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 "3.18.2" 125#define SQLITE_VERSION_NUMBER 3018002 126#define SQLITE_SOURCE_ID "2017-06-17 09:59:36 036ebf729e4b21035d7f4f8e35a6f705e6bf99887889e2dc14ebf2242e7930dd" 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_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 498#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 499#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 500#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 501#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 502#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 503#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 504#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 505#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 506#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 507#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 508#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 509#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 510#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 511#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 512#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 513#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 514#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 515#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 516#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 517#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 518#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 519#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 520#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 521#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 522#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 523#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 524#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 525 526/* 527** CAPI3REF: Flags For File Open Operations 528** 529** These bit values are intended for use in the 530** 3rd parameter to the [sqlite3_open_v2()] interface and 531** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 532*/ 533#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 534#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 535#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 536#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 537#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 538#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 539#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 540#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 541#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 542#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 543#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 544#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 545#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 546#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 547#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 548#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 549#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 550#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 551#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 552#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 553 554/* Reserved: 0x00F00000 */ 555 556/* 557** CAPI3REF: Device Characteristics 558** 559** The xDeviceCharacteristics method of the [sqlite3_io_methods] 560** object returns an integer which is a vector of these 561** bit values expressing I/O characteristics of the mass storage 562** device that holds the file that the [sqlite3_io_methods] 563** refers to. 564** 565** The SQLITE_IOCAP_ATOMIC property means that all writes of 566** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 567** mean that writes of blocks that are nnn bytes in size and 568** are aligned to an address which is an integer multiple of 569** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 570** that when data is appended to a file, the data is appended 571** first then the size of the file is extended, never the other 572** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 573** information is written to disk in the same order as calls 574** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 575** after reboot following a crash or power loss, the only bytes in a 576** file that were written at the application level might have changed 577** and that adjacent bytes, even bytes within the same sector are 578** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 579** flag indicates that a file cannot be deleted when open. The 580** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 581** read-only media and cannot be changed even by processes with 582** elevated privileges. 583*/ 584#define SQLITE_IOCAP_ATOMIC 0x00000001 585#define SQLITE_IOCAP_ATOMIC512 0x00000002 586#define SQLITE_IOCAP_ATOMIC1K 0x00000004 587#define SQLITE_IOCAP_ATOMIC2K 0x00000008 588#define SQLITE_IOCAP_ATOMIC4K 0x00000010 589#define SQLITE_IOCAP_ATOMIC8K 0x00000020 590#define SQLITE_IOCAP_ATOMIC16K 0x00000040 591#define SQLITE_IOCAP_ATOMIC32K 0x00000080 592#define SQLITE_IOCAP_ATOMIC64K 0x00000100 593#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 594#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 595#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 596#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 597#define SQLITE_IOCAP_IMMUTABLE 0x00002000 598 599/* 600** CAPI3REF: File Locking Levels 601** 602** SQLite uses one of these integer values as the second 603** argument to calls it makes to the xLock() and xUnlock() methods 604** of an [sqlite3_io_methods] object. 605*/ 606#define SQLITE_LOCK_NONE 0 607#define SQLITE_LOCK_SHARED 1 608#define SQLITE_LOCK_RESERVED 2 609#define SQLITE_LOCK_PENDING 3 610#define SQLITE_LOCK_EXCLUSIVE 4 611 612/* 613** CAPI3REF: Synchronization Type Flags 614** 615** When SQLite invokes the xSync() method of an 616** [sqlite3_io_methods] object it uses a combination of 617** these integer values as the second argument. 618** 619** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 620** sync operation only needs to flush data to mass storage. Inode 621** information need not be flushed. If the lower four bits of the flag 622** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 623** If the lower four bits equal SQLITE_SYNC_FULL, that means 624** to use Mac OS X style fullsync instead of fsync(). 625** 626** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 627** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 628** settings. The [synchronous pragma] determines when calls to the 629** xSync VFS method occur and applies uniformly across all platforms. 630** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 631** energetic or rigorous or forceful the sync operations are and 632** only make a difference on Mac OSX for the default SQLite code. 633** (Third-party VFS implementations might also make the distinction 634** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 635** operating systems natively supported by SQLite, only Mac OSX 636** cares about the difference.) 637*/ 638#define SQLITE_SYNC_NORMAL 0x00002 639#define SQLITE_SYNC_FULL 0x00003 640#define SQLITE_SYNC_DATAONLY 0x00010 641 642/* 643** CAPI3REF: OS Interface Open File Handle 644** 645** An [sqlite3_file] object represents an open file in the 646** [sqlite3_vfs | OS interface layer]. Individual OS interface 647** implementations will 648** want to subclass this object by appending additional fields 649** for their own use. The pMethods entry is a pointer to an 650** [sqlite3_io_methods] object that defines methods for performing 651** I/O operations on the open file. 652*/ 653typedef struct sqlite3_file sqlite3_file; 654struct sqlite3_file { 655 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 656}; 657 658/* 659** CAPI3REF: OS Interface File Virtual Methods Object 660** 661** Every file opened by the [sqlite3_vfs.xOpen] method populates an 662** [sqlite3_file] object (or, more commonly, a subclass of the 663** [sqlite3_file] object) with a pointer to an instance of this object. 664** This object defines the methods used to perform various operations 665** against the open file represented by the [sqlite3_file] object. 666** 667** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 668** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 669** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 670** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 671** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 672** to NULL. 673** 674** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 675** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 676** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 677** flag may be ORed in to indicate that only the data of the file 678** and not its inode needs to be synced. 679** 680** The integer values to xLock() and xUnlock() are one of 681** <ul> 682** <li> [SQLITE_LOCK_NONE], 683** <li> [SQLITE_LOCK_SHARED], 684** <li> [SQLITE_LOCK_RESERVED], 685** <li> [SQLITE_LOCK_PENDING], or 686** <li> [SQLITE_LOCK_EXCLUSIVE]. 687** </ul> 688** xLock() increases the lock. xUnlock() decreases the lock. 689** The xCheckReservedLock() method checks whether any database connection, 690** either in this process or in some other process, is holding a RESERVED, 691** PENDING, or EXCLUSIVE lock on the file. It returns true 692** if such a lock exists and false otherwise. 693** 694** The xFileControl() method is a generic interface that allows custom 695** VFS implementations to directly control an open file using the 696** [sqlite3_file_control()] interface. The second "op" argument is an 697** integer opcode. The third argument is a generic pointer intended to 698** point to a structure that may contain arguments or space in which to 699** write return values. Potential uses for xFileControl() might be 700** functions to enable blocking locks with timeouts, to change the 701** locking strategy (for example to use dot-file locks), to inquire 702** about the status of a lock, or to break stale locks. The SQLite 703** core reserves all opcodes less than 100 for its own use. 704** A [file control opcodes | list of opcodes] less than 100 is available. 705** Applications that define a custom xFileControl method should use opcodes 706** greater than 100 to avoid conflicts. VFS implementations should 707** return [SQLITE_NOTFOUND] for file control opcodes that they do not 708** recognize. 709** 710** The xSectorSize() method returns the sector size of the 711** device that underlies the file. The sector size is the 712** minimum write that can be performed without disturbing 713** other bytes in the file. The xDeviceCharacteristics() 714** method returns a bit vector describing behaviors of the 715** underlying device: 716** 717** <ul> 718** <li> [SQLITE_IOCAP_ATOMIC] 719** <li> [SQLITE_IOCAP_ATOMIC512] 720** <li> [SQLITE_IOCAP_ATOMIC1K] 721** <li> [SQLITE_IOCAP_ATOMIC2K] 722** <li> [SQLITE_IOCAP_ATOMIC4K] 723** <li> [SQLITE_IOCAP_ATOMIC8K] 724** <li> [SQLITE_IOCAP_ATOMIC16K] 725** <li> [SQLITE_IOCAP_ATOMIC32K] 726** <li> [SQLITE_IOCAP_ATOMIC64K] 727** <li> [SQLITE_IOCAP_SAFE_APPEND] 728** <li> [SQLITE_IOCAP_SEQUENTIAL] 729** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 730** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 731** <li> [SQLITE_IOCAP_IMMUTABLE] 732** </ul> 733** 734** The SQLITE_IOCAP_ATOMIC property means that all writes of 735** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 736** mean that writes of blocks that are nnn bytes in size and 737** are aligned to an address which is an integer multiple of 738** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 739** that when data is appended to a file, the data is appended 740** first then the size of the file is extended, never the other 741** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 742** information is written to disk in the same order as calls 743** to xWrite(). 744** 745** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 746** in the unread portions of the buffer with zeros. A VFS that 747** fails to zero-fill short reads might seem to work. However, 748** failure to zero-fill short reads will eventually lead to 749** database corruption. 750*/ 751typedef struct sqlite3_io_methods sqlite3_io_methods; 752struct sqlite3_io_methods { 753 int iVersion; 754 int (*xClose)(sqlite3_file*); 755 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 756 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 757 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 758 int (*xSync)(sqlite3_file*, int flags); 759 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 760 int (*xLock)(sqlite3_file*, int); 761 int (*xUnlock)(sqlite3_file*, int); 762 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 763 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 764 int (*xSectorSize)(sqlite3_file*); 765 int (*xDeviceCharacteristics)(sqlite3_file*); 766 /* Methods above are valid for version 1 */ 767 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 768 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 769 void (*xShmBarrier)(sqlite3_file*); 770 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 771 /* Methods above are valid for version 2 */ 772 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 773 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 774 /* Methods above are valid for version 3 */ 775 /* Additional methods may be added in future releases */ 776}; 777 778/* 779** CAPI3REF: Standard File Control Opcodes 780** KEYWORDS: {file control opcodes} {file control opcode} 781** 782** These integer constants are opcodes for the xFileControl method 783** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 784** interface. 785** 786** <ul> 787** <li>[[SQLITE_FCNTL_LOCKSTATE]] 788** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 789** opcode causes the xFileControl method to write the current state of 790** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 791** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 792** into an integer that the pArg argument points to. This capability 793** is used during testing and is only available when the SQLITE_TEST 794** compile-time option is used. 795** 796** <li>[[SQLITE_FCNTL_SIZE_HINT]] 797** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 798** layer a hint of how large the database file will grow to be during the 799** current transaction. This hint is not guaranteed to be accurate but it 800** is often close. The underlying VFS might choose to preallocate database 801** file space based on this hint in order to help writes to the database 802** file run faster. 803** 804** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 805** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 806** extends and truncates the database file in chunks of a size specified 807** by the user. The fourth argument to [sqlite3_file_control()] should 808** point to an integer (type int) containing the new chunk-size to use 809** for the nominated database. Allocating database file space in large 810** chunks (say 1MB at a time), may reduce file-system fragmentation and 811** improve performance on some systems. 812** 813** <li>[[SQLITE_FCNTL_FILE_POINTER]] 814** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 815** to the [sqlite3_file] object associated with a particular database 816** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 817** 818** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 819** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 820** to the [sqlite3_file] object associated with the journal file (either 821** the [rollback journal] or the [write-ahead log]) for a particular database 822** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 823** 824** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 825** No longer in use. 826** 827** <li>[[SQLITE_FCNTL_SYNC]] 828** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 829** sent to the VFS immediately before the xSync method is invoked on a 830** database file descriptor. Or, if the xSync method is not invoked 831** because the user has configured SQLite with 832** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 833** of the xSync method. In most cases, the pointer argument passed with 834** this file-control is NULL. However, if the database file is being synced 835** as part of a multi-database commit, the argument points to a nul-terminated 836** string containing the transactions master-journal file name. VFSes that 837** do not need this signal should silently ignore this opcode. Applications 838** should not call [sqlite3_file_control()] with this opcode as doing so may 839** disrupt the operation of the specialized VFSes that do require it. 840** 841** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 842** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 843** and sent to the VFS after a transaction has been committed immediately 844** but before the database is unlocked. VFSes that do not need this signal 845** should silently ignore this opcode. Applications should not call 846** [sqlite3_file_control()] with this opcode as doing so may disrupt the 847** operation of the specialized VFSes that do require it. 848** 849** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 850** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 851** retry counts and intervals for certain disk I/O operations for the 852** windows [VFS] in order to provide robustness in the presence of 853** anti-virus programs. By default, the windows VFS will retry file read, 854** file write, and file delete operations up to 10 times, with a delay 855** of 25 milliseconds before the first retry and with the delay increasing 856** by an additional 25 milliseconds with each subsequent retry. This 857** opcode allows these two values (10 retries and 25 milliseconds of delay) 858** to be adjusted. The values are changed for all database connections 859** within the same process. The argument is a pointer to an array of two 860** integers where the first integer i the new retry count and the second 861** integer is the delay. If either integer is negative, then the setting 862** is not changed but instead the prior value of that setting is written 863** into the array entry, allowing the current retry settings to be 864** interrogated. The zDbName parameter is ignored. 865** 866** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 867** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 868** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 869** write ahead log and shared memory files used for transaction control 870** are automatically deleted when the latest connection to the database 871** closes. Setting persistent WAL mode causes those files to persist after 872** close. Persisting the files is useful when other processes that do not 873** have write permission on the directory containing the database file want 874** to read the database file, as the WAL and shared memory files must exist 875** in order for the database to be readable. The fourth parameter to 876** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 877** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 878** WAL mode. If the integer is -1, then it is overwritten with the current 879** WAL persistence setting. 880** 881** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 882** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 883** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 884** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 885** xDeviceCharacteristics methods. 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 zero-damage mode or 1 to enable zero-damage 888** mode. If the integer is -1, then it is overwritten with the current 889** zero-damage mode setting. 890** 891** <li>[[SQLITE_FCNTL_OVERWRITE]] 892** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 893** a write transaction to indicate that, unless it is rolled back for some 894** reason, the entire database file will be overwritten by the current 895** transaction. This is used by VACUUM operations. 896** 897** <li>[[SQLITE_FCNTL_VFSNAME]] 898** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 899** all [VFSes] in the VFS stack. The names are of all VFS shims and the 900** final bottom-level VFS are written into memory obtained from 901** [sqlite3_malloc()] and the result is stored in the char* variable 902** that the fourth parameter of [sqlite3_file_control()] points to. 903** The caller is responsible for freeing the memory when done. As with 904** all file-control actions, there is no guarantee that this will actually 905** do anything. Callers should initialize the char* variable to a NULL 906** pointer in case this file-control is not implemented. This file-control 907** is intended for diagnostic use only. 908** 909** <li>[[SQLITE_FCNTL_VFS_POINTER]] 910** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 911** [VFSes] currently in use. ^(The argument X in 912** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 913** of type "[sqlite3_vfs] **". This opcodes will set *X 914** to a pointer to the top-level VFS.)^ 915** ^When there are multiple VFS shims in the stack, this opcode finds the 916** upper-most shim only. 917** 918** <li>[[SQLITE_FCNTL_PRAGMA]] 919** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 920** file control is sent to the open [sqlite3_file] object corresponding 921** to the database file to which the pragma statement refers. ^The argument 922** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 923** pointers to strings (char**) in which the second element of the array 924** is the name of the pragma and the third element is the argument to the 925** pragma or NULL if the pragma has no argument. ^The handler for an 926** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 927** of the char** argument point to a string obtained from [sqlite3_mprintf()] 928** or the equivalent and that string will become the result of the pragma or 929** the error message if the pragma fails. ^If the 930** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 931** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 932** file control returns [SQLITE_OK], then the parser assumes that the 933** VFS has handled the PRAGMA itself and the parser generates a no-op 934** prepared statement if result string is NULL, or that returns a copy 935** of the result string if the string is non-NULL. 936** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 937** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 938** that the VFS encountered an error while handling the [PRAGMA] and the 939** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 940** file control occurs at the beginning of pragma statement analysis and so 941** it is able to override built-in [PRAGMA] statements. 942** 943** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 944** ^The [SQLITE_FCNTL_BUSYHANDLER] 945** file-control may be invoked by SQLite on the database file handle 946** shortly after it is opened in order to provide a custom VFS with access 947** to the connections busy-handler callback. The argument is of type (void **) 948** - an array of two (void *) values. The first (void *) actually points 949** to a function of type (int (*)(void *)). In order to invoke the connections 950** busy-handler, this function should be invoked with the second (void *) in 951** the array as the only argument. If it returns non-zero, then the operation 952** should be retried. If it returns zero, the custom VFS should abandon the 953** current operation. 954** 955** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 956** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 957** to have SQLite generate a 958** temporary filename using the same algorithm that is followed to generate 959** temporary filenames for TEMP tables and other internal uses. The 960** argument should be a char** which will be filled with the filename 961** written into memory obtained from [sqlite3_malloc()]. The caller should 962** invoke [sqlite3_free()] on the result to avoid a memory leak. 963** 964** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 965** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 966** maximum number of bytes that will be used for memory-mapped I/O. 967** The argument is a pointer to a value of type sqlite3_int64 that 968** is an advisory maximum number of bytes in the file to memory map. The 969** pointer is overwritten with the old value. The limit is not changed if 970** the value originally pointed to is negative, and so the current limit 971** can be queried by passing in a pointer to a negative number. This 972** file-control is used internally to implement [PRAGMA mmap_size]. 973** 974** <li>[[SQLITE_FCNTL_TRACE]] 975** The [SQLITE_FCNTL_TRACE] file control provides advisory information 976** to the VFS about what the higher layers of the SQLite stack are doing. 977** This file control is used by some VFS activity tracing [shims]. 978** The argument is a zero-terminated string. Higher layers in the 979** SQLite stack may generate instances of this file control if 980** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 981** 982** <li>[[SQLITE_FCNTL_HAS_MOVED]] 983** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 984** pointer to an integer and it writes a boolean into that integer depending 985** on whether or not the file has been renamed, moved, or deleted since it 986** was first opened. 987** 988** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 989** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 990** underlying native file handle associated with a file handle. This file 991** control interprets its argument as a pointer to a native file handle and 992** writes the resulting value there. 993** 994** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 995** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 996** opcode causes the xFileControl method to swap the file handle with the one 997** pointed to by the pArg argument. This capability is used during testing 998** and only needs to be supported when SQLITE_TEST is defined. 999** 1000** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1001** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1002** be advantageous to block on the next WAL lock if the lock is not immediately 1003** available. The WAL subsystem issues this signal during rare 1004** circumstances in order to fix a problem with priority inversion. 1005** Applications should <em>not</em> use this file-control. 1006** 1007** <li>[[SQLITE_FCNTL_ZIPVFS]] 1008** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1009** VFS should return SQLITE_NOTFOUND for this opcode. 1010** 1011** <li>[[SQLITE_FCNTL_RBU]] 1012** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1013** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1014** this opcode. 1015** </ul> 1016*/ 1017#define SQLITE_FCNTL_LOCKSTATE 1 1018#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1019#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1020#define SQLITE_FCNTL_LAST_ERRNO 4 1021#define SQLITE_FCNTL_SIZE_HINT 5 1022#define SQLITE_FCNTL_CHUNK_SIZE 6 1023#define SQLITE_FCNTL_FILE_POINTER 7 1024#define SQLITE_FCNTL_SYNC_OMITTED 8 1025#define SQLITE_FCNTL_WIN32_AV_RETRY 9 1026#define SQLITE_FCNTL_PERSIST_WAL 10 1027#define SQLITE_FCNTL_OVERWRITE 11 1028#define SQLITE_FCNTL_VFSNAME 12 1029#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1030#define SQLITE_FCNTL_PRAGMA 14 1031#define SQLITE_FCNTL_BUSYHANDLER 15 1032#define SQLITE_FCNTL_TEMPFILENAME 16 1033#define SQLITE_FCNTL_MMAP_SIZE 18 1034#define SQLITE_FCNTL_TRACE 19 1035#define SQLITE_FCNTL_HAS_MOVED 20 1036#define SQLITE_FCNTL_SYNC 21 1037#define SQLITE_FCNTL_COMMIT_PHASETWO 22 1038#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1039#define SQLITE_FCNTL_WAL_BLOCK 24 1040#define SQLITE_FCNTL_ZIPVFS 25 1041#define SQLITE_FCNTL_RBU 26 1042#define SQLITE_FCNTL_VFS_POINTER 27 1043#define SQLITE_FCNTL_JOURNAL_POINTER 28 1044#define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1045#define SQLITE_FCNTL_PDB 30 1046 1047/* deprecated names */ 1048#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1049#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1050#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1051 1052 1053/* 1054** CAPI3REF: Mutex Handle 1055** 1056** The mutex module within SQLite defines [sqlite3_mutex] to be an 1057** abstract type for a mutex object. The SQLite core never looks 1058** at the internal representation of an [sqlite3_mutex]. It only 1059** deals with pointers to the [sqlite3_mutex] object. 1060** 1061** Mutexes are created using [sqlite3_mutex_alloc()]. 1062*/ 1063typedef struct sqlite3_mutex sqlite3_mutex; 1064 1065/* 1066** CAPI3REF: Loadable Extension Thunk 1067** 1068** A pointer to the opaque sqlite3_api_routines structure is passed as 1069** the third parameter to entry points of [loadable extensions]. This 1070** structure must be typedefed in order to work around compiler warnings 1071** on some platforms. 1072*/ 1073typedef struct sqlite3_api_routines sqlite3_api_routines; 1074 1075/* 1076** CAPI3REF: OS Interface Object 1077** 1078** An instance of the sqlite3_vfs object defines the interface between 1079** the SQLite core and the underlying operating system. The "vfs" 1080** in the name of the object stands for "virtual file system". See 1081** the [VFS | VFS documentation] for further information. 1082** 1083** The value of the iVersion field is initially 1 but may be larger in 1084** future versions of SQLite. Additional fields may be appended to this 1085** object when the iVersion value is increased. Note that the structure 1086** of the sqlite3_vfs object changes in the transaction between 1087** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 1088** modified. 1089** 1090** The szOsFile field is the size of the subclassed [sqlite3_file] 1091** structure used by this VFS. mxPathname is the maximum length of 1092** a pathname in this VFS. 1093** 1094** Registered sqlite3_vfs objects are kept on a linked list formed by 1095** the pNext pointer. The [sqlite3_vfs_register()] 1096** and [sqlite3_vfs_unregister()] interfaces manage this list 1097** in a thread-safe way. The [sqlite3_vfs_find()] interface 1098** searches the list. Neither the application code nor the VFS 1099** implementation should use the pNext pointer. 1100** 1101** The pNext field is the only field in the sqlite3_vfs 1102** structure that SQLite will ever modify. SQLite will only access 1103** or modify this field while holding a particular static mutex. 1104** The application should never modify anything within the sqlite3_vfs 1105** object once the object has been registered. 1106** 1107** The zName field holds the name of the VFS module. The name must 1108** be unique across all VFS modules. 1109** 1110** [[sqlite3_vfs.xOpen]] 1111** ^SQLite guarantees that the zFilename parameter to xOpen 1112** is either a NULL pointer or string obtained 1113** from xFullPathname() with an optional suffix added. 1114** ^If a suffix is added to the zFilename parameter, it will 1115** consist of a single "-" character followed by no more than 1116** 11 alphanumeric and/or "-" characters. 1117** ^SQLite further guarantees that 1118** the string will be valid and unchanged until xClose() is 1119** called. Because of the previous sentence, 1120** the [sqlite3_file] can safely store a pointer to the 1121** filename if it needs to remember the filename for some reason. 1122** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1123** must invent its own temporary name for the file. ^Whenever the 1124** xFilename parameter is NULL it will also be the case that the 1125** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1126** 1127** The flags argument to xOpen() includes all bits set in 1128** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1129** or [sqlite3_open16()] is used, then flags includes at least 1130** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1131** If xOpen() opens a file read-only then it sets *pOutFlags to 1132** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1133** 1134** ^(SQLite will also add one of the following flags to the xOpen() 1135** call, depending on the object being opened: 1136** 1137** <ul> 1138** <li> [SQLITE_OPEN_MAIN_DB] 1139** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1140** <li> [SQLITE_OPEN_TEMP_DB] 1141** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1142** <li> [SQLITE_OPEN_TRANSIENT_DB] 1143** <li> [SQLITE_OPEN_SUBJOURNAL] 1144** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1145** <li> [SQLITE_OPEN_WAL] 1146** </ul>)^ 1147** 1148** The file I/O implementation can use the object type flags to 1149** change the way it deals with files. For example, an application 1150** that does not care about crash recovery or rollback might make 1151** the open of a journal file a no-op. Writes to this journal would 1152** also be no-ops, and any attempt to read the journal would return 1153** SQLITE_IOERR. Or the implementation might recognize that a database 1154** file will be doing page-aligned sector reads and writes in a random 1155** order and set up its I/O subsystem accordingly. 1156** 1157** SQLite might also add one of the following flags to the xOpen method: 1158** 1159** <ul> 1160** <li> [SQLITE_OPEN_DELETEONCLOSE] 1161** <li> [SQLITE_OPEN_EXCLUSIVE] 1162** </ul> 1163** 1164** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1165** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1166** will be set for TEMP databases and their journals, transient 1167** databases, and subjournals. 1168** 1169** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1170** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1171** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1172** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1173** SQLITE_OPEN_CREATE, is used to indicate that file should always 1174** be created, and that it is an error if it already exists. 1175** It is <i>not</i> used to indicate the file should be opened 1176** for exclusive access. 1177** 1178** ^At least szOsFile bytes of memory are allocated by SQLite 1179** to hold the [sqlite3_file] structure passed as the third 1180** argument to xOpen. The xOpen method does not have to 1181** allocate the structure; it should just fill it in. Note that 1182** the xOpen method must set the sqlite3_file.pMethods to either 1183** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1184** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1185** element will be valid after xOpen returns regardless of the success 1186** or failure of the xOpen call. 1187** 1188** [[sqlite3_vfs.xAccess]] 1189** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1190** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1191** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1192** to test whether a file is at least readable. The file can be a 1193** directory. 1194** 1195** ^SQLite will always allocate at least mxPathname+1 bytes for the 1196** output buffer xFullPathname. The exact size of the output buffer 1197** is also passed as a parameter to both methods. If the output buffer 1198** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1199** handled as a fatal error by SQLite, vfs implementations should endeavor 1200** to prevent this by setting mxPathname to a sufficiently large value. 1201** 1202** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1203** interfaces are not strictly a part of the filesystem, but they are 1204** included in the VFS structure for completeness. 1205** The xRandomness() function attempts to return nBytes bytes 1206** of good-quality randomness into zOut. The return value is 1207** the actual number of bytes of randomness obtained. 1208** The xSleep() method causes the calling thread to sleep for at 1209** least the number of microseconds given. ^The xCurrentTime() 1210** method returns a Julian Day Number for the current date and time as 1211** a floating point value. 1212** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1213** Day Number multiplied by 86400000 (the number of milliseconds in 1214** a 24-hour day). 1215** ^SQLite will use the xCurrentTimeInt64() method to get the current 1216** date and time if that method is available (if iVersion is 2 or 1217** greater and the function pointer is not NULL) and will fall back 1218** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1219** 1220** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1221** are not used by the SQLite core. These optional interfaces are provided 1222** by some VFSes to facilitate testing of the VFS code. By overriding 1223** system calls with functions under its control, a test program can 1224** simulate faults and error conditions that would otherwise be difficult 1225** or impossible to induce. The set of system calls that can be overridden 1226** varies from one VFS to another, and from one version of the same VFS to the 1227** next. Applications that use these interfaces must be prepared for any 1228** or all of these interfaces to be NULL or for their behavior to change 1229** from one release to the next. Applications must not attempt to access 1230** any of these methods if the iVersion of the VFS is less than 3. 1231*/ 1232typedef struct sqlite3_vfs sqlite3_vfs; 1233typedef void (*sqlite3_syscall_ptr)(void); 1234struct sqlite3_vfs { 1235 int iVersion; /* Structure version number (currently 3) */ 1236 int szOsFile; /* Size of subclassed sqlite3_file */ 1237 int mxPathname; /* Maximum file pathname length */ 1238 sqlite3_vfs *pNext; /* Next registered VFS */ 1239 const char *zName; /* Name of this virtual file system */ 1240 void *pAppData; /* Pointer to application-specific data */ 1241 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1242 int flags, int *pOutFlags); 1243 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1244 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1245 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1246 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1247 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1248 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1249 void (*xDlClose)(sqlite3_vfs*, void*); 1250 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1251 int (*xSleep)(sqlite3_vfs*, int microseconds); 1252 int (*xCurrentTime)(sqlite3_vfs*, double*); 1253 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1254 /* 1255 ** The methods above are in version 1 of the sqlite_vfs object 1256 ** definition. Those that follow are added in version 2 or later 1257 */ 1258 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1259 /* 1260 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1261 ** Those below are for version 3 and greater. 1262 */ 1263 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1264 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1265 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1266 /* 1267 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1268 ** New fields may be appended in future versions. The iVersion 1269 ** value will increment whenever this happens. 1270 */ 1271}; 1272 1273/* 1274** CAPI3REF: Flags for the xAccess VFS method 1275** 1276** These integer constants can be used as the third parameter to 1277** the xAccess method of an [sqlite3_vfs] object. They determine 1278** what kind of permissions the xAccess method is looking for. 1279** With SQLITE_ACCESS_EXISTS, the xAccess method 1280** simply checks whether the file exists. 1281** With SQLITE_ACCESS_READWRITE, the xAccess method 1282** checks whether the named directory is both readable and writable 1283** (in other words, if files can be added, removed, and renamed within 1284** the directory). 1285** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1286** [temp_store_directory pragma], though this could change in a future 1287** release of SQLite. 1288** With SQLITE_ACCESS_READ, the xAccess method 1289** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1290** currently unused, though it might be used in a future release of 1291** SQLite. 1292*/ 1293#define SQLITE_ACCESS_EXISTS 0 1294#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1295#define SQLITE_ACCESS_READ 2 /* Unused */ 1296 1297/* 1298** CAPI3REF: Flags for the xShmLock VFS method 1299** 1300** These integer constants define the various locking operations 1301** allowed by the xShmLock method of [sqlite3_io_methods]. The 1302** following are the only legal combinations of flags to the 1303** xShmLock method: 1304** 1305** <ul> 1306** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1307** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1308** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1309** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1310** </ul> 1311** 1312** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1313** was given on the corresponding lock. 1314** 1315** The xShmLock method can transition between unlocked and SHARED or 1316** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1317** and EXCLUSIVE. 1318*/ 1319#define SQLITE_SHM_UNLOCK 1 1320#define SQLITE_SHM_LOCK 2 1321#define SQLITE_SHM_SHARED 4 1322#define SQLITE_SHM_EXCLUSIVE 8 1323 1324/* 1325** CAPI3REF: Maximum xShmLock index 1326** 1327** The xShmLock method on [sqlite3_io_methods] may use values 1328** between 0 and this upper bound as its "offset" argument. 1329** The SQLite core will never attempt to acquire or release a 1330** lock outside of this range 1331*/ 1332#define SQLITE_SHM_NLOCK 8 1333 1334 1335/* 1336** CAPI3REF: Initialize The SQLite Library 1337** 1338** ^The sqlite3_initialize() routine initializes the 1339** SQLite library. ^The sqlite3_shutdown() routine 1340** deallocates any resources that were allocated by sqlite3_initialize(). 1341** These routines are designed to aid in process initialization and 1342** shutdown on embedded systems. Workstation applications using 1343** SQLite normally do not need to invoke either of these routines. 1344** 1345** A call to sqlite3_initialize() is an "effective" call if it is 1346** the first time sqlite3_initialize() is invoked during the lifetime of 1347** the process, or if it is the first time sqlite3_initialize() is invoked 1348** following a call to sqlite3_shutdown(). ^(Only an effective call 1349** of sqlite3_initialize() does any initialization. All other calls 1350** are harmless no-ops.)^ 1351** 1352** A call to sqlite3_shutdown() is an "effective" call if it is the first 1353** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1354** an effective call to sqlite3_shutdown() does any deinitialization. 1355** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1356** 1357** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1358** is not. The sqlite3_shutdown() interface must only be called from a 1359** single thread. All open [database connections] must be closed and all 1360** other SQLite resources must be deallocated prior to invoking 1361** sqlite3_shutdown(). 1362** 1363** Among other things, ^sqlite3_initialize() will invoke 1364** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1365** will invoke sqlite3_os_end(). 1366** 1367** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1368** ^If for some reason, sqlite3_initialize() is unable to initialize 1369** the library (perhaps it is unable to allocate a needed resource such 1370** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1371** 1372** ^The sqlite3_initialize() routine is called internally by many other 1373** SQLite interfaces so that an application usually does not need to 1374** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1375** calls sqlite3_initialize() so the SQLite library will be automatically 1376** initialized when [sqlite3_open()] is called if it has not be initialized 1377** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1378** compile-time option, then the automatic calls to sqlite3_initialize() 1379** are omitted and the application must call sqlite3_initialize() directly 1380** prior to using any other SQLite interface. For maximum portability, 1381** it is recommended that applications always invoke sqlite3_initialize() 1382** directly prior to using any other SQLite interface. Future releases 1383** of SQLite may require this. In other words, the behavior exhibited 1384** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1385** default behavior in some future release of SQLite. 