict( 9289 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9290 int iVal, /* Column number */ 9291 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 9292); 9293 9294/* 9295** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 9296** 9297** This function may only be called with an iterator passed to an 9298** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 9299** it sets the output variable to the total number of known foreign key 9300** violations in the destination database and returns SQLITE_OK. 9301** 9302** In all other cases this function returns SQLITE_MISUSE. 9303*/ 9304SQLITE_API int sqlite3changeset_fk_conflicts( 9305 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9306 int *pnOut /* OUT: Number of FK violations */ 9307); 9308 9309 9310/* 9311** CAPI3REF: Finalize A Changeset Iterator 9312** 9313** This function is used to finalize an iterator allocated with 9314** [sqlite3changeset_start()]. 9315** 9316** This function should only be called on iterators created using the 9317** [sqlite3changeset_start()] function. If an application calls this 9318** function with an iterator passed to a conflict-handler by 9319** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 9320** call has no effect. 9321** 9322** If an error was encountered within a call to an sqlite3changeset_xxx() 9323** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 9324** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 9325** to that error is returned by this function. Otherwise, SQLITE_OK is 9326** returned. This is to allow the following pattern (pseudo-code): 9327** 9328** sqlite3changeset_start(); 9329** while( SQLITE_ROW==sqlite3changeset_next() ){ 9330** // Do something with change. 9331** } 9332** rc = sqlite3changeset_finalize(); 9333** if( rc!=SQLITE_OK ){ 9334** // An error has occurred 9335** } 9336*/ 9337SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 9338 9339/* 9340** CAPI3REF: Invert A Changeset 9341** 9342** This function is used to "invert" a changeset object. Applying an inverted 9343** changeset to a database reverses the effects of applying the uninverted 9344** changeset. Specifically: 9345** 9346** <ul> 9347** <li> Each DELETE change is changed to an INSERT, and 9348** <li> Each INSERT change is changed to a DELETE, and 9349** <li> For each UPDATE change, the old.* and new.* values are exchanged. 9350** </ul> 9351** 9352** This function does not change the order in which changes appear within 9353** the changeset. It merely reverses the sense of each individual change. 9354** 9355** If successful, a pointer to a buffer containing the inverted changeset 9356** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 9357** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 9358** zeroed and an SQLite error code returned. 9359** 9360** It is the responsibility of the caller to eventually call sqlite3_free() 9361** on the *ppOut pointer to free the buffer allocation following a successful 9362** call to this function. 9363** 9364** WARNING/TODO: This function currently assumes that the input is a valid 9365** changeset. If it is not, the results are undefined. 9366*/ 9367SQLITE_API int sqlite3changeset_invert( 9368 int nIn, const void *pIn, /* Input changeset */ 9369 int *pnOut, void **ppOut /* OUT: Inverse of input */ 9370); 9371 9372/* 9373** CAPI3REF: Concatenate Two Changeset Objects 9374** 9375** This function is used to concatenate two changesets, A and B, into a 9376** single changeset. The result is a changeset equivalent to applying 9377** changeset A followed by changeset B. 9378** 9379** This function combines the two input changesets using an 9380** sqlite3_changegroup object. Calling it produces similar results as the 9381** following code fragment: 9382** 9383** sqlite3_changegroup *pGrp; 9384** rc = sqlite3_changegroup_new(&pGrp); 9385** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 9386** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 9387** if( rc==SQLITE_OK ){ 9388** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 9389** }else{ 9390** *ppOut = 0; 9391** *pnOut = 0; 9392** } 9393** 9394** Refer to the sqlite3_changegroup documentation below for details. 9395*/ 9396SQLITE_API int sqlite3changeset_concat( 9397 int nA, /* Number of bytes in buffer pA */ 9398 void *pA, /* Pointer to buffer containing changeset A */ 9399 int nB, /* Number of bytes in buffer pB */ 9400 void *pB, /* Pointer to buffer containing changeset B */ 9401 int *pnOut, /* OUT: Number of bytes in output changeset */ 9402 void **ppOut /* OUT: Buffer containing output changeset */ 9403); 9404 9405 9406/* 9407** CAPI3REF: Changegroup Handle 9408*/ 9409typedef struct sqlite3_changegroup sqlite3_changegroup; 9410 9411/* 9412** CAPI3REF: Create A New Changegroup Object 9413** 9414** An sqlite3_changegroup object is used to combine two or more changesets 9415** (or patchsets) into a single changeset (or patchset). A single changegroup 9416** object may combine changesets or patchsets, but not both. The output is 9417** always in the same format as the input. 9418** 9419** If successful, this function returns SQLITE_OK and populates (*pp) with 9420** a pointer to a new sqlite3_changegroup object before returning. The caller 9421** should eventually free the returned object using a call to 9422** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 9423** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 9424** 9425** The usual usage pattern for an sqlite3_changegroup object is as follows: 9426** 9427** <ul> 9428** <li> It is created using a call to sqlite3changegroup_new(). 9429** 9430** <li> Zero or more changesets (or patchsets) are added to the object 9431** by calling sqlite3changegroup_add(). 9432** 9433** <li> The result of combining all input changesets together is obtained 9434** by the application via a call to sqlite3changegroup_output(). 9435** 9436** <li> The object is deleted using a call to sqlite3changegroup_delete(). 9437** </ul> 9438** 9439** Any number of calls to add() and output() may be made between the calls to 9440** new() and delete(), and in any order. 9441** 9442** As well as the regular sqlite3changegroup_add() and 9443** sqlite3changegroup_output() functions, also available are the streaming 9444** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 9445*/ 9446SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 9447 9448/* 9449** CAPI3REF: Add A Changeset To A Changegroup 9450** 9451** Add all changes within the changeset (or patchset) in buffer pData (size 9452** nData bytes) to the changegroup. 9453** 9454** If the buffer contains a patchset, then all prior calls to this function 9455** on the same changegroup object must also have specified patchsets. Or, if 9456** the buffer contains a changeset, so must have the earlier calls to this 9457** function. Otherwise, SQLITE_ERROR is returned and no changes are added 9458** to the changegroup. 