1386** 1387** The sqlite3_os_init() routine does operating-system specific 1388** initialization of the SQLite library. The sqlite3_os_end() 1389** routine undoes the effect of sqlite3_os_init(). Typical tasks 1390** performed by these routines include allocation or deallocation 1391** of static resources, initialization of global variables, 1392** setting up a default [sqlite3_vfs] module, or setting up 1393** a default configuration using [sqlite3_config()]. 1394** 1395** The application should never invoke either sqlite3_os_init() 1396** or sqlite3_os_end() directly. The application should only invoke 1397** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1398** interface is called automatically by sqlite3_initialize() and 1399** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1400** implementations for sqlite3_os_init() and sqlite3_os_end() 1401** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1402** When [custom builds | built for other platforms] 1403** (using the [SQLITE_OS_OTHER=1] compile-time 1404** option) the application must supply a suitable implementation for 1405** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1406** implementation of sqlite3_os_init() or sqlite3_os_end() 1407** must return [SQLITE_OK] on success and some other [error code] upon 1408** failure. 1409*/ 1410SQLITE_API int sqlite3_initialize(void); 1411SQLITE_API int sqlite3_shutdown(void); 1412SQLITE_API int sqlite3_os_init(void); 1413SQLITE_API int sqlite3_os_end(void); 1414 1415/* 1416** CAPI3REF: Configuring The SQLite Library 1417** 1418** The sqlite3_config() interface is used to make global configuration 1419** changes to SQLite in order to tune SQLite to the specific needs of 1420** the application. The default configuration is recommended for most 1421** applications and so this routine is usually not necessary. It is 1422** provided to support rare applications with unusual needs. 1423** 1424** <b>The sqlite3_config() interface is not threadsafe. The application 1425** must ensure that no other SQLite interfaces are invoked by other 1426** threads while sqlite3_config() is running.</b> 1427** 1428** The sqlite3_config() interface 1429** may only be invoked prior to library initialization using 1430** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1431** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1432** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1433** Note, however, that ^sqlite3_config() can be called as part of the 1434** implementation of an application-defined [sqlite3_os_init()]. 1435** 1436** The first argument to sqlite3_config() is an integer 1437** [configuration option] that determines 1438** what property of SQLite is to be configured. Subsequent arguments 1439** vary depending on the [configuration option] 1440** in the first argument. 1441** 1442** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1443** ^If the option is unknown or SQLite is unable to set the option 1444** then this routine returns a non-zero [error code]. 1445*/ 1446SQLITE_API int sqlite3_config(int, ...); 1447 1448/* 1449** CAPI3REF: Configure database connections 1450** METHOD: sqlite3 1451** 1452** The sqlite3_db_config() interface is used to make configuration 1453** changes to a [database connection]. The interface is similar to 1454** [sqlite3_config()] except that the changes apply to a single 1455** [database connection] (specified in the first argument). 1456** 1457** The second argument to sqlite3_db_config(D,V,...) is the 1458** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1459** that indicates what aspect of the [database connection] is being configured. 1460** Subsequent arguments vary depending on the configuration verb. 1461** 1462** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1463** the call is considered successful. 1464*/ 1465SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1466 1467/* 1468** CAPI3REF: Memory Allocation Routines 1469** 1470** An instance of this object defines the interface between SQLite 1471** and low-level memory allocation routines. 1472** 1473** This object is used in only one place in the SQLite interface. 1474** A pointer to an instance of this object is the argument to 1475** [sqlite3_config()] when the configuration option is 1476** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1477** By creating an instance of this object 1478** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1479** during configuration, an application can specify an alternative 1480** memory allocation subsystem for SQLite to use for all of its 1481** dynamic memory needs. 1482** 1483** Note that SQLite comes with several [built-in memory allocators] 1484** that are perfectly adequate for the overwhelming majority of applications 1485** and that this object is only useful to a tiny minority of applications 1486** with specialized memory allocation requirements. This object is 1487** also used during testing of SQLite in order to specify an alternative 1488** memory allocator that simulates memory out-of-memory conditions in 1489** order to verify that SQLite recovers gracefully from such 1490** conditions. 1491** 1492** The xMalloc, xRealloc, and xFree methods must work like the 1493** malloc(), realloc() and free() functions from the standard C library. 1494** ^SQLite guarantees that the second argument to 1495** xRealloc is always a value returned by a prior call to xRoundup. 1496** 1497** xSize should return the allocated size of a memory allocation 1498** previously obtained from xMalloc or xRealloc. The allocated size 1499** is always at least as big as the requested size but may be larger. 1500** 1501** The xRoundup method returns what would be the allocated size of 1502** a memory allocation given a particular requested size. Most memory 1503** allocators round up memory allocations at least to the next multiple 1504** of 8. Some allocators round up to a larger multiple or to a power of 2. 1505** Every memory allocation request coming in through [sqlite3_malloc()] 1506** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1507** that causes the corresponding memory allocation to fail. 1508** 1509** The xInit method initializes the memory allocator. For example, 1510** it might allocate any require mutexes or initialize internal data 1511** structures. The xShutdown method is invoked (indirectly) by 1512** [sqlite3_shutdown()] and should deallocate any resources acquired 1513** by xInit. The pAppData pointer is used as the only parameter to 1514** xInit and xShutdown. 1515** 1516** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1517** the xInit method, so the xInit method need not be threadsafe. The 1518** xShutdown method is only called from [sqlite3_shutdown()] so it does 1519** not need to be threadsafe either. For all other methods, SQLite 1520** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1521** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1522** it is by default) and so the methods are automatically serialized. 1523** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1524** methods must be threadsafe or else make their own arrangements for 1525** serialization. 1526** 1527** SQLite will never invoke xInit() more than once without an intervening 1528** call to xShutdown(). 1529*/ 1530typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1531struct sqlite3_mem_methods { 1532 void *(*xMalloc)(int); /* Memory allocation function */ 1533 void (*xFree)(void*); /* Free a prior allocation */ 1534 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1535 int (*xSize)(void*); /* Return the size of an allocation */ 1536 int (*xRoundup)(int); /* Round up request size to allocation size */ 1537 int (*xInit)(void*); /* Initialize the memory allocator */ 1538 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1539 void *pAppData; /* Argument to xInit() and xShutdown() */ 1540}; 1541 1542/* 1543** CAPI3REF: Configuration Options 1544** KEYWORDS: {configuration option} 1545** 1546** These constants are the available integer configuration options that 1547** can be passed as the first argument to the [sqlite3_config()] interface. 1548** 1549** New configuration options may be added in future releases of SQLite. 1550** Existing configuration options might be discontinued. Applications 1551** should check the return code from [sqlite3_config()] to make sure that 1552** the call worked. The [sqlite3_config()] interface will return a 1553** non-zero [error code] if a discontinued or unsupported configuration option 1554** is invoked. 1555** 1556** <dl> 1557** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1558** <dd>There are no arguments to this option. ^This option sets the 1559** [threading mode] to Single-thread. In other words, it disables 1560** all mutexing and puts SQLite into a mode where it can only be used 1561** by a single thread. ^If SQLite is compiled with 1562** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1563** it is not possible to change the [threading mode] from its default 1564** value of Single-thread and so [sqlite3_config()] will return 1565** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1566** configuration option.</dd> 1567** 1568** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1569** <dd>There are no arguments to this option. ^This option sets the 1570** [threading mode] to Multi-thread. In other words, it disables 1571** mutexing on [database connection] and [prepared statement] objects. 1572** The application is responsible for serializing access to 1573** [database connections] and [prepared statements]. But other mutexes 1574** are enabled so that SQLite will be safe to use in a multi-threaded 1575** environment as long as no two threads attempt to use the same 1576** [database connection] at the same time. ^If SQLite is compiled with 1577** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1578** it is not possible to set the Multi-thread [threading mode] and 1579** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1580** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1581** 1582** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1583** <dd>There are no arguments to this option. ^This option sets the 1584** [threading mode] to Serialized. In other words, this option enables 1585** all mutexes including the recursive 1586** mutexes on [database connection] and [prepared statement] objects. 1587** In this mode (which is the default when SQLite is compiled with 1588** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1589** to [database connections] and [prepared statements] so that the 1590** application is free to use the same [database connection] or the 1591** same [prepared statement] in different threads at the same time. 1592** ^If SQLite is compiled with 1593** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1594** it is not possible to set the Serialized [threading mode] and 1595** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1596** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1597** 1598** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1599** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1600** a pointer to an instance of the [sqlite3_mem_methods] structure. 1601** The argument specifies 1602** alternative low-level memory allocation routines to be used in place of 1603** the memory allocation routines built into SQLite.)^ ^SQLite makes 1604** its own private copy of the content of the [sqlite3_mem_methods] structure 1605** before the [sqlite3_config()] call returns.</dd> 1606** 1607** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1608** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1609** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1610** The [sqlite3_mem_methods] 1611** structure is filled with the currently defined memory allocation routines.)^ 1612** This option can be used to overload the default memory allocation 1613** routines with a wrapper that simulations memory allocation failure or 1614** tracks memory usage, for example. </dd> 1615** 1616** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1617** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1618** interpreted as a boolean, which enables or disables the collection of 1619** memory allocation statistics. ^(When memory allocation statistics are 1620** disabled, the following SQLite interfaces become non-operational: 1621** <ul> 1622** <li> [sqlite3_memory_used()] 1623** <li> [sqlite3_memory_highwater()] 1624** <li> [sqlite3_soft_heap_limit64()] 1625** <li> [sqlite3_status64()] 1626** </ul>)^ 1627** ^Memory allocation statistics are enabled by default unless SQLite is 1628** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1629** allocation statistics are disabled by default. 1630** </dd> 1631** 1632** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1633** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer 1634** that SQLite can use for scratch memory. ^(There are three arguments 1635** to SQLITE_CONFIG_SCRATCH: A pointer an 8-byte 1636** aligned memory buffer from which the scratch allocations will be 1637** drawn, the size of each scratch allocation (sz), 1638** and the maximum number of scratch allocations (N).)^ 1639** The first argument must be a pointer to an 8-byte aligned buffer 1640** of at least sz*N bytes of memory. 1641** ^SQLite will not use more than one scratch buffers per thread. 1642** ^SQLite will never request a scratch buffer that is more than 6 1643** times the database page size. 1644** ^If SQLite needs needs additional 1645** scratch memory beyond what is provided by this configuration option, then 1646** [sqlite3_malloc()] will be used to obtain the memory needed.<p> 1647** ^When the application provides any amount of scratch memory using 1648** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large 1649** [sqlite3_malloc|heap allocations]. 1650** This can help [Robson proof|prevent memory allocation failures] due to heap 1651** fragmentation in low-memory embedded systems. 1652** </dd> 1653** 1654** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1655** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1656** that SQLite can use for the database page cache with the default page 1657** cache implementation. 1658** This configuration option is a no-op if an application-define page 1659** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1660** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1661** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1662** and the number of cache lines (N). 1663** The sz argument should be the size of the largest database page 1664** (a power of two between 512 and 65536) plus some extra bytes for each 1665** page header. ^The number of extra bytes needed by the page header 1666** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1667** ^It is harmless, apart from the wasted memory, 1668** for the sz parameter to be larger than necessary. The pMem 1669** argument must be either a NULL pointer or a pointer to an 8-byte 1670** aligned block of memory of at least sz*N bytes, otherwise 1671** subsequent behavior is undefined. 1672** ^When pMem is not NULL, SQLite will strive to use the memory provided 1673** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1674** a page cache line is larger than sz bytes or if all of the pMem buffer 1675** is exhausted. 1676** ^If pMem is NULL and N is non-zero, then each database connection 1677** does an initial bulk allocation for page cache memory 1678** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1679** of -1024*N bytes if N is negative, . ^If additional 1680** page cache memory is needed beyond what is provided by the initial 1681** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1682** additional cache line. </dd> 1683** 1684** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1685** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1686** that SQLite will use for all of its dynamic memory allocation needs 1687** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and 1688** [SQLITE_CONFIG_PAGECACHE]. 1689** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1690** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1691** [SQLITE_ERROR] if invoked otherwise. 1692** ^There are three arguments to SQLITE_CONFIG_HEAP: 1693** An 8-byte aligned pointer to the memory, 1694** the number of bytes in the memory buffer, and the minimum allocation size. 1695** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1696** to using its default memory allocator (the system malloc() implementation), 1697** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1698** memory pointer is not NULL then the alternative memory 1699** allocator is engaged to handle all of SQLites memory allocation needs. 1700** The first pointer (the memory pointer) must be aligned to an 8-byte 1701** boundary or subsequent behavior of SQLite will be undefined. 1702** The minimum allocation size is capped at 2**12. Reasonable values 1703** for the minimum allocation size are 2**5 through 2**8.</dd> 1704** 1705** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1706** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1707** pointer to an instance of the [sqlite3_mutex_methods] structure. 1708** The argument specifies alternative low-level mutex routines to be used 1709** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1710** the content of the [sqlite3_mutex_methods] structure before the call to 1711** [sqlite3_config()] returns. ^If SQLite is compiled with 1712** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1713** the entire mutexing subsystem is omitted from the build and hence calls to 1714** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1715** return [SQLITE_ERROR].</dd> 1716** 1717** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1718** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1719** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1720** [sqlite3_mutex_methods] 1721** structure is filled with the currently defined mutex routines.)^ 1722** This option can be used to overload the default mutex allocation 1723** routines with a wrapper used to track mutex usage for performance 1724** profiling or testing, for example. ^If SQLite is compiled with 1725** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1726** the entire mutexing subsystem is omitted from the build and hence calls to 1727** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1728** return [SQLITE_ERROR].</dd> 1729** 1730** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1731** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1732** the default size of lookaside memory on each [database connection]. 1733** The first argument is the 1734** size of each lookaside buffer slot and the second is the number of 1735** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1736** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1737** option to [sqlite3_db_config()] can be used to change the lookaside 1738** configuration on individual connections.)^ </dd> 1739** 1740** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1741** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1742** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1743** the interface to a custom page cache implementation.)^ 1744** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1745** 1746** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1747** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1748** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1749** the current page cache implementation into that object.)^ </dd> 1750** 1751** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1752** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1753** global [error log]. 1754** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1755** function with a call signature of void(*)(void*,int,const char*), 1756** and a pointer to void. ^If the function pointer is not NULL, it is 1757** invoked by [sqlite3_log()] to process each logging event. ^If the 1758** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1759** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1760** passed through as the first parameter to the application-defined logger 1761** function whenever that function is invoked. ^The second parameter to 1762** the logger function is a copy of the first parameter to the corresponding 1763** [sqlite3_log()] call and is intended to be a [result code] or an 1764** [extended result code]. ^The third parameter passed to the logger is 1765** log message after formatting via [sqlite3_snprintf()]. 1766** The SQLite logging interface is not reentrant; the logger function 1767** supplied by the application must not invoke any SQLite interface. 1768** In a multi-threaded application, the application-defined logger 1769** function must be threadsafe. </dd> 1770** 1771** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1772** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1773** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1774** then URI handling is globally disabled.)^ ^If URI handling is globally 1775** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1776** [sqlite3_open16()] or 1777** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1778** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1779** connection is opened. ^If it is globally disabled, filenames are 1780** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1781** database connection is opened. ^(By default, URI handling is globally 1782** disabled. The default value may be changed by compiling with the 1783** [SQLITE_USE_URI] symbol defined.)^ 1784** 1785** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1786** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1787** argument which is interpreted as a boolean in order to enable or disable 1788** the use of covering indices for full table scans in the query optimizer. 1789** ^The default setting is determined 1790** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1791** if that compile-time option is omitted. 1792** The ability to disable the use of covering indices for full table scans 1793** is because some incorrectly coded legacy applications might malfunction 1794** when the optimization is enabled. Providing the ability to 1795** disable the optimization allows the older, buggy application code to work 1796** without change even with newer versions of SQLite. 1797** 1798** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1799** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1800** <dd> These options are obsolete and should not be used by new code. 1801** They are retained for backwards compatibility but are now no-ops. 1802** </dd> 1803** 1804** [[SQLITE_CONFIG_SQLLOG]] 1805** <dt>SQLITE_CONFIG_SQLLOG 1806** <dd>This option is only available if sqlite is compiled with the 1807** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1808** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1809** The second should be of type (void*). The callback is invoked by the library 1810** in three separate circumstances, identified by the value passed as the 1811** fourth parameter. If the fourth parameter is 0, then the database connection 1812** passed as the second argument has just been opened. The third argument 1813** points to a buffer containing the name of the main database file. If the 1814** fourth parameter is 1, then the SQL statement that the third parameter 1815** points to has just been executed. Or, if the fourth parameter is 2, then 1816** the connection being passed as the second parameter is being closed. The 1817** third parameter is passed NULL In this case. An example of using this 1818** configuration option can be seen in the "test_sqllog.c" source file in 1819** the canonical SQLite source tree.</dd> 1820** 1821** [[SQLITE_CONFIG_MMAP_SIZE]] 1822** <dt>SQLITE_CONFIG_MMAP_SIZE 1823** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1824** that are the default mmap size limit (the default setting for 1825** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1826** ^The default setting can be overridden by each database connection using 1827** either the [PRAGMA mmap_size] command, or by using the 1828** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1829** will be silently truncated if necessary so that it does not exceed the 1830** compile-time maximum mmap size set by the 1831** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1832** ^If either argument to this option is negative, then that argument is 1833** changed to its compile-time default. 1834** 1835** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1836** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1837** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1838** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1839** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1840** that specifies the maximum size of the created heap. 1841** 1842** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1843** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1844** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1845** is a pointer to an integer and writes into that integer the number of extra 1846** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1847** The amount of extra space required can change depending on the compiler, 1848** target platform, and SQLite version. 1849** 1850** [[SQLITE_CONFIG_PMASZ]] 1851** <dt>SQLITE_CONFIG_PMASZ 1852** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1853** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1854** sorter to that integer. The default minimum PMA Size is set by the 1855** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1856** to help with sort operations when multithreaded sorting 1857** is enabled (using the [PRAGMA threads] command) and the amount of content 1858** to be sorted exceeds the page size times the minimum of the 1859** [PRAGMA cache_size] setting and this value. 1860** 1861** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1862** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1863** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1864** becomes the [statement journal] spill-to-disk threshold. 1865** [Statement journals] are held in memory until their size (in bytes) 1866** exceeds this threshold, at which point they are written to disk. 1867** Or if the threshold is -1, statement journals are always held 1868** exclusively in memory. 1869** Since many statement journals never become large, setting the spill 1870** threshold to a value such as 64KiB can greatly reduce the amount of 1871** I/O required to support statement rollback. 1872** The default value for this setting is controlled by the 1873** [SQLITE_STMTJRNL_SPILL] compile-time option. 1874** </dl> 1875*/ 1876#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1877#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1878#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1879#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1880#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1881#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1882#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1883#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1884#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1885#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1886#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1887/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1888#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1889#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1890#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1891#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1892#define SQLITE_CONFIG_URI 17 /* int */ 1893#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1894#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1895#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1896#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1897#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1898#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1899#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 1900#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 1901#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 1902 1903/* 1904** CAPI3REF: Database Connection Configuration Options 1905** 1906** These constants are the available integer configuration options that 1907** can be passed as the second argument to the [sqlite3_db_config()] interface. 1908** 1909** New configuration options may be added in future releases of SQLite. 1910** Existing configuration options might be discontinued. Applications 1911** should check the return code from [sqlite3_db_config()] to make sure that 1912** the call worked. ^The [sqlite3_db_config()] interface will return a 1913** non-zero [error code] if a discontinued or unsupported configuration option 1914** is invoked. 1915** 1916** <dl> 1917** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1918** <dd> ^This option takes three additional arguments that determine the 1919** [lookaside memory allocator] configuration for the [database connection]. 1920** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1921** pointer to a memory buffer to use for lookaside memory. 1922** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1923** may be NULL in which case SQLite will allocate the 1924** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1925** size of each lookaside buffer slot. ^The third argument is the number of 1926** slots. The size of the buffer in the first argument must be greater than 1927** or equal to the product of the second and third arguments. The buffer 1928** must be aligned to an 8-byte boundary. ^If the second argument to 1929** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1930** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1931** configuration for a database connection can only be changed when that 1932** connection is not currently using lookaside memory, or in other words 1933** when the "current value" returned by 1934** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1935** Any attempt to change the lookaside memory configuration when lookaside 1936** memory is in use leaves the configuration unchanged and returns 1937** [SQLITE_BUSY].)^</dd> 1938** 1939** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1940** <dd> ^This option is used to enable or disable the enforcement of 1941** [foreign key constraints]. There should be two additional arguments. 1942** The first argument is an integer which is 0 to disable FK enforcement, 1943** positive to enable FK enforcement or negative to leave FK enforcement 1944** unchanged. The second parameter is a pointer to an integer into which 1945** is written 0 or 1 to indicate whether FK enforcement is off or on 1946** following this call. The second parameter may be a NULL pointer, in 1947** which case the FK enforcement setting is not reported back. </dd> 1948** 1949** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1950** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1951** There should be two additional arguments. 1952** The first argument is an integer which is 0 to disable triggers, 1953** positive to enable triggers or negative to leave the setting unchanged. 1954** The second parameter is a pointer to an integer into which 1955** is written 0 or 1 to indicate whether triggers are disabled or enabled 1956** following this call. The second parameter may be a NULL pointer, in 1957** which case the trigger setting is not reported back. </dd> 1958** 1959** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 1960** <dd> ^This option is used to enable or disable the two-argument 1961** version of the [fts3_tokenizer()] function which is part of the 1962** [FTS3] full-text search engine extension. 1963** There should be two additional arguments. 1964** The first argument is an integer which is 0 to disable fts3_tokenizer() or 1965** positive to enable fts3_tokenizer() or negative to leave the setting 1966** unchanged. 1967** The second parameter is a pointer to an integer into which 1968** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 1969** following this call. The second parameter may be a NULL pointer, in 1970** which case the new setting is not reported back. </dd> 1971** 1972** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 1973** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 1974** interface independently of the [load_extension()] SQL function. 1975** The [sqlite3_enable_load_extension()] API enables or disables both the 1976** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 1977** There should be two additional arguments. 1978** When the first argument to this interface is 1, then only the C-API is 1979** enabled and the SQL function remains disabled. If the first argument to 1980** this interface is 0, then both the C-API and the SQL function are disabled. 1981** If the first argument is -1, then no changes are made to state of either the 1982** C-API or the SQL function. 1983** The second parameter is a pointer to an integer into which 1984** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 1985** is disabled or enabled following this call. The second parameter may 1986** be a NULL pointer, in which case the new setting is not reported back. 1987** </dd> 1988** 1989** <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 1990** <dd> ^This option is used to change the name of the "main" database 1991** schema. ^The sole argument is a pointer to a constant UTF8 string 1992** which will become the new schema name in place of "main". ^SQLite 1993** does not make a copy of the new main schema name string, so the application 1994** must ensure that the argument passed into this DBCONFIG option is unchanged 1995** until after the database connection closes. 1996** </dd> 1997** 1998** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 1999** <dd> Usually, when a database in wal mode is closed or detached from a 2000** database handle, SQLite checks if this will mean that there are now no 2001** connections at all to the database. If so, it performs a checkpoint 2002** operation before closing the connection. This option may be used to 2003** override this behaviour. The first parameter passed to this operation 2004** is an integer - non-zero to disable checkpoints-on-close, or zero (the 2005** default) to enable them. The second parameter is a pointer to an integer 2006** into which is written 0 or 1 to indicate whether checkpoints-on-close 2007** have been disabled - 0 if they are not disabled, 1 if they are. 2008** </dd> 2009** 2010** </dl> 2011*/ 2012#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2013#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2014#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2015#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2016#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2017#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2018#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2019 2020 2021/* 2022** CAPI3REF: Enable Or Disable Extended Result Codes 2023** METHOD: sqlite3 2024** 2025** ^The sqlite3_extended_result_codes() routine enables or disables the 2026** [extended result codes] feature of SQLite. ^The extended result 2027** codes are disabled by default for historical compatibility. 2028*/ 2029SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2030 2031/* 2032** CAPI3REF: Last Insert Rowid 2033** METHOD: sqlite3 2034** 2035** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2036** has a unique 64-bit signed 2037** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2038** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2039** names are not also used by explicitly declared columns. ^If 2040** the table has a column of type [INTEGER PRIMARY KEY] then that column 2041** is another alias for the rowid. 2042** 2043** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2044** the most recent successful [INSERT] into a rowid table or [virtual table] 2045** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2046** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2047** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2048** zero. 2049** 2050** As well as being set automatically as rows are inserted into database 2051** tables, the value returned by this function may be set explicitly by 2052** [sqlite3_set_last_insert_rowid()] 2053** 2054** Some virtual table implementations may INSERT rows into rowid tables as 2055** part of committing a transaction (e.g. to flush data accumulated in memory 2056** to disk). In this case subsequent calls to this function return the rowid 2057** associated with these internal INSERT operations, which leads to 2058** unintuitive results. Virtual table implementations that do write to rowid 2059** tables in this way can avoid this problem by restoring the original 2060** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2061** control to the user. 2062** 2063** ^(If an [INSERT] occurs within a trigger then this routine will 2064** return the [rowid] of the inserted row as long as the trigger is 2065** running. Once the trigger program ends, the value returned 2066** by this routine reverts to what it was before the trigger was fired.)^ 2067** 2068** ^An [INSERT] that fails due to a constraint violation is not a 2069** successful [INSERT] and does not change the value returned by this 2070** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2071** and INSERT OR ABORT make no changes to the return value of this 2072** routine when their insertion fails. ^(When INSERT OR REPLACE 2073** encounters a constraint violation, it does not fail. The 2074** INSERT continues to completion after deleting rows that caused 2075** the constraint problem so INSERT OR REPLACE will always change 2076** the return value of this interface.)^ 2077** 2078** ^For the purposes of this routine, an [INSERT] is considered to 2079** be successful even if it is subsequently rolled back. 2080** 2081** This function is accessible to SQL statements via the 2082** [last_insert_rowid() SQL function]. 2083** 2084** If a separate thread performs a new [INSERT] on the same 2085** database connection while the [sqlite3_last_insert_rowid()] 2086** function is running and thus changes the last insert [rowid], 2087** then the value returned by [sqlite3_last_insert_rowid()] is 2088** unpredictable and might not equal either the old or the new 2089** last insert [rowid]. 2090*/ 2091SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2092 2093/* 2094** CAPI3REF: Set the Last Insert Rowid value. 2095** METHOD: sqlite3 2096** 2097** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2098** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2099** without inserting a row into the database. 2100*/ 2101SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2102 2103/* 2104** CAPI3REF: Count The Number Of Rows Modified 2105** METHOD: sqlite3 2106** 2107** ^This function returns the number of rows modified, inserted or 2108** deleted by the most recently completed INSERT, UPDATE or DELETE 2109** statement on the database connection specified by the only parameter. 2110** ^Executing any other type of SQL statement does not modify the value 2111** returned by this function. 2112** 2113** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2114** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2115** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2116** 2117** Changes to a view that are intercepted by 2118** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2119** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2120** DELETE statement run on a view is always zero. Only changes made to real 2121** tables are counted. 2122** 2123** Things are more complicated if the sqlite3_changes() function is 2124** executed while a trigger program is running. This may happen if the 2125** program uses the [changes() SQL function], or if some other callback 2126** function invokes sqlite3_changes() directly. Essentially: 2127** 2128** <ul> 2129** <li> ^(Before entering a trigger program the value returned by 2130** sqlite3_changes() function is saved. After the trigger program 2131** has finished, the original value is restored.)^ 2132** 2133** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2134** statement sets the value returned by sqlite3_changes() 2135** upon completion as normal. Of course, this value will not include 2136** any changes performed by sub-triggers, as the sqlite3_changes() 2137** value will be saved and restored after each sub-trigger has run.)^ 2138** </ul> 2139** 2140** ^This means that if the changes() SQL function (or similar) is used 2141** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2142** returns the value as set when the calling statement began executing. 2143** ^If it is used by the second or subsequent such statement within a trigger 2144** program, the value returned reflects the number of rows modified by the 2145** previous INSERT, UPDATE or DELETE statement within the same trigger. 2146** 2147** See also the [sqlite3_total_changes()] interface, the 2148** [count_changes pragma], and the [changes() SQL function]. 2149** 2150** If a separate thread makes changes on the same database connection 2151** while [sqlite3_changes()] is running then the value returned 2152** is unpredictable and not meaningful. 2153*/ 2154SQLITE_API int sqlite3_changes(sqlite3*); 2155 2156/* 2157** CAPI3REF: Total Number Of Rows Modified 2158** METHOD: sqlite3 2159** 2160** ^This function returns the total number of rows inserted, modified or 2161** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2162** since the database connection was opened, including those executed as 2163** part of trigger programs. ^Executing any other type of SQL statement 2164** does not affect the value returned by sqlite3_total_changes(). 2165** 2166** ^Changes made as part of [foreign key actions] are included in the 2167** count, but those made as part of REPLACE constraint resolution are 2168** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2169** are not counted. 2170** 2171** See also the [sqlite3_changes()] interface, the 2172** [count_changes pragma], and the [total_changes() SQL function]. 2173** 2174** If a separate thread makes changes on the same database connection 2175** while [sqlite3_total_changes()] is running then the value 2176** returned is unpredictable and not meaningful. 2177*/ 2178SQLITE_API int sqlite3_total_changes(sqlite3*); 2179 2180/* 2181** CAPI3REF: Interrupt A Long-Running Query 2182** METHOD: sqlite3 2183** 2184** ^This function causes any pending database operation to abort and 2185** return at its earliest opportunity. This routine is typically 2186** called in response to a user action such as pressing "Cancel" 2187** or Ctrl-C where the user wants a long query operation to halt 2188** immediately. 2189** 2190** ^It is safe to call this routine from a thread different from the 2191** thread that is currently running the database operation. But it 2192** is not safe to call this routine with a [database connection] that 2193** is closed or might close before sqlite3_interrupt() returns. 2194** 2195** ^If an SQL operation is very nearly finished at the time when 2196** sqlite3_interrupt() is called, then it might not have an opportunity 2197** to be interrupted and might continue to completion. 2198** 2199** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2200** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2201** that is inside an explicit transaction, then the entire transaction 2202** will be rolled back automatically. 2203** 2204** ^The sqlite3_interrupt(D) call is in effect until all currently running 2205** SQL statements on [database connection] D complete. ^Any new SQL statements 2206** that are started after the sqlite3_interrupt() call and before the 2207** running statements reaches zero are interrupted as if they had been 2208** running prior to the sqlite3_interrupt() call. ^New SQL statements 2209** that are started after the running statement count reaches zero are 2210** not effected by the sqlite3_interrupt(). 2211** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2212** SQL statements is a no-op and has no effect on SQL statements 2213** that are started after the sqlite3_interrupt() call returns. 2214** 2215** If the database connection closes while [sqlite3_interrupt()] 2216** is running then bad things will likely happen. 2217*/ 2218SQLITE_API void sqlite3_interrupt(sqlite3*); 2219 2220/* 2221** CAPI3REF: Determine If An SQL Statement Is Complete 2222** 2223** These routines are useful during command-line input to determine if the 2224** currently entered text seems to form a complete SQL statement or 2225** if additional input is needed before sending the text into 2226** SQLite for parsing. ^These routines return 1 if the input string 2227** appears to be a complete SQL statement. ^A statement is judged to be 2228** complete if it ends with a semicolon token and is not a prefix of a 2229** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2230** string literals or quoted identifier names or comments are not 2231** independent tokens (they are part of the token in which they are 2232** embedded) and thus do not count as a statement terminator. ^Whitespace 2233** and comments that follow the final semicolon are ignored. 2234** 2235** ^These routines return 0 if the statement is incomplete. ^If a 2236** memory allocation fails, then SQLITE_NOMEM is returned. 2237** 2238** ^These routines do not parse the SQL statements thus 2239** will not detect syntactically incorrect SQL. 2240** 2241** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2242** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2243** automatically by sqlite3_complete16(). If that initialization fails, 2244** then the return value from sqlite3_complete16() will be non-zero 2245** regardless of whether or not the input SQL is complete.)^ 2246** 2247** The input to [sqlite3_complete()] must be a zero-terminated 2248** UTF-8 string. 2249** 2250** The input to [sqlite3_complete16()] must be a zero-terminated 2251** UTF-16 string in native byte order. 2252*/ 2253SQLITE_API int sqlite3_complete(const char *sql); 2254SQLITE_API int sqlite3_complete16(const void *sql); 2255 2256/* 2257** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2258** KEYWORDS: {busy-handler callback} {busy handler} 2259** METHOD: sqlite3 2260** 2261** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2262** that might be invoked with argument P whenever 2263** an attempt is made to access a database table associated with 2264** [database connection] D when another thread 2265** or process has the table locked. 2266** The sqlite3_busy_handler() interface is used to implement 2267** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2268** 2269** ^If the busy callback is NULL, then [SQLITE_BUSY] 2270** is returned immediately upon encountering the lock. ^If the busy callback 2271** is not NULL, then the callback might be invoked with two arguments. 2272** 2273** ^The first argument to the busy handler is a copy of the void* pointer which 2274** is the third argument to sqlite3_busy_handler(). ^The second argument to 2275** the busy handler callback is the number of times that the busy handler has 2276** been invoked previously for the same locking event. ^If the 2277** busy callback returns 0, then no additional attempts are made to 2278** access the database and [SQLITE_BUSY] is returned 2279** to the application. 2280** ^If the callback returns non-zero, then another attempt 2281** is made to access the database and the cycle repeats. 2282** 2283** The presence of a busy handler does not guarantee that it will be invoked 2284** when there is lock contention. ^If SQLite determines that invoking the busy 2285** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2286** to the application instead of invoking the 2287** busy handler. 2288** Consider a scenario where one process is holding a read lock that 2289** it is trying to promote to a reserved lock and 2290** a second process is holding a reserved lock that it is trying 2291** to promote to an exclusive lock. The first process cannot proceed 2292** because it is blocked by the second and the second process cannot 2293** proceed because it is blocked by the first. If both processes 2294** invoke the busy handlers, neither will make any progress. Therefore, 2295** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2296** will induce the first process to release its read lock and allow 2297** the second process to proceed. 2298** 2299** ^The default busy callback is NULL. 2300** 2301** ^(There can only be a single busy handler defined for each 2302** [database connection]. Setting a new busy handler clears any 2303** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2304** or evaluating [PRAGMA busy_timeout=N] will change the 2305** busy handler and thus clear any previously set busy handler. 2306** 2307** The busy callback should not take any actions which modify the 2308** database connection that invoked the busy handler. In other words, 2309** the busy handler is not reentrant. Any such actions 2310** result in undefined behavior. 2311** 2312** A busy handler must not close the database connection 2313** or [prepared statement] that invoked the busy handler. 2314*/ 2315SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2316 2317/* 2318** CAPI3REF: Set A Busy Timeout 2319** METHOD: sqlite3 2320** 2321** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2322** for a specified amount of time when a table is locked. ^The handler 2323** will sleep multiple times until at least "ms" milliseconds of sleeping 2324** have accumulated. ^After at least "ms" milliseconds of sleeping, 2325** the handler returns 0 which causes [sqlite3_step()] to return 2326** [SQLITE_BUSY]. 2327** 2328** ^Calling this routine with an argument less than or equal to zero 2329** turns off all busy handlers. 2330** 2331** ^(There can only be a single busy handler for a particular 2332** [database connection] at any given moment. If another busy handler 2333** was defined (using [sqlite3_busy_handler()]) prior to calling 2334** this routine, that other busy handler is cleared.)^ 2335** 2336** See also: [PRAGMA busy_timeout] 2337*/ 2338SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2339 2340/* 2341** CAPI3REF: Convenience Routines For Running Queries 2342** METHOD: sqlite3 2343** 2344** This is a legacy interface that is preserved for backwards compatibility. 2345** Use of this interface is not recommended. 2346** 2347** Definition: A <b>result table</b> is memory data structure created by the 2348** [sqlite3_get_table()] interface. A result table records the 2349** complete query results from one or more queries. 2350** 2351** The table conceptually has a number of rows and columns. But 2352** these numbers are not part of the result table itself. These 2353** numbers are obtained separately. Let N be the number of rows 2354** and M be the number of columns. 2355** 2356** A result table is an array of pointers to zero-terminated UTF-8 strings. 2357** There are (N+1)*M elements in the array. The first M pointers point 2358** to zero-terminated strings that contain the names of the columns. 2359** The remaining entries all point to query results. NULL values result 2360** in NULL pointers. All other values are in their UTF-8 zero-terminated 2361** string representation as returned by [sqlite3_column_text()]. 2362** 2363** A result table might consist of one or more memory allocations. 2364** It is not safe to pass a result table directly to [sqlite3_free()]. 2365** A result table should be deallocated using [sqlite3_free_table()]. 2366** 2367** ^(As an example of the result table format, suppose a query result 2368** is as follows: 2369** 2370** <blockquote><pre> 2371** Name | Age 2372** ----------------------- 2373** Alice | 43 2374** Bob | 28 2375** Cindy | 21 2376** </pre></blockquote> 2377** 2378** There are two column (M==2) and three rows (N==3). Thus the 2379** result table has 8 entries. Suppose the result table is stored 2380** in an array names azResult. Then azResult holds this content: 2381** 2382** <blockquote><pre> 2383** azResult[0] = "Name"; 2384** azResult[1] = "Age"; 2385** azResult[2] = "Alice"; 2386** azResult[3] = "43"; 2387** azResult[4] = "Bob"; 2388** azResult[5] = "28"; 2389** azResult[6] = "Cindy"; 2390** azResult[7] = "21"; 2391** </pre></blockquote>)^ 2392** 2393** ^The sqlite3_get_table() function evaluates one or more 2394** semicolon-separated SQL statements in the zero-terminated UTF-8 2395** string of its 2nd parameter and returns a result table to the 2396** pointer given in its 3rd parameter. 2397** 2398** After the application has finished with the result from sqlite3_get_table(), 2399** it must pass the result table pointer to sqlite3_free_table() in order to 2400** release the memory that was malloced. Because of the way the 2401** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2402** function must not try to call [sqlite3_free()] directly. Only 2403** [sqlite3_free_table()] is able to release the memory properly and safely. 2404** 2405** The sqlite3_get_table() interface is implemented as a wrapper around 2406** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2407** to any internal data structures of SQLite. It uses only the public 2408** interface defined here. As a consequence, errors that occur in the 2409** wrapper layer outside of the internal [sqlite3_exec()] call are not 2410** reflected in subsequent calls to [sqlite3_errcode()] or 2411** [sqlite3_errmsg()]. 2412*/ 2413SQLITE_API int sqlite3_get_table( 2414 sqlite3 *db, /* An open database */ 2415 const char *zSql, /* SQL to be evaluated */ 2416 char ***pazResult, /* Results of the query */ 2417 int *pnRow, /* Number of result rows written here */ 2418 int *pnColumn, /* Number of result columns written here */ 2419 char **pzErrmsg /* Error msg written here */ 2420); 2421SQLITE_API void sqlite3_free_table(char **result); 2422 2423/* 2424** CAPI3REF: Formatted String Printing Functions 2425** 2426** These routines are work-alikes of the "printf()" family of functions 2427** from the standard C library. 2428** These routines understand most of the common K&R formatting options, 2429** plus some additional non-standard formats, detailed below. 2430** Note that some of the more obscure formatting options from recent 2431** C-library standards are omitted from this implementation. 2432** 2433** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2434** results into memory obtained from [sqlite3_malloc()]. 2435** The strings returned by these two routines should be 2436** released by [sqlite3_free()]. ^Both routines return a 2437** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2438** memory to hold the resulting string. 2439** 2440** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2441** the standard C library. The result is written into the 2442** buffer supplied as the second parameter whose size is given by 2443** the first parameter. Note that the order of the 2444** first two parameters is reversed from snprintf().)^ This is an 2445** historical accident that cannot be fixed without breaking 2446** backwards compatibility. ^(Note also that sqlite3_snprintf() 2447** returns a pointer to its buffer instead of the number of 2448** characters actually written into the buffer.)^ We admit that 2449** the number of characters written would be a more useful return 2450** value but we cannot change the implementation of sqlite3_snprintf() 2451** now without breaking compatibility. 2452** 2453** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2454** guarantees that the buffer is always zero-terminated. ^The first 2455** parameter "n" is the total size of the buffer, including space for 2456** the zero terminator. So the longest string that can be completely 2457** written will be n-1 characters. 2458** 2459** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2460** 2461** These routines all implement some additional formatting 2462** options that are useful for constructing SQL statements. 2463** All of the usual printf() formatting options apply. In addition, there 2464** is are "%q", "%Q", "%w" and "%z" options. 2465** 2466** ^(The %q option works like %s in that it substitutes a nul-terminated 2467** string from the argument list. But %q also doubles every '\'' character. 2468** %q is designed for use inside a string literal.)^ By doubling each '\'' 2469** character it escapes that character and allows it to be inserted into 2470** the string. 2471** 2472** For example, assume the string variable zText contains text as follows: 2473** 2474** <blockquote><pre> 2475** char *zText = "It's a happy day!"; 2476** </pre></blockquote> 2477** 2478** One can use this text in an SQL statement as follows: 2479** 2480** <blockquote><pre> 2481** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2482** sqlite3_exec(db, zSQL, 0, 0, 0); 2483** sqlite3_free(zSQL); 2484** </pre></blockquote> 2485** 2486** Because the %q format string is used, the '\'' character in zText 2487** is escaped and the SQL generated is as follows: 2488** 2489** <blockquote><pre> 2490** INSERT INTO table1 VALUES('It''s a happy day!') 2491** </pre></blockquote> 2492** 2493** This is correct. Had we used %s instead of %q, the generated SQL 2494** would have looked like this: 2495** 2496** <blockquote><pre> 2497** INSERT INTO table1 VALUES('It's a happy day!'); 2498** </pre></blockquote> 2499** 2500** This second example is an SQL syntax error. As a general rule you should 2501** always use %q instead of %s when inserting text into a string literal. 2502** 2503** ^(The %Q option works like %q except it also adds single quotes around 2504** the outside of the total string. Additionally, if the parameter in the 2505** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2506** single quotes).)^ So, for example, one could say: 2507** 2508** <blockquote><pre> 2509** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2510** sqlite3_exec(db, zSQL, 0, 0, 0); 2511** sqlite3_free(zSQL); 2512** </pre></blockquote> 2513** 2514** The code above will render a correct SQL statement in the zSQL 2515** variable even if the zText variable is a NULL pointer. 2516** 2517** ^(The "%w" formatting option is like "%q" except that it expects to 2518** be contained within double-quotes instead of single quotes, and it 2519** escapes the double-quote character instead of the single-quote 2520** character.)^ The "%w" formatting option is intended for safely inserting 2521** table and column names into a constructed SQL statement. 2522** 2523** ^(The "%z" formatting option works like "%s" but with the 2524** addition that after the string has been read and copied into 2525** the result, [sqlite3_free()] is called on the input string.)^ 2526*/ 2527SQLITE_API char *sqlite3_mprintf(const char*,...); 2528SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2529SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2530SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2531 2532/* 2533** CAPI3REF: Memory Allocation Subsystem 2534** 2535** The SQLite core uses these three routines for all of its own 2536** internal memory allocation needs. "Core" in the previous sentence 2537** does not include operating-system specific VFS implementation. The 2538** Windows VFS uses native malloc() and free() for some operations. 2539** 2540** ^The sqlite3_malloc() routine returns a pointer to a block 2541** of memory at least N bytes in length, where N is the parameter. 2542** ^If sqlite3_malloc() is unable to obtain sufficient free 2543** memory, it returns a NULL pointer. ^If the parameter N to 2544** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2545** a NULL pointer. 2546** 2547** ^The sqlite3_malloc64(N) routine works just like 2548** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2549** of a signed 32-bit integer. 2550** 2551** ^Calling sqlite3_free() with a pointer previously returned 2552** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2553** that it might be reused. ^The sqlite3_free() routine is 2554** a no-op if is called with a NULL pointer. Passing a NULL pointer 2555** to sqlite3_free() is harmless. After being freed, memory 2556** should neither be read nor written. Even reading previously freed 2557** memory might result in a segmentation fault or other severe error. 2558** Memory corruption, a segmentation fault, or other severe error 2559** might result if sqlite3_free() is called with a non-NULL pointer that 2560** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2561** 2562** ^The sqlite3_realloc(X,N) interface attempts to resize a 2563** prior memory allocation X to be at least N bytes. 2564** ^If the X parameter to sqlite3_realloc(X,N) 2565** is a NULL pointer then its behavior is identical to calling 2566** sqlite3_malloc(N). 2567** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2568** negative then the behavior is exactly the same as calling 2569** sqlite3_free(X). 2570** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2571** of at least N bytes in size or NULL if insufficient memory is available. 2572** ^If M is the size of the prior allocation, then min(N,M) bytes 2573** of the prior allocation are copied into the beginning of buffer returned 2574** by sqlite3_realloc(X,N) and the prior allocation is freed. 2575** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2576** prior allocation is not freed. 2577** 2578** ^The sqlite3_realloc64(X,N) interfaces works the same as 2579** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2580** of a 32-bit signed integer. 2581** 2582** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2583** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2584** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2585** ^The value returned by sqlite3_msize(X) might be larger than the number 2586** of bytes requested when X was allocated. ^If X is a NULL pointer then 2587** sqlite3_msize(X) returns zero. If X points to something that is not 2588** the beginning of memory allocation, or if it points to a formerly 2589** valid memory allocation that has now been freed, then the behavior 2590** of sqlite3_msize(X) is undefined and possibly harmful. 2591** 2592** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2593** sqlite3_malloc64(), and sqlite3_realloc64() 2594** is always aligned to at least an 8 byte boundary, or to a 2595** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2596** option is used. 2597** 2598** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2599** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2600** implementation of these routines to be omitted. That capability 2601** is no longer provided. Only built-in memory allocators can be used. 2602** 2603** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2604** the system malloc() and free() directly when converting 2605** filenames between the UTF-8 encoding used by SQLite 2606** and whatever filename encoding is used by the particular Windows 2607** installation. Memory allocation errors were detected, but 2608** they were reported back as [SQLITE_CANTOPEN] or 2609** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2610** 2611** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2612** must be either NULL or else pointers obtained from a prior 2613** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2614** not yet been released. 2615** 2616** The application must not read or write any part of 2617** a block of memory after it has been released using 2618** [sqlite3_free()] or [sqlite3_realloc()]. 2619*/ 2620SQLITE_API void *sqlite3_malloc(int); 2621SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 2622SQLITE_API void *sqlite3_realloc(void*, int); 2623SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 2624SQLITE_API void sqlite3_free(void*); 2625SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 2626 2627/* 2628** CAPI3REF: Memory Allocator Statistics 2629** 2630** SQLite provides these two interfaces for reporting on the status 2631** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2632** routines, which form the built-in memory allocation subsystem. 2633** 2634** ^The [sqlite3_memory_used()] routine returns the number of bytes 2635** of memory currently outstanding (malloced but not freed). 2636** ^The [sqlite3_memory_highwater()] routine returns the maximum 2637** value of [sqlite3_memory_used()] since the high-water mark 2638** was last reset. ^The values returned by [sqlite3_memory_used()] and 2639** [sqlite3_memory_highwater()] include any overhead 2640** added by SQLite in its implementation of [sqlite3_malloc()], 2641** but not overhead added by the any underlying system library 2642** routines that [sqlite3_malloc()] may call. 2643** 2644** ^The memory high-water mark is reset to the current value of 2645** [sqlite3_memory_used()] if and only if the parameter to 2646** [sqlite3_memory_highwater()] is true. ^The value returned 2647** by [sqlite3_memory_highwater(1)] is the high-water mark 2648** prior to the reset. 2649*/ 2650SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2651SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2652 2653/* 2654** CAPI3REF: Pseudo-Random Number Generator 2655** 2656** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2657** select random [ROWID | ROWIDs] when inserting new records into a table that 2658** already uses the largest possible [ROWID]. The PRNG is also used for 2659** the build-in random() and randomblob() SQL functions. This interface allows 2660** applications to access the same PRNG for other purposes. 2661** 2662** ^A call to this routine stores N bytes of randomness into buffer P. 2663** ^The P parameter can be a NULL pointer. 2664** 2665** ^If this routine has not been previously called or if the previous 2666** call had N less than one or a NULL pointer for P, then the PRNG is 2667** seeded using randomness obtained from the xRandomness method of 2668** the default [sqlite3_vfs] object. 2669** ^If the previous call to this routine had an N of 1 or more and a 2670** non-NULL P then the pseudo-randomness is generated 2671** internally and without recourse to the [sqlite3_vfs] xRandomness 2672** method. 2673*/ 2674SQLITE_API void sqlite3_randomness(int N, void *P); 2675 2676/* 2677** CAPI3REF: Compile-Time Authorization Callbacks 2678** METHOD: sqlite3 2679** 2680** ^This routine registers an authorizer callback with a particular 2681** [database connection], supplied in the first argument. 2682** ^The authorizer callback is invoked as SQL statements are being compiled 2683** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2684** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2685** points during the compilation process, as logic is being created 2686** to perform various actions, the authorizer callback is invoked to 2687** see if those actions are allowed. ^The authorizer callback should 2688** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2689** specific action but allow the SQL statement to continue to be 2690** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2691** rejected with an error. ^If the authorizer callback returns 2692** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2693** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2694** the authorizer will fail with an error message. 2695** 2696** When the callback returns [SQLITE_OK], that means the operation 2697** requested is ok. ^When the callback returns [SQLITE_DENY], the 2698** [sqlite3_prepare_v2()] or equivalent call that triggered the 2699** authorizer will fail with an error message explaining that 2700** access is denied. 2701** 2702** ^The first parameter to the authorizer callback is a copy of the third 2703** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2704** to the callback is an integer [SQLITE_COPY | action code] that specifies 2705** the particular action to be authorized. ^The third through sixth parameters 2706** to the callback are zero-terminated strings that contain additional 2707** details about the action to be authorized. 2708** 2709** ^If the action code is [SQLITE_READ] 2710** and the callback returns [SQLITE_IGNORE] then the 2711** [prepared statement] statement is constructed to substitute 2712** a NULL value in place of the table column that would have 2713** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2714** return can be used to deny an untrusted user access to individual 2715** columns of a table. 2716** ^If the action code is [SQLITE_DELETE] and the callback returns 2717** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2718** [truncate optimization] is disabled and all rows are deleted individually. 2719** 2720** An authorizer is used when [sqlite3_prepare | preparing] 2721** SQL statements from an untrusted source, to ensure that the SQL statements 2722** do not try to access data they are not allowed to see, or that they do not 2723** try to execute malicious statements that damage the database. For 2724** example, an application may allow a user to enter arbitrary 2725** SQL queries for evaluation by a database. But the application does 2726** not want the user to be able to make arbitrary changes to the 2727** database. An authorizer could then be put in place while the 2728** user-entered SQL is being [sqlite3_prepare | prepared] that 2729** disallows everything except [SELECT] statements. 2730** 2731** Applications that need to process SQL from untrusted sources 2732** might also consider lowering resource limits using [sqlite3_limit()] 2733** and limiting database size using the [max_page_count] [PRAGMA] 2734** in addition to using an authorizer. 2735** 2736** ^(Only a single authorizer can be in place on a database connection 2737** at a time. Each call to sqlite3_set_authorizer overrides the 2738** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2739** The authorizer is disabled by default. 2740** 2741** The authorizer callback must not do anything that will modify 2742** the database connection that invoked the authorizer callback. 2743** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2744** database connections for the meaning of "modify" in this paragraph. 2745** 2746** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2747** statement might be re-prepared during [sqlite3_step()] due to a 2748** schema change. Hence, the application should ensure that the 2749** correct authorizer callback remains in place during the [sqlite3_step()]. 2750** 2751** ^Note that the authorizer callback is invoked only during 2752** [sqlite3_prepare()] or its variants. Authorization is not 2753** performed during statement evaluation in [sqlite3_step()], unless 2754** as stated in the previous paragraph, sqlite3_step() invokes 2755** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2756*/ 2757SQLITE_API int sqlite3_set_authorizer( 2758 sqlite3*, 2759 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2760 void *pUserData 2761); 2762 2763/* 2764** CAPI3REF: Authorizer Return Codes 2765** 2766** The [sqlite3_set_authorizer | authorizer callback function] must 2767** return either [SQLITE_OK] or one of these two constants in order 2768** to signal SQLite whether or not the action is permitted. See the 2769** [sqlite3_set_authorizer | authorizer documentation] for additional 2770** information. 2771** 2772** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2773** returned from the [sqlite3_vtab_on_conflict()] interface. 2774*/ 2775#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2776#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2777 2778/* 2779** CAPI3REF: Authorizer Action Codes 2780** 2781** The [sqlite3_set_authorizer()] interface registers a callback function 2782** that is invoked to authorize certain SQL statement actions. The 2783** second parameter to the callback is an integer code that specifies 2784** what action is being authorized. These are the integer action codes that 2785** the authorizer callback may be passed. 2786** 2787** These action code values signify what kind of operation is to be 2788** authorized. The 3rd and 4th parameters to the authorization 2789** callback function will be parameters or NULL depending on which of these 2790** codes is used as the second parameter. ^(The 5th parameter to the 2791** authorizer callback is the name of the database ("main", "temp", 2792** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2793** is the name of the inner-most trigger or view that is responsible for 2794** the access attempt or NULL if this access attempt is directly from 2795** top-level SQL code. 2796*/ 2797/******************************************* 3rd ************ 4th ***********/ 2798#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2799#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2800#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2801#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2802#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2803#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2804#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2805#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2806#define SQLITE_DELETE 9 /* Table Name NULL */ 2807#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2808#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2809#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2810#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2811#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2812#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2813#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2814#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2815#define SQLITE_INSERT 18 /* Table Name NULL */ 2816#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2817#define SQLITE_READ 20 /* Table Name Column Name */ 2818#define SQLITE_SELECT 21 /* NULL NULL */ 2819#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2820#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2821#define SQLITE_ATTACH 24 /* Filename NULL */ 2822#define SQLITE_DETACH 25 /* Database Name NULL */ 2823#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2824#define SQLITE_REINDEX 27 /* Index Name NULL */ 2825#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2826#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2827#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2828#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2829#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2830#define SQLITE_COPY 0 /* No longer used */ 2831#define SQLITE_RECURSIVE 33 /* NULL NULL */ 2832 2833/* 2834** CAPI3REF: Tracing And Profiling Functions 2835** METHOD: sqlite3 2836** 2837** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 2838** instead of the routines described here. 2839** 2840** These routines register callback functions that can be used for 2841** tracing and profiling the execution of SQL statements. 2842** 2843** ^The callback function registered by sqlite3_trace() is invoked at 2844** various times when an SQL statement is being run by [sqlite3_step()]. 2845** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2846** SQL statement text as the statement first begins executing. 2847** ^(Additional sqlite3_trace() callbacks might occur 2848** as each triggered subprogram is entered. The callbacks for triggers 2849** contain a UTF-8 SQL comment that identifies the trigger.)^ 2850** 2851** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2852** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2853** 2854** ^The callback function registered by sqlite3_profile() is invoked 2855** as each SQL statement finishes. ^The profile callback contains 2856** the original statement text and an estimate of wall-clock time 2857** of how long that statement took to run. ^The profile callback 2858** time is in units of nanoseconds, however the current implementation 2859** is only capable of millisecond resolution so the six least significant 2860** digits in the time are meaningless. Future versions of SQLite 2861** might provide greater resolution on the profiler callback. The 2862** sqlite3_profile() function is considered experimental and is 2863** subject to change in future versions of SQLite. 2864*/ 2865SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 2866 void(*xTrace)(void*,const char*), void*); 2867SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 2868 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2869 2870/* 2871** CAPI3REF: SQL Trace Event Codes 2872** KEYWORDS: SQLITE_TRACE 2873** 2874** These constants identify classes of events that can be monitored 2875** using the [sqlite3_trace_v2()] tracing logic. The third argument 2876** to [sqlite3_trace_v2()] is an OR-ed combination of one or more of 2877** the following constants. ^The first argument to the trace callback 2878** is one of the following constants. 2879** 2880** New tracing constants may be added in future releases. 2881** 2882** ^A trace callback has four arguments: xCallback(T,C,P,X). 2883** ^The T argument is one of the integer type codes above. 2884** ^The C argument is a copy of the context pointer passed in as the 2885** fourth argument to [sqlite3_trace_v2()]. 2886** The P and X arguments are pointers whose meanings depend on T. 2887** 2888** <dl> 2889** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 2890** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 2891** first begins running and possibly at other times during the 2892** execution of the prepared statement, such as at the start of each 2893** trigger subprogram. ^The P argument is a pointer to the 2894** [prepared statement]. ^The X argument is a pointer to a string which 2895** is the unexpanded SQL text of the prepared statement or an SQL comment 2896** that indicates the invocation of a trigger. ^The callback can compute 2897** the same text that would have been returned by the legacy [sqlite3_trace()] 2898** interface by using the X argument when X begins with "--" and invoking 2899** [sqlite3_expanded_sql(P)] otherwise. 2900** 2901** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 2902** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 2903** information as is provided by the [sqlite3_profile()] callback. 2904** ^The P argument is a pointer to the [prepared statement] and the 2905** X argument points to a 64-bit integer which is the estimated of 2906** the number of nanosecond that the prepared statement took to run. 2907** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 2908** 2909** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 2910** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 2911** statement generates a single row of result. 2912** ^The P argument is a pointer to the [prepared statement] and the 2913** X argument is unused. 2914** 2915** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 2916** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 2917** connection closes. 2918** ^The P argument is a pointer to the [database connection] object 2919** and the X argument is unused. 2920** </dl> 2921*/ 2922#define SQLITE_TRACE_STMT 0x01 2923#define SQLITE_TRACE_PROFILE 0x02 2924#define SQLITE_TRACE_ROW 0x04 2925#define SQLITE_TRACE_CLOSE 0x08 2926 2927/* 2928** CAPI3REF: SQL Trace Hook 2929** METHOD: sqlite3 2930** 2931** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 2932** function X against [database connection] D, using property mask M 2933** and context pointer P. ^If the X callback is 2934** NULL or if the M mask is zero, then tracing is disabled. The 2935** M argument should be the bitwise OR-ed combination of 2936** zero or more [SQLITE_TRACE] constants. 2937** 2938** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 2939** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 2940** 2941** ^The X callback is invoked whenever any of the events identified by 2942** mask M occur. ^The integer return value from the callback is currently 2943** ignored, though this may change in future releases. Callback 2944** implementations should return zero to ensure future compatibility. 2945** 2946** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 2947** ^The T argument is one of the [SQLITE_TRACE] 2948** constants to indicate why the callback was invoked. 2949** ^The C argument is a copy of the context pointer. 2950** The P and X arguments are pointers whose meanings depend on T. 2951** 2952** The sqlite3_trace_v2() interface is intended to replace the legacy 2953** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 2954** are deprecated. 2955*/ 2956SQLITE_API int sqlite3_trace_v2( 2957 sqlite3*, 2958 unsigned uMask, 2959 int(*xCallback)(unsigned,void*,void*,void*), 2960 void *pCtx 2961); 2962 2963/* 2964** CAPI3REF: Query Progress Callbacks 2965** METHOD: sqlite3 2966** 2967** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2968** function X to be invoked periodically during long running calls to 2969** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2970** database connection D. An example use for this 2971** interface is to keep a GUI updated during a large query. 2972** 2973** ^The parameter P is passed through as the only parameter to the 2974** callback function X. ^The parameter N is the approximate number of 2975** [virtual machine instructions] that are evaluated between successive 2976** invocations of the callback X. ^If N is less than one then the progress 2977** handler is disabled. 2978** 2979** ^Only a single progress handler may be defined at one time per 2980** [database connection]; setting a new progress handler cancels the 2981** old one. ^Setting parameter X to NULL disables the progress handler. 2982** ^The progress handler is also disabled by setting N to a value less 2983** than 1. 2984** 2985** ^If the progress callback returns non-zero, the operation is 2986** interrupted. This feature can be used to implement a 2987** "Cancel" button on a GUI progress dialog box. 2988** 2989** The progress handler callback must not do anything that will modify 2990** the database connection that invoked the progress handler. 2991** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2992** database connections for the meaning of "modify" in this paragraph. 2993** 2994*/ 2995SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2996 2997/* 2998** CAPI3REF: Opening A New Database Connection 2999** CONSTRUCTOR: sqlite3 3000** 3001** ^These routines open an SQLite database file as specified by the 3002** filename argument. ^The filename argument is interpreted as UTF-8 for 3003** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3004** order for sqlite3_open16(). ^(A [database connection] handle is usually 3005** returned in *ppDb, even if an error occurs. The only exception is that 3006** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3007** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3008** object.)^ ^(If the database is opened (and/or created) successfully, then 3009** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3010** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3011** an English language description of the error following a failure of any 3012** of the sqlite3_open() routines. 3013** 3014** ^The default encoding will be UTF-8 for databases created using 3015** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3016** created using sqlite3_open16() will be UTF-16 in the native byte order. 3017** 3018** Whether or not an error occurs when it is opened, resources 3019** associated with the [database connection] handle should be released by 3020** passing it to [sqlite3_close()] when it is no longer required. 3021** 3022** The sqlite3_open_v2() interface works like sqlite3_open() 3023** except that it accepts two additional parameters for additional control 3024** over the new database connection. ^(The flags parameter to 3025** sqlite3_open_v2() can take one of 3026** the following three values, optionally combined with the 3027** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 3028** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 3029** 3030** <dl> 3031** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3032** <dd>The database is opened in read-only mode. If the database does not 3033** already exist, an error is returned.</dd>)^ 3034** 3035** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3036** <dd>The database is opened for reading and writing if possible, or reading 3037** only if the file is write protected by the operating system. In either 3038** case the database must already exist, otherwise an error is returned.</dd>)^ 3039** 3040** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3041** <dd>The database is opened for reading and writing, and is created if 3042** it does not already exist. This is the behavior that is always used for 3043** sqlite3_open() and sqlite3_open16().</dd>)^ 3044** </dl> 3045** 3046** If the 3rd parameter to sqlite3_open_v2() is not one of the 3047** combinations shown above optionally combined with other 3048** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3049** then the behavior is undefined. 3050** 3051** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 3052** opens in the multi-thread [threading mode] as long as the single-thread 3053** mode has not been set at compile-time or start-time. ^If the 3054** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 3055** in the serialized [threading mode] unless single-thread was 3056** previously selected at compile-time or start-time. 3057** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 3058** eligible to use [shared cache mode], regardless of whether or not shared 3059** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 3060** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 3061** participate in [shared cache mode] even if it is enabled. 3062** 3063** ^The fourth parameter to sqlite3_open_v2() is the name of the 3064** [sqlite3_vfs] object that defines the operating system interface that 3065** the new database connection should use. ^If the fourth parameter is 3066** a NULL pointer then the default [sqlite3_vfs] object is used. 3067** 3068** ^If the filename is ":memory:", then a private, temporary in-memory database 3069** is created for the connection. ^This in-memory database will vanish when 3070** the database connection is closed. Future versions of SQLite might 3071** make use of additional special filenames that begin with the ":" character. 3072** It is recommended that when a database filename actually does begin with 3073** a ":" character you should prefix the filename with a pathname such as 3074** "./" to avoid ambiguity. 3075** 3076** ^If the filename is an empty string, then a private, temporary 3077** on-disk database will be created. ^This private database will be 3078** automatically deleted as soon as the database connection is closed. 3079** 3080** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3081** 3082** ^If [URI filename] interpretation is enabled, and the filename argument 3083** begins with "file:", then the filename is interpreted as a URI. ^URI 3084** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3085** set in the fourth argument to sqlite3_open_v2(), or if it has 3086** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3087** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3088** As of SQLite version 3.7.7, URI filename interpretation is turned off 3089** by default, but future releases of SQLite might enable URI filename 3090** interpretation by default. See "[URI filenames]" for additional 3091** information. 3092** 3093** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3094** authority, then it must be either an empty string or the string 3095** "localhost". ^If the authority is not an empty string or "localhost", an 3096** error is returned to the caller. ^The fragment component of a URI, if 3097** present, is ignored. 3098** 3099** ^SQLite uses the path component of the URI as the name of the disk file 3100** which contains the database. ^If the path begins with a '/' character, 3101** then it is interpreted as an absolute path. ^If the path does not begin 3102** with a '/' (meaning that the authority section is omitted from the URI) 3103** then the path is interpreted as a relative path. 3104** ^(On windows, the first component of an absolute path 3105** is a drive specification (e.g. "C:").)^ 3106** 3107** [[core URI query parameters]] 3108** The query component of a URI may contain parameters that are interpreted 3109** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3110** SQLite and its built-in [VFSes] interpret the 3111** following query parameters: 3112** 3113** <ul> 3114** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3115** a VFS object that provides the operating system interface that should 3116** be used to access the database file on disk. ^If this option is set to 3117** an empty string the default VFS object is used. ^Specifying an unknown 3118** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3119** present, then the VFS specified by the option takes precedence over 3120** the value passed as the fourth parameter to sqlite3_open_v2(). 3121** 3122** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3123** "rwc", or "memory". Attempting to set it to any other value is 3124** an error)^. 