9459** 9460** Rows within the changeset and changegroup are identified by the values in 9461** their PRIMARY KEY columns. A change in the changeset is considered to 9462** apply to the same row as a change already present in the changegroup if 9463** the two rows have the same primary key. 9464** 9465** Changes to rows that do not already appear in the changegroup are 9466** simply copied into it. Or, if both the new changeset and the changegroup 9467** contain changes that apply to a single row, the final contents of the 9468** changegroup depends on the type of each change, as follows: 9469** 9470** <table border=1 style="margin-left:8ex;margin-right:8ex"> 9471** <tr><th style="white-space:pre">Existing Change </th> 9472** <th style="white-space:pre">New Change </th> 9473** <th>Output Change 9474** <tr><td>INSERT <td>INSERT <td> 9475** The new change is ignored. This case does not occur if the new 9476** changeset was recorded immediately after the changesets already 9477** added to the changegroup. 9478** <tr><td>INSERT <td>UPDATE <td> 9479** The INSERT change remains in the changegroup. The values in the 9480** INSERT change are modified as if the row was inserted by the 9481** existing change and then updated according to the new change. 9482** <tr><td>INSERT <td>DELETE <td> 9483** The existing INSERT is removed from the changegroup. The DELETE is 9484** not added. 9485** <tr><td>UPDATE <td>INSERT <td> 9486** The new change is ignored. This case does not occur if the new 9487** changeset was recorded immediately after the changesets already 9488** added to the changegroup. 9489** <tr><td>UPDATE <td>UPDATE <td> 9490** The existing UPDATE remains within the changegroup. It is amended 9491** so that the accompanying values are as if the row was updated once 9492** by the existing change and then again by the new change. 9493** <tr><td>UPDATE <td>DELETE <td> 9494** The existing UPDATE is replaced by the new DELETE within the 9495** changegroup. 9496** <tr><td>DELETE <td>INSERT <td> 9497** If one or more of the column values in the row inserted by the 9498** new change differ from those in the row deleted by the existing 9499** change, the existing DELETE is replaced by an UPDATE within the 9500** changegroup. Otherwise, if the inserted row is exactly the same 9501** as the deleted row, the existing DELETE is simply discarded. 9502** <tr><td>DELETE <td>UPDATE <td> 9503** The new change is ignored. This case does not occur if the new 9504** changeset was recorded immediately after the changesets already 9505** added to the changegroup. 9506** <tr><td>DELETE <td>DELETE <td> 9507** The new change is ignored. This case does not occur if the new 9508** changeset was recorded immediately after the changesets already 9509** added to the changegroup. 9510** </table> 9511** 9512** If the new changeset contains changes to a table that is already present 9513** in the changegroup, then the number of columns and the position of the 9514** primary key columns for the table must be consistent. If this is not the 9515** case, this function fails with SQLITE_SCHEMA. If the input changeset 9516** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 9517** returned. Or, if an out-of-memory condition occurs during processing, this 9518** function returns SQLITE_NOMEM. In all cases, if an error occurs the 9519** final contents of the changegroup is undefined. 9520** 9521** If no error occurs, SQLITE_OK is returned. 9522*/ 9523SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 9524 9525/* 9526** CAPI3REF: Obtain A Composite Changeset From A Changegroup 9527** 9528** Obtain a buffer containing a changeset (or patchset) representing the 9529** current contents of the changegroup. If the inputs to the changegroup 9530** were themselves changesets, the output is a changeset. Or, if the 9531** inputs were patchsets, the output is also a patchset. 9532** 9533** As with the output of the sqlite3session_changeset() and 9534** sqlite3session_patchset() functions, all changes related to a single 9535** table are grouped together in the output of this function. Tables appear 9536** in the same order as for the very first changeset added to the changegroup. 9537** If the second or subsequent changesets added to the changegroup contain 9538** changes for tables that do not appear in the first changeset, they are 9539** appended onto the end of the output changeset, again in the order in 9540** which they are first encountered. 9541** 9542** If an error occurs, an SQLite error code is returned and the output 9543** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 9544** is returned and the output variables are set to the size of and a 9545** pointer to the output buffer, respectively. In this case it is the 9546** responsibility of the caller to eventually free the buffer using a 9547** call to sqlite3_free(). 9548*/ 9549SQLITE_API int sqlite3changegroup_output( 9550 sqlite3_changegroup*, 9551 int *pnData, /* OUT: Size of output buffer in bytes */ 9552 void **ppData /* OUT: Pointer to output buffer */ 9553); 9554 9555/* 9556** CAPI3REF: Delete A Changegroup Object 9557*/ 9558SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 9559 9560/* 9561** CAPI3REF: Apply A Changeset To A Database 9562** 9563** Apply a changeset to a database. This function attempts to update the 9564** "main" database attached to handle db with the changes found in the 9565** changeset passed via the second and third arguments. 9566** 9567** The fourth argument (xFilter) passed to this function is the "filter 9568** callback". If it is not NULL, then for each table affected by at least one 9569** change in the changeset, the filter callback is invoked with 9570** the table name as the second argument, and a copy of the context pointer 9571** passed as the sixth argument to this function as the first. If the "filter 9572** callback" returns zero, then no attempt is made to apply any changes to 9573** the table. Otherwise, if the return value is non-zero or the xFilter 9574** argument to this function is NULL, all changes related to the table are 9575** attempted. 9576** 9577** For each table that is not excluded by the filter callback, this function 9578** tests that the target database contains a compatible table. A table is 9579** considered compatible if all of the following are true: 9580** 9581** <ul> 9582** <li> The table has the same name as the name recorded in the 9583** changeset, and 9584** <li> The table has at least as many columns as recorded in the 9585** changeset, and 9586** <li> The table has primary key columns in the same position as 9587** recorded in the changeset. 9588** </ul> 9589** 9590** If there is no compatible table, it is not an error, but none of the 9591** changes associated with the table are applied. A warning message is issued 9592** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 9593** one such warning is issued for each table in the changeset. 9594** 9595** For each change for which there is a compatible table, an attempt is made 9596** to modify the table contents according to the UPDATE, INSERT or DELETE 9597** change. If a change cannot be applied cleanly, the conflict handler 9598** function passed as the fifth argument to sqlite3changeset_apply() may be 9599** invoked. A description of exactly when the conflict handler is invoked for 9600** each type of change is below. 