3125** ^If "ro" is specified, then the database is opened for read-only 3126** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3127** third argument to sqlite3_open_v2(). ^If the mode option is set to 3128** "rw", then the database is opened for read-write (but not create) 3129** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3130** been set. ^Value "rwc" is equivalent to setting both 3131** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3132** set to "memory" then a pure [in-memory database] that never reads 3133** or writes from disk is used. ^It is an error to specify a value for 3134** the mode parameter that is less restrictive than that specified by 3135** the flags passed in the third parameter to sqlite3_open_v2(). 3136** 3137** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3138** "private". ^Setting it to "shared" is equivalent to setting the 3139** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3140** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3141** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3142** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3143** a URI filename, its value overrides any behavior requested by setting 3144** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3145** 3146** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3147** [powersafe overwrite] property does or does not apply to the 3148** storage media on which the database file resides. 3149** 3150** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3151** which if set disables file locking in rollback journal modes. This 3152** is useful for accessing a database on a filesystem that does not 3153** support locking. Caution: Database corruption might result if two 3154** or more processes write to the same database and any one of those 3155** processes uses nolock=1. 3156** 3157** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3158** parameter that indicates that the database file is stored on 3159** read-only media. ^When immutable is set, SQLite assumes that the 3160** database file cannot be changed, even by a process with higher 3161** privilege, and so the database is opened read-only and all locking 3162** and change detection is disabled. Caution: Setting the immutable 3163** property on a database file that does in fact change can result 3164** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3165** See also: [SQLITE_IOCAP_IMMUTABLE]. 3166** 3167** </ul> 3168** 3169** ^Specifying an unknown parameter in the query component of a URI is not an 3170** error. Future versions of SQLite might understand additional query 3171** parameters. See "[query parameters with special meaning to SQLite]" for 3172** additional information. 3173** 3174** [[URI filename examples]] <h3>URI filename examples</h3> 3175** 3176** <table border="1" align=center cellpadding=5> 3177** <tr><th> URI filenames <th> Results 3178** <tr><td> file:data.db <td> 3179** Open the file "data.db" in the current directory. 3180** <tr><td> file:/home/fred/data.db<br> 3181** file:///home/fred/data.db <br> 3182** file://localhost/home/fred/data.db <br> <td> 3183** Open the database file "/home/fred/data.db". 3184** <tr><td> file://darkstar/home/fred/data.db <td> 3185** An error. "darkstar" is not a recognized authority. 3186** <tr><td style="white-space:nowrap"> 3187** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3188** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3189** C:. Note that the %20 escaping in this example is not strictly 3190** necessary - space characters can be used literally 3191** in URI filenames. 3192** <tr><td> file:data.db?mode=ro&cache=private <td> 3193** Open file "data.db" in the current directory for read-only access. 3194** Regardless of whether or not shared-cache mode is enabled by 3195** default, use a private cache. 3196** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3197** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3198** that uses dot-files in place of posix advisory locking. 3199** <tr><td> file:data.db?mode=readonly <td> 3200** An error. "readonly" is not a valid option for the "mode" parameter. 3201** </table> 3202** 3203** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3204** query components of a URI. A hexadecimal escape sequence consists of a 3205** percent sign - "%" - followed by exactly two hexadecimal digits 3206** specifying an octet value. ^Before the path or query components of a 3207** URI filename are interpreted, they are encoded using UTF-8 and all 3208** hexadecimal escape sequences replaced by a single byte containing the 3209** corresponding octet. If this process generates an invalid UTF-8 encoding, 3210** the results are undefined. 3211** 3212** <b>Note to Windows users:</b> The encoding used for the filename argument 3213** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3214** codepage is currently defined. Filenames containing international 3215** characters must be converted to UTF-8 prior to passing them into 3216** sqlite3_open() or sqlite3_open_v2(). 3217** 3218** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3219** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3220** features that require the use of temporary files may fail. 3221** 3222** See also: [sqlite3_temp_directory] 3223*/ 3224SQLITE_API int sqlite3_open( 3225 const char *filename, /* Database filename (UTF-8) */ 3226 sqlite3 **ppDb /* OUT: SQLite db handle */ 3227); 3228SQLITE_API int sqlite3_open16( 3229 const void *filename, /* Database filename (UTF-16) */ 3230 sqlite3 **ppDb /* OUT: SQLite db handle */ 3231); 3232SQLITE_API int sqlite3_open_v2( 3233 const char *filename, /* Database filename (UTF-8) */ 3234 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3235 int flags, /* Flags */ 3236 const char *zVfs /* Name of VFS module to use */ 3237); 3238 3239/* 3240** CAPI3REF: Obtain Values For URI Parameters 3241** 3242** These are utility routines, useful to VFS implementations, that check 3243** to see if a database file was a URI that contained a specific query 3244** parameter, and if so obtains the value of that query parameter. 3245** 3246** If F is the database filename pointer passed into the xOpen() method of 3247** a VFS implementation when the flags parameter to xOpen() has one or 3248** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3249** P is the name of the query parameter, then 3250** sqlite3_uri_parameter(F,P) returns the value of the P 3251** parameter if it exists or a NULL pointer if P does not appear as a 3252** query parameter on F. If P is a query parameter of F 3253** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3254** a pointer to an empty string. 3255** 3256** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3257** parameter and returns true (1) or false (0) according to the value 3258** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3259** value of query parameter P is one of "yes", "true", or "on" in any 3260** case or if the value begins with a non-zero number. The 3261** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3262** query parameter P is one of "no", "false", or "off" in any case or 3263** if the value begins with a numeric zero. If P is not a query 3264** parameter on F or if the value of P is does not match any of the 3265** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3266** 3267** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3268** 64-bit signed integer and returns that integer, or D if P does not 3269** exist. If the value of P is something other than an integer, then 3270** zero is returned. 3271** 3272** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3273** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3274** is not a database file pathname pointer that SQLite passed into the xOpen 3275** VFS method, then the behavior of this routine is undefined and probably 3276** undesirable. 3277*/ 3278SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3279SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3280SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3281 3282 3283/* 3284** CAPI3REF: Error Codes And Messages 3285** METHOD: sqlite3 3286** 3287** ^If the most recent sqlite3_* API call associated with 3288** [database connection] D failed, then the sqlite3_errcode(D) interface 3289** returns the numeric [result code] or [extended result code] for that 3290** API call. 3291** If the most recent API call was successful, 3292** then the return value from sqlite3_errcode() is undefined. 3293** ^The sqlite3_extended_errcode() 3294** interface is the same except that it always returns the 3295** [extended result code] even when extended result codes are 3296** disabled. 3297** 3298** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3299** text that describes the error, as either UTF-8 or UTF-16 respectively. 3300** ^(Memory to hold the error message string is managed internally. 3301** The application does not need to worry about freeing the result. 3302** However, the error string might be overwritten or deallocated by 3303** subsequent calls to other SQLite interface functions.)^ 3304** 3305** ^The sqlite3_errstr() interface returns the English-language text 3306** that describes the [result code], as UTF-8. 3307** ^(Memory to hold the error message string is managed internally 3308** and must not be freed by the application)^. 3309** 3310** When the serialized [threading mode] is in use, it might be the 3311** case that a second error occurs on a separate thread in between 3312** the time of the first error and the call to these interfaces. 3313** When that happens, the second error will be reported since these 3314** interfaces always report the most recent result. To avoid 3315** this, each thread can obtain exclusive use of the [database connection] D 3316** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3317** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3318** all calls to the interfaces listed here are completed. 3319** 3320** If an interface fails with SQLITE_MISUSE, that means the interface 3321** was invoked incorrectly by the application. In that case, the 3322** error code and message may or may not be set. 3323*/ 3324SQLITE_API int sqlite3_errcode(sqlite3 *db); 3325SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3326SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3327SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3328SQLITE_API const char *sqlite3_errstr(int); 3329 3330/* 3331** CAPI3REF: Prepared Statement Object 3332** KEYWORDS: {prepared statement} {prepared statements} 3333** 3334** An instance of this object represents a single SQL statement that 3335** has been compiled into binary form and is ready to be evaluated. 3336** 3337** Think of each SQL statement as a separate computer program. The 3338** original SQL text is source code. A prepared statement object 3339** is the compiled object code. All SQL must be converted into a 3340** prepared statement before it can be run. 3341** 3342** The life-cycle of a prepared statement object usually goes like this: 3343** 3344** <ol> 3345** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3346** <li> Bind values to [parameters] using the sqlite3_bind_*() 3347** interfaces. 3348** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3349** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3350** to step 2. Do this zero or more times. 3351** <li> Destroy the object using [sqlite3_finalize()]. 3352** </ol> 3353*/ 3354typedef struct sqlite3_stmt sqlite3_stmt; 3355 3356/* 3357** CAPI3REF: Run-time Limits 3358** METHOD: sqlite3 3359** 3360** ^(This interface allows the size of various constructs to be limited 3361** on a connection by connection basis. The first parameter is the 3362** [database connection] whose limit is to be set or queried. The 3363** second parameter is one of the [limit categories] that define a 3364** class of constructs to be size limited. The third parameter is the 3365** new limit for that construct.)^ 3366** 3367** ^If the new limit is a negative number, the limit is unchanged. 3368** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3369** [limits | hard upper bound] 3370** set at compile-time by a C preprocessor macro called 3371** [limits | SQLITE_MAX_<i>NAME</i>]. 3372** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3373** ^Attempts to increase a limit above its hard upper bound are 3374** silently truncated to the hard upper bound. 3375** 3376** ^Regardless of whether or not the limit was changed, the 3377** [sqlite3_limit()] interface returns the prior value of the limit. 3378** ^Hence, to find the current value of a limit without changing it, 3379** simply invoke this interface with the third parameter set to -1. 3380** 3381** Run-time limits are intended for use in applications that manage 3382** both their own internal database and also databases that are controlled 3383** by untrusted external sources. An example application might be a 3384** web browser that has its own databases for storing history and 3385** separate databases controlled by JavaScript applications downloaded 3386** off the Internet. The internal databases can be given the 3387** large, default limits. Databases managed by external sources can 3388** be given much smaller limits designed to prevent a denial of service 3389** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3390** interface to further control untrusted SQL. The size of the database 3391** created by an untrusted script can be contained using the 3392** [max_page_count] [PRAGMA]. 3393** 3394** New run-time limit categories may be added in future releases. 3395*/ 3396SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 3397 3398/* 3399** CAPI3REF: Run-Time Limit Categories 3400** KEYWORDS: {limit category} {*limit categories} 3401** 3402** These constants define various performance limits 3403** that can be lowered at run-time using [sqlite3_limit()]. 3404** The synopsis of the meanings of the various limits is shown below. 3405** Additional information is available at [limits | Limits in SQLite]. 3406** 3407** <dl> 3408** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3409** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3410** 3411** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3412** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3413** 3414** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3415** <dd>The maximum number of columns in a table definition or in the 3416** result set of a [SELECT] or the maximum number of columns in an index 3417** or in an ORDER BY or GROUP BY clause.</dd>)^ 3418** 3419** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3420** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3421** 3422** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3423** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3424** 3425** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3426** <dd>The maximum number of instructions in a virtual machine program 3427** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3428** the equivalent tries to allocate space for more than this many opcodes 3429** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3430** 3431** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3432** <dd>The maximum number of arguments on a function.</dd>)^ 3433** 3434** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3435** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3436** 3437** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3438** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3439** <dd>The maximum length of the pattern argument to the [LIKE] or 3440** [GLOB] operators.</dd>)^ 3441** 3442** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3443** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3444** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3445** 3446** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3447** <dd>The maximum depth of recursion for triggers.</dd>)^ 3448** 3449** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3450** <dd>The maximum number of auxiliary worker threads that a single 3451** [prepared statement] may start.</dd>)^ 3452** </dl> 3453*/ 3454#define SQLITE_LIMIT_LENGTH 0 3455#define SQLITE_LIMIT_SQL_LENGTH 1 3456#define SQLITE_LIMIT_COLUMN 2 3457#define SQLITE_LIMIT_EXPR_DEPTH 3 3458#define SQLITE_LIMIT_COMPOUND_SELECT 4 3459#define SQLITE_LIMIT_VDBE_OP 5 3460#define SQLITE_LIMIT_FUNCTION_ARG 6 3461#define SQLITE_LIMIT_ATTACHED 7 3462#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3463#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3464#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3465#define SQLITE_LIMIT_WORKER_THREADS 11 3466 3467 3468/* 3469** CAPI3REF: Compiling An SQL Statement 3470** KEYWORDS: {SQL statement compiler} 3471** METHOD: sqlite3 3472** CONSTRUCTOR: sqlite3_stmt 3473** 3474** To execute an SQL query, it must first be compiled into a byte-code 3475** program using one of these routines. 3476** 3477** The first argument, "db", is a [database connection] obtained from a 3478** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3479** [sqlite3_open16()]. The database connection must not have been closed. 3480** 3481** The second argument, "zSql", is the statement to be compiled, encoded 3482** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 3483** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 3484** use UTF-16. 3485** 3486** ^If the nByte argument is negative, then zSql is read up to the 3487** first zero terminator. ^If nByte is positive, then it is the 3488** number of bytes read from zSql. ^If nByte is zero, then no prepared 3489** statement is generated. 3490** If the caller knows that the supplied string is nul-terminated, then 3491** there is a small performance advantage to passing an nByte parameter that 3492** is the number of bytes in the input string <i>including</i> 3493** the nul-terminator. 3494** 3495** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3496** past the end of the first SQL statement in zSql. These routines only 3497** compile the first statement in zSql, so *pzTail is left pointing to 3498** what remains uncompiled. 3499** 3500** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3501** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3502** to NULL. ^If the input text contains no SQL (if the input is an empty 3503** string or a comment) then *ppStmt is set to NULL. 3504** The calling procedure is responsible for deleting the compiled 3505** SQL statement using [sqlite3_finalize()] after it has finished with it. 3506** ppStmt may not be NULL. 3507** 3508** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3509** otherwise an [error code] is returned. 3510** 3511** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 3512** recommended for all new programs. The two older interfaces are retained 3513** for backwards compatibility, but their use is discouraged. 3514** ^In the "v2" interfaces, the prepared statement 3515** that is returned (the [sqlite3_stmt] object) contains a copy of the 3516** original SQL text. This causes the [sqlite3_step()] interface to 3517** behave differently in three ways: 3518** 3519** <ol> 3520** <li> 3521** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3522** always used to do, [sqlite3_step()] will automatically recompile the SQL 3523** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3524** retries will occur before sqlite3_step() gives up and returns an error. 3525** </li> 3526** 3527** <li> 3528** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3529** [error codes] or [extended error codes]. ^The legacy behavior was that 3530** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3531** and the application would have to make a second call to [sqlite3_reset()] 3532** in order to find the underlying cause of the problem. With the "v2" prepare 3533** interfaces, the underlying reason for the error is returned immediately. 3534** </li> 3535** 3536** <li> 3537** ^If the specific value bound to [parameter | host parameter] in the 3538** WHERE clause might influence the choice of query plan for a statement, 3539** then the statement will be automatically recompiled, as if there had been 3540** a schema change, on the first [sqlite3_step()] call following any change 3541** to the [sqlite3_bind_text | bindings] of that [parameter]. 3542** ^The specific value of WHERE-clause [parameter] might influence the 3543** choice of query plan if the parameter is the left-hand side of a [LIKE] 3544** or [GLOB] operator or if the parameter is compared to an indexed column 3545** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3546** </li> 3547** </ol> 3548*/ 3549SQLITE_API int sqlite3_prepare( 3550 sqlite3 *db, /* Database handle */ 3551 const char *zSql, /* SQL statement, UTF-8 encoded */ 3552 int nByte, /* Maximum length of zSql in bytes. */ 3553 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3554 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3555); 3556SQLITE_API int sqlite3_prepare_v2( 3557 sqlite3 *db, /* Database handle */ 3558 const char *zSql, /* SQL statement, UTF-8 encoded */ 3559 int nByte, /* Maximum length of zSql in bytes. */ 3560 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3561 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3562); 3563SQLITE_API int sqlite3_prepare16( 3564 sqlite3 *db, /* Database handle */ 3565 const void *zSql, /* SQL statement, UTF-16 encoded */ 3566 int nByte, /* Maximum length of zSql in bytes. */ 3567 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3568 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3569); 3570SQLITE_API int sqlite3_prepare16_v2( 3571 sqlite3 *db, /* Database handle */ 3572 const void *zSql, /* SQL statement, UTF-16 encoded */ 3573 int nByte, /* Maximum length of zSql in bytes. */ 3574 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3575 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3576); 3577 3578/* 3579** CAPI3REF: Retrieving Statement SQL 3580** METHOD: sqlite3_stmt 3581** 3582** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 3583** SQL text used to create [prepared statement] P if P was 3584** created by either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3585** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 3586** string containing the SQL text of prepared statement P with 3587** [bound parameters] expanded. 3588** 3589** ^(For example, if a prepared statement is created using the SQL 3590** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 3591** and parameter :xyz is unbound, then sqlite3_sql() will return 3592** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 3593** will return "SELECT 2345,NULL".)^ 3594** 3595** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 3596** is available to hold the result, or if the result would exceed the 3597** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 3598** 3599** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 3600** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 3601** option causes sqlite3_expanded_sql() to always return NULL. 3602** 3603** ^The string returned by sqlite3_sql(P) is managed by SQLite and is 3604** automatically freed when the prepared statement is finalized. 3605** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 3606** is obtained from [sqlite3_malloc()] and must be free by the application 3607** by passing it to [sqlite3_free()]. 3608*/ 3609SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 3610SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 3611 3612/* 3613** CAPI3REF: Determine If An SQL Statement Writes The Database 3614** METHOD: sqlite3_stmt 3615** 3616** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3617** and only if the [prepared statement] X makes no direct changes to 3618** the content of the database file. 3619** 3620** Note that [application-defined SQL functions] or 3621** [virtual tables] might change the database indirectly as a side effect. 3622** ^(For example, if an application defines a function "eval()" that 3623** calls [sqlite3_exec()], then the following SQL statement would 3624** change the database file through side-effects: 3625** 3626** <blockquote><pre> 3627** SELECT eval('DELETE FROM t1') FROM t2; 3628** </pre></blockquote> 3629** 3630** But because the [SELECT] statement does not change the database file 3631** directly, sqlite3_stmt_readonly() would still return true.)^ 3632** 3633** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3634** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3635** since the statements themselves do not actually modify the database but 3636** rather they control the timing of when other statements modify the 3637** database. ^The [ATTACH] and [DETACH] statements also cause 3638** sqlite3_stmt_readonly() to return true since, while those statements 3639** change the configuration of a database connection, they do not make 3640** changes to the content of the database files on disk. 3641** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 3642** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 3643** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 3644** sqlite3_stmt_readonly() returns false for those commands. 3645*/ 3646SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3647 3648/* 3649** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3650** METHOD: sqlite3_stmt 3651** 3652** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3653** [prepared statement] S has been stepped at least once using 3654** [sqlite3_step(S)] but has neither run to completion (returned 3655** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3656** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3657** interface returns false if S is a NULL pointer. If S is not a 3658** NULL pointer and is not a pointer to a valid [prepared statement] 3659** object, then the behavior is undefined and probably undesirable. 3660** 3661** This interface can be used in combination [sqlite3_next_stmt()] 3662** to locate all prepared statements associated with a database 3663** connection that are in need of being reset. This can be used, 3664** for example, in diagnostic routines to search for prepared 3665** statements that are holding a transaction open. 3666*/ 3667SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 3668 3669/* 3670** CAPI3REF: Dynamically Typed Value Object 3671** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3672** 3673** SQLite uses the sqlite3_value object to represent all values 3674** that can be stored in a database table. SQLite uses dynamic typing 3675** for the values it stores. ^Values stored in sqlite3_value objects 3676** can be integers, floating point values, strings, BLOBs, or NULL. 3677** 3678** An sqlite3_value object may be either "protected" or "unprotected". 3679** Some interfaces require a protected sqlite3_value. Other interfaces 3680** will accept either a protected or an unprotected sqlite3_value. 3681** Every interface that accepts sqlite3_value arguments specifies 3682** whether or not it requires a protected sqlite3_value. The 3683** [sqlite3_value_dup()] interface can be used to construct a new 3684** protected sqlite3_value from an unprotected sqlite3_value. 3685** 3686** The terms "protected" and "unprotected" refer to whether or not 3687** a mutex is held. An internal mutex is held for a protected 3688** sqlite3_value object but no mutex is held for an unprotected 3689** sqlite3_value object. If SQLite is compiled to be single-threaded 3690** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3691** or if SQLite is run in one of reduced mutex modes 3692** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3693** then there is no distinction between protected and unprotected 3694** sqlite3_value objects and they can be used interchangeably. However, 3695** for maximum code portability it is recommended that applications 3696** still make the distinction between protected and unprotected 3697** sqlite3_value objects even when not strictly required. 3698** 3699** ^The sqlite3_value objects that are passed as parameters into the 3700** implementation of [application-defined SQL functions] are protected. 3701** ^The sqlite3_value object returned by 3702** [sqlite3_column_value()] is unprotected. 3703** Unprotected sqlite3_value objects may only be used with 3704** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3705** The [sqlite3_value_blob | sqlite3_value_type()] family of 3706** interfaces require protected sqlite3_value objects. 3707*/ 3708typedef struct Mem sqlite3_value; 3709 3710/* 3711** CAPI3REF: SQL Function Context Object 3712** 3713** The context in which an SQL function executes is stored in an 3714** sqlite3_context object. ^A pointer to an sqlite3_context object 3715** is always first parameter to [application-defined SQL functions]. 3716** The application-defined SQL function implementation will pass this 3717** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3718** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3719** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3720** and/or [sqlite3_set_auxdata()]. 3721*/ 3722typedef struct sqlite3_context sqlite3_context; 3723 3724/* 3725** CAPI3REF: Binding Values To Prepared Statements 3726** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3727** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3728** METHOD: sqlite3_stmt 3729** 3730** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3731** literals may be replaced by a [parameter] that matches one of following 3732** templates: 3733** 3734** <ul> 3735** <li> ? 3736** <li> ?NNN 3737** <li> :VVV 3738** <li> @VVV 3739** <li> $VVV 3740** </ul> 3741** 3742** In the templates above, NNN represents an integer literal, 3743** and VVV represents an alphanumeric identifier.)^ ^The values of these 3744** parameters (also called "host parameter names" or "SQL parameters") 3745** can be set using the sqlite3_bind_*() routines defined here. 3746** 3747** ^The first argument to the sqlite3_bind_*() routines is always 3748** a pointer to the [sqlite3_stmt] object returned from 3749** [sqlite3_prepare_v2()] or its variants. 3750** 3751** ^The second argument is the index of the SQL parameter to be set. 3752** ^The leftmost SQL parameter has an index of 1. ^When the same named 3753** SQL parameter is used more than once, second and subsequent 3754** occurrences have the same index as the first occurrence. 3755** ^The index for named parameters can be looked up using the 3756** [sqlite3_bind_parameter_index()] API if desired. ^The index 3757** for "?NNN" parameters is the value of NNN. 3758** ^The NNN value must be between 1 and the [sqlite3_limit()] 3759** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3760** 3761** ^The third argument is the value to bind to the parameter. 3762** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3763** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3764** is ignored and the end result is the same as sqlite3_bind_null(). 3765** 3766** ^(In those routines that have a fourth argument, its value is the 3767** number of bytes in the parameter. To be clear: the value is the 3768** number of <u>bytes</u> in the value, not the number of characters.)^ 3769** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3770** is negative, then the length of the string is 3771** the number of bytes up to the first zero terminator. 3772** If the fourth parameter to sqlite3_bind_blob() is negative, then 3773** the behavior is undefined. 3774** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3775** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3776** that parameter must be the byte offset 3777** where the NUL terminator would occur assuming the string were NUL 3778** terminated. If any NUL characters occur at byte offsets less than 3779** the value of the fourth parameter then the resulting string value will 3780** contain embedded NULs. The result of expressions involving strings 3781** with embedded NULs is undefined. 3782** 3783** ^The fifth argument to the BLOB and string binding interfaces 3784** is a destructor used to dispose of the BLOB or 3785** string after SQLite has finished with it. ^The destructor is called 3786** to dispose of the BLOB or string even if the call to bind API fails. 3787** ^If the fifth argument is 3788** the special value [SQLITE_STATIC], then SQLite assumes that the 3789** information is in static, unmanaged space and does not need to be freed. 3790** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3791** SQLite makes its own private copy of the data immediately, before 3792** the sqlite3_bind_*() routine returns. 3793** 3794** ^The sixth argument to sqlite3_bind_text64() must be one of 3795** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 3796** to specify the encoding of the text in the third parameter. If 3797** the sixth argument to sqlite3_bind_text64() is not one of the 3798** allowed values shown above, or if the text encoding is different 3799** from the encoding specified by the sixth parameter, then the behavior 3800** is undefined. 3801** 3802** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3803** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3804** (just an integer to hold its size) while it is being processed. 3805** Zeroblobs are intended to serve as placeholders for BLOBs whose 3806** content is later written using 3807** [sqlite3_blob_open | incremental BLOB I/O] routines. 3808** ^A negative value for the zeroblob results in a zero-length BLOB. 3809** 3810** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3811** for the [prepared statement] or with a prepared statement for which 3812** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3813** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3814** routine is passed a [prepared statement] that has been finalized, the 3815** result is undefined and probably harmful. 3816** 3817** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3818** ^Unbound parameters are interpreted as NULL. 3819** 3820** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3821** [error code] if anything goes wrong. 3822** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 3823** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 3824** [SQLITE_MAX_LENGTH]. 3825** ^[SQLITE_RANGE] is returned if the parameter 3826** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3827** 3828** See also: [sqlite3_bind_parameter_count()], 3829** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3830*/ 3831SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3832SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 3833 void(*)(void*)); 3834SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 3835SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 3836SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3837SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 3838SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 3839SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3840SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 3841 void(*)(void*), unsigned char encoding); 3842SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3843SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3844SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 3845 3846/* 3847** CAPI3REF: Number Of SQL Parameters 3848** METHOD: sqlite3_stmt 3849** 3850** ^This routine can be used to find the number of [SQL parameters] 3851** in a [prepared statement]. SQL parameters are tokens of the 3852** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3853** placeholders for values that are [sqlite3_bind_blob | bound] 3854** to the parameters at a later time. 3855** 3856** ^(This routine actually returns the index of the largest (rightmost) 3857** parameter. For all forms except ?NNN, this will correspond to the 3858** number of unique parameters. If parameters of the ?NNN form are used, 3859** there may be gaps in the list.)^ 3860** 3861** See also: [sqlite3_bind_blob|sqlite3_bind()], 3862** [sqlite3_bind_parameter_name()], and 3863** [sqlite3_bind_parameter_index()]. 3864*/ 3865SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 3866 3867/* 3868** CAPI3REF: Name Of A Host Parameter 3869** METHOD: sqlite3_stmt 3870** 3871** ^The sqlite3_bind_parameter_name(P,N) interface returns 3872** the name of the N-th [SQL parameter] in the [prepared statement] P. 3873** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3874** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3875** respectively. 3876** In other words, the initial ":" or "$" or "@" or "?" 3877** is included as part of the name.)^ 3878** ^Parameters of the form "?" without a following integer have no name 3879** and are referred to as "nameless" or "anonymous parameters". 3880** 3881** ^The first host parameter has an index of 1, not 0. 3882** 3883** ^If the value N is out of range or if the N-th parameter is 3884** nameless, then NULL is returned. ^The returned string is 3885** always in UTF-8 encoding even if the named parameter was 3886** originally specified as UTF-16 in [sqlite3_prepare16()] or 3887** [sqlite3_prepare16_v2()]. 3888** 3889** See also: [sqlite3_bind_blob|sqlite3_bind()], 3890** [sqlite3_bind_parameter_count()], and 3891** [sqlite3_bind_parameter_index()]. 3892*/ 3893SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3894 3895/* 3896** CAPI3REF: Index Of A Parameter With A Given Name 3897** METHOD: sqlite3_stmt 3898** 3899** ^Return the index of an SQL parameter given its name. ^The 3900** index value returned is suitable for use as the second 3901** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3902** is returned if no matching parameter is found. ^The parameter 3903** name must be given in UTF-8 even if the original statement 3904** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3905** 3906** See also: [sqlite3_bind_blob|sqlite3_bind()], 3907** [sqlite3_bind_parameter_count()], and 3908** [sqlite3_bind_parameter_name()]. 3909*/ 3910SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3911 3912/* 3913** CAPI3REF: Reset All Bindings On A Prepared Statement 3914** METHOD: sqlite3_stmt 3915** 3916** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3917** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3918** ^Use this routine to reset all host parameters to NULL. 3919*/ 3920SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 3921 3922/* 3923** CAPI3REF: Number Of Columns In A Result Set 3924** METHOD: sqlite3_stmt 3925** 3926** ^Return the number of columns in the result set returned by the 3927** [prepared statement]. ^If this routine returns 0, that means the 3928** [prepared statement] returns no data (for example an [UPDATE]). 3929** ^However, just because this routine returns a positive number does not 3930** mean that one or more rows of data will be returned. ^A SELECT statement 3931** will always have a positive sqlite3_column_count() but depending on the 3932** WHERE clause constraints and the table content, it might return no rows. 3933** 3934** See also: [sqlite3_data_count()] 3935*/ 3936SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 3937 3938/* 3939** CAPI3REF: Column Names In A Result Set 3940** METHOD: sqlite3_stmt 3941** 3942** ^These routines return the name assigned to a particular column 3943** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3944** interface returns a pointer to a zero-terminated UTF-8 string 3945** and sqlite3_column_name16() returns a pointer to a zero-terminated 3946** UTF-16 string. ^The first parameter is the [prepared statement] 3947** that implements the [SELECT] statement. ^The second parameter is the 3948** column number. ^The leftmost column is number 0. 3949** 3950** ^The returned string pointer is valid until either the [prepared statement] 3951** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3952** reprepared by the first call to [sqlite3_step()] for a particular run 3953** or until the next call to 3954** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3955** 3956** ^If sqlite3_malloc() fails during the processing of either routine 3957** (for example during a conversion from UTF-8 to UTF-16) then a 3958** NULL pointer is returned. 3959** 3960** ^The name of a result column is the value of the "AS" clause for 3961** that column, if there is an AS clause. If there is no AS clause 3962** then the name of the column is unspecified and may change from 3963** one release of SQLite to the next. 3964*/ 3965SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 3966SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 3967 3968/* 3969** CAPI3REF: Source Of Data In A Query Result 3970** METHOD: sqlite3_stmt 3971** 3972** ^These routines provide a means to determine the database, table, and 3973** table column that is the origin of a particular result column in 3974** [SELECT] statement. 3975** ^The name of the database or table or column can be returned as 3976** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3977** the database name, the _table_ routines return the table name, and 3978** the origin_ routines return the column name. 3979** ^The returned string is valid until the [prepared statement] is destroyed 3980** using [sqlite3_finalize()] or until the statement is automatically 3981** reprepared by the first call to [sqlite3_step()] for a particular run 3982** or until the same information is requested 3983** again in a different encoding. 3984** 3985** ^The names returned are the original un-aliased names of the 3986** database, table, and column. 3987** 3988** ^The first argument to these interfaces is a [prepared statement]. 3989** ^These functions return information about the Nth result column returned by 3990** the statement, where N is the second function argument. 3991** ^The left-most column is column 0 for these routines. 3992** 3993** ^If the Nth column returned by the statement is an expression or 3994** subquery and is not a column value, then all of these functions return 3995** NULL. ^These routine might also return NULL if a memory allocation error 3996** occurs. ^Otherwise, they return the name of the attached database, table, 3997** or column that query result column was extracted from. 3998** 3999** ^As with all other SQLite APIs, those whose names end with "16" return 4000** UTF-16 encoded strings and the other functions return UTF-8. 4001** 4002** ^These APIs are only available if the library was compiled with the 4003** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4004** 4005** If two or more threads call one or more of these routines against the same 4006** prepared statement and column at the same time then the results are 4007** undefined. 4008** 4009** If two or more threads call one or more 4010** [sqlite3_column_database_name | column metadata interfaces] 4011** for the same [prepared statement] and result column 4012** at the same time then the results are undefined. 4013*/ 4014SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4015SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4016SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4017SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4018SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4019SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4020 4021/* 4022** CAPI3REF: Declared Datatype Of A Query Result 4023** METHOD: sqlite3_stmt 4024** 4025** ^(The first parameter is a [prepared statement]. 4026** If this statement is a [SELECT] statement and the Nth column of the 4027** returned result set of that [SELECT] is a table column (not an 4028** expression or subquery) then the declared type of the table 4029** column is returned.)^ ^If the Nth column of the result set is an 4030** expression or subquery, then a NULL pointer is returned. 4031** ^The returned string is always UTF-8 encoded. 4032** 4033** ^(For example, given the database schema: 4034** 4035** CREATE TABLE t1(c1 VARIANT); 4036** 4037** and the following statement to be compiled: 4038** 4039** SELECT c1 + 1, c1 FROM t1; 4040** 4041** this routine would return the string "VARIANT" for the second result 4042** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4043** 4044** ^SQLite uses dynamic run-time typing. ^So just because a column 4045** is declared to contain a particular type does not mean that the 4046** data stored in that column is of the declared type. SQLite is 4047** strongly typed, but the typing is dynamic not static. ^Type 4048** is associated with individual values, not with the containers 4049** used to hold those values. 4050*/ 4051SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4052SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4053 4054/* 4055** CAPI3REF: Evaluate An SQL Statement 4056** METHOD: sqlite3_stmt 4057** 4058** After a [prepared statement] has been prepared using either 4059** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 4060** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4061** must be called one or more times to evaluate the statement. 