9601** 9602** Unlike the xFilter argument, xConflict may not be passed NULL. The results 9603** of passing anything other than a valid function pointer as the xConflict 9604** argument are undefined. 9605** 9606** Each time the conflict handler function is invoked, it must return one 9607** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 9608** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 9609** if the second argument passed to the conflict handler is either 9610** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 9611** returns an illegal value, any changes already made are rolled back and 9612** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 9613** actions are taken by sqlite3changeset_apply() depending on the value 9614** returned by each invocation of the conflict-handler function. Refer to 9615** the documentation for the three 9616** [SQLITE_CHANGESET_OMIT|available return values] for details. 9617** 9618** <dl> 9619** <dt>DELETE Changes<dd> 9620** For each DELETE change, this function checks if the target database 9621** contains a row with the same primary key value (or values) as the 9622** original row values stored in the changeset. If it does, and the values 9623** stored in all non-primary key columns also match the values stored in 9624** the changeset the row is deleted from the target database. 9625** 9626** If a row with matching primary key values is found, but one or more of 9627** the non-primary key fields contains a value different from the original 9628** row value stored in the changeset, the conflict-handler function is 9629** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 9630** database table has more columns than are recorded in the changeset, 9631** only the values of those non-primary key fields are compared against 9632** the current database contents - any trailing database table columns 9633** are ignored. 9634** 9635** If no row with matching primary key values is found in the database, 9636** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 9637** passed as the second argument. 9638** 9639** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 9640** (which can only happen if a foreign key constraint is violated), the 9641** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 9642** passed as the second argument. This includes the case where the DELETE 9643** operation is attempted because an earlier call to the conflict handler 9644** function returned [SQLITE_CHANGESET_REPLACE]. 9645** 9646** <dt>INSERT Changes<dd> 9647** For each INSERT change, an attempt is made to insert the new row into 9648** the database. If the changeset row contains fewer fields than the 9649** database table, the trailing fields are populated with their default 9650** values. 9651** 9652** If the attempt to insert the row fails because the database already 9653** contains a row with the same primary key values, the conflict handler 9654** function is invoked with the second argument set to 9655** [SQLITE_CHANGESET_CONFLICT]. 9656** 9657** If the attempt to insert the row fails because of some other constraint 9658** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 9659** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 9660** This includes the case where the INSERT operation is re-attempted because 9661** an earlier call to the conflict handler function returned 9662** [SQLITE_CHANGESET_REPLACE]. 9663** 9664** <dt>UPDATE Changes<dd> 9665** For each UPDATE change, this function checks if the target database 9666** contains a row with the same primary key value (or values) as the 9667** original row values stored in the changeset. If it does, and the values 9668** stored in all modified non-primary key columns also match the values 9669** stored in the changeset the row is updated within the target database. 9670** 9671** If a row with matching primary key values is found, but one or more of 9672** the modified non-primary key fields contains a value different from an 9673** original row value stored in the changeset, the conflict-handler function 9674** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 9675** UPDATE changes only contain values for non-primary key fields that are 9676** to be modified, only those fields need to match the original values to 9677** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 9678** 9679** If no row with matching primary key values is found in the database, 9680** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 9681** passed as the second argument. 9682** 9683** If the UPDATE operation is attempted, but SQLite returns 9684** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 9685** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 9686** This includes the case where the UPDATE operation is attempted after 9687** an earlier call to the conflict handler function returned 9688** [SQLITE_CHANGESET_REPLACE]. 9689** </dl> 9690** 9691** It is safe to execute SQL statements, including those that write to the 9692** table that the callback related to, from within the xConflict callback. 9693** This can be used to further customize the applications conflict 9694** resolution strategy. 9695** 9696** All changes made by this function are enclosed in a savepoint transaction. 9697** If any other error (aside from a constraint failure when attempting to 9698** write to the target database) occurs, then the savepoint transaction is 9699** rolled back, restoring the target database to its original state, and an 9700** SQLite error code returned. 9701*/ 9702SQLITE_API int sqlite3changeset_apply( 9703 sqlite3 *db, /* Apply change to "main" db of this handle */ 9704 int nChangeset, /* Size of changeset in bytes */ 9705 void *pChangeset, /* Changeset blob */ 9706 int(*xFilter)( 9707 void *pCtx, /* Copy of sixth arg to _apply() */ 9708 const char *zTab /* Table name */ 9709 ), 9710 int(*xConflict)( 9711 void *pCtx, /* Copy of sixth arg to _apply() */ 9712 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 9713 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 9714 ), 9715 void *pCtx /* First argument passed to xConflict */ 9716); 9717 9718/* 9719** CAPI3REF: Constants Passed To The Conflict Handler 9720** 9721** Values that may be passed as the second argument to a conflict-handler. 9722** 9723** <dl> 9724** <dt>SQLITE_CHANGESET_DATA<dd> 9725** The conflict handler is invoked with CHANGESET_DATA as the second argument 9726** when processing a DELETE or UPDATE change if a row with the required 9727** PRIMARY KEY fields is present in the database, but one or more other 9728** (non primary-key) fields modified by the update do not contain the 9729** expected "before" values. 9730** 9731** The conflicting row, in this case, is the database row with the matching 9732** primary key. 9733** 9734** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 9735** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 9736** argument when processing a DELETE or UPDATE change if a row with the 9737** required PRIMARY KEY fields is not present in the database. 9738** 9739** There is no conflicting row in this case. The results of invoking the 9740** sqlite3changeset_conflict() API are undefined. 9741** 9742** <dt>SQLITE_CHANGESET_CONFLICT<dd> 9743** CHANGESET_CONFLICT is passed as the second argument to the conflict 9744** handler while processing an INSERT change if the operation would result 9745** in duplicate primary key values. 9746** 9747** The conflicting row in this case is the database row with the matching 9748** primary key. 9749** 9750** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 9751** If foreign key handling is enabled, and applying a changeset leaves the 9752** database in a state containing foreign key violations, the conflict 9753** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 9754** exactly once before the changeset is committed. If the conflict handler 9755** returns CHANGESET_OMIT, the changes, including those that caused the 9756** foreign key constraint violation, are committed. Or, if it returns 9757** CHANGESET_ABORT, the changeset is rolled back. 9758** 9759** No current or conflicting row information is provided. The only function 9760** it is possible to call on the supplied sqlite3_changeset_iter handle 9761** is sqlite3changeset_fk_conflicts(). 9762** 9763** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 9764** If any other constraint violation occurs while applying a change (i.e. 9765** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 9766** invoked with CHANGESET_CONSTRAINT as the second argument. 9767** 9768** There is no conflicting row in this case. The results of invoking the 9769** sqlite3changeset_conflict() API are undefined. 9770** 9771** </dl> 9772*/ 9773#define SQLITE_CHANGESET_DATA 1 9774#define SQLITE_CHANGESET_NOTFOUND 2 9775#define SQLITE_CHANGESET_CONFLICT 3 9776#define SQLITE_CHANGESET_CONSTRAINT 4 9777#define SQLITE_CHANGESET_FOREIGN_KEY 5 9778 9779/* 9780** CAPI3REF: Constants Returned By The Conflict Handler 9781** 9782** A conflict handler callback must return one of the following three values. 9783** 9784** <dl> 9785** <dt>SQLITE_CHANGESET_OMIT<dd> 9786** If a conflict handler returns this value no special action is taken. The 9787** change that caused the conflict is not applied. The session module 9788** continues to the next change in the changeset. 9789** 9790** <dt>SQLITE_CHANGESET_REPLACE<dd> 9791** This value may only be returned if the second argument to the conflict 9792** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 9793** is not the case, any changes applied so far are rolled back and the 9794** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 9795** 9796** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 9797** handler, then the conflicting row is either updated or deleted, depending 9798** on the type of change. 9799** 9800** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 9801** handler, then the conflicting row is removed from the database and a 9802** second attempt to apply the change is made. If this second attempt fails, 9803** the original row is restored to the database before continuing. 9804** 9805** <dt>SQLITE_CHANGESET_ABORT<dd> 9806** If this value is returned, any changes applied so far are rolled back 9807** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 9808** </dl> 9809*/ 9810#define SQLITE_CHANGESET_OMIT 0 9811#define SQLITE_CHANGESET_REPLACE 1 9812#define SQLITE_CHANGESET_ABORT 2 9813 9814/* 9815** CAPI3REF: Streaming Versions of API functions. 9816** 9817** The six streaming API xxx_strm() functions serve similar purposes to the 9818** corresponding non-streaming API functions: 9819** 9820** <table border=1 style="margin-left:8ex;margin-right:8ex"> 9821** <tr><th>Streaming function<th>Non-streaming equivalent</th> 9822** <tr><td>sqlite3changeset_apply_str<td>[sqlite3changeset_apply] 9823** <tr><td>sqlite3changeset_concat_str<td>[sqlite3changeset_concat] 9824** <tr><td>sqlite3changeset_invert_str<td>[sqlite3changeset_invert] 9825** <tr><td>sqlite3changeset_start_str<td>[sqlite3changeset_start] 9826** <tr><td>sqlite3session_changeset_str<td>[sqlite3session_changeset] 9827** <tr><td>sqlite3session_patchset_str<td>[sqlite3session_patchset] 9828** </table> 9829** 9830** Non-streaming functions that accept changesets (or patchsets) as input 9831** require that the entire changeset be stored in a single buffer in memory. 9832** Similarly, those that return a changeset or patchset do so by returning 9833** a pointer to a single large buffer allocated using sqlite3_malloc(). 9834** Normally this is convenient. However, if an application running in a 9835** low-memory environment is required to handle very large changesets, the 9836** large contiguous memory allocations required can become onerous. 9837** 9838** In order to avoid this problem, instead of a single large buffer, input 9839** is passed to a streaming API functions by way of a callback function that 9840** the sessions module invokes to incrementally request input data as it is 9841** required. In all cases, a pair of API function parameters such as 9842** 9843** <pre> 9844** int nChangeset, 9845** void *pChangeset, 9846** </pre> 9847** 9848** Is replaced by: 9849** 9850** <pre> 9851** int (*xInput)(void *pIn, void *pData, int *pnData), 9852** void *pIn, 9853** </pre> 9854** 9855** Each time the xInput callback is invoked by the sessions module, the first 9856** argument passed is a copy of the supplied pIn context pointer. The second 9857** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 9858** error occurs the xInput method should copy up to (*pnData) bytes of data 9859** into the buffer and set (*pnData) to the actual number of bytes copied 9860** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 9861** should be set to zero to indicate this. Or, if an error occurs, an SQLite 9862** error code should be returned. In all cases, if an xInput callback returns 9863** an error, all processing is abandoned and the streaming API function 9864** returns a copy of the error code to the caller. 9865** 9866** In the case of sqlite3changeset_start_strm(), the xInput callback may be 9867** invoked by the sessions module at any point during the lifetime of the 9868** iterator. If such an xInput callback returns an error, the iterator enters 9869** an error state, whereby all subsequent calls to iterator functions 9870** immediately fail with the same error code as returned by xInput. 9871** 9872** Similarly, streaming API functions that return changesets (or patchsets) 9873** return them in chunks by way of a callback function instead of via a 9874** pointer to a single large buffer. In this case, a pair of parameters such 9875** as: 9876** 9877** <pre> 9878** int *pnChangeset, 9879** void **ppChangeset, 9880** </pre> 9881** 9882** Is replaced by: 9883** 9884** <pre> 9885** int (*xOutput)(void *pOut, const void *pData, int nData), 9886** void *pOut 9887** </pre> 9888** 9889** The xOutput callback is invoked zero or more times to return data to 9890** the application. The first parameter passed to each call is a copy of the 9891** pOut pointer supplied by the application. The second parameter, pData, 9892** points to a buffer nData bytes in size containing the chunk of output 9893** data being returned. If the xOutput callback successfully processes the 9894** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 9895** it should return some other SQLite error code. In this case processing 9896** is immediately abandoned and the streaming API function returns a copy 9897** of the xOutput error code to the application. 