4062** 4063** The details of the behavior of the sqlite3_step() interface depend 4064** on whether the statement was prepared using the newer "v2" interface 4065** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 4066** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4067** new "v2" interface is recommended for new applications but the legacy 4068** interface will continue to be supported. 4069** 4070** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4071** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4072** ^With the "v2" interface, any of the other [result codes] or 4073** [extended result codes] might be returned as well. 4074** 4075** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4076** database locks it needs to do its job. ^If the statement is a [COMMIT] 4077** or occurs outside of an explicit transaction, then you can retry the 4078** statement. If the statement is not a [COMMIT] and occurs within an 4079** explicit transaction then you should rollback the transaction before 4080** continuing. 4081** 4082** ^[SQLITE_DONE] means that the statement has finished executing 4083** successfully. sqlite3_step() should not be called again on this virtual 4084** machine without first calling [sqlite3_reset()] to reset the virtual 4085** machine back to its initial state. 4086** 4087** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4088** is returned each time a new row of data is ready for processing by the 4089** caller. The values may be accessed using the [column access functions]. 4090** sqlite3_step() is called again to retrieve the next row of data. 4091** 4092** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4093** violation) has occurred. sqlite3_step() should not be called again on 4094** the VM. More information may be found by calling [sqlite3_errmsg()]. 4095** ^With the legacy interface, a more specific error code (for example, 4096** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4097** can be obtained by calling [sqlite3_reset()] on the 4098** [prepared statement]. ^In the "v2" interface, 4099** the more specific error code is returned directly by sqlite3_step(). 4100** 4101** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4102** Perhaps it was called on a [prepared statement] that has 4103** already been [sqlite3_finalize | finalized] or on one that had 4104** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4105** be the case that the same database connection is being used by two or 4106** more threads at the same moment in time. 4107** 4108** For all versions of SQLite up to and including 3.6.23.1, a call to 4109** [sqlite3_reset()] was required after sqlite3_step() returned anything 4110** other than [SQLITE_ROW] before any subsequent invocation of 4111** sqlite3_step(). Failure to reset the prepared statement using 4112** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4113** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4114** sqlite3_step() began 4115** calling [sqlite3_reset()] automatically in this circumstance rather 4116** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4117** break because any application that ever receives an SQLITE_MISUSE error 4118** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4119** can be used to restore the legacy behavior. 4120** 4121** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4122** API always returns a generic error code, [SQLITE_ERROR], following any 4123** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4124** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4125** specific [error codes] that better describes the error. 4126** We admit that this is a goofy design. The problem has been fixed 4127** with the "v2" interface. If you prepare all of your SQL statements 4128** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 4129** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4130** then the more specific [error codes] are returned directly 4131** by sqlite3_step(). The use of the "v2" interface is recommended. 4132*/ 4133SQLITE_API int sqlite3_step(sqlite3_stmt*); 4134 4135/* 4136** CAPI3REF: Number of columns in a result set 4137** METHOD: sqlite3_stmt 4138** 4139** ^The sqlite3_data_count(P) interface returns the number of columns in the 4140** current row of the result set of [prepared statement] P. 4141** ^If prepared statement P does not have results ready to return 4142** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 4143** interfaces) then sqlite3_data_count(P) returns 0. 4144** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4145** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4146** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4147** will return non-zero if previous call to [sqlite3_step](P) returned 4148** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4149** where it always returns zero since each step of that multi-step 4150** pragma returns 0 columns of data. 4151** 4152** See also: [sqlite3_column_count()] 4153*/ 4154SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 4155 4156/* 4157** CAPI3REF: Fundamental Datatypes 4158** KEYWORDS: SQLITE_TEXT 4159** 4160** ^(Every value in SQLite has one of five fundamental datatypes: 4161** 4162** <ul> 4163** <li> 64-bit signed integer 4164** <li> 64-bit IEEE floating point number 4165** <li> string 4166** <li> BLOB 4167** <li> NULL 4168** </ul>)^ 4169** 4170** These constants are codes for each of those types. 4171** 4172** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4173** for a completely different meaning. Software that links against both 4174** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4175** SQLITE_TEXT. 4176*/ 4177#define SQLITE_INTEGER 1 4178#define SQLITE_FLOAT 2 4179#define SQLITE_BLOB 4 4180#define SQLITE_NULL 5 4181#ifdef SQLITE_TEXT 4182# undef SQLITE_TEXT 4183#else 4184# define SQLITE_TEXT 3 4185#endif 4186#define SQLITE3_TEXT 3 4187 4188/* 4189** CAPI3REF: Result Values From A Query 4190** KEYWORDS: {column access functions} 4191** METHOD: sqlite3_stmt 4192** 4193** ^These routines return information about a single column of the current 4194** result row of a query. ^In every case the first argument is a pointer 4195** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4196** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4197** and the second argument is the index of the column for which information 4198** should be returned. ^The leftmost column of the result set has the index 0. 4199** ^The number of columns in the result can be determined using 4200** [sqlite3_column_count()]. 4201** 4202** If the SQL statement does not currently point to a valid row, or if the 4203** column index is out of range, the result is undefined. 4204** These routines may only be called when the most recent call to 4205** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4206** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4207** If any of these routines are called after [sqlite3_reset()] or 4208** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4209** something other than [SQLITE_ROW], the results are undefined. 4210** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4211** are called from a different thread while any of these routines 4212** are pending, then the results are undefined. 4213** 4214** ^The sqlite3_column_type() routine returns the 4215** [SQLITE_INTEGER | datatype code] for the initial data type 4216** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4217** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 4218** returned by sqlite3_column_type() is only meaningful if no type 4219** conversions have occurred as described below. After a type conversion, 4220** the value returned by sqlite3_column_type() is undefined. Future 4221** versions of SQLite may change the behavior of sqlite3_column_type() 4222** following a type conversion. 4223** 4224** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4225** routine returns the number of bytes in that BLOB or string. 4226** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4227** the string to UTF-8 and then returns the number of bytes. 4228** ^If the result is a numeric value then sqlite3_column_bytes() uses 4229** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4230** the number of bytes in that string. 4231** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4232** 4233** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4234** routine returns the number of bytes in that BLOB or string. 4235** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4236** the string to UTF-16 and then returns the number of bytes. 4237** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4238** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4239** the number of bytes in that string. 4240** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4241** 4242** ^The values returned by [sqlite3_column_bytes()] and 4243** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4244** of the string. ^For clarity: the values returned by 4245** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4246** bytes in the string, not the number of characters. 4247** 4248** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4249** even empty strings, are always zero-terminated. ^The return 4250** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4251** 4252** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4253** [unprotected sqlite3_value] object. In a multithreaded environment, 4254** an unprotected sqlite3_value object may only be used safely with 4255** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4256** If the [unprotected sqlite3_value] object returned by 4257** [sqlite3_column_value()] is used in any other way, including calls 4258** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4259** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4260** 4261** These routines attempt to convert the value where appropriate. ^For 4262** example, if the internal representation is FLOAT and a text result 4263** is requested, [sqlite3_snprintf()] is used internally to perform the 4264** conversion automatically. ^(The following table details the conversions 4265** that are applied: 4266** 4267** <blockquote> 4268** <table border="1"> 4269** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4270** 4271** <tr><td> NULL <td> INTEGER <td> Result is 0 4272** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4273** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4274** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4275** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4276** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4277** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4278** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4279** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4280** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4281** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4282** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4283** <tr><td> TEXT <td> BLOB <td> No change 4284** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4285** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4286** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4287** </table> 4288** </blockquote>)^ 4289** 4290** Note that when type conversions occur, pointers returned by prior 4291** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4292** sqlite3_column_text16() may be invalidated. 4293** Type conversions and pointer invalidations might occur 4294** in the following cases: 4295** 4296** <ul> 4297** <li> The initial content is a BLOB and sqlite3_column_text() or 4298** sqlite3_column_text16() is called. A zero-terminator might 4299** need to be added to the string.</li> 4300** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4301** sqlite3_column_text16() is called. The content must be converted 4302** to UTF-16.</li> 4303** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4304** sqlite3_column_text() is called. The content must be converted 4305** to UTF-8.</li> 4306** </ul> 4307** 4308** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4309** not invalidate a prior pointer, though of course the content of the buffer 4310** that the prior pointer references will have been modified. Other kinds 4311** of conversion are done in place when it is possible, but sometimes they 4312** are not possible and in those cases prior pointers are invalidated. 4313** 4314** The safest policy is to invoke these routines 4315** in one of the following ways: 4316** 4317** <ul> 4318** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4319** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4320** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4321** </ul> 4322** 4323** In other words, you should call sqlite3_column_text(), 4324** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4325** into the desired format, then invoke sqlite3_column_bytes() or 4326** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4327** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4328** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4329** with calls to sqlite3_column_bytes(). 4330** 4331** ^The pointers returned are valid until a type conversion occurs as 4332** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4333** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4334** and BLOBs is freed automatically. Do <em>not</em> pass the pointers returned 4335** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4336** [sqlite3_free()]. 4337** 4338** ^(If a memory allocation error occurs during the evaluation of any 4339** of these routines, a default value is returned. The default value 4340** is either the integer 0, the floating point number 0.0, or a NULL 4341** pointer. Subsequent calls to [sqlite3_errcode()] will return 4342** [SQLITE_NOMEM].)^ 4343*/ 4344SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4345SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4346SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4347SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 4348SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 4349SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4350SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4351SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4352SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 4353SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4354 4355/* 4356** CAPI3REF: Destroy A Prepared Statement Object 4357** DESTRUCTOR: sqlite3_stmt 4358** 4359** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4360** ^If the most recent evaluation of the statement encountered no errors 4361** or if the statement is never been evaluated, then sqlite3_finalize() returns 4362** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4363** sqlite3_finalize(S) returns the appropriate [error code] or 4364** [extended error code]. 4365** 4366** ^The sqlite3_finalize(S) routine can be called at any point during 4367** the life cycle of [prepared statement] S: 4368** before statement S is ever evaluated, after 4369** one or more calls to [sqlite3_reset()], or after any call 4370** to [sqlite3_step()] regardless of whether or not the statement has 4371** completed execution. 4372** 4373** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4374** 4375** The application must finalize every [prepared statement] in order to avoid 4376** resource leaks. It is a grievous error for the application to try to use 4377** a prepared statement after it has been finalized. Any use of a prepared 4378** statement after it has been finalized can result in undefined and 4379** undesirable behavior such as segfaults and heap corruption. 4380*/ 4381SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 4382 4383/* 4384** CAPI3REF: Reset A Prepared Statement Object 4385** METHOD: sqlite3_stmt 4386** 4387** The sqlite3_reset() function is called to reset a [prepared statement] 4388** object back to its initial state, ready to be re-executed. 4389** ^Any SQL statement variables that had values bound to them using 4390** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4391** Use [sqlite3_clear_bindings()] to reset the bindings. 4392** 4393** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4394** back to the beginning of its program. 4395** 4396** ^If the most recent call to [sqlite3_step(S)] for the 4397** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4398** or if [sqlite3_step(S)] has never before been called on S, 4399** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4400** 4401** ^If the most recent call to [sqlite3_step(S)] for the 4402** [prepared statement] S indicated an error, then 4403** [sqlite3_reset(S)] returns an appropriate [error code]. 4404** 4405** ^The [sqlite3_reset(S)] interface does not change the values 4406** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4407*/ 4408SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 4409 4410/* 4411** CAPI3REF: Create Or Redefine SQL Functions 4412** KEYWORDS: {function creation routines} 4413** KEYWORDS: {application-defined SQL function} 4414** KEYWORDS: {application-defined SQL functions} 4415** METHOD: sqlite3 4416** 4417** ^These functions (collectively known as "function creation routines") 4418** are used to add SQL functions or aggregates or to redefine the behavior 4419** of existing SQL functions or aggregates. The only differences between 4420** these routines are the text encoding expected for 4421** the second parameter (the name of the function being created) 4422** and the presence or absence of a destructor callback for 4423** the application data pointer. 4424** 4425** ^The first parameter is the [database connection] to which the SQL 4426** function is to be added. ^If an application uses more than one database 4427** connection then application-defined SQL functions must be added 4428** to each database connection separately. 4429** 4430** ^The second parameter is the name of the SQL function to be created or 4431** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4432** representation, exclusive of the zero-terminator. ^Note that the name 4433** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4434** ^Any attempt to create a function with a longer name 4435** will result in [SQLITE_MISUSE] being returned. 4436** 4437** ^The third parameter (nArg) 4438** is the number of arguments that the SQL function or 4439** aggregate takes. ^If this parameter is -1, then the SQL function or 4440** aggregate may take any number of arguments between 0 and the limit 4441** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4442** parameter is less than -1 or greater than 127 then the behavior is 4443** undefined. 4444** 4445** ^The fourth parameter, eTextRep, specifies what 4446** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4447** its parameters. The application should set this parameter to 4448** [SQLITE_UTF16LE] if the function implementation invokes 4449** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4450** implementation invokes [sqlite3_value_text16be()] on an input, or 4451** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4452** otherwise. ^The same SQL function may be registered multiple times using 4453** different preferred text encodings, with different implementations for 4454** each encoding. 4455** ^When multiple implementations of the same function are available, SQLite 4456** will pick the one that involves the least amount of data conversion. 4457** 4458** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4459** to signal that the function will always return the same result given 4460** the same inputs within a single SQL statement. Most SQL functions are 4461** deterministic. The built-in [random()] SQL function is an example of a 4462** function that is not deterministic. The SQLite query planner is able to 4463** perform additional optimizations on deterministic functions, so use 4464** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4465** 4466** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4467** function can gain access to this pointer using [sqlite3_user_data()].)^ 4468** 4469** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4470** pointers to C-language functions that implement the SQL function or 4471** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4472** callback only; NULL pointers must be passed as the xStep and xFinal 4473** parameters. ^An aggregate SQL function requires an implementation of xStep 4474** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4475** SQL function or aggregate, pass NULL pointers for all three function 4476** callbacks. 4477** 4478** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4479** then it is destructor for the application data pointer. 4480** The destructor is invoked when the function is deleted, either by being 4481** overloaded or when the database connection closes.)^ 4482** ^The destructor is also invoked if the call to 4483** sqlite3_create_function_v2() fails. 4484** ^When the destructor callback of the tenth parameter is invoked, it 4485** is passed a single argument which is a copy of the application data 4486** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4487** 4488** ^It is permitted to register multiple implementations of the same 4489** functions with the same name but with either differing numbers of 4490** arguments or differing preferred text encodings. ^SQLite will use 4491** the implementation that most closely matches the way in which the 4492** SQL function is used. ^A function implementation with a non-negative 4493** nArg parameter is a better match than a function implementation with 4494** a negative nArg. ^A function where the preferred text encoding 4495** matches the database encoding is a better 4496** match than a function where the encoding is different. 4497** ^A function where the encoding difference is between UTF16le and UTF16be 4498** is a closer match than a function where the encoding difference is 4499** between UTF8 and UTF16. 4500** 4501** ^Built-in functions may be overloaded by new application-defined functions. 4502** 4503** ^An application-defined function is permitted to call other 4504** SQLite interfaces. However, such calls must not 4505** close the database connection nor finalize or reset the prepared 4506** statement in which the function is running. 4507*/ 4508SQLITE_API int sqlite3_create_function( 4509 sqlite3 *db, 4510 const char *zFunctionName, 4511 int nArg, 4512 int eTextRep, 4513 void *pApp, 4514 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4515 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4516 void (*xFinal)(sqlite3_context*) 4517); 4518SQLITE_API int sqlite3_create_function16( 4519 sqlite3 *db, 4520 const void *zFunctionName, 4521 int nArg, 4522 int eTextRep, 4523 void *pApp, 4524 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4525 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4526 void (*xFinal)(sqlite3_context*) 4527); 4528SQLITE_API int sqlite3_create_function_v2( 4529 sqlite3 *db, 4530 const char *zFunctionName, 4531 int nArg, 4532 int eTextRep, 4533 void *pApp, 4534 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4535 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4536 void (*xFinal)(sqlite3_context*), 4537 void(*xDestroy)(void*) 4538); 4539 4540/* 4541** CAPI3REF: Text Encodings 4542** 4543** These constant define integer codes that represent the various 4544** text encodings supported by SQLite. 4545*/ 4546#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4547#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4548#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4549#define SQLITE_UTF16 4 /* Use native byte order */ 4550#define SQLITE_ANY 5 /* Deprecated */ 4551#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4552 4553/* 4554** CAPI3REF: Function Flags 4555** 4556** These constants may be ORed together with the 4557** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4558** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4559** [sqlite3_create_function_v2()]. 4560*/ 4561#define SQLITE_DETERMINISTIC 0x800 4562 4563/* 4564** CAPI3REF: Deprecated Functions 4565** DEPRECATED 4566** 4567** These functions are [deprecated]. In order to maintain 4568** backwards compatibility with older code, these functions continue 4569** to be supported. However, new applications should avoid 4570** the use of these functions. To encourage programmers to avoid 4571** these functions, we will not explain what they do. 4572*/ 4573#ifndef SQLITE_OMIT_DEPRECATED 4574SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4575SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4576SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4577SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 4578SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4579SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4580 void*,sqlite3_int64); 4581#endif 4582 4583/* 4584** CAPI3REF: Obtaining SQL Values 4585** METHOD: sqlite3_value 4586** 4587** The C-language implementation of SQL functions and aggregates uses 4588** this set of interface routines to access the parameter values on 4589** the function or aggregate. 4590** 4591** The xFunc (for scalar functions) or xStep (for aggregates) parameters 4592** to [sqlite3_create_function()] and [sqlite3_create_function16()] 4593** define callbacks that implement the SQL functions and aggregates. 4594** The 3rd parameter to these callbacks is an array of pointers to 4595** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 4596** each parameter to the SQL function. These routines are used to 4597** extract values from the [sqlite3_value] objects. 4598** 4599** These routines work only with [protected sqlite3_value] objects. 4600** Any attempt to use these routines on an [unprotected sqlite3_value] 4601** object results in undefined behavior. 4602** 4603** ^These routines work just like the corresponding [column access functions] 4604** except that these routines take a single [protected sqlite3_value] object 4605** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4606** 4607** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4608** in the native byte-order of the host machine. ^The 4609** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4610** extract UTF-16 strings as big-endian and little-endian respectively. 4611** 4612** ^(The sqlite3_value_numeric_type() interface attempts to apply 4613** numeric affinity to the value. This means that an attempt is 4614** made to convert the value to an integer or floating point. If 4615** such a conversion is possible without loss of information (in other 4616** words, if the value is a string that looks like a number) 4617** then the conversion is performed. Otherwise no conversion occurs. 4618** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4619** 4620** Please pay particular attention to the fact that the pointer returned 4621** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4622** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4623** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4624** or [sqlite3_value_text16()]. 4625** 4626** These routines must be called from the same thread as 4627** the SQL function that supplied the [sqlite3_value*] parameters. 4628*/ 4629SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 4630SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 4631SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 4632SQLITE_API double sqlite3_value_double(sqlite3_value*); 4633SQLITE_API int sqlite3_value_int(sqlite3_value*); 4634SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4635SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 4636SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 4637SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 4638SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 4639SQLITE_API int sqlite3_value_type(sqlite3_value*); 4640SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 4641 4642/* 4643** CAPI3REF: Finding The Subtype Of SQL Values 4644** METHOD: sqlite3_value 4645** 4646** The sqlite3_value_subtype(V) function returns the subtype for 4647** an [application-defined SQL function] argument V. The subtype 4648** information can be used to pass a limited amount of context from 4649** one SQL function to another. Use the [sqlite3_result_subtype()] 4650** routine to set the subtype for the return value of an SQL function. 4651** 4652** SQLite makes no use of subtype itself. It merely passes the subtype 4653** from the result of one [application-defined SQL function] into the 4654** input of another. 4655*/ 4656SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 4657 4658/* 4659** CAPI3REF: Copy And Free SQL Values 4660** METHOD: sqlite3_value 4661** 4662** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 4663** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 4664** is a [protected sqlite3_value] object even if the input is not. 4665** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 4666** memory allocation fails. 4667** 4668** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 4669** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 4670** then sqlite3_value_free(V) is a harmless no-op. 4671*/ 4672SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 4673SQLITE_API void sqlite3_value_free(sqlite3_value*); 4674 4675/* 4676** CAPI3REF: Obtain Aggregate Function Context 4677** METHOD: sqlite3_context 4678** 4679** Implementations of aggregate SQL functions use this 4680** routine to allocate memory for storing their state. 4681** 4682** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4683** for a particular aggregate function, SQLite 4684** allocates N of memory, zeroes out that memory, and returns a pointer 4685** to the new memory. ^On second and subsequent calls to 4686** sqlite3_aggregate_context() for the same aggregate function instance, 4687** the same buffer is returned. Sqlite3_aggregate_context() is normally 4688** called once for each invocation of the xStep callback and then one 4689** last time when the xFinal callback is invoked. ^(When no rows match 4690** an aggregate query, the xStep() callback of the aggregate function 4691** implementation is never called and xFinal() is called exactly once. 4692** In those cases, sqlite3_aggregate_context() might be called for the 4693** first time from within xFinal().)^ 4694** 4695** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4696** when first called if N is less than or equal to zero or if a memory 4697** allocate error occurs. 4698** 4699** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4700** determined by the N parameter on first successful call. Changing the 4701** value of N in subsequent call to sqlite3_aggregate_context() within 4702** the same aggregate function instance will not resize the memory 4703** allocation.)^ Within the xFinal callback, it is customary to set 4704** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4705** pointless memory allocations occur. 4706** 4707** ^SQLite automatically frees the memory allocated by 4708** sqlite3_aggregate_context() when the aggregate query concludes. 4709** 4710** The first parameter must be a copy of the 4711** [sqlite3_context | SQL function context] that is the first parameter 4712** to the xStep or xFinal callback routine that implements the aggregate 4713** function. 4714** 4715** This routine must be called from the same thread in which 4716** the aggregate SQL function is running. 4717*/ 4718SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4719 4720/* 4721** CAPI3REF: User Data For Functions 4722** METHOD: sqlite3_context 4723** 4724** ^The sqlite3_user_data() interface returns a copy of 4725** the pointer that was the pUserData parameter (the 5th parameter) 4726** of the [sqlite3_create_function()] 4727** and [sqlite3_create_function16()] routines that originally 4728** registered the application defined function. 4729** 4730** This routine must be called from the same thread in which 4731** the application-defined function is running. 4732*/ 4733SQLITE_API void *sqlite3_user_data(sqlite3_context*); 4734 4735/* 4736** CAPI3REF: Database Connection For Functions 4737** METHOD: sqlite3_context 4738** 4739** ^The sqlite3_context_db_handle() interface returns a copy of 4740** the pointer to the [database connection] (the 1st parameter) 4741** of the [sqlite3_create_function()] 4742** and [sqlite3_create_function16()] routines that originally 4743** registered the application defined function. 4744*/ 4745SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 4746 4747/* 4748** CAPI3REF: Function Auxiliary Data 4749** METHOD: sqlite3_context 4750** 4751** These functions may be used by (non-aggregate) SQL functions to 4752** associate metadata with argument values. If the same value is passed to 4753** multiple invocations of the same SQL function during query execution, under 4754** some circumstances the associated metadata may be preserved. An example 4755** of where this might be useful is in a regular-expression matching 4756** function. The compiled version of the regular expression can be stored as 4757** metadata associated with the pattern string. 4758** Then as long as the pattern string remains the same, 4759** the compiled regular expression can be reused on multiple 4760** invocations of the same function. 4761** 4762** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4763** associated by the sqlite3_set_auxdata() function with the Nth argument 4764** value to the application-defined function. ^If there is no metadata 4765** associated with the function argument, this sqlite3_get_auxdata() interface 4766** returns a NULL pointer. 4767** 4768** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 4769** argument of the application-defined function. ^Subsequent 4770** calls to sqlite3_get_auxdata(C,N) return P from the most recent 4771** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 4772** NULL if the metadata has been discarded. 4773** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 4774** SQLite will invoke the destructor function X with parameter P exactly 4775** once, when the metadata is discarded. 4776** SQLite is free to discard the metadata at any time, including: <ul> 4777** <li> ^(when the corresponding function parameter changes)^, or 4778** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 4779** SQL statement)^, or 4780** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 4781** parameter)^, or 4782** <li> ^(during the original sqlite3_set_auxdata() call when a memory 4783** allocation error occurs.)^ </ul> 4784** 4785** Note the last bullet in particular. The destructor X in 4786** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 4787** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 4788** should be called near the end of the function implementation and the 4789** function implementation should not make any use of P after 4790** sqlite3_set_auxdata() has been called. 4791** 4792** ^(In practice, metadata is preserved between function calls for 4793** function parameters that are compile-time constants, including literal 4794** values and [parameters] and expressions composed from the same.)^ 4795** 4796** These routines must be called from the same thread in which 4797** the SQL function is running. 4798*/ 4799SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 4800SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4801 4802 4803/* 4804** CAPI3REF: Constants Defining Special Destructor Behavior 4805** 4806** These are special values for the destructor that is passed in as the 4807** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4808** argument is SQLITE_STATIC, it means that the content pointer is constant 4809** and will never change. It does not need to be destroyed. ^The 4810** SQLITE_TRANSIENT value means that the content will likely change in 4811** the near future and that SQLite should make its own private copy of 4812** the content before returning. 4813** 4814** The typedef is necessary to work around problems in certain 4815** C++ compilers. 4816*/ 4817typedef void (*sqlite3_destructor_type)(void*); 4818#define SQLITE_STATIC ((sqlite3_destructor_type)0) 4819#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4820 4821/* 4822** CAPI3REF: Setting The Result Of An SQL Function 4823** METHOD: sqlite3_context 4824** 4825** These routines are used by the xFunc or xFinal callbacks that 4826** implement SQL functions and aggregates. See 4827** [sqlite3_create_function()] and [sqlite3_create_function16()] 4828** for additional information. 4829** 4830** These functions work very much like the [parameter binding] family of 4831** functions used to bind values to host parameters in prepared statements. 4832** Refer to the [SQL parameter] documentation for additional information. 4833** 4834** ^The sqlite3_result_blob() interface sets the result from 4835** an application-defined function to be the BLOB whose content is pointed 4836** to by the second parameter and which is N bytes long where N is the 4837** third parameter. 4838** 4839** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 4840** interfaces set the result of the application-defined function to be 4841** a BLOB containing all zero bytes and N bytes in size. 4842** 4843** ^The sqlite3_result_double() interface sets the result from 4844** an application-defined function to be a floating point value specified 4845** by its 2nd argument. 4846** 4847** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4848** cause the implemented SQL function to throw an exception. 4849** ^SQLite uses the string pointed to by the 4850** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4851** as the text of an error message. ^SQLite interprets the error 4852** message string from sqlite3_result_error() as UTF-8. ^SQLite 4853** interprets the string from sqlite3_result_error16() as UTF-16 in native 4854** byte order. ^If the third parameter to sqlite3_result_error() 4855** or sqlite3_result_error16() is negative then SQLite takes as the error 4856** message all text up through the first zero character. 4857** ^If the third parameter to sqlite3_result_error() or 4858** sqlite3_result_error16() is non-negative then SQLite takes that many 4859** bytes (not characters) from the 2nd parameter as the error message. 4860** ^The sqlite3_result_error() and sqlite3_result_error16() 4861** routines make a private copy of the error message text before 4862** they return. Hence, the calling function can deallocate or 4863** modify the text after they return without harm. 4864** ^The sqlite3_result_error_code() function changes the error code 4865** returned by SQLite as a result of an error in a function. ^By default, 4866** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4867** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4868** 4869** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4870** error indicating that a string or BLOB is too long to represent. 4871** 4872** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4873** error indicating that a memory allocation failed. 4874** 4875** ^The sqlite3_result_int() interface sets the return value 4876** of the application-defined function to be the 32-bit signed integer 4877** value given in the 2nd argument. 4878** ^The sqlite3_result_int64() interface sets the return value 4879** of the application-defined function to be the 64-bit signed integer 4880** value given in the 2nd argument. 4881** 4882** ^The sqlite3_result_null() interface sets the return value 4883** of the application-defined function to be NULL. 4884** 4885** ^The sqlite3_result_text(), sqlite3_result_text16(), 4886** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4887** set the return value of the application-defined function to be 4888** a text string which is represented as UTF-8, UTF-16 native byte order, 4889** UTF-16 little endian, or UTF-16 big endian, respectively. 4890** ^The sqlite3_result_text64() interface sets the return value of an 4891** application-defined function to be a text string in an encoding 4892** specified by the fifth (and last) parameter, which must be one 4893** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 4894** ^SQLite takes the text result from the application from 4895** the 2nd parameter of the sqlite3_result_text* interfaces. 4896** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4897** is negative, then SQLite takes result text from the 2nd parameter 4898** through the first zero character. 4899** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4900** is non-negative, then as many bytes (not characters) of the text 4901** pointed to by the 2nd parameter are taken as the application-defined 4902** function result. If the 3rd parameter is non-negative, then it 4903** must be the byte offset into the string where the NUL terminator would 4904** appear if the string where NUL terminated. If any NUL characters occur 4905** in the string at a byte offset that is less than the value of the 3rd 4906** parameter, then the resulting string will contain embedded NULs and the 4907** result of expressions operating on strings with embedded NULs is undefined. 4908** ^If the 4th parameter to the sqlite3_result_text* interfaces 4909** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4910** function as the destructor on the text or BLOB result when it has 4911** finished using that result. 4912** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4913** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4914** assumes that the text or BLOB result is in constant space and does not 4915** copy the content of the parameter nor call a destructor on the content 4916** when it has finished using that result. 4917** ^If the 4th parameter to the sqlite3_result_text* interfaces 4918** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4919** then SQLite makes a copy of the result into space obtained from 4920** from [sqlite3_malloc()] before it returns. 4921** 4922** ^The sqlite3_result_value() interface sets the result of 4923** the application-defined function to be a copy of the 4924** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4925** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4926** so that the [sqlite3_value] specified in the parameter may change or 4927** be deallocated after sqlite3_result_value() returns without harm. 4928** ^A [protected sqlite3_value] object may always be used where an 4929** [unprotected sqlite3_value] object is required, so either 4930** kind of [sqlite3_value] object can be used with this interface. 4931** 4932** If these routines are called from within the different thread 4933** than the one containing the application-defined function that received 4934** the [sqlite3_context] pointer, the results are undefined. 4935*/ 4936SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4937SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 4938 sqlite3_uint64,void(*)(void*)); 4939SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 4940SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 4941SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 4942SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 4943SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 4944SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 4945SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 4946SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4947SQLITE_API void sqlite3_result_null(sqlite3_context*); 4948SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4949SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 4950 void(*)(void*), unsigned char encoding); 4951SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4952SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4953SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4954SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4955SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 4956SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 4957 4958 4959/* 4960** CAPI3REF: Setting The Subtype Of An SQL Function 4961** METHOD: sqlite3_context 4962** 4963** The sqlite3_result_subtype(C,T) function causes the subtype of 4964** the result from the [application-defined SQL function] with 4965** [sqlite3_context] C to be the value T. Only the lower 8 bits 4966** of the subtype T are preserved in current versions of SQLite; 4967** higher order bits are discarded. 4968** The number of subtype bytes preserved by SQLite might increase 4969** in future releases of SQLite. 