9898** 9899** The sessions module never invokes an xOutput callback with the third 9900** parameter set to a value less than or equal to zero. Other than this, 9901** no guarantees are made as to the size of the chunks of data returned. 9902*/ 9903SQLITE_API int sqlite3changeset_apply_strm( 9904 sqlite3 *db, /* Apply change to "main" db of this handle */ 9905 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 9906 void *pIn, /* First arg for xInput */ 9907 int(*xFilter)( 9908 void *pCtx, /* Copy of sixth arg to _apply() */ 9909 const char *zTab /* Table name */ 9910 ), 9911 int(*xConflict)( 9912 void *pCtx, /* Copy of sixth arg to _apply() */ 9913 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 9914 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 9915 ), 9916 void *pCtx /* First argument passed to xConflict */ 9917); 9918SQLITE_API int sqlite3changeset_concat_strm( 9919 int (*xInputA)(void *pIn, void *pData, int *pnData), 9920 void *pInA, 9921 int (*xInputB)(void *pIn, void *pData, int *pnData), 9922 void *pInB, 9923 int (*xOutput)(void *pOut, const void *pData, int nData), 9924 void *pOut 9925); 9926SQLITE_API int sqlite3changeset_invert_strm( 9927 int (*xInput)(void *pIn, void *pData, int *pnData), 9928 void *pIn, 9929 int (*xOutput)(void *pOut, const void *pData, int nData), 9930 void *pOut 9931); 9932SQLITE_API int sqlite3changeset_start_strm( 9933 sqlite3_changeset_iter **pp, 9934 int (*xInput)(void *pIn, void *pData, int *pnData), 9935 void *pIn 9936); 9937SQLITE_API int sqlite3session_changeset_strm( 9938 sqlite3_session *pSession, 9939 int (*xOutput)(void *pOut, const void *pData, int nData), 9940 void *pOut 9941); 9942SQLITE_API int sqlite3session_patchset_strm( 9943 sqlite3_session *pSession, 9944 int (*xOutput)(void *pOut, const void *pData, int nData), 9945 void *pOut 9946); 9947SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 9948 int (*xInput)(void *pIn, void *pData, int *pnData), 9949 void *pIn 9950); 9951SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 9952 int (*xOutput)(void *pOut, const void *pData, int nData), 9953 void *pOut 9954); 9955 9956 9957/* 9958** Make sure we can call this stuff from C++. 9959*/ 9960#ifdef __cplusplus 9961} 9962#endif 9963 9964#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 9965 9966/******** End of sqlite3session.h *********/ 9967/******** Begin file fts5.h *********/ 9968/* 9969** 2014 May 31 9970** 9971** The author disclaims copyright to this source code. In place of 9972** a legal notice, here is a blessing: 9973** 9974** May you do good and not evil. 9975** May you find forgiveness for yourself and forgive others. 9976** May you share freely, never taking more than you give. 9977** 9978****************************************************************************** 9979** 9980** Interfaces to extend FTS5. Using the interfaces defined in this file, 9981** FTS5 may be extended with: 9982** 9983** * custom tokenizers, and 9984** * custom auxiliary functions. 9985*/ 9986 9987 9988#ifndef _FTS5_H 9989#define _FTS5_H 9990 9991 9992#ifdef __cplusplus 9993extern "C" { 9994#endif 9995 9996/************************************************************************* 9997** CUSTOM AUXILIARY FUNCTIONS 9998** 9999** Virtual table implementations may overload SQL functions by implementing 10000** the sqlite3_module.xFindFunction() method. 10001*/ 10002 10003typedef struct Fts5ExtensionApi Fts5ExtensionApi; 10004typedef struct Fts5Context Fts5Context; 10005typedef struct Fts5PhraseIter Fts5PhraseIter; 10006 10007typedef void (*fts5_extension_function)( 10008 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 10009 Fts5Context *pFts, /* First arg to pass to pApi functions */ 10010 sqlite3_context *pCtx, /* Context for returning result/error */ 10011 int nVal, /* Number of values in apVal[] array */ 10012 sqlite3_value **apVal /* Array of trailing arguments */ 10013); 10014 10015struct Fts5PhraseIter { 10016 const unsigned char *a; 10017 const unsigned char *b; 10018}; 10019 10020/* 10021** EXTENSION API FUNCTIONS 10022** 10023** xUserData(pFts): 10024** Return a copy of the context pointer the extension function was 10025** registered with. 10026** 10027** xColumnTotalSize(pFts, iCol, pnToken): 10028** If parameter iCol is less than zero, set output variable *pnToken 10029** to the total number of tokens in the FTS5 table. Or, if iCol is 10030** non-negative but less than the number of columns in the table, return 10031** the total number of tokens in column iCol, considering all rows in 10032** the FTS5 table. 10033** 10034** If parameter iCol is greater than or equal to the number of columns 10035** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 10036** an OOM condition or IO error), an appropriate SQLite error code is 10037** returned. 10038** 10039** xColumnCount(pFts): 10040** Return the number of columns in the table. 10041** 10042** xColumnSize(pFts, iCol, pnToken): 10043** If parameter iCol is less than zero, set output variable *pnToken 10044** to the total number of tokens in the current row. Or, if iCol is 10045** non-negative but less than the number of columns in the table, set 10046** *pnToken to the number of tokens in column iCol of the current row. 10047** 10048** If parameter iCol is greater than or equal to the number of columns 10049** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 10050** an OOM condition or IO error), an appropriate SQLite error code is 10051** returned. 10052** 10053** This function may be quite inefficient if used with an FTS5 table 10054** created with the "columnsize=0" option. 10055** 10056** xColumnText: 10057** This function attempts to retrieve the text of column iCol of the 10058** current document. If successful, (*pz) is set to point to a buffer 10059** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 10060** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 10061** if an error occurs, an SQLite error code is returned and the final values 10062** of (*pz) and (*pn) are undefined. 10063** 10064** xPhraseCount: 10065** Returns the number of phrases in the current query expression. 10066** 10067** xPhraseSize: 10068** Returns the number of tokens in phrase iPhrase of the query. Phrases 10069** are numbered starting from zero. 10070** 10071** xInstCount: 10072** Set *pnInst to the total number of occurrences of all phrases within 10073** the query within the current row. Return SQLITE_OK if successful, or 10074** an error code (i.e. SQLITE_NOMEM) if an error occurs. 10075** 10076** This API can be quite slow if used with an FTS5 table created with the 10077** "detail=none" or "detail=column" option. If the FTS5 table is created 10078** with either "detail=none" or "detail=column" and "content=" option 10079** (i.e. if it is a contentless table), then this API always returns 0. 10080** 10081** xInst: 10082** Query for the details of phrase match iIdx within the current row. 10083** Phrase matches are numbered starting from zero, so the iIdx argument 10084** should be greater than or equal to zero and smaller than the value 10085** output by xInstCount(). 10086** 10087** Usually, output parameter *piPhrase is set to the phrase number, *piCol 10088** to the column in which it occurs and *piOff the token offset of the 10089** first token of the phrase. The exception is if the table was created 10090** with the offsets=0 option specified. In this case *piOff is always 10091** set to -1. 10092** 10093** Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM) 10094** if an error occurs. 10095** 10096** This API can be quite slow if used with an FTS5 table created with the 10097** "detail=none" or "detail=column" option. 10098** 10099** xRowid: 10100** Returns the rowid of the current row. 10101** 10102** xTokenize: 10103** Tokenize text using the tokenizer belonging to the FTS5 table. 10104** 10105** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 10106** This API function is used to query the FTS table for phrase iPhrase 10107** of the current query. Specifically, a query equivalent to: 10108** 10109** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 10110** 10111** with $p set to a phrase equivalent to the phrase iPhrase of the 10112** current query is executed. Any column filter that applies to 10113** phrase iPhrase of the current query is included in $p. For each 10114** row visited, the callback function passed as the fourth argument 10115** is invoked. The context and API objects passed to the callback 10116** function may be used to access the properties of each matched row. 10117** Invoking Api.xUserData() returns a copy of the pointer passed as 10118** the third argument to pUserData. 10119** 10120** If the callback function returns any value other than SQLITE_OK, the 10121** query is abandoned and the xQueryPhrase function returns immediately. 10122** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 10123** Otherwise, the error code is propagated upwards. 10124** 10125** If the query runs to completion without incident, SQLITE_OK is returned. 10126** Or, if some error occurs before the query completes or is aborted by 10127** the callback, an SQLite error code is returned. 10128** 10129** 10130** xSetAuxdata(pFts5, pAux, xDelete) 10131** 10132** Save the pointer passed as the second argument as the extension functions 10133** "auxiliary data". The pointer may then be retrieved by the current or any 10134** future invocation of the same fts5 extension function made as part of 10135** of the same MATCH query using the xGetAuxdata() API. 10136** 10137** Each extension function is allocated a single auxiliary data slot for 10138** each FTS query (MATCH expression). If the extension function is invoked 10139** more than once for a single FTS query, then all invocations share a 10140** single auxiliary data context. 10141** 10142** If there is already an auxiliary data pointer when this function is 10143** invoked, then it is replaced by the new pointer. If an xDelete callback 10144** was specified along with the original pointer, it is invoked at this 10145** point. 10146** 10147** The xDelete callback, if one is specified, is also invoked on the 10148** auxiliary data pointer after the FTS5 query has finished. 10149** 10150** If an error (e.g. an OOM condition) occurs within this function, an 10151** the auxiliary data is set to NULL and an error code returned. If the 10152** xDelete parameter was not NULL, it is invoked on the auxiliary data 10153** pointer before returning. 10154** 10155** 10156** xGetAuxdata(pFts5, bClear) 10157** 10158** Returns the current auxiliary data pointer for the fts5 extension 10159** function. See the xSetAuxdata() method for details. 10160** 10161** If the bClear argument is non-zero, then the auxiliary data is cleared 10162** (set to NULL) before this function returns. In this case the xDelete, 10163** if any, is not invoked. 10164** 10165** 10166** xRowCount(pFts5, pnRow) 10167** 10168** This function is used to retrieve the total number of rows in the table. 10169** In other words, the same value that would be returned by: 10170** 10171** SELECT count(*) FROM ftstable; 10172** 10173** xPhraseFirst() 10174** This function is used, along with type Fts5PhraseIter and the xPhraseNext 10175** method, to iterate through all instances of a single query phrase within 10176** the current row. This is the same information as is accessible via the 10177** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 10178** to use, this API may be faster under some circumstances. To iterate 10179** through instances of phrase iPhrase, use the following code: 10180** 10181** Fts5PhraseIter iter; 10182** int iCol, iOff; 10183** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 10184** iCol>=0; 10185** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 10186** ){ 10187** // An instance of phrase iPhrase at offset iOff of column iCol 10188** } 10189** 10190** The Fts5PhraseIter structure is defined above. Applications should not 10191** modify this structure directly - it should only be used as shown above 10192** with the xPhraseFirst() and xPhraseNext() API methods (and by 10193** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 10194** 10195** This API can be quite slow if used with an FTS5 table created with the 10196** "detail=none" or "detail=column" option. If the FTS5 table is created 10197** with either "detail=none" or "detail=column" and "content=" option 10198** (i.e. if it is a contentless table), then this API always iterates 10199** through an empty set (all calls to xPhraseFirst() set iCol to -1). 10200** 10201** xPhraseNext() 10202** See xPhraseFirst above. 10203** 10204** xPhraseFirstColumn() 10205** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 10206** and xPhraseNext() APIs described above. The difference is that instead 10207** of iterating through all instances of a phrase in the current row, these 10208** APIs are used to iterate through the set of columns in the current row 10209** that contain one or more instances of a specified phrase. For example: 10210** 10211** Fts5PhraseIter iter; 10212** int iCol; 10213** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 10214** iCol>=0; 10215** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 10216** ){ 10217** // Column iCol contains at least one instance of phrase iPhrase 10218** } 10219** 10220** This API can be quite slow if used with an FTS5 table created with the 10221** "detail=none" option. If the FTS5 table is created with either 10222** "detail=none" "content=" option (i.e. if it is a contentless table), 10223** then this API always iterates through an empty set (all calls to 10224** xPhraseFirstColumn() set iCol to -1). 10225** 10226** The information accessed using this API and its companion 10227** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 10228** (or xInst/xInstCount). The chief advantage of this API is that it is 10229** significantly more efficient than those alternatives when used with 10230** "detail=column" tables. 