4970*/ 4971SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 4972 4973/* 4974** CAPI3REF: Define New Collating Sequences 4975** METHOD: sqlite3 4976** 4977** ^These functions add, remove, or modify a [collation] associated 4978** with the [database connection] specified as the first argument. 4979** 4980** ^The name of the collation is a UTF-8 string 4981** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4982** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4983** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4984** considered to be the same name. 4985** 4986** ^(The third argument (eTextRep) must be one of the constants: 4987** <ul> 4988** <li> [SQLITE_UTF8], 4989** <li> [SQLITE_UTF16LE], 4990** <li> [SQLITE_UTF16BE], 4991** <li> [SQLITE_UTF16], or 4992** <li> [SQLITE_UTF16_ALIGNED]. 4993** </ul>)^ 4994** ^The eTextRep argument determines the encoding of strings passed 4995** to the collating function callback, xCallback. 4996** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4997** force strings to be UTF16 with native byte order. 4998** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4999** on an even byte address. 5000** 5001** ^The fourth argument, pArg, is an application data pointer that is passed 5002** through as the first argument to the collating function callback. 5003** 5004** ^The fifth argument, xCallback, is a pointer to the collating function. 5005** ^Multiple collating functions can be registered using the same name but 5006** with different eTextRep parameters and SQLite will use whichever 5007** function requires the least amount of data transformation. 5008** ^If the xCallback argument is NULL then the collating function is 5009** deleted. ^When all collating functions having the same name are deleted, 5010** that collation is no longer usable. 5011** 5012** ^The collating function callback is invoked with a copy of the pArg 5013** application data pointer and with two strings in the encoding specified 5014** by the eTextRep argument. The collating function must return an 5015** integer that is negative, zero, or positive 5016** if the first string is less than, equal to, or greater than the second, 5017** respectively. A collating function must always return the same answer 5018** given the same inputs. If two or more collating functions are registered 5019** to the same collation name (using different eTextRep values) then all 5020** must give an equivalent answer when invoked with equivalent strings. 5021** The collating function must obey the following properties for all 5022** strings A, B, and C: 5023** 5024** <ol> 5025** <li> If A==B then B==A. 5026** <li> If A==B and B==C then A==C. 5027** <li> If A<B THEN B>A. 5028** <li> If A<B and B<C then A<C. 5029** </ol> 5030** 5031** If a collating function fails any of the above constraints and that 5032** collating function is registered and used, then the behavior of SQLite 5033** is undefined. 5034** 5035** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5036** with the addition that the xDestroy callback is invoked on pArg when 5037** the collating function is deleted. 5038** ^Collating functions are deleted when they are overridden by later 5039** calls to the collation creation functions or when the 5040** [database connection] is closed using [sqlite3_close()]. 5041** 5042** ^The xDestroy callback is <u>not</u> called if the 5043** sqlite3_create_collation_v2() function fails. Applications that invoke 5044** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5045** check the return code and dispose of the application data pointer 5046** themselves rather than expecting SQLite to deal with it for them. 5047** This is different from every other SQLite interface. The inconsistency 5048** is unfortunate but cannot be changed without breaking backwards 5049** compatibility. 5050** 5051** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5052*/ 5053SQLITE_API int sqlite3_create_collation( 5054 sqlite3*, 5055 const char *zName, 5056 int eTextRep, 5057 void *pArg, 5058 int(*xCompare)(void*,int,const void*,int,const void*) 5059); 5060SQLITE_API int sqlite3_create_collation_v2( 5061 sqlite3*, 5062 const char *zName, 5063 int eTextRep, 5064 void *pArg, 5065 int(*xCompare)(void*,int,const void*,int,const void*), 5066 void(*xDestroy)(void*) 5067); 5068SQLITE_API int sqlite3_create_collation16( 5069 sqlite3*, 5070 const void *zName, 5071 int eTextRep, 5072 void *pArg, 5073 int(*xCompare)(void*,int,const void*,int,const void*) 5074); 5075 5076/* 5077** CAPI3REF: Collation Needed Callbacks 5078** METHOD: sqlite3 5079** 5080** ^To avoid having to register all collation sequences before a database 5081** can be used, a single callback function may be registered with the 5082** [database connection] to be invoked whenever an undefined collation 5083** sequence is required. 5084** 5085** ^If the function is registered using the sqlite3_collation_needed() API, 5086** then it is passed the names of undefined collation sequences as strings 5087** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5088** the names are passed as UTF-16 in machine native byte order. 5089** ^A call to either function replaces the existing collation-needed callback. 5090** 5091** ^(When the callback is invoked, the first argument passed is a copy 5092** of the second argument to sqlite3_collation_needed() or 5093** sqlite3_collation_needed16(). The second argument is the database 5094** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5095** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5096** sequence function required. The fourth parameter is the name of the 5097** required collation sequence.)^ 5098** 5099** The callback function should register the desired collation using 5100** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5101** [sqlite3_create_collation_v2()]. 5102*/ 5103SQLITE_API int sqlite3_collation_needed( 5104 sqlite3*, 5105 void*, 5106 void(*)(void*,sqlite3*,int eTextRep,const char*) 5107); 5108SQLITE_API int sqlite3_collation_needed16( 5109 sqlite3*, 5110 void*, 5111 void(*)(void*,sqlite3*,int eTextRep,const void*) 5112); 5113 5114#ifdef SQLITE_HAS_CODEC 5115/* 5116** Specify the key for an encrypted database. This routine should be 5117** called right after sqlite3_open(). 5118** 5119** The code to implement this API is not available in the public release 5120** of SQLite. 5121*/ 5122SQLITE_API int sqlite3_key( 5123 sqlite3 *db, /* Database to be rekeyed */ 5124 const void *pKey, int nKey /* The key */ 5125); 5126SQLITE_API int sqlite3_key_v2( 5127 sqlite3 *db, /* Database to be rekeyed */ 5128 const char *zDbName, /* Name of the database */ 5129 const void *pKey, int nKey /* The key */ 5130); 5131 5132/* 5133** Change the key on an open database. If the current database is not 5134** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5135** database is decrypted. 5136** 5137** The code to implement this API is not available in the public release 5138** of SQLite. 5139*/ 5140SQLITE_API int sqlite3_rekey( 5141 sqlite3 *db, /* Database to be rekeyed */ 5142 const void *pKey, int nKey /* The new key */ 5143); 5144SQLITE_API int sqlite3_rekey_v2( 5145 sqlite3 *db, /* Database to be rekeyed */ 5146 const char *zDbName, /* Name of the database */ 5147 const void *pKey, int nKey /* The new key */ 5148); 5149 5150/* 5151** Specify the activation key for a SEE database. Unless 5152** activated, none of the SEE routines will work. 5153*/ 5154SQLITE_API void sqlite3_activate_see( 5155 const char *zPassPhrase /* Activation phrase */ 5156); 5157#endif 5158 5159#ifdef SQLITE_ENABLE_CEROD 5160/* 5161** Specify the activation key for a CEROD database. Unless 5162** activated, none of the CEROD routines will work. 5163*/ 5164SQLITE_API void sqlite3_activate_cerod( 5165 const char *zPassPhrase /* Activation phrase */ 5166); 5167#endif 5168 5169/* 5170** CAPI3REF: Suspend Execution For A Short Time 5171** 5172** The sqlite3_sleep() function causes the current thread to suspend execution 5173** for at least a number of milliseconds specified in its parameter. 5174** 5175** If the operating system does not support sleep requests with 5176** millisecond time resolution, then the time will be rounded up to 5177** the nearest second. The number of milliseconds of sleep actually 5178** requested from the operating system is returned. 5179** 5180** ^SQLite implements this interface by calling the xSleep() 5181** method of the default [sqlite3_vfs] object. If the xSleep() method 5182** of the default VFS is not implemented correctly, or not implemented at 5183** all, then the behavior of sqlite3_sleep() may deviate from the description 5184** in the previous paragraphs. 5185*/ 5186SQLITE_API int sqlite3_sleep(int); 5187 5188/* 5189** CAPI3REF: Name Of The Folder Holding Temporary Files 5190** 5191** ^(If this global variable is made to point to a string which is 5192** the name of a folder (a.k.a. directory), then all temporary files 5193** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5194** will be placed in that directory.)^ ^If this variable 5195** is a NULL pointer, then SQLite performs a search for an appropriate 5196** temporary file directory. 5197** 5198** Applications are strongly discouraged from using this global variable. 5199** It is required to set a temporary folder on Windows Runtime (WinRT). 5200** But for all other platforms, it is highly recommended that applications 5201** neither read nor write this variable. This global variable is a relic 5202** that exists for backwards compatibility of legacy applications and should 5203** be avoided in new projects. 5204** 5205** It is not safe to read or modify this variable in more than one 5206** thread at a time. It is not safe to read or modify this variable 5207** if a [database connection] is being used at the same time in a separate 5208** thread. 5209** It is intended that this variable be set once 5210** as part of process initialization and before any SQLite interface 5211** routines have been called and that this variable remain unchanged 5212** thereafter. 5213** 5214** ^The [temp_store_directory pragma] may modify this variable and cause 5215** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5216** the [temp_store_directory pragma] always assumes that any string 5217** that this variable points to is held in memory obtained from 5218** [sqlite3_malloc] and the pragma may attempt to free that memory 5219** using [sqlite3_free]. 5220** Hence, if this variable is modified directly, either it should be 5221** made NULL or made to point to memory obtained from [sqlite3_malloc] 5222** or else the use of the [temp_store_directory pragma] should be avoided. 5223** Except when requested by the [temp_store_directory pragma], SQLite 5224** does not free the memory that sqlite3_temp_directory points to. If 5225** the application wants that memory to be freed, it must do 5226** so itself, taking care to only do so after all [database connection] 5227** objects have been destroyed. 5228** 5229** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5230** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5231** features that require the use of temporary files may fail. Here is an 5232** example of how to do this using C++ with the Windows Runtime: 5233** 5234** <blockquote><pre> 5235** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5236** TemporaryFolder->Path->Data(); 5237** char zPathBuf[MAX_PATH + 1]; 5238** memset(zPathBuf, 0, sizeof(zPathBuf)); 5239** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5240** NULL, NULL); 5241** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5242** </pre></blockquote> 5243*/ 5244SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 5245 5246/* 5247** CAPI3REF: Name Of The Folder Holding Database Files 5248** 5249** ^(If this global variable is made to point to a string which is 5250** the name of a folder (a.k.a. directory), then all database files 5251** specified with a relative pathname and created or accessed by 5252** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5253** to be relative to that directory.)^ ^If this variable is a NULL 5254** pointer, then SQLite assumes that all database files specified 5255** with a relative pathname are relative to the current directory 5256** for the process. Only the windows VFS makes use of this global 5257** variable; it is ignored by the unix VFS. 5258** 5259** Changing the value of this variable while a database connection is 5260** open can result in a corrupt database. 5261** 5262** It is not safe to read or modify this variable in more than one 5263** thread at a time. It is not safe to read or modify this variable 5264** if a [database connection] is being used at the same time in a separate 5265** thread. 5266** It is intended that this variable be set once 5267** as part of process initialization and before any SQLite interface 5268** routines have been called and that this variable remain unchanged 5269** thereafter. 5270** 5271** ^The [data_store_directory pragma] may modify this variable and cause 5272** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5273** the [data_store_directory pragma] always assumes that any string 5274** that this variable points to is held in memory obtained from 5275** [sqlite3_malloc] and the pragma may attempt to free that memory 5276** using [sqlite3_free]. 5277** Hence, if this variable is modified directly, either it should be 5278** made NULL or made to point to memory obtained from [sqlite3_malloc] 5279** or else the use of the [data_store_directory pragma] should be avoided. 5280*/ 5281SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 5282 5283/* 5284** CAPI3REF: Test For Auto-Commit Mode 5285** KEYWORDS: {autocommit mode} 5286** METHOD: sqlite3 5287** 5288** ^The sqlite3_get_autocommit() interface returns non-zero or 5289** zero if the given database connection is or is not in autocommit mode, 5290** respectively. ^Autocommit mode is on by default. 5291** ^Autocommit mode is disabled by a [BEGIN] statement. 5292** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5293** 5294** If certain kinds of errors occur on a statement within a multi-statement 5295** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5296** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5297** transaction might be rolled back automatically. The only way to 5298** find out whether SQLite automatically rolled back the transaction after 5299** an error is to use this function. 5300** 5301** If another thread changes the autocommit status of the database 5302** connection while this routine is running, then the return value 5303** is undefined. 5304*/ 5305SQLITE_API int sqlite3_get_autocommit(sqlite3*); 5306 5307/* 5308** CAPI3REF: Find The Database Handle Of A Prepared Statement 5309** METHOD: sqlite3_stmt 5310** 5311** ^The sqlite3_db_handle interface returns the [database connection] handle 5312** to which a [prepared statement] belongs. ^The [database connection] 5313** returned by sqlite3_db_handle is the same [database connection] 5314** that was the first argument 5315** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5316** create the statement in the first place. 5317*/ 5318SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 5319 5320/* 5321** CAPI3REF: Return The Filename For A Database Connection 5322** METHOD: sqlite3 5323** 5324** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5325** associated with database N of connection D. ^The main database file 5326** has the name "main". If there is no attached database N on the database 5327** connection D, or if database N is a temporary or in-memory database, then 5328** a NULL pointer is returned. 5329** 5330** ^The filename returned by this function is the output of the 5331** xFullPathname method of the [VFS]. ^In other words, the filename 5332** will be an absolute pathname, even if the filename used 5333** to open the database originally was a URI or relative pathname. 5334*/ 5335SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5336 5337/* 5338** CAPI3REF: Determine if a database is read-only 5339** METHOD: sqlite3 5340** 5341** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5342** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5343** the name of a database on connection D. 5344*/ 5345SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5346 5347/* 5348** CAPI3REF: Find the next prepared statement 5349** METHOD: sqlite3 5350** 5351** ^This interface returns a pointer to the next [prepared statement] after 5352** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5353** then this interface returns a pointer to the first prepared statement 5354** associated with the database connection pDb. ^If no prepared statement 5355** satisfies the conditions of this routine, it returns NULL. 5356** 5357** The [database connection] pointer D in a call to 5358** [sqlite3_next_stmt(D,S)] must refer to an open database 5359** connection and in particular must not be a NULL pointer. 5360*/ 5361SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5362 5363/* 5364** CAPI3REF: Commit And Rollback Notification Callbacks 5365** METHOD: sqlite3 5366** 5367** ^The sqlite3_commit_hook() interface registers a callback 5368** function to be invoked whenever a transaction is [COMMIT | committed]. 5369** ^Any callback set by a previous call to sqlite3_commit_hook() 5370** for the same database connection is overridden. 5371** ^The sqlite3_rollback_hook() interface registers a callback 5372** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5373** ^Any callback set by a previous call to sqlite3_rollback_hook() 5374** for the same database connection is overridden. 5375** ^The pArg argument is passed through to the callback. 5376** ^If the callback on a commit hook function returns non-zero, 5377** then the commit is converted into a rollback. 5378** 5379** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5380** return the P argument from the previous call of the same function 5381** on the same [database connection] D, or NULL for 5382** the first call for each function on D. 5383** 5384** The commit and rollback hook callbacks are not reentrant. 5385** The callback implementation must not do anything that will modify 5386** the database connection that invoked the callback. Any actions 5387** to modify the database connection must be deferred until after the 5388** completion of the [sqlite3_step()] call that triggered the commit 5389** or rollback hook in the first place. 5390** Note that running any other SQL statements, including SELECT statements, 5391** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5392** the database connections for the meaning of "modify" in this paragraph. 5393** 5394** ^Registering a NULL function disables the callback. 5395** 5396** ^When the commit hook callback routine returns zero, the [COMMIT] 5397** operation is allowed to continue normally. ^If the commit hook 5398** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5399** ^The rollback hook is invoked on a rollback that results from a commit 5400** hook returning non-zero, just as it would be with any other rollback. 5401** 5402** ^For the purposes of this API, a transaction is said to have been 5403** rolled back if an explicit "ROLLBACK" statement is executed, or 5404** an error or constraint causes an implicit rollback to occur. 5405** ^The rollback callback is not invoked if a transaction is 5406** automatically rolled back because the database connection is closed. 5407** 5408** See also the [sqlite3_update_hook()] interface. 5409*/ 5410SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5411SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5412 5413/* 5414** CAPI3REF: Data Change Notification Callbacks 5415** METHOD: sqlite3 5416** 5417** ^The sqlite3_update_hook() interface registers a callback function 5418** with the [database connection] identified by the first argument 5419** to be invoked whenever a row is updated, inserted or deleted in 5420** a [rowid table]. 5421** ^Any callback set by a previous call to this function 5422** for the same database connection is overridden. 5423** 5424** ^The second argument is a pointer to the function to invoke when a 5425** row is updated, inserted or deleted in a rowid table. 5426** ^The first argument to the callback is a copy of the third argument 5427** to sqlite3_update_hook(). 5428** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5429** or [SQLITE_UPDATE], depending on the operation that caused the callback 5430** to be invoked. 5431** ^The third and fourth arguments to the callback contain pointers to the 5432** database and table name containing the affected row. 5433** ^The final callback parameter is the [rowid] of the row. 5434** ^In the case of an update, this is the [rowid] after the update takes place. 5435** 5436** ^(The update hook is not invoked when internal system tables are 5437** modified (i.e. sqlite_master and sqlite_sequence).)^ 5438** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5439** 5440** ^In the current implementation, the update hook 5441** is not invoked when conflicting rows are deleted because of an 5442** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5443** invoked when rows are deleted using the [truncate optimization]. 5444** The exceptions defined in this paragraph might change in a future 5445** release of SQLite. 5446** 5447** The update hook implementation must not do anything that will modify 5448** the database connection that invoked the update hook. Any actions 5449** to modify the database connection must be deferred until after the 5450** completion of the [sqlite3_step()] call that triggered the update hook. 5451** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5452** database connections for the meaning of "modify" in this paragraph. 5453** 5454** ^The sqlite3_update_hook(D,C,P) function 5455** returns the P argument from the previous call 5456** on the same [database connection] D, or NULL for 5457** the first call on D. 5458** 5459** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 5460** and [sqlite3_preupdate_hook()] interfaces. 5461*/ 5462SQLITE_API void *sqlite3_update_hook( 5463 sqlite3*, 5464 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5465 void* 5466); 5467 5468/* 5469** CAPI3REF: Enable Or Disable Shared Pager Cache 5470** 5471** ^(This routine enables or disables the sharing of the database cache 5472** and schema data structures between [database connection | connections] 5473** to the same database. Sharing is enabled if the argument is true 5474** and disabled if the argument is false.)^ 5475** 5476** ^Cache sharing is enabled and disabled for an entire process. 5477** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 5478** In prior versions of SQLite, 5479** sharing was enabled or disabled for each thread separately. 5480** 5481** ^(The cache sharing mode set by this interface effects all subsequent 5482** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5483** Existing database connections continue use the sharing mode 5484** that was in effect at the time they were opened.)^ 5485** 5486** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5487** successfully. An [error code] is returned otherwise.)^ 5488** 5489** ^Shared cache is disabled by default. But this might change in 5490** future releases of SQLite. Applications that care about shared 5491** cache setting should set it explicitly. 5492** 5493** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5494** and will always return SQLITE_MISUSE. On those systems, 5495** shared cache mode should be enabled per-database connection via 5496** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5497** 5498** This interface is threadsafe on processors where writing a 5499** 32-bit integer is atomic. 5500** 5501** See Also: [SQLite Shared-Cache Mode] 5502*/ 5503SQLITE_API int sqlite3_enable_shared_cache(int); 5504 5505/* 5506** CAPI3REF: Attempt To Free Heap Memory 5507** 5508** ^The sqlite3_release_memory() interface attempts to free N bytes 5509** of heap memory by deallocating non-essential memory allocations 5510** held by the database library. Memory used to cache database 5511** pages to improve performance is an example of non-essential memory. 5512** ^sqlite3_release_memory() returns the number of bytes actually freed, 5513** which might be more or less than the amount requested. 5514** ^The sqlite3_release_memory() routine is a no-op returning zero 5515** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5516** 5517** See also: [sqlite3_db_release_memory()] 5518*/ 5519SQLITE_API int sqlite3_release_memory(int); 5520 5521/* 5522** CAPI3REF: Free Memory Used By A Database Connection 5523** METHOD: sqlite3 5524** 5525** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5526** memory as possible from database connection D. Unlike the 5527** [sqlite3_release_memory()] interface, this interface is in effect even 5528** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5529** omitted. 5530** 5531** See also: [sqlite3_release_memory()] 5532*/ 5533SQLITE_API int sqlite3_db_release_memory(sqlite3*); 5534 5535/* 5536** CAPI3REF: Impose A Limit On Heap Size 5537** 5538** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5539** soft limit on the amount of heap memory that may be allocated by SQLite. 5540** ^SQLite strives to keep heap memory utilization below the soft heap 5541** limit by reducing the number of pages held in the page cache 5542** as heap memory usages approaches the limit. 5543** ^The soft heap limit is "soft" because even though SQLite strives to stay 5544** below the limit, it will exceed the limit rather than generate 5545** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5546** is advisory only. 5547** 5548** ^The return value from sqlite3_soft_heap_limit64() is the size of 5549** the soft heap limit prior to the call, or negative in the case of an 5550** error. ^If the argument N is negative 5551** then no change is made to the soft heap limit. Hence, the current 5552** size of the soft heap limit can be determined by invoking 5553** sqlite3_soft_heap_limit64() with a negative argument. 5554** 5555** ^If the argument N is zero then the soft heap limit is disabled. 5556** 5557** ^(The soft heap limit is not enforced in the current implementation 5558** if one or more of following conditions are true: 5559** 5560** <ul> 5561** <li> The soft heap limit is set to zero. 5562** <li> Memory accounting is disabled using a combination of the 5563** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5564** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5565** <li> An alternative page cache implementation is specified using 5566** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5567** <li> The page cache allocates from its own memory pool supplied 5568** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5569** from the heap. 5570** </ul>)^ 5571** 5572** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]), 5573** the soft heap limit is enforced 5574** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5575** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5576** the soft heap limit is enforced on every memory allocation. Without 5577** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5578** when memory is allocated by the page cache. Testing suggests that because 5579** the page cache is the predominate memory user in SQLite, most 5580** applications will achieve adequate soft heap limit enforcement without 5581** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5582** 5583** The circumstances under which SQLite will enforce the soft heap limit may 5584** changes in future releases of SQLite. 5585*/ 5586SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 5587 5588/* 5589** CAPI3REF: Deprecated Soft Heap Limit Interface 5590** DEPRECATED 5591** 5592** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5593** interface. This routine is provided for historical compatibility 5594** only. All new applications should use the 5595** [sqlite3_soft_heap_limit64()] interface rather than this one. 5596*/ 5597SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 5598 5599 5600/* 5601** CAPI3REF: Extract Metadata About A Column Of A Table 5602** METHOD: sqlite3 5603** 5604** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 5605** information about column C of table T in database D 5606** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 5607** interface returns SQLITE_OK and fills in the non-NULL pointers in 5608** the final five arguments with appropriate values if the specified 5609** column exists. ^The sqlite3_table_column_metadata() interface returns 5610** SQLITE_ERROR and if the specified column does not exist. 5611** ^If the column-name parameter to sqlite3_table_column_metadata() is a 5612** NULL pointer, then this routine simply checks for the existence of the 5613** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 5614** does not. 5615** 5616** ^The column is identified by the second, third and fourth parameters to 5617** this function. ^(The second parameter is either the name of the database 5618** (i.e. "main", "temp", or an attached database) containing the specified 5619** table or NULL.)^ ^If it is NULL, then all attached databases are searched 5620** for the table using the same algorithm used by the database engine to 5621** resolve unqualified table references. 5622** 5623** ^The third and fourth parameters to this function are the table and column 5624** name of the desired column, respectively. 5625** 5626** ^Metadata is returned by writing to the memory locations passed as the 5th 5627** and subsequent parameters to this function. ^Any of these arguments may be 5628** NULL, in which case the corresponding element of metadata is omitted. 5629** 5630** ^(<blockquote> 5631** <table border="1"> 5632** <tr><th> Parameter <th> Output<br>Type <th> Description 5633** 5634** <tr><td> 5th <td> const char* <td> Data type 5635** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5636** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5637** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5638** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5639** </table> 5640** </blockquote>)^ 5641** 5642** ^The memory pointed to by the character pointers returned for the 5643** declaration type and collation sequence is valid until the next 5644** call to any SQLite API function. 5645** 5646** ^If the specified table is actually a view, an [error code] is returned. 5647** 5648** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 5649** is not a [WITHOUT ROWID] table and an 5650** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5651** parameters are set for the explicitly declared column. ^(If there is no 5652** [INTEGER PRIMARY KEY] column, then the outputs 5653** for the [rowid] are set as follows: 5654** 5655** <pre> 5656** data type: "INTEGER" 5657** collation sequence: "BINARY" 5658** not null: 0 5659** primary key: 1 5660** auto increment: 0 5661** </pre>)^ 5662** 5663** ^This function causes all database schemas to be read from disk and 5664** parsed, if that has not already been done, and returns an error if 5665** any errors are encountered while loading the schema. 5666*/ 5667SQLITE_API int sqlite3_table_column_metadata( 5668 sqlite3 *db, /* Connection handle */ 5669 const char *zDbName, /* Database name or NULL */ 5670 const char *zTableName, /* Table name */ 5671 const char *zColumnName, /* Column name */ 5672 char const **pzDataType, /* OUTPUT: Declared data type */ 5673 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5674 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5675 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5676 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5677); 5678 5679/* 5680** CAPI3REF: Load An Extension 5681** METHOD: sqlite3 5682** 5683** ^This interface loads an SQLite extension library from the named file. 5684** 5685** ^The sqlite3_load_extension() interface attempts to load an 5686** [SQLite extension] library contained in the file zFile. If 5687** the file cannot be loaded directly, attempts are made to load 5688** with various operating-system specific extensions added. 5689** So for example, if "samplelib" cannot be loaded, then names like 5690** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5691** be tried also. 5692** 5693** ^The entry point is zProc. 5694** ^(zProc may be 0, in which case SQLite will try to come up with an 5695** entry point name on its own. It first tries "sqlite3_extension_init". 5696** If that does not work, it constructs a name "sqlite3_X_init" where the 5697** X is consists of the lower-case equivalent of all ASCII alphabetic 5698** characters in the filename from the last "/" to the first following 5699** "." and omitting any initial "lib".)^ 5700** ^The sqlite3_load_extension() interface returns 5701** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5702** ^If an error occurs and pzErrMsg is not 0, then the 5703** [sqlite3_load_extension()] interface shall attempt to 5704** fill *pzErrMsg with error message text stored in memory 5705** obtained from [sqlite3_malloc()]. The calling function 5706** should free this memory by calling [sqlite3_free()]. 5707** 5708** ^Extension loading must be enabled using 5709** [sqlite3_enable_load_extension()] or 5710** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 5711** prior to calling this API, 5712** otherwise an error will be returned. 5713** 5714** <b>Security warning:</b> It is recommended that the 5715** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 5716** interface. The use of the [sqlite3_enable_load_extension()] interface 5717** should be avoided. This will keep the SQL function [load_extension()] 5718** disabled and prevent SQL injections from giving attackers 5719** access to extension loading capabilities. 5720** 5721** See also the [load_extension() SQL function]. 5722*/ 5723SQLITE_API int sqlite3_load_extension( 5724 sqlite3 *db, /* Load the extension into this database connection */ 5725 const char *zFile, /* Name of the shared library containing extension */ 5726 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5727 char **pzErrMsg /* Put error message here if not 0 */ 5728); 5729 5730/* 5731** CAPI3REF: Enable Or Disable Extension Loading 5732** METHOD: sqlite3 5733** 5734** ^So as not to open security holes in older applications that are 5735** unprepared to deal with [extension loading], and as a means of disabling 5736** [extension loading] while evaluating user-entered SQL, the following API 5737** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5738** 5739** ^Extension loading is off by default. 5740** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5741** to turn extension loading on and call it with onoff==0 to turn 5742** it back off again. 5743** 5744** ^This interface enables or disables both the C-API 5745** [sqlite3_load_extension()] and the SQL function [load_extension()]. 5746** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 5747** to enable or disable only the C-API.)^ 5748** 5749** <b>Security warning:</b> It is recommended that extension loading 5750** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 5751** rather than this interface, so the [load_extension()] SQL function 5752** remains disabled. This will prevent SQL injections from giving attackers 5753** access to extension loading capabilities. 5754*/ 5755SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5756 5757/* 5758** CAPI3REF: Automatically Load Statically Linked Extensions 5759** 5760** ^This interface causes the xEntryPoint() function to be invoked for 5761** each new [database connection] that is created. The idea here is that 5762** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5763** that is to be automatically loaded into all new database connections. 5764** 5765** ^(Even though the function prototype shows that xEntryPoint() takes 5766** no arguments and returns void, SQLite invokes xEntryPoint() with three 5767** arguments and expects an integer result as if the signature of the 5768** entry point where as follows: 5769** 5770** <blockquote><pre> 5771** int xEntryPoint( 5772** sqlite3 *db, 5773** const char **pzErrMsg, 5774** const struct sqlite3_api_routines *pThunk 5775** ); 5776** </pre></blockquote>)^ 5777** 5778** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5779** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5780** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5781** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5782** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5783** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5784** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5785** 5786** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5787** on the list of automatic extensions is a harmless no-op. ^No entry point 5788** will be called more than once for each database connection that is opened. 5789** 5790** See also: [sqlite3_reset_auto_extension()] 5791** and [sqlite3_cancel_auto_extension()] 5792*/ 5793SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 5794 5795/* 5796** CAPI3REF: Cancel Automatic Extension Loading 5797** 5798** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 5799** initialization routine X that was registered using a prior call to 5800** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 5801** routine returns 1 if initialization routine X was successfully 5802** unregistered and it returns 0 if X was not on the list of initialization 5803** routines. 5804*/ 5805SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 5806 5807/* 5808** CAPI3REF: Reset Automatic Extension Loading 5809** 5810** ^This interface disables all automatic extensions previously 5811** registered using [sqlite3_auto_extension()]. 5812*/ 5813SQLITE_API void sqlite3_reset_auto_extension(void); 5814 5815/* 5816** The interface to the virtual-table mechanism is currently considered 5817** to be experimental. The interface might change in incompatible ways. 5818** If this is a problem for you, do not use the interface at this time. 5819** 5820** When the virtual-table mechanism stabilizes, we will declare the 5821** interface fixed, support it indefinitely, and remove this comment. 5822*/ 5823 5824/* 5825** Structures used by the virtual table interface 5826*/ 5827typedef struct sqlite3_vtab sqlite3_vtab; 5828typedef struct sqlite3_index_info sqlite3_index_info; 5829typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5830typedef struct sqlite3_module sqlite3_module; 5831 5832/* 5833** CAPI3REF: Virtual Table Object 5834** KEYWORDS: sqlite3_module {virtual table module} 5835** 5836** This structure, sometimes called a "virtual table module", 5837** defines the implementation of a [virtual tables]. 5838** This structure consists mostly of methods for the module. 5839** 5840** ^A virtual table module is created by filling in a persistent 5841** instance of this structure and passing a pointer to that instance 5842** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5843** ^The registration remains valid until it is replaced by a different 5844** module or until the [database connection] closes. The content 5845** of this structure must not change while it is registered with 5846** any database connection. 5847*/ 5848struct sqlite3_module { 5849 int iVersion; 5850 int (*xCreate)(sqlite3*, void *pAux, 5851 int argc, const char *const*argv, 5852 sqlite3_vtab **ppVTab, char**); 5853 int (*xConnect)(sqlite3*, void *pAux, 5854 int argc, const char *const*argv, 5855 sqlite3_vtab **ppVTab, char**); 5856 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5857 int (*xDisconnect)(sqlite3_vtab *pVTab); 5858 int (*xDestroy)(sqlite3_vtab *pVTab); 5859 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5860 int (*xClose)(sqlite3_vtab_cursor*); 5861 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5862 int argc, sqlite3_value **argv); 5863 int (*xNext)(sqlite3_vtab_cursor*); 5864 int (*xEof)(sqlite3_vtab_cursor*); 5865 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5866 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5867 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5868 int (*xBegin)(sqlite3_vtab *pVTab); 5869 int (*xSync)(sqlite3_vtab *pVTab); 5870 int (*xCommit)(sqlite3_vtab *pVTab); 5871 int (*xRollback)(sqlite3_vtab *pVTab); 5872 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5873 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5874 void **ppArg); 5875 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5876 /* The methods above are in version 1 of the sqlite_module object. Those 5877 ** below are for version 2 and greater. */ 5878 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5879 int (*xRelease)(sqlite3_vtab *pVTab, int); 5880 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5881}; 5882 5883/* 5884** CAPI3REF: Virtual Table Indexing Information 5885** KEYWORDS: sqlite3_index_info 5886** 5887** The sqlite3_index_info structure and its substructures is used as part 5888** of the [virtual table] interface to 5889** pass information into and receive the reply from the [xBestIndex] 5890** method of a [virtual table module]. The fields under **Inputs** are the 5891** inputs to xBestIndex and are read-only. xBestIndex inserts its 5892** results into the **Outputs** fields. 5893** 5894** ^(The aConstraint[] array records WHERE clause constraints of the form: 5895** 5896** <blockquote>column OP expr</blockquote> 5897** 5898** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5899** stored in aConstraint[].op using one of the 5900** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5901** ^(The index of the column is stored in 5902** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5903** expr on the right-hand side can be evaluated (and thus the constraint 5904** is usable) and false if it cannot.)^ 5905** 5906** ^The optimizer automatically inverts terms of the form "expr OP column" 5907** and makes other simplifications to the WHERE clause in an attempt to 5908** get as many WHERE clause terms into the form shown above as possible. 5909** ^The aConstraint[] array only reports WHERE clause terms that are 5910** relevant to the particular virtual table being queried. 5911** 5912** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5913** ^Each term of aOrderBy records a column of the ORDER BY clause. 5914** 5915** The colUsed field indicates which columns of the virtual table may be 5916** required by the current scan. Virtual table columns are numbered from 5917** zero in the order in which they appear within the CREATE TABLE statement 5918** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 5919** the corresponding bit is set within the colUsed mask if the column may be 5920** required by SQLite. If the table has at least 64 columns and any column 5921** to the right of the first 63 is required, then bit 63 of colUsed is also 5922** set. In other words, column iCol may be required if the expression 5923** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 5924** non-zero. 5925** 5926** The [xBestIndex] method must fill aConstraintUsage[] with information 5927** about what parameters to pass to xFilter. ^If argvIndex>0 then 5928** the right-hand side of the corresponding aConstraint[] is evaluated 5929** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5930** is true, then the constraint is assumed to be fully handled by the 5931** virtual table and is not checked again by SQLite.)^ 5932** 5933** ^The idxNum and idxPtr values are recorded and passed into the 5934** [xFilter] method. 5935** ^[sqlite3_free()] is used to free idxPtr if and only if 5936** needToFreeIdxPtr is true. 5937** 5938** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5939** the correct order to satisfy the ORDER BY clause so that no separate 5940** sorting step is required. 5941** 5942** ^The estimatedCost value is an estimate of the cost of a particular 5943** strategy. A cost of N indicates that the cost of the strategy is similar 5944** to a linear scan of an SQLite table with N rows. A cost of log(N) 5945** indicates that the expense of the operation is similar to that of a 5946** binary search on a unique indexed field of an SQLite table with N rows. 5947** 5948** ^The estimatedRows value is an estimate of the number of rows that 5949** will be returned by the strategy. 