10231** 10232** xPhraseNextColumn() 10233** See xPhraseFirstColumn above. 10234*/ 10235struct Fts5ExtensionApi { 10236 int iVersion; /* Currently always set to 3 */ 10237 10238 void *(*xUserData)(Fts5Context*); 10239 10240 int (*xColumnCount)(Fts5Context*); 10241 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 10242 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 10243 10244 int (*xTokenize)(Fts5Context*, 10245 const char *pText, int nText, /* Text to tokenize */ 10246 void *pCtx, /* Context passed to xToken() */ 10247 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 10248 ); 10249 10250 int (*xPhraseCount)(Fts5Context*); 10251 int (*xPhraseSize)(Fts5Context*, int iPhrase); 10252 10253 int (*xInstCount)(Fts5Context*, int *pnInst); 10254 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 10255 10256 sqlite3_int64 (*xRowid)(Fts5Context*); 10257 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 10258 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 10259 10260 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 10261 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 10262 ); 10263 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 10264 void *(*xGetAuxdata)(Fts5Context*, int bClear); 10265 10266 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 10267 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 10268 10269 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 10270 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 10271}; 10272 10273/* 10274** CUSTOM AUXILIARY FUNCTIONS 10275*************************************************************************/ 10276 10277/************************************************************************* 10278** CUSTOM TOKENIZERS 10279** 10280** Applications may also register custom tokenizer types. A tokenizer 10281** is registered by providing fts5 with a populated instance of the 10282** following structure. All structure methods must be defined, setting 10283** any member of the fts5_tokenizer struct to NULL leads to undefined 10284** behaviour. The structure methods are expected to function as follows: 10285** 10286** xCreate: 10287** This function is used to allocate and initialize a tokenizer instance. 10288** A tokenizer instance is required to actually tokenize text. 10289** 10290** The first argument passed to this function is a copy of the (void*) 10291** pointer provided by the application when the fts5_tokenizer object 10292** was registered with FTS5 (the third argument to xCreateTokenizer()). 10293** The second and third arguments are an array of nul-terminated strings 10294** containing the tokenizer arguments, if any, specified following the 10295** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 10296** to create the FTS5 table. 10297** 10298** The final argument is an output variable. If successful, (*ppOut) 10299** should be set to point to the new tokenizer handle and SQLITE_OK 10300** returned. If an error occurs, some value other than SQLITE_OK should 10301** be returned. In this case, fts5 assumes that the final value of *ppOut 10302** is undefined. 10303** 10304** xDelete: 10305** This function is invoked to delete a tokenizer handle previously 10306** allocated using xCreate(). Fts5 guarantees that this function will 10307** be invoked exactly once for each successful call to xCreate(). 10308** 10309** xTokenize: 10310** This function is expected to tokenize the nText byte string indicated 10311** by argument pText. pText may or may not be nul-terminated. The first 10312** argument passed to this function is a pointer to an Fts5Tokenizer object 10313** returned by an earlier call to xCreate(). 10314** 10315** The second argument indicates the reason that FTS5 is requesting 10316** tokenization of the supplied text. This is always one of the following 10317** four values: 10318** 10319** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 10320** or removed from the FTS table. The tokenizer is being invoked to 10321** determine the set of tokens to add to (or delete from) the 10322** FTS index. 10323** 10324** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 10325** against the FTS index. The tokenizer is being called to tokenize 10326** a bareword or quoted string specified as part of the query. 10327** 10328** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 10329** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 10330** followed by a "*" character, indicating that the last token 10331** returned by the tokenizer will be treated as a token prefix. 10332** 10333** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 10334** satisfy an fts5_api.xTokenize() request made by an auxiliary 10335** function. Or an fts5_api.xColumnSize() request made by the same 10336** on a columnsize=0 database. 10337** </ul> 10338** 10339** For each token in the input string, the supplied callback xToken() must 10340** be invoked. The first argument to it should be a copy of the pointer 10341** passed as the second argument to xTokenize(). The third and fourth 10342** arguments are a pointer to a buffer containing the token text, and the 10343** size of the token in bytes. The 4th and 5th arguments are the byte offsets 10344** of the first byte of and first byte immediately following the text from 10345** which the token is derived within the input. 10346** 10347** The second argument passed to the xToken() callback ("tflags") should 10348** normally be set to 0. The exception is if the tokenizer supports 10349** synonyms. In this case see the discussion below for details. 10350** 10351** FTS5 assumes the xToken() callback is invoked for each token in the 10352** order that they occur within the input text. 10353** 10354** If an xToken() callback returns any value other than SQLITE_OK, then 10355** the tokenization should be abandoned and the xTokenize() method should 10356** immediately return a copy of the xToken() return value. Or, if the 10357** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 10358** if an error occurs with the xTokenize() implementation itself, it 10359** may abandon the tokenization and return any error code other than 10360** SQLITE_OK or SQLITE_DONE. 10361** 10362** SYNONYM SUPPORT 10363** 10364** Custom tokenizers may also support synonyms. Consider a case in which a 10365** user wishes to query for a phrase such as "first place". Using the 10366** built-in tokenizers, the FTS5 query 'first + place' will match instances 10367** of "first place" within the document set, but not alternative forms 10368** such as "1st place". In some applications, it would be better to match 10369** all instances of "first place" or "1st place" regardless of which form 10370** the user specified in the MATCH query text. 10371** 10372** There are several ways to approach this in FTS5: 10373** 10374** <ol><li> By mapping all synonyms to a single token. In this case, the 10375** In the above example, this means that the tokenizer returns the 10376** same token for inputs "first" and "1st". Say that token is in 10377** fact "first", so that when the user inserts the document "I won 10378** 1st place" entries are added to the index for tokens "i", "won", 10379** "first" and "place". If the user then queries for '1st + place', 10380** the tokenizer substitutes "first" for "1st" and the query works 10381** as expected. 10382** 10383** <li> By adding multiple synonyms for a single term to the FTS index. 10384** In this case, when tokenizing query text, the tokenizer may 10385** provide multiple synonyms for a single term within the document. 10386** FTS5 then queries the index for each synonym individually. For 10387** example, faced with the query: 10388** 10389** <codeblock> 10390** ... MATCH 'first place'</codeblock> 10391** 10392** the tokenizer offers both "1st" and "first" as synonyms for the 10393** first token in the MATCH query and FTS5 effectively runs a query 10394** similar to: 10395** 10396** <codeblock> 10397** ... MATCH '(first OR 1st) place'</codeblock> 10398** 10399** except that, for the purposes of auxiliary functions, the query 10400** still appears to contain just two phrases - "(first OR 1st)" 10401** being treated as a single phrase. 10402** 10403** <li> By adding multiple synonyms for a single term to the FTS index. 10404** Using this method, when tokenizing document text, the tokenizer 10405** provides multiple synonyms for each token. So that when a 10406** document such as "I won first place" is tokenized, entries are 10407** added to the FTS index for "i", "won", "first", "1st" and 10408** "place". 10409** 10410** This way, even if the tokenizer does not provide synonyms 10411** when tokenizing query text (it should not - to do would be 10412** inefficient), it doesn't matter if the user queries for 10413** 'first + place' or '1st + place', as there are entires in the 10414** FTS index corresponding to both forms of the first token. 10415** </ol> 10416** 10417** Whether it is parsing document or query text, any call to xToken that 10418** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 10419** is considered to supply a synonym for the previous token. For example, 10420** when parsing the document "I won first place", a tokenizer that supports 10421** synonyms would call xToken() 5 times, as follows: 10422** 10423** <codeblock> 10424** xToken(pCtx, 0, "i", 1, 0, 1); 10425** xToken(pCtx, 0, "won", 3, 2, 5); 10426** xToken(pCtx, 0, "first", 5, 6, 11); 10427** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 10428** xToken(pCtx, 0, "place", 5, 12, 17); 10429**</codeblock> 10430** 10431** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 10432** xToken() is called. Multiple synonyms may be specified for a single token 10433** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 10434** There is no limit to the number of synonyms that may be provided for a 10435** single token. 10436** 10437** In many cases, method (1) above is the best approach. It does not add 10438** extra data to the FTS index or require FTS5 to query for multiple terms, 10439** so it is efficient in terms of disk space and query speed. However, it 10440** does not support prefix queries very well. If, as suggested above, the 10441** token "first" is subsituted for "1st" by the tokenizer, then the query: 10442** 10443** <codeblock> 10444** ... MATCH '1s*'</codeblock> 10445** 10446** will not match documents that contain the token "1st" (as the tokenizer 10447** will probably not map "1s" to any prefix of "first"). 10448** 10449** For full prefix support, method (3) may be preferred. In this case, 10450** because the index contains entries for both "first" and "1st", prefix 10451** queries such as 'fi*' or '1s*' will match correctly. However, because 10452** extra entries are added to the FTS index, this method uses more space 10453** within the database. 10454** 10455** Method (2) offers a midpoint between (1) and (3). Using this method, 10456** a query such as '1s*' will match documents that contain the literal 10457** token "1st", but not "first" (assuming the tokenizer is not able to 10458** provide synonyms for prefixes). However, a non-prefix query like '1st' 10459** will match against "1st" and "first". This method does not require 10460** extra disk space, as no extra entries are added to the FTS index. 10461** On the other hand, it may require more CPU cycles to run MATCH queries, 10462** as separate queries of the FTS index are required for each synonym. 10463** 10464** When using methods (2) or (3), it is important that the tokenizer only 10465** provide synonyms when tokenizing document text (method (2)) or query 10466** text (method (3)), not both. Doing so will not cause any errors, but is 10467** inefficient. 10468*/ 10469typedef struct Fts5Tokenizer Fts5Tokenizer; 10470typedef struct fts5_tokenizer fts5_tokenizer; 10471struct fts5_tokenizer { 10472 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 10473 void (*xDelete)(Fts5Tokenizer*); 10474 int (*xTokenize)(Fts5Tokenizer*, 10475 void *pCtx, 10476 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 10477 const char *pText, int nText, 10478 int (*xToken)( 10479 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 10480 int tflags, /* Mask of FTS5_TOKEN_* flags */ 10481 const char *pToken, /* Pointer to buffer containing token */ 10482 int nToken, /* Size of token in bytes */ 10483 int iStart, /* Byte offset of token within input text */ 10484 int iEnd /* Byte offset of end of token within input text */ 10485 ) 10486 ); 10487}; 10488 10489/* Flags that may be passed as the third argument to xTokenize() */ 10490#define FTS5_TOKENIZE_QUERY 0x0001 10491#define FTS5_TOKENIZE_PREFIX 0x0002 10492#define FTS5_TOKENIZE_DOCUMENT 0x0004 10493#define FTS5_TOKENIZE_AUX 0x0008 10494 10495/* Flags that may be passed by the tokenizer implementation back to FTS5 10496** as the third argument to the supplied xToken callback. */ 10497#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 10498 10499/* 10500** END OF CUSTOM TOKENIZERS 10501*************************************************************************/ 10502 10503/************************************************************************* 10504** FTS5 EXTENSION REGISTRATION API 10505*/ 10506typedef struct fts5_api fts5_api; 10507struct fts5_api { 10508 int iVersion; /* Currently always set to 2 */ 10509 10510 /* Create a new tokenizer */ 10511 int (*xCreateTokenizer)( 10512 fts5_api *pApi, 10513 const char *zName, 10514 void *pContext, 10515 fts5_tokenizer *pTokenizer, 10516 void (*xDestroy)(void*) 10517 ); 10518 10519 /* Find an existing tokenizer */ 10520 int (*xFindTokenizer)( 10521 fts5_api *pApi, 10522 const char *zName, 10523 void **ppContext, 10524 fts5_tokenizer *pTokenizer 10525 ); 10526 10527 /* Create a new auxiliary function */ 10528 int (*xCreateFunction)( 10529 fts5_api *pApi, 10530 const char *zName, 10531 void *pContext, 10532 fts5_extension_function xFunction, 10533 void (*xDestroy)(void*) 10534 ); 10535}; 10536 10537/* 10538** END OF REGISTRATION API 10539*************************************************************************/ 10540 10541#ifdef __cplusplus 10542} /* end of the 'extern "C"' block */ 10543#endif 10544 10545#endif /* _FTS5_H */ 10546 10547/******** End of fts5.h *********/ 10548