5950** 5951** The xBestIndex method may optionally populate the idxFlags field with a 5952** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 5953** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 5954** assumes that the strategy may visit at most one row. 5955** 5956** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 5957** SQLite also assumes that if a call to the xUpdate() method is made as 5958** part of the same statement to delete or update a virtual table row and the 5959** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 5960** any database changes. In other words, if the xUpdate() returns 5961** SQLITE_CONSTRAINT, the database contents must be exactly as they were 5962** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 5963** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 5964** the xUpdate method are automatically rolled back by SQLite. 5965** 5966** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 5967** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 5968** If a virtual table extension is 5969** used with an SQLite version earlier than 3.8.2, the results of attempting 5970** to read or write the estimatedRows field are undefined (but are likely 5971** to included crashing the application). The estimatedRows field should 5972** therefore only be used if [sqlite3_libversion_number()] returns a 5973** value greater than or equal to 3008002. Similarly, the idxFlags field 5974** was added for [version 3.9.0] ([dateof:3.9.0]). 5975** It may therefore only be used if 5976** sqlite3_libversion_number() returns a value greater than or equal to 5977** 3009000. 5978*/ 5979struct sqlite3_index_info { 5980 /* Inputs */ 5981 int nConstraint; /* Number of entries in aConstraint */ 5982 struct sqlite3_index_constraint { 5983 int iColumn; /* Column constrained. -1 for ROWID */ 5984 unsigned char op; /* Constraint operator */ 5985 unsigned char usable; /* True if this constraint is usable */ 5986 int iTermOffset; /* Used internally - xBestIndex should ignore */ 5987 } *aConstraint; /* Table of WHERE clause constraints */ 5988 int nOrderBy; /* Number of terms in the ORDER BY clause */ 5989 struct sqlite3_index_orderby { 5990 int iColumn; /* Column number */ 5991 unsigned char desc; /* True for DESC. False for ASC. */ 5992 } *aOrderBy; /* The ORDER BY clause */ 5993 /* Outputs */ 5994 struct sqlite3_index_constraint_usage { 5995 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5996 unsigned char omit; /* Do not code a test for this constraint */ 5997 } *aConstraintUsage; 5998 int idxNum; /* Number used to identify the index */ 5999 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6000 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6001 int orderByConsumed; /* True if output is already ordered */ 6002 double estimatedCost; /* Estimated cost of using this index */ 6003 /* Fields below are only available in SQLite 3.8.2 and later */ 6004 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6005 /* Fields below are only available in SQLite 3.9.0 and later */ 6006 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6007 /* Fields below are only available in SQLite 3.10.0 and later */ 6008 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6009}; 6010 6011/* 6012** CAPI3REF: Virtual Table Scan Flags 6013*/ 6014#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6015 6016/* 6017** CAPI3REF: Virtual Table Constraint Operator Codes 6018** 6019** These macros defined the allowed values for the 6020** [sqlite3_index_info].aConstraint[].op field. Each value represents 6021** an operator that is part of a constraint term in the wHERE clause of 6022** a query that uses a [virtual table]. 6023*/ 6024#define SQLITE_INDEX_CONSTRAINT_EQ 2 6025#define SQLITE_INDEX_CONSTRAINT_GT 4 6026#define SQLITE_INDEX_CONSTRAINT_LE 8 6027#define SQLITE_INDEX_CONSTRAINT_LT 16 6028#define SQLITE_INDEX_CONSTRAINT_GE 32 6029#define SQLITE_INDEX_CONSTRAINT_MATCH 64 6030#define SQLITE_INDEX_CONSTRAINT_LIKE 65 6031#define SQLITE_INDEX_CONSTRAINT_GLOB 66 6032#define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6033 6034/* 6035** CAPI3REF: Register A Virtual Table Implementation 6036** METHOD: sqlite3 6037** 6038** ^These routines are used to register a new [virtual table module] name. 6039** ^Module names must be registered before 6040** creating a new [virtual table] using the module and before using a 6041** preexisting [virtual table] for the module. 6042** 6043** ^The module name is registered on the [database connection] specified 6044** by the first parameter. ^The name of the module is given by the 6045** second parameter. ^The third parameter is a pointer to 6046** the implementation of the [virtual table module]. ^The fourth 6047** parameter is an arbitrary client data pointer that is passed through 6048** into the [xCreate] and [xConnect] methods of the virtual table module 6049** when a new virtual table is be being created or reinitialized. 6050** 6051** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6052** is a pointer to a destructor for the pClientData. ^SQLite will 6053** invoke the destructor function (if it is not NULL) when SQLite 6054** no longer needs the pClientData pointer. ^The destructor will also 6055** be invoked if the call to sqlite3_create_module_v2() fails. 6056** ^The sqlite3_create_module() 6057** interface is equivalent to sqlite3_create_module_v2() with a NULL 6058** destructor. 6059*/ 6060SQLITE_API int sqlite3_create_module( 6061 sqlite3 *db, /* SQLite connection to register module with */ 6062 const char *zName, /* Name of the module */ 6063 const sqlite3_module *p, /* Methods for the module */ 6064 void *pClientData /* Client data for xCreate/xConnect */ 6065); 6066SQLITE_API int sqlite3_create_module_v2( 6067 sqlite3 *db, /* SQLite connection to register module with */ 6068 const char *zName, /* Name of the module */ 6069 const sqlite3_module *p, /* Methods for the module */ 6070 void *pClientData, /* Client data for xCreate/xConnect */ 6071 void(*xDestroy)(void*) /* Module destructor function */ 6072); 6073 6074/* 6075** CAPI3REF: Virtual Table Instance Object 6076** KEYWORDS: sqlite3_vtab 6077** 6078** Every [virtual table module] implementation uses a subclass 6079** of this object to describe a particular instance 6080** of the [virtual table]. Each subclass will 6081** be tailored to the specific needs of the module implementation. 6082** The purpose of this superclass is to define certain fields that are 6083** common to all module implementations. 6084** 6085** ^Virtual tables methods can set an error message by assigning a 6086** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6087** take care that any prior string is freed by a call to [sqlite3_free()] 6088** prior to assigning a new string to zErrMsg. ^After the error message 6089** is delivered up to the client application, the string will be automatically 6090** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6091*/ 6092struct sqlite3_vtab { 6093 const sqlite3_module *pModule; /* The module for this virtual table */ 6094 int nRef; /* Number of open cursors */ 6095 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6096 /* Virtual table implementations will typically add additional fields */ 6097}; 6098 6099/* 6100** CAPI3REF: Virtual Table Cursor Object 6101** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6102** 6103** Every [virtual table module] implementation uses a subclass of the 6104** following structure to describe cursors that point into the 6105** [virtual table] and are used 6106** to loop through the virtual table. Cursors are created using the 6107** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6108** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6109** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6110** of the module. Each module implementation will define 6111** the content of a cursor structure to suit its own needs. 6112** 6113** This superclass exists in order to define fields of the cursor that 6114** are common to all implementations. 6115*/ 6116struct sqlite3_vtab_cursor { 6117 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6118 /* Virtual table implementations will typically add additional fields */ 6119}; 6120 6121/* 6122** CAPI3REF: Declare The Schema Of A Virtual Table 6123** 6124** ^The [xCreate] and [xConnect] methods of a 6125** [virtual table module] call this interface 6126** to declare the format (the names and datatypes of the columns) of 6127** the virtual tables they implement. 6128*/ 6129SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6130 6131/* 6132** CAPI3REF: Overload A Function For A Virtual Table 6133** METHOD: sqlite3 6134** 6135** ^(Virtual tables can provide alternative implementations of functions 6136** using the [xFindFunction] method of the [virtual table module]. 6137** But global versions of those functions 6138** must exist in order to be overloaded.)^ 6139** 6140** ^(This API makes sure a global version of a function with a particular 6141** name and number of parameters exists. If no such function exists 6142** before this API is called, a new function is created.)^ ^The implementation 6143** of the new function always causes an exception to be thrown. So 6144** the new function is not good for anything by itself. Its only 6145** purpose is to be a placeholder function that can be overloaded 6146** by a [virtual table]. 6147*/ 6148SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6149 6150/* 6151** The interface to the virtual-table mechanism defined above (back up 6152** to a comment remarkably similar to this one) is currently considered 6153** to be experimental. The interface might change in incompatible ways. 6154** If this is a problem for you, do not use the interface at this time. 6155** 6156** When the virtual-table mechanism stabilizes, we will declare the 6157** interface fixed, support it indefinitely, and remove this comment. 6158*/ 6159 6160/* 6161** CAPI3REF: A Handle To An Open BLOB 6162** KEYWORDS: {BLOB handle} {BLOB handles} 6163** 6164** An instance of this object represents an open BLOB on which 6165** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6166** ^Objects of this type are created by [sqlite3_blob_open()] 6167** and destroyed by [sqlite3_blob_close()]. 6168** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6169** can be used to read or write small subsections of the BLOB. 6170** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6171*/ 6172typedef struct sqlite3_blob sqlite3_blob; 6173 6174/* 6175** CAPI3REF: Open A BLOB For Incremental I/O 6176** METHOD: sqlite3 6177** CONSTRUCTOR: sqlite3_blob 6178** 6179** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6180** in row iRow, column zColumn, table zTable in database zDb; 6181** in other words, the same BLOB that would be selected by: 6182** 6183** <pre> 6184** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 6185** </pre>)^ 6186** 6187** ^(Parameter zDb is not the filename that contains the database, but 6188** rather the symbolic name of the database. For attached databases, this is 6189** the name that appears after the AS keyword in the [ATTACH] statement. 6190** For the main database file, the database name is "main". For TEMP 6191** tables, the database name is "temp".)^ 6192** 6193** ^If the flags parameter is non-zero, then the BLOB is opened for read 6194** and write access. ^If the flags parameter is zero, the BLOB is opened for 6195** read-only access. 6196** 6197** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 6198** in *ppBlob. Otherwise an [error code] is returned and, unless the error 6199** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 6200** the API is not misused, it is always safe to call [sqlite3_blob_close()] 6201** on *ppBlob after this function it returns. 6202** 6203** This function fails with SQLITE_ERROR if any of the following are true: 6204** <ul> 6205** <li> ^(Database zDb does not exist)^, 6206** <li> ^(Table zTable does not exist within database zDb)^, 6207** <li> ^(Table zTable is a WITHOUT ROWID table)^, 6208** <li> ^(Column zColumn does not exist)^, 6209** <li> ^(Row iRow is not present in the table)^, 6210** <li> ^(The specified column of row iRow contains a value that is not 6211** a TEXT or BLOB value)^, 6212** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 6213** constraint and the blob is being opened for read/write access)^, 6214** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 6215** column zColumn is part of a [child key] definition and the blob is 6216** being opened for read/write access)^. 6217** </ul> 6218** 6219** ^Unless it returns SQLITE_MISUSE, this function sets the 6220** [database connection] error code and message accessible via 6221** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6222** 6223** A BLOB referenced by sqlite3_blob_open() may be read using the 6224** [sqlite3_blob_read()] interface and modified by using 6225** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 6226** different row of the same table using the [sqlite3_blob_reopen()] 6227** interface. However, the column, table, or database of a [BLOB handle] 6228** cannot be changed after the [BLOB handle] is opened. 6229** 6230** ^(If the row that a BLOB handle points to is modified by an 6231** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 6232** then the BLOB handle is marked as "expired". 6233** This is true if any column of the row is changed, even a column 6234** other than the one the BLOB handle is open on.)^ 6235** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 6236** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 6237** ^(Changes written into a BLOB prior to the BLOB expiring are not 6238** rolled back by the expiration of the BLOB. Such changes will eventually 6239** commit if the transaction continues to completion.)^ 6240** 6241** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 6242** the opened blob. ^The size of a blob may not be changed by this 6243** interface. Use the [UPDATE] SQL command to change the size of a 6244** blob. 6245** 6246** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 6247** and the built-in [zeroblob] SQL function may be used to create a 6248** zero-filled blob to read or write using the incremental-blob interface. 6249** 6250** To avoid a resource leak, every open [BLOB handle] should eventually 6251** be released by a call to [sqlite3_blob_close()]. 6252** 6253** See also: [sqlite3_blob_close()], 6254** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 6255** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 6256*/ 6257SQLITE_API int sqlite3_blob_open( 6258 sqlite3*, 6259 const char *zDb, 6260 const char *zTable, 6261 const char *zColumn, 6262 sqlite3_int64 iRow, 6263 int flags, 6264 sqlite3_blob **ppBlob 6265); 6266 6267/* 6268** CAPI3REF: Move a BLOB Handle to a New Row 6269** METHOD: sqlite3_blob 6270** 6271** ^This function is used to move an existing [BLOB handle] so that it points 6272** to a different row of the same database table. ^The new row is identified 6273** by the rowid value passed as the second argument. Only the row can be 6274** changed. ^The database, table and column on which the blob handle is open 6275** remain the same. Moving an existing [BLOB handle] to a new row is 6276** faster than closing the existing handle and opening a new one. 6277** 6278** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6279** it must exist and there must be either a blob or text value stored in 6280** the nominated column.)^ ^If the new row is not present in the table, or if 6281** it does not contain a blob or text value, or if another error occurs, an 6282** SQLite error code is returned and the blob handle is considered aborted. 6283** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6284** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6285** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6286** always returns zero. 6287** 6288** ^This function sets the database handle error code and message. 6289*/ 6290SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6291 6292/* 6293** CAPI3REF: Close A BLOB Handle 6294** DESTRUCTOR: sqlite3_blob 6295** 6296** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6297** unconditionally. Even if this routine returns an error code, the 6298** handle is still closed.)^ 6299** 6300** ^If the blob handle being closed was opened for read-write access, and if 6301** the database is in auto-commit mode and there are no other open read-write 6302** blob handles or active write statements, the current transaction is 6303** committed. ^If an error occurs while committing the transaction, an error 6304** code is returned and the transaction rolled back. 6305** 6306** Calling this function with an argument that is not a NULL pointer or an 6307** open blob handle results in undefined behaviour. ^Calling this routine 6308** with a null pointer (such as would be returned by a failed call to 6309** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6310** is passed a valid open blob handle, the values returned by the 6311** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6312*/ 6313SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 6314 6315/* 6316** CAPI3REF: Return The Size Of An Open BLOB 6317** METHOD: sqlite3_blob 6318** 6319** ^Returns the size in bytes of the BLOB accessible via the 6320** successfully opened [BLOB handle] in its only argument. ^The 6321** incremental blob I/O routines can only read or overwriting existing 6322** blob content; they cannot change the size of a blob. 6323** 6324** This routine only works on a [BLOB handle] which has been created 6325** by a prior successful call to [sqlite3_blob_open()] and which has not 6326** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6327** to this routine results in undefined and probably undesirable behavior. 6328*/ 6329SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 6330 6331/* 6332** CAPI3REF: Read Data From A BLOB Incrementally 6333** METHOD: sqlite3_blob 6334** 6335** ^(This function is used to read data from an open [BLOB handle] into a 6336** caller-supplied buffer. N bytes of data are copied into buffer Z 6337** from the open BLOB, starting at offset iOffset.)^ 6338** 6339** ^If offset iOffset is less than N bytes from the end of the BLOB, 6340** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6341** less than zero, [SQLITE_ERROR] is returned and no data is read. 6342** ^The size of the blob (and hence the maximum value of N+iOffset) 6343** can be determined using the [sqlite3_blob_bytes()] interface. 6344** 6345** ^An attempt to read from an expired [BLOB handle] fails with an 6346** error code of [SQLITE_ABORT]. 6347** 6348** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6349** Otherwise, an [error code] or an [extended error code] is returned.)^ 6350** 6351** This routine only works on a [BLOB handle] which has been created 6352** by a prior successful call to [sqlite3_blob_open()] and which has not 6353** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6354** to this routine results in undefined and probably undesirable behavior. 6355** 6356** See also: [sqlite3_blob_write()]. 6357*/ 6358SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6359 6360/* 6361** CAPI3REF: Write Data Into A BLOB Incrementally 6362** METHOD: sqlite3_blob 6363** 6364** ^(This function is used to write data into an open [BLOB handle] from a 6365** caller-supplied buffer. N bytes of data are copied from the buffer Z 6366** into the open BLOB, starting at offset iOffset.)^ 6367** 6368** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6369** Otherwise, an [error code] or an [extended error code] is returned.)^ 6370** ^Unless SQLITE_MISUSE is returned, this function sets the 6371** [database connection] error code and message accessible via 6372** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6373** 6374** ^If the [BLOB handle] passed as the first argument was not opened for 6375** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6376** this function returns [SQLITE_READONLY]. 6377** 6378** This function may only modify the contents of the BLOB; it is 6379** not possible to increase the size of a BLOB using this API. 6380** ^If offset iOffset is less than N bytes from the end of the BLOB, 6381** [SQLITE_ERROR] is returned and no data is written. The size of the 6382** BLOB (and hence the maximum value of N+iOffset) can be determined 6383** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 6384** than zero [SQLITE_ERROR] is returned and no data is written. 6385** 6386** ^An attempt to write to an expired [BLOB handle] fails with an 6387** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 6388** before the [BLOB handle] expired are not rolled back by the 6389** expiration of the handle, though of course those changes might 6390** have been overwritten by the statement that expired the BLOB handle 6391** or by other independent statements. 6392** 6393** This routine only works on a [BLOB handle] which has been created 6394** by a prior successful call to [sqlite3_blob_open()] and which has not 6395** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6396** to this routine results in undefined and probably undesirable behavior. 6397** 6398** See also: [sqlite3_blob_read()]. 6399*/ 6400SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 6401 6402/* 6403** CAPI3REF: Virtual File System Objects 6404** 6405** A virtual filesystem (VFS) is an [sqlite3_vfs] object 6406** that SQLite uses to interact 6407** with the underlying operating system. Most SQLite builds come with a 6408** single default VFS that is appropriate for the host computer. 6409** New VFSes can be registered and existing VFSes can be unregistered. 6410** The following interfaces are provided. 6411** 6412** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 6413** ^Names are case sensitive. 6414** ^Names are zero-terminated UTF-8 strings. 6415** ^If there is no match, a NULL pointer is returned. 6416** ^If zVfsName is NULL then the default VFS is returned. 6417** 6418** ^New VFSes are registered with sqlite3_vfs_register(). 6419** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6420** ^The same VFS can be registered multiple times without injury. 6421** ^To make an existing VFS into the default VFS, register it again 6422** with the makeDflt flag set. If two different VFSes with the 6423** same name are registered, the behavior is undefined. If a 6424** VFS is registered with a name that is NULL or an empty string, 6425** then the behavior is undefined. 6426** 6427** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6428** ^(If the default VFS is unregistered, another VFS is chosen as 6429** the default. The choice for the new VFS is arbitrary.)^ 6430*/ 6431SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 6432SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6433SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 6434 6435/* 6436** CAPI3REF: Mutexes 6437** 6438** The SQLite core uses these routines for thread 6439** synchronization. Though they are intended for internal 6440** use by SQLite, code that links against SQLite is 6441** permitted to use any of these routines. 6442** 6443** The SQLite source code contains multiple implementations 6444** of these mutex routines. An appropriate implementation 6445** is selected automatically at compile-time. The following 6446** implementations are available in the SQLite core: 6447** 6448** <ul> 6449** <li> SQLITE_MUTEX_PTHREADS 6450** <li> SQLITE_MUTEX_W32 6451** <li> SQLITE_MUTEX_NOOP 6452** </ul> 6453** 6454** The SQLITE_MUTEX_NOOP implementation is a set of routines 6455** that does no real locking and is appropriate for use in 6456** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6457** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6458** and Windows. 6459** 6460** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6461** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6462** implementation is included with the library. In this case the 6463** application must supply a custom mutex implementation using the 6464** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6465** before calling sqlite3_initialize() or any other public sqlite3_ 6466** function that calls sqlite3_initialize(). 6467** 6468** ^The sqlite3_mutex_alloc() routine allocates a new 6469** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6470** routine returns NULL if it is unable to allocate the requested 6471** mutex. The argument to sqlite3_mutex_alloc() must one of these 6472** integer constants: 6473** 6474** <ul> 6475** <li> SQLITE_MUTEX_FAST 6476** <li> SQLITE_MUTEX_RECURSIVE 6477** <li> SQLITE_MUTEX_STATIC_MASTER 6478** <li> SQLITE_MUTEX_STATIC_MEM 6479** <li> SQLITE_MUTEX_STATIC_OPEN 6480** <li> SQLITE_MUTEX_STATIC_PRNG 6481** <li> SQLITE_MUTEX_STATIC_LRU 6482** <li> SQLITE_MUTEX_STATIC_PMEM 6483** <li> SQLITE_MUTEX_STATIC_APP1 6484** <li> SQLITE_MUTEX_STATIC_APP2 6485** <li> SQLITE_MUTEX_STATIC_APP3 6486** <li> SQLITE_MUTEX_STATIC_VFS1 6487** <li> SQLITE_MUTEX_STATIC_VFS2 6488** <li> SQLITE_MUTEX_STATIC_VFS3 6489** </ul> 6490** 6491** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6492** cause sqlite3_mutex_alloc() to create 6493** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6494** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6495** The mutex implementation does not need to make a distinction 6496** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6497** not want to. SQLite will only request a recursive mutex in 6498** cases where it really needs one. If a faster non-recursive mutex 6499** implementation is available on the host platform, the mutex subsystem 6500** might return such a mutex in response to SQLITE_MUTEX_FAST. 6501** 6502** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6503** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6504** a pointer to a static preexisting mutex. ^Nine static mutexes are 6505** used by the current version of SQLite. Future versions of SQLite 6506** may add additional static mutexes. Static mutexes are for internal 6507** use by SQLite only. Applications that use SQLite mutexes should 6508** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6509** SQLITE_MUTEX_RECURSIVE. 6510** 6511** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6512** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6513** returns a different mutex on every call. ^For the static 6514** mutex types, the same mutex is returned on every call that has 6515** the same type number. 6516** 6517** ^The sqlite3_mutex_free() routine deallocates a previously 6518** allocated dynamic mutex. Attempting to deallocate a static 6519** mutex results in undefined behavior. 6520** 6521** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6522** to enter a mutex. ^If another thread is already within the mutex, 6523** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6524** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6525** upon successful entry. ^(Mutexes created using 6526** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6527** In such cases, the 6528** mutex must be exited an equal number of times before another thread 6529** can enter.)^ If the same thread tries to enter any mutex other 6530** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6531** 6532** ^(Some systems (for example, Windows 95) do not support the operation 6533** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6534** will always return SQLITE_BUSY. The SQLite core only ever uses 6535** sqlite3_mutex_try() as an optimization so this is acceptable 6536** behavior.)^ 6537** 6538** ^The sqlite3_mutex_leave() routine exits a mutex that was 6539** previously entered by the same thread. The behavior 6540** is undefined if the mutex is not currently entered by the 6541** calling thread or is not currently allocated. 6542** 6543** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6544** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6545** behave as no-ops. 6546** 6547** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6548*/ 6549SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 6550SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 6551SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 6552SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 6553SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 6554 6555/* 6556** CAPI3REF: Mutex Methods Object 6557** 6558** An instance of this structure defines the low-level routines 6559** used to allocate and use mutexes. 6560** 6561** Usually, the default mutex implementations provided by SQLite are 6562** sufficient, however the application has the option of substituting a custom 6563** implementation for specialized deployments or systems for which SQLite 6564** does not provide a suitable implementation. In this case, the application 6565** creates and populates an instance of this structure to pass 6566** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6567** Additionally, an instance of this structure can be used as an 6568** output variable when querying the system for the current mutex 6569** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6570** 6571** ^The xMutexInit method defined by this structure is invoked as 6572** part of system initialization by the sqlite3_initialize() function. 6573** ^The xMutexInit routine is called by SQLite exactly once for each 6574** effective call to [sqlite3_initialize()]. 6575** 6576** ^The xMutexEnd method defined by this structure is invoked as 6577** part of system shutdown by the sqlite3_shutdown() function. The 6578** implementation of this method is expected to release all outstanding 6579** resources obtained by the mutex methods implementation, especially 6580** those obtained by the xMutexInit method. ^The xMutexEnd() 6581** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6582** 6583** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6584** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6585** xMutexNotheld) implement the following interfaces (respectively): 6586** 6587** <ul> 6588** <li> [sqlite3_mutex_alloc()] </li> 6589** <li> [sqlite3_mutex_free()] </li> 6590** <li> [sqlite3_mutex_enter()] </li> 6591** <li> [sqlite3_mutex_try()] </li> 6592** <li> [sqlite3_mutex_leave()] </li> 6593** <li> [sqlite3_mutex_held()] </li> 6594** <li> [sqlite3_mutex_notheld()] </li> 6595** </ul>)^ 6596** 6597** The only difference is that the public sqlite3_XXX functions enumerated 6598** above silently ignore any invocations that pass a NULL pointer instead 6599** of a valid mutex handle. The implementations of the methods defined 6600** by this structure are not required to handle this case, the results 6601** of passing a NULL pointer instead of a valid mutex handle are undefined 6602** (i.e. it is acceptable to provide an implementation that segfaults if 6603** it is passed a NULL pointer). 6604** 6605** The xMutexInit() method must be threadsafe. It must be harmless to 6606** invoke xMutexInit() multiple times within the same process and without 6607** intervening calls to xMutexEnd(). Second and subsequent calls to 6608** xMutexInit() must be no-ops. 6609** 6610** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 6611** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 6612** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 6613** memory allocation for a fast or recursive mutex. 6614** 6615** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 6616** called, but only if the prior call to xMutexInit returned SQLITE_OK. 6617** If xMutexInit fails in any way, it is expected to clean up after itself 6618** prior to returning. 6619*/ 6620typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6621struct sqlite3_mutex_methods { 6622 int (*xMutexInit)(void); 6623 int (*xMutexEnd)(void); 6624 sqlite3_mutex *(*xMutexAlloc)(int); 6625 void (*xMutexFree)(sqlite3_mutex *); 6626 void (*xMutexEnter)(sqlite3_mutex *); 6627 int (*xMutexTry)(sqlite3_mutex *); 6628 void (*xMutexLeave)(sqlite3_mutex *); 6629 int (*xMutexHeld)(sqlite3_mutex *); 6630 int (*xMutexNotheld)(sqlite3_mutex *); 6631}; 6632 6633/* 6634** CAPI3REF: Mutex Verification Routines 6635** 6636** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 6637** are intended for use inside assert() statements. The SQLite core 6638** never uses these routines except inside an assert() and applications 6639** are advised to follow the lead of the core. The SQLite core only 6640** provides implementations for these routines when it is compiled 6641** with the SQLITE_DEBUG flag. External mutex implementations 6642** are only required to provide these routines if SQLITE_DEBUG is 6643** defined and if NDEBUG is not defined. 6644** 6645** These routines should return true if the mutex in their argument 6646** is held or not held, respectively, by the calling thread. 6647** 6648** The implementation is not required to provide versions of these 6649** routines that actually work. If the implementation does not provide working 6650** versions of these routines, it should at least provide stubs that always 6651** return true so that one does not get spurious assertion failures. 6652** 6653** If the argument to sqlite3_mutex_held() is a NULL pointer then 6654** the routine should return 1. This seems counter-intuitive since 6655** clearly the mutex cannot be held if it does not exist. But 6656** the reason the mutex does not exist is because the build is not 6657** using mutexes. And we do not want the assert() containing the 6658** call to sqlite3_mutex_held() to fail, so a non-zero return is 6659** the appropriate thing to do. The sqlite3_mutex_notheld() 6660** interface should also return 1 when given a NULL pointer. 6661*/ 6662#ifndef NDEBUG 6663SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 6664SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 6665#endif 6666 6667/* 6668** CAPI3REF: Mutex Types 6669** 6670** The [sqlite3_mutex_alloc()] interface takes a single argument 6671** which is one of these integer constants. 6672** 6673** The set of static mutexes may change from one SQLite release to the 6674** next. Applications that override the built-in mutex logic must be 6675** prepared to accommodate additional static mutexes. 6676*/ 6677#define SQLITE_MUTEX_FAST 0 6678#define SQLITE_MUTEX_RECURSIVE 1 6679#define SQLITE_MUTEX_STATIC_MASTER 2 6680#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6681#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6682#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6683#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 6684#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6685#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6686#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6687#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 6688#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 6689#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 6690#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 6691#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 6692#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 6693 6694/* 6695** CAPI3REF: Retrieve the mutex for a database connection 6696** METHOD: sqlite3 6697** 6698** ^This interface returns a pointer the [sqlite3_mutex] object that 6699** serializes access to the [database connection] given in the argument 6700** when the [threading mode] is Serialized. 6701** ^If the [threading mode] is Single-thread or Multi-thread then this 6702** routine returns a NULL pointer. 6703*/ 6704SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 6705 6706/* 6707** CAPI3REF: Low-Level Control Of Database Files 6708** METHOD: sqlite3 6709** 6710** ^The [sqlite3_file_control()] interface makes a direct call to the 6711** xFileControl method for the [sqlite3_io_methods] object associated 6712** with a particular database identified by the second argument. ^The 6713** name of the database is "main" for the main database or "temp" for the 6714** TEMP database, or the name that appears after the AS keyword for 6715** databases that are added using the [ATTACH] SQL command. 6716** ^A NULL pointer can be used in place of "main" to refer to the 6717** main database file. 6718** ^The third and fourth parameters to this routine 6719** are passed directly through to the second and third parameters of 6720** the xFileControl method. ^The return value of the xFileControl 6721** method becomes the return value of this routine. 6722** 6723** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 6724** a pointer to the underlying [sqlite3_file] object to be written into 6725** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 6726** case is a short-circuit path which does not actually invoke the 6727** underlying sqlite3_io_methods.xFileControl method. 6728** 6729** ^If the second parameter (zDbName) does not match the name of any 6730** open database file, then SQLITE_ERROR is returned. ^This error 6731** code is not remembered and will not be recalled by [sqlite3_errcode()] 6732** or [sqlite3_errmsg()]. The underlying xFileControl method might 6733** also return SQLITE_ERROR. There is no way to distinguish between 6734** an incorrect zDbName and an SQLITE_ERROR return from the underlying 6735** xFileControl method. 6736** 6737** See also: [SQLITE_FCNTL_LOCKSTATE] 6738*/ 6739SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 6740 6741/* 6742** CAPI3REF: Testing Interface 6743** 6744** ^The sqlite3_test_control() interface is used to read out internal 6745** state of SQLite and to inject faults into SQLite for testing 6746** purposes. ^The first parameter is an operation code that determines 6747** the number, meaning, and operation of all subsequent parameters. 6748** 6749** This interface is not for use by applications. It exists solely 6750** for verifying the correct operation of the SQLite library. Depending 6751** on how the SQLite library is compiled, this interface might not exist. 6752** 6753** The details of the operation codes, their meanings, the parameters 6754** they take, and what they do are all subject to change without notice. 6755** Unlike most of the SQLite API, this function is not guaranteed to 6756** operate consistently from one release to the next. 6757*/ 6758SQLITE_API int sqlite3_test_control(int op, ...); 6759 6760/* 6761** CAPI3REF: Testing Interface Operation Codes 6762** 6763** These constants are the valid operation code parameters used 6764** as the first argument to [sqlite3_test_control()]. 6765** 6766** These parameters and their meanings are subject to change 6767** without notice. These values are for testing purposes only. 6768** Applications should not use any of these parameters or the 6769** [sqlite3_test_control()] interface. 6770*/ 6771#define SQLITE_TESTCTRL_FIRST 5 6772#define SQLITE_TESTCTRL_PRNG_SAVE 5 6773#define SQLITE_TESTCTRL_PRNG_RESTORE 6 6774#define SQLITE_TESTCTRL_PRNG_RESET 7 6775#define SQLITE_TESTCTRL_BITVEC_TEST 8 6776#define SQLITE_TESTCTRL_FAULT_INSTALL 9 6777#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 6778#define SQLITE_TESTCTRL_PENDING_BYTE 11 6779#define SQLITE_TESTCTRL_ASSERT 12 6780#define SQLITE_TESTCTRL_ALWAYS 13 6781#define SQLITE_TESTCTRL_RESERVE 14 6782#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 6783#define SQLITE_TESTCTRL_ISKEYWORD 16 6784#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 6785#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 6786#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 6787#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 6788#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 6789#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 6790#define SQLITE_TESTCTRL_BYTEORDER 22 6791#define SQLITE_TESTCTRL_ISINIT 23 6792#define SQLITE_TESTCTRL_SORTER_MMAP 24 6793#define SQLITE_TESTCTRL_IMPOSTER 25 6794#define SQLITE_TESTCTRL_LAST 25 6795 6796/* 6797** CAPI3REF: SQLite Runtime Status 6798** 6799** ^These interfaces are used to retrieve runtime status information 6800** about the performance of SQLite, and optionally to reset various 6801** highwater marks. ^The first argument is an integer code for 6802** the specific parameter to measure. ^(Recognized integer codes 6803** are of the form [status parameters | SQLITE_STATUS_...].)^ 6804** ^The current value of the parameter is returned into *pCurrent. 6805** ^The highest recorded value is returned in *pHighwater. ^If the 6806** resetFlag is true, then the highest record value is reset after 6807** *pHighwater is written. ^(Some parameters do not record the highest 6808** value. For those parameters 6809** nothing is written into *pHighwater and the resetFlag is ignored.)^ 6810** ^(Other parameters record only the highwater mark and not the current 6811** value. For these latter parameters nothing is written into *pCurrent.)^ 6812** 6813** ^The sqlite3_status() and sqlite3_status64() routines return 6814** SQLITE_OK on success and a non-zero [error code] on failure. 6815** 6816** If either the current value or the highwater mark is too large to 6817** be represented by a 32-bit integer, then the values returned by 6818** sqlite3_status() are undefined. 6819** 6820** See also: [sqlite3_db_status()] 6821*/ 6822SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 6823SQLITE_API int sqlite3_status64( 6824 int op, 6825 sqlite3_int64 *pCurrent, 6826 sqlite3_int64 *pHighwater, 6827 int resetFlag 6828); 6829 6830 6831/* 6832** CAPI3REF: Status Parameters 6833** KEYWORDS: {status parameters} 6834** 6835** These integer constants designate various run-time status parameters 6836** that can be returned by [sqlite3_status()]. 6837** 6838** <dl> 6839** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 6840** <dd>This parameter is the current amount of memory checked out 6841** using [sqlite3_malloc()], either directly or indirectly. The 6842** figure includes calls made to [sqlite3_malloc()] by the application 6843** and internal memory usage by the SQLite library. Scratch memory 6844** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 6845** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 6846** this parameter. The amount returned is the sum of the allocation 6847** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 6848** 6849** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 6850** <dd>This parameter records the largest memory allocation request 6851** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 6852** internal equivalents). Only the value returned in the 6853** *pHighwater parameter to [sqlite3_status()] is of interest. 6854** The value written into the *pCurrent parameter is undefined.</dd>)^ 6855** 6856** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 6857** <dd>This parameter records the number of separate memory allocations 6858** currently checked out.</dd>)^ 6859** 6860** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 6861** <dd>This parameter returns the number of pages used out of the 6862** [pagecache memory allocator] that was configured using 6863** [SQLITE_CONFIG_PAGECACHE]. The 6864** value returned is in pages, not in bytes.</dd>)^ 6865** 6866** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 6867** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6868** <dd>This parameter returns the number of bytes of page cache 6869** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 6870** buffer and where forced to overflow to [sqlite3_malloc()]. The 6871** returned value includes allocations that overflowed because they 6872** where too large (they were larger than the "sz" parameter to 6873** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 6874** no space was left in the page cache.</dd>)^ 6875** 6876** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 6877** <dd>This parameter records the largest memory allocation request 6878** handed to [pagecache memory allocator]. Only the value returned in the 6879** *pHighwater parameter to [sqlite3_status()] is of interest. 6880** The value written into the *pCurrent parameter is undefined.</dd>)^ 6881** 6882** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 6883** <dd>This parameter returns the number of allocations used out of the 6884** [scratch memory allocator] configured using 6885** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6886** in bytes. Since a single thread may only have one scratch allocation 6887** outstanding at time, this parameter also reports the number of threads 6888** using scratch memory at the same time.</dd>)^ 6889** 6890** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6891** <dd>This parameter returns the number of bytes of scratch memory 6892** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 6893** buffer and where forced to overflow to [sqlite3_malloc()]. The values 6894** returned include overflows because the requested allocation was too 6895** larger (that is, because the requested allocation was larger than the 6896** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 6897** slots were available. 6898** </dd>)^ 6899** 6900** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6901** <dd>This parameter records the largest memory allocation request 6902** handed to [scratch memory allocator]. Only the value returned in the 6903** *pHighwater parameter to [sqlite3_status()] is of interest. 6904** The value written into the *pCurrent parameter is undefined.</dd>)^ 6905** 6906** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6907** <dd>The *pHighwater parameter records the deepest parser stack. 6908** The *pCurrent value is undefined. The *pHighwater value is only 6909** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6910** </dl> 6911** 6912** New status parameters may be added from time to time. 6913*/ 6914#define SQLITE_STATUS_MEMORY_USED 0 6915#define SQLITE_STATUS_PAGECACHE_USED 1 6916#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6917#define SQLITE_STATUS_SCRATCH_USED 3 6918#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6919#define SQLITE_STATUS_MALLOC_SIZE 5 6920#define SQLITE_STATUS_PARSER_STACK 6 6921#define SQLITE_STATUS_PAGECACHE_SIZE 7 6922#define SQLITE_STATUS_SCRATCH_SIZE 8 6923#define SQLITE_STATUS_MALLOC_COUNT 9 6924 6925/* 6926** CAPI3REF: Database Connection Status 6927** METHOD: sqlite3 6928** 6929** ^This interface is used to retrieve runtime status information 6930** about a single [database connection]. ^The first argument is the 6931** database connection object to be interrogated. ^The second argument 6932** is an integer constant, taken from the set of 6933** [SQLITE_DBSTATUS options], that 6934** determines the parameter to interrogate. The set of 6935** [SQLITE_DBSTATUS options] is likely 6936** to grow in future releases of SQLite. 6937** 6938** ^The current value of the requested parameter is written into *pCur 6939** and the highest instantaneous value is written into *pHiwtr. ^If 6940** the resetFlg is true, then the highest instantaneous value is 6941** reset back down to the current value. 6942** 6943** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 6944** non-zero [error code] on failure. 6945** 6946** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 6947*/ 6948SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 6949 6950/* 6951** CAPI3REF: Status Parameters for database connections 6952** KEYWORDS: {SQLITE_DBSTATUS options} 6953** 6954** These constants are the available integer "verbs" that can be passed as 6955** the second argument to the [sqlite3_db_status()] interface. 6956** 6957** New verbs may be added in future releases of SQLite. Existing verbs 6958** might be discontinued. Applications should check the return code from 6959** [sqlite3_db_status()] to make sure that the call worked. 6960** The [sqlite3_db_status()] interface will return a non-zero error code 6961** if a discontinued or unsupported verb is invoked. 6962** 6963** <dl> 6964** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6965** <dd>This parameter returns the number of lookaside memory slots currently 6966** checked out.</dd>)^ 6967** 6968** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6969** <dd>This parameter returns the number malloc attempts that were 6970** satisfied using lookaside memory. Only the high-water value is meaningful; 6971** the current value is always zero.)^ 6972** 6973** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6974** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6975** <dd>This parameter returns the number malloc attempts that might have 6976** been satisfied using lookaside memory but failed due to the amount of 6977** memory requested being larger than the lookaside slot size. 6978** Only the high-water value is meaningful; 6979** the current value is always zero.)^ 6980** 6981** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6982** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6983** <dd>This parameter returns the number malloc attempts that might have 6984** been satisfied using lookaside memory but failed due to all lookaside 6985** memory already being in use. 6986** Only the high-water value is meaningful; 6987** the current value is always zero.)^ 6988** 6989** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6990** <dd>This parameter returns the approximate number of bytes of heap 6991** memory used by all pager caches associated with the database connection.)^ 6992** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6993** 6994** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 6995** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 6996** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 6997** pager cache is shared between two or more connections the bytes of heap 6998** memory used by that pager cache is divided evenly between the attached 6999** connections.)^ In other words, if none of the pager caches associated 7000** with the database connection are shared, this request returns the same 7001** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 7002** shared, the value returned by this call will be smaller than that returned 7003** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 7004** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 7005** 7006** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 7007** <dd>This parameter returns the approximate number of bytes of heap 7008** memory used to store the schema for all databases associated 7009** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 7010** ^The full amount of memory used by the schemas is reported, even if the 7011** schema memory is shared with other database connections due to 7012** [shared cache mode] being enabled. 7013** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 7014** 7015** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 7016** <dd>This parameter returns the approximate number of bytes of heap 7017** and lookaside memory used by all prepared statements associated with 7018** the database connection.)^ 7019** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 7020** </dd> 7021** 7022** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 7023** <dd>This parameter returns the number of pager cache hits that have 7024** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 7025** is always 0. 7026** </dd> 7027** 7028** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 7029** <dd>This parameter returns the number of pager cache misses that have 7030** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 7031** is always 0. 7032** </dd> 7033** 7034** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 7035** <dd>This parameter returns the number of dirty cache entries that have 7036** been written to disk. Specifically, the number of pages written to the 7037** wal file in wal mode databases, or the number of pages written to the 7038** database file in rollback mode databases. Any pages written as part of 7039** transaction rollback or database recovery operations are not included. 7040** If an IO or other error occurs while writing a page to disk, the effect 7041** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 7042** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 7043** </dd> 7044** 7045** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 7046** <dd>This parameter returns zero for the current value if and only if 7047** all foreign key constraints (deferred or immediate) have been 7048** resolved.)^ ^The highwater mark is always 0. 7049** </dd> 7050** </dl> 7051*/ 7052#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 7053#define SQLITE_DBSTATUS_CACHE_USED 1 7054#define SQLITE_DBSTATUS_SCHEMA_USED 2 7055#define SQLITE_DBSTATUS_STMT_USED 3 7056#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 7057#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 7058#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 7059#define SQLITE_DBSTATUS_CACHE_HIT 7 7060#define SQLITE_DBSTATUS_CACHE_MISS 8 7061#define SQLITE_DBSTATUS_CACHE_WRITE 9 7062#define SQLITE_DBSTATUS_DEFERRED_FKS 10 7063#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 7064#define SQLITE_DBSTATUS_MAX 11 /* Largest defined DBSTATUS */ 7065 7066 7067/* 7068** CAPI3REF: Prepared Statement Status 7069** METHOD: sqlite3_stmt 7070** 7071** ^(Each prepared statement maintains various 7072** [SQLITE_STMTSTATUS counters] that measure the number 7073** of times it has performed specific operations.)^ These counters can 7074** be used to monitor the performance characteristics of the prepared 7075** statements. For example, if the number of table steps greatly exceeds 7076** the number of table searches or result rows, that would tend to indicate 7077** that the prepared statement is using a full table scan rather than 7078** an index. 7079** 7080** ^(This interface is used to retrieve and reset counter values from 7081** a [prepared statement]. The first argument is the prepared statement 7082** object to be interrogated. The second argument 7083** is an integer code for a specific [SQLITE_STMTSTATUS counter] 7084** to be interrogated.)^ 7085** ^The current value of the requested counter is returned. 7086** ^If the resetFlg is true, then the counter is reset to zero after this 7087** interface call returns. 7088** 7089** See also: [sqlite3_status()] and [sqlite3_db_status()]. 7090*/ 7091SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 7092 7093/* 7094** CAPI3REF: Status Parameters for prepared statements 7095** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 7096** 7097** These preprocessor macros define integer codes that name counter 7098** values associated with the [sqlite3_stmt_status()] interface. 7099** The meanings of the various counters are as follows: 7100** 7101** <dl> 7102** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 7103** <dd>^This is the number of times that SQLite has stepped forward in 7104** a table as part of a full table scan. Large numbers for this counter 7105** may indicate opportunities for performance improvement through 7106** careful use of indices.</dd> 7107** 7108** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 7109** <dd>^This is the number of sort operations that have occurred. 7110** A non-zero value in this counter may indicate an opportunity to 7111** improvement performance through careful use of indices.</dd> 7112** 7113** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 7114** <dd>^This is the number of rows inserted into transient indices that 7115** were created automatically in order to help joins run faster. 7116** A non-zero value in this counter may indicate an opportunity to 7117** improvement performance by adding permanent indices that do not 7118** need to be reinitialized each time the statement is run.</dd> 7119** 7120** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 7121** <dd>^This is the number of virtual machine operations executed 7122** by the prepared statement if that number is less than or equal 7123** to 2147483647. The number of virtual machine operations can be 7124** used as a proxy for the total work done by the prepared statement. 7125** If the number of virtual machine operations exceeds 2147483647 7126** then the value returned by this statement status code is undefined. 7127** </dd> 7128** </dl> 7129*/ 7130#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 7131#define SQLITE_STMTSTATUS_SORT 2 7132#define SQLITE_STMTSTATUS_AUTOINDEX 3 7133#define SQLITE_STMTSTATUS_VM_STEP 4 7134 7135/* 7136** CAPI3REF: Custom Page Cache Object 7137** 7138** The sqlite3_pcache type is opaque. It is implemented by 7139** the pluggable module. The SQLite core has no knowledge of 7140** its size or internal structure and never deals with the 7141** sqlite3_pcache object except by holding and passing pointers 7142** to the object. 7143** 7144** See [sqlite3_pcache_methods2] for additional information. 7145*/ 7146typedef struct sqlite3_pcache sqlite3_pcache; 7147 7148/* 7149** CAPI3REF: Custom Page Cache Object 7150** 7151** The sqlite3_pcache_page object represents a single page in the 7152** page cache. The page cache will allocate instances of this 7153** object. Various methods of the page cache use pointers to instances 7154** of this object as parameters or as their return value. 7155** 7156** See [sqlite3_pcache_methods2] for additional information. 7157*/ 7158typedef struct sqlite3_pcache_page sqlite3_pcache_page; 7159struct sqlite3_pcache_page { 7160 void *pBuf; /* The content of the page */ 7161 void *pExtra; /* Extra information associated with the page */ 7162}; 7163 7164/* 7165** CAPI3REF: Application Defined Page Cache. 7166** KEYWORDS: {page cache} 7167** 7168** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 7169** register an alternative page cache implementation by passing in an 7170** instance of the sqlite3_pcache_methods2 structure.)^ 7171** In many applications, most of the heap memory allocated by 7172** SQLite is used for the page cache. 7173** By implementing a 7174** custom page cache using this API, an application can better control 7175** the amount of memory consumed by SQLite, the way in which 7176** that memory is allocated and released, and the policies used to 7177** determine exactly which parts of a database file are cached and for 7178** how long. 7179** 7180** The alternative page cache mechanism is an 7181** extreme measure that is only needed by the most demanding applications. 7182** The built-in page cache is recommended for most uses. 7183** 7184** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 7185** internal buffer by SQLite within the call to [sqlite3_config]. Hence 7186** the application may discard the parameter after the call to 7187** [sqlite3_config()] returns.)^ 7188** 7189** [[the xInit() page cache method]] 7190** ^(The xInit() method is called once for each effective 7191** call to [sqlite3_initialize()])^ 7192** (usually only once during the lifetime of the process). ^(The xInit() 7193** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 7194** The intent of the xInit() method is to set up global data structures 7195** required by the custom page cache implementation. 7196** ^(If the xInit() method is NULL, then the 7197** built-in default page cache is used instead of the application defined 7198** page cache.)^ 7199** 7200** [[the xShutdown() page cache method]] 7201** ^The xShutdown() method is called by [sqlite3_shutdown()]. 7202** It can be used to clean up 7203** any outstanding resources before process shutdown, if required. 7204** ^The xShutdown() method may be NULL. 7205** 7206** ^SQLite automatically serializes calls to the xInit method, 7207** so the xInit method need not be threadsafe. ^The 7208** xShutdown method is only called from [sqlite3_shutdown()] so it does 7209** not need to be threadsafe either. All other methods must be threadsafe 7210** in multithreaded applications. 7211** 7212** ^SQLite will never invoke xInit() more than once without an intervening 7213** call to xShutdown(). 7214** 7215** [[the xCreate() page cache methods]] 7216** ^SQLite invokes the xCreate() method to construct a new cache instance. 7217** SQLite will typically create one cache instance for each open database file, 7218** though this is not guaranteed. ^The 7219** first parameter, szPage, is the size in bytes of the pages that must 7220** be allocated by the cache. ^szPage will always a power of two. ^The 7221** second parameter szExtra is a number of bytes of extra storage 7222** associated with each page cache entry. ^The szExtra parameter will 7223** a number less than 250. SQLite will use the 7224** extra szExtra bytes on each page to store metadata about the underlying 7225** database page on disk. The value passed into szExtra depends 7226** on the SQLite version, the target platform, and how SQLite was compiled. 7227** ^The third argument to xCreate(), bPurgeable, is true if the cache being 7228** created will be used to cache database pages of a file stored on disk, or 7229** false if it is used for an in-memory database. The cache implementation 7230** does not have to do anything special based with the value of bPurgeable; 7231** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 7232** never invoke xUnpin() except to deliberately delete a page. 7233** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 7234** false will always have the "discard" flag set to true. 7235** ^Hence, a cache created with bPurgeable false will 7236** never contain any unpinned pages. 7237** 7238** [[the xCachesize() page cache method]] 7239** ^(The xCachesize() method may be called at any time by SQLite to set the 7240** suggested maximum cache-size (number of pages stored by) the cache 7241** instance passed as the first argument. This is the value configured using 7242** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 7243** parameter, the implementation is not required to do anything with this 7244** value; it is advisory only. 7245** 7246** [[the xPagecount() page cache methods]] 7247** The xPagecount() method must return the number of pages currently 7248** stored in the cache, both pinned and unpinned. 7249** 7250** [[the xFetch() page cache methods]] 7251** The xFetch() method locates a page in the cache and returns a pointer to 7252** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 7253** The pBuf element of the returned sqlite3_pcache_page object will be a 7254** pointer to a buffer of szPage bytes used to store the content of a 7255** single database page. The pExtra element of sqlite3_pcache_page will be 7256** a pointer to the szExtra bytes of extra storage that SQLite has requested 7257** for each entry in the page cache. 7258** 7259** The page to be fetched is determined by the key. ^The minimum key value 7260** is 1. After it has been retrieved using xFetch, the page is considered 7261** to be "pinned". 7262** 7263** If the requested page is already in the page cache, then the page cache 7264** implementation must return a pointer to the page buffer with its content 7265** intact. If the requested page is not already in the cache, then the 7266** cache implementation should use the value of the createFlag 7267** parameter to help it determined what action to take: 7268** 7269** <table border=1 width=85% align=center> 7270** <tr><th> createFlag <th> Behavior when page is not already in cache 7271** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 7272** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 7273** Otherwise return NULL. 7274** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 7275** NULL if allocating a new page is effectively impossible. 7276** </table> 7277** 7278** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 7279** will only use a createFlag of 2 after a prior call with a createFlag of 1 7280** failed.)^ In between the to xFetch() calls, SQLite may 7281** attempt to unpin one or more cache pages by spilling the content of 7282** pinned pages to disk and synching the operating system disk cache. 7283** 7284** [[the xUnpin() page cache method]] 7285** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 7286** as its second argument. If the third parameter, discard, is non-zero, 7287** then the page must be evicted from the cache. 7288** ^If the discard parameter is 7289** zero, then the page may be discarded or retained at the discretion of 7290** page cache implementation. ^The page cache implementation 7291** may choose to evict unpinned pages at any time. 7292** 7293** The cache must not perform any reference counting. A single 7294** call to xUnpin() unpins the page regardless of the number of prior calls 7295** to xFetch(). 7296** 7297** [[the xRekey() page cache methods]] 7298** The xRekey() method is used to change the key value associated with the 7299** page passed as the second argument. If the cache 7300** previously contains an entry associated with newKey, it must be 7301** discarded. ^Any prior cache entry associated with newKey is guaranteed not 7302** to be pinned. 7303** 7304** When SQLite calls the xTruncate() method, the cache must discard all 7305** existing cache entries with page numbers (keys) greater than or equal 7306** to the value of the iLimit parameter passed to xTruncate(). If any 7307** of these pages are pinned, they are implicitly unpinned, meaning that 7308** they can be safely discarded. 7309** 7310** [[the xDestroy() page cache method]] 7311** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 7312** All resources associated with the specified cache should be freed. ^After 7313** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 7314** handle invalid, and will not use it with any other sqlite3_pcache_methods2 7315** functions. 7316** 7317** [[the xShrink() page cache method]] 7318** ^SQLite invokes the xShrink() method when it wants the page cache to 7319** free up as much of heap memory as possible. The page cache implementation 7320** is not obligated to free any memory, but well-behaved implementations should 7321** do their best. 7322*/ 7323typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 7324struct sqlite3_pcache_methods2 { 7325 int iVersion; 7326 void *pArg; 7327 int (*xInit)(void*); 7328 void (*xShutdown)(void*); 7329 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 7330 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7331 int (*xPagecount)(sqlite3_pcache*); 7332 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7333 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 7334 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 7335 unsigned oldKey, unsigned newKey); 7336 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7337 void (*xDestroy)(sqlite3_pcache*); 7338 void (*xShrink)(sqlite3_pcache*); 7339}; 7340 7341/* 7342** This is the obsolete pcache_methods object that has now been replaced 7343** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 7344** retained in the header file for backwards compatibility only. 7345*/ 7346typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 7347struct sqlite3_pcache_methods { 7348 void *pArg; 7349 int (*xInit)(void*); 7350 void (*xShutdown)(void*); 7351 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 7352 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7353 int (*xPagecount)(sqlite3_pcache*); 7354 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7355 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 7356 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 7357 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7358 void (*xDestroy)(sqlite3_pcache*); 7359}; 7360 7361 7362/* 7363** CAPI3REF: Online Backup Object 7364** 7365** The sqlite3_backup object records state information about an ongoing 7366** online backup operation. ^The sqlite3_backup object is created by 7367** a call to [sqlite3_backup_init()] and is destroyed by a call to 7368** [sqlite3_backup_finish()]. 7369** 7370** See Also: [Using the SQLite Online Backup API] 7371*/ 7372typedef struct sqlite3_backup sqlite3_backup; 7373 7374/* 7375** CAPI3REF: Online Backup API. 7376** 7377** The backup API copies the content of one database into another. 7378** It is useful either for creating backups of databases or 7379** for copying in-memory databases to or from persistent files. 7380** 7381** See Also: [Using the SQLite Online Backup API] 7382** 7383** ^SQLite holds a write transaction open on the destination database file 7384** for the duration of the backup operation. 7385** ^The source database is read-locked only while it is being read; 7386** it is not locked continuously for the entire backup operation. 7387** ^Thus, the backup may be performed on a live source database without 7388** preventing other database connections from 7389** reading or writing to the source database while the backup is underway. 7390** 7391** ^(To perform a backup operation: 7392** <ol> 7393** <li><b>sqlite3_backup_init()</b> is called once to initialize the 7394** backup, 7395** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 7396** the data between the two databases, and finally 7397** <li><b>sqlite3_backup_finish()</b> is called to release all resources 7398** associated with the backup operation. 7399** </ol>)^ 7400** There should be exactly one call to sqlite3_backup_finish() for each 7401** successful call to sqlite3_backup_init(). 7402** 7403** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 7404** 7405** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 7406** [database connection] associated with the destination database 7407** and the database name, respectively. 7408** ^The database name is "main" for the main database, "temp" for the 7409** temporary database, or the name specified after the AS keyword in 7410** an [ATTACH] statement for an attached database. 7411** ^The S and M arguments passed to 7412** sqlite3_backup_init(D,N,S,M) identify the [database connection] 7413** and database name of the source database, respectively. 7414** ^The source and destination [database connections] (parameters S and D) 7415** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 7416** an error. 7417** 7418** ^A call to sqlite3_backup_init() will fail, returning NULL, if 7419** there is already a read or read-write transaction open on the 7420** destination database. 7421** 7422** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 7423** returned and an error code and error message are stored in the 7424** destination [database connection] D. 7425** ^The error code and message for the failed call to sqlite3_backup_init() 7426** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 7427** [sqlite3_errmsg16()] functions. 7428** ^A successful call to sqlite3_backup_init() returns a pointer to an 7429** [sqlite3_backup] object. 7430** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 7431** sqlite3_backup_finish() functions to perform the specified backup 7432** operation. 7433** 7434** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 7435** 7436** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 7437** the source and destination databases specified by [sqlite3_backup] object B. 7438** ^If N is negative, all remaining source pages are copied. 7439** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 7440** are still more pages to be copied, then the function returns [SQLITE_OK]. 7441** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 7442** from source to destination, then it returns [SQLITE_DONE]. 7443** ^If an error occurs while running sqlite3_backup_step(B,N), 7444** then an [error code] is returned. ^As well as [SQLITE_OK] and 7445** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 7446** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 7447** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 7448** 7449** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 7450** <ol> 7451** <li> the destination database was opened read-only, or 7452** <li> the destination database is using write-ahead-log journaling 7453** and the destination and source page sizes differ, or 7454** <li> the destination database is an in-memory database and the 7455** destination and source page sizes differ. 7456** </ol>)^ 7457** 7458** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 7459** the [sqlite3_busy_handler | busy-handler function] 7460** is invoked (if one is specified). ^If the 7461** busy-handler returns non-zero before the lock is available, then 7462** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 7463** sqlite3_backup_step() can be retried later. ^If the source 7464** [database connection] 7465** is being used to write to the source database when sqlite3_backup_step() 7466** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 7467** case the call to sqlite3_backup_step() can be retried later on. ^(If 7468** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 7469** [SQLITE_READONLY] is returned, then 7470** there is no point in retrying the call to sqlite3_backup_step(). These 7471** errors are considered fatal.)^ The application must accept 7472** that the backup operation has failed and pass the backup operation handle 7473** to the sqlite3_backup_finish() to release associated resources. 7474** 7475** ^The first call to sqlite3_backup_step() obtains an exclusive lock 7476** on the destination file. ^The exclusive lock is not released until either 7477** sqlite3_backup_finish() is called or the backup operation is complete 7478** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 7479** sqlite3_backup_step() obtains a [shared lock] on the source database that 7480** lasts for the duration of the sqlite3_backup_step() call. 7481** ^Because the source database is not locked between calls to 7482** sqlite3_backup_step(), the source database may be modified mid-way 7483** through the backup process. ^If the source database is modified by an 7484** external process or via a database connection other than the one being 7485** used by the backup operation, then the backup will be automatically 7486** restarted by the next call to sqlite3_backup_step(). ^If the source 7487** database is modified by the using the same database connection as is used 7488** by the backup operation, then the backup database is automatically 7489** updated at the same time. 7490** 7491** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 7492** 7493** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 7494** application wishes to abandon the backup operation, the application 7495** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 7496** ^The sqlite3_backup_finish() interfaces releases all 7497** resources associated with the [sqlite3_backup] object. 7498** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 7499** active write-transaction on the destination database is rolled back. 7500** The [sqlite3_backup] object is invalid 7501** and may not be used following a call to sqlite3_backup_finish(). 7502** 7503** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 7504** sqlite3_backup_step() errors occurred, regardless or whether or not 7505** sqlite3_backup_step() completed. 7506** ^If an out-of-memory condition or IO error occurred during any prior 7507** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 7508** sqlite3_backup_finish() returns the corresponding [error code]. 7509** 7510** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 7511** is not a permanent error and does not affect the return value of 7512** sqlite3_backup_finish(). 7513** 7514** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 7515** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 7516** 7517** ^The sqlite3_backup_remaining() routine returns the number of pages still 7518** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 7519** ^The sqlite3_backup_pagecount() routine returns the total number of pages 7520** in the source database at the conclusion of the most recent 7521** sqlite3_backup_step(). 7522** ^(The values returned by these functions are only updated by 7523** sqlite3_backup_step(). If the source database is modified in a way that 7524** changes the size of the source database or the number of pages remaining, 7525** those changes are not reflected in the output of sqlite3_backup_pagecount() 7526** and sqlite3_backup_remaining() until after the next 7527** sqlite3_backup_step().)^ 7528** 7529** <b>Concurrent Usage of Database Handles</b> 7530** 7531** ^The source [database connection] may be used by the application for other 7532** purposes while a backup operation is underway or being initialized. 7533** ^If SQLite is compiled and configured to support threadsafe database 7534** connections, then the source database connection may be used concurrently 7535** from within other threads. 7536** 7537** However, the application must guarantee that the destination 7538** [database connection] is not passed to any other API (by any thread) after 7539** sqlite3_backup_init() is called and before the corresponding call to 7540** sqlite3_backup_finish(). SQLite does not currently check to see 7541** if the application incorrectly accesses the destination [database connection] 7542** and so no error code is reported, but the operations may malfunction 7543** nevertheless. Use of the destination database connection while a 7544** backup is in progress might also also cause a mutex deadlock. 7545** 7546** If running in [shared cache mode], the application must 7547** guarantee that the shared cache used by the destination database 7548** is not accessed while the backup is running. In practice this means 7549** that the application must guarantee that the disk file being 7550** backed up to is not accessed by any connection within the process, 7551** not just the specific connection that was passed to sqlite3_backup_init(). 7552** 7553** The [sqlite3_backup] object itself is partially threadsafe. Multiple 7554** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 7555** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 7556** APIs are not strictly speaking threadsafe. If they are invoked at the 7557** same time as another thread is invoking sqlite3_backup_step() it is 7558** possible that they return invalid values. 7559*/ 7560SQLITE_API sqlite3_backup *sqlite3_backup_init( 7561 sqlite3 *pDest, /* Destination database handle */ 7562 const char *zDestName, /* Destination database name */ 7563 sqlite3 *pSource, /* Source database handle */ 7564 const char *zSourceName /* Source database name */ 7565); 7566SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 7567SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 7568SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 7569SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 7570 7571/* 7572** CAPI3REF: Unlock Notification 7573** METHOD: sqlite3 7574** 7575** ^When running in shared-cache mode, a database operation may fail with 7576** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 7577** individual tables within the shared-cache cannot be obtained. See 7578** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 7579** ^This API may be used to register a callback that SQLite will invoke 7580** when the connection currently holding the required lock relinquishes it. 7581** ^This API is only available if the library was compiled with the 7582** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 7583** 7584** See Also: [Using the SQLite Unlock Notification Feature]. 7585** 7586** ^Shared-cache locks are released when a database connection concludes 7587** its current transaction, either by committing it or rolling it back. 7588** 7589** ^When a connection (known as the blocked connection) fails to obtain a 7590** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 7591** identity of the database connection (the blocking connection) that 7592** has locked the required resource is stored internally. ^After an 7593** application receives an SQLITE_LOCKED error, it may call the 7594** sqlite3_unlock_notify() method with the blocked connection handle as 7595** the first argument to register for a callback that will be invoked 7596** when the blocking connections current transaction is concluded. ^The 7597** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 7598** call that concludes the blocking connections transaction. 7599** 7600** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 7601** there is a chance that the blocking connection will have already 7602** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 7603** If this happens, then the specified callback is invoked immediately, 7604** from within the call to sqlite3_unlock_notify().)^ 7605** 7606** ^If the blocked connection is attempting to obtain a write-lock on a 7607** shared-cache table, and more than one other connection currently holds 7608** a read-lock on the same table, then SQLite arbitrarily selects one of 7609** the other connections to use as the blocking connection. 7610** 7611** ^(There may be at most one unlock-notify callback registered by a 7612** blocked connection. If sqlite3_unlock_notify() is called when the 7613** blocked connection already has a registered unlock-notify callback, 7614** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 7615** called with a NULL pointer as its second argument, then any existing 7616** unlock-notify callback is canceled. ^The blocked connections 7617** unlock-notify callback may also be canceled by closing the blocked 7618** connection using [sqlite3_close()]. 7619** 7620** The unlock-notify callback is not reentrant. If an application invokes 7621** any sqlite3_xxx API functions from within an unlock-notify callback, a 7622** crash or deadlock may be the result. 7623** 7624** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 7625** returns SQLITE_OK. 7626** 7627** <b>Callback Invocation Details</b> 7628** 7629** When an unlock-notify callback is registered, the application provides a 7630** single void* pointer that is passed to the callback when it is invoked. 7631** However, the signature of the callback function allows SQLite to pass 7632** it an array of void* context pointers. The first argument passed to 7633** an unlock-notify callback is a pointer to an array of void* pointers, 7634** and the second is the number of entries in the array. 7635** 7636** When a blocking connections transaction is concluded, there may be 7637** more than one blocked connection that has registered for an unlock-notify 7638** callback. ^If two or more such blocked connections have specified the 7639** same callback function, then instead of invoking the callback function 7640** multiple times, it is invoked once with the set of void* context pointers 7641** specified by the blocked connections bundled together into an array. 7642** This gives the application an opportunity to prioritize any actions 7643** related to the set of unblocked database connections. 7644** 7645** <b>Deadlock Detection</b> 7646** 7647** Assuming that after registering for an unlock-notify callback a 7648** database waits for the callback to be issued before taking any further 7649** action (a reasonable assumption), then using this API may cause the 7650** application to deadlock. For example, if connection X is waiting for 7651** connection Y's transaction to be concluded, and similarly connection 7652** Y is waiting on connection X's transaction, then neither connection 7653** will proceed and the system may remain deadlocked indefinitely. 7654** 7655** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 7656** detection. ^If a given call to sqlite3_unlock_notify() would put the 7657** system in a deadlocked state, then SQLITE_LOCKED is returned and no 7658** unlock-notify callback is registered. The system is said to be in 7659** a deadlocked state if connection A has registered for an unlock-notify 7660** callback on the conclusion of connection B's transaction, and connection 7661** B has itself registered for an unlock-notify callback when connection 7662** A's transaction is concluded. ^Indirect deadlock is also detected, so 7663** the system is also considered to be deadlocked if connection B has 7664** registered for an unlock-notify callback on the conclusion of connection 7665** C's transaction, where connection C is waiting on connection A. ^Any 7666** number of levels of indirection are allowed. 7667** 7668** <b>The "DROP TABLE" Exception</b> 7669** 7670** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 7671** always appropriate to call sqlite3_unlock_notify(). There is however, 7672** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 7673** SQLite checks if there are any currently executing SELECT statements 7674** that belong to the same connection. If there are, SQLITE_LOCKED is 7675** returned. In this case there is no "blocking connection", so invoking 7676** sqlite3_unlock_notify() results in the unlock-notify callback being 7677** invoked immediately. If the application then re-attempts the "DROP TABLE" 7678** or "DROP INDEX" query, an infinite loop might be the result. 7679** 7680** One way around this problem is to check the extended error code returned 7681** by an sqlite3_step() call. ^(If there is a blocking connection, then the 7682** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 7683** the special "DROP TABLE/INDEX" case, the extended error code is just 7684** SQLITE_LOCKED.)^ 7685*/ 7686SQLITE_API int sqlite3_unlock_notify( 7687 sqlite3 *pBlocked, /* Waiting connection */ 7688 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 7689 void *pNotifyArg /* Argument to pass to xNotify */ 7690); 7691 7692 7693/* 7694** CAPI3REF: String Comparison 7695** 7696** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 7697** and extensions to compare the contents of two buffers containing UTF-8 7698** strings in a case-independent fashion, using the same definition of "case 7699** independence" that SQLite uses internally when comparing identifiers. 7700*/ 7701SQLITE_API int sqlite3_stricmp(const char *, const char *); 7702SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 7703 7704/* 7705** CAPI3REF: String Globbing 7706* 7707** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 7708** string X matches the [GLOB] pattern P. 7709** ^The definition of [GLOB] pattern matching used in 7710** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 7711** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 7712** is case sensitive. 7713** 7714** Note that this routine returns zero on a match and non-zero if the strings 7715** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7716** 7717** See also: [sqlite3_strlike()]. 7718*/ 7719SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 7720 7721/* 7722** CAPI3REF: String LIKE Matching 7723* 7724** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 7725** string X matches the [LIKE] pattern P with escape character E. 7726** ^The definition of [LIKE] pattern matching used in 7727** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 7728** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 7729** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 7730** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 7731** insensitive - equivalent upper and lower case ASCII characters match 7732** one another. 7733** 7734** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 7735** only ASCII characters are case folded. 7736** 7737** Note that this routine returns zero on a match and non-zero if the strings 7738** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7739** 7740** See also: [sqlite3_strglob()]. 7741*/ 7742SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 7743 7744/* 7745** CAPI3REF: Error Logging Interface 7746** 7747** ^The [sqlite3_log()] interface writes a message into the [error log] 7748** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 7749** ^If logging is enabled, the zFormat string and subsequent arguments are 7750** used with [sqlite3_snprintf()] to generate the final output string. 7751** 7752** The sqlite3_log() interface is intended for use by extensions such as 7753** virtual tables, collating functions, and SQL functions. While there is 7754** nothing to prevent an application from calling sqlite3_log(), doing so 7755** is considered bad form. 7756** 7757** The zFormat string must not be NULL. 7758** 7759** To avoid deadlocks and other threading problems, the sqlite3_log() routine 7760** will not use dynamically allocated memory. The log message is stored in 7761** a fixed-length buffer on the stack. If the log message is longer than 7762** a few hundred characters, it will be truncated to the length of the 7763** buffer. 7764*/ 7765SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 7766 7767/* 7768** CAPI3REF: Write-Ahead Log Commit Hook 7769** METHOD: sqlite3 7770** 7771** ^The [sqlite3_wal_hook()] function is used to register a callback that 7772** is invoked each time data is committed to a database in wal mode. 7773** 7774** ^(The callback is invoked by SQLite after the commit has taken place and 7775** the associated write-lock on the database released)^, so the implementation 7776** may read, write or [checkpoint] the database as required. 7777** 7778** ^The first parameter passed to the callback function when it is invoked 7779** is a copy of the third parameter passed to sqlite3_wal_hook() when 7780** registering the callback. ^The second is a copy of the database handle. 7781** ^The third parameter is the name of the database that was written to - 7782** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 7783** is the number of pages currently in the write-ahead log file, 7784** including those that were just committed. 7785** 7786** The callback function should normally return [SQLITE_OK]. ^If an error 7787** code is returned, that error will propagate back up through the 7788** SQLite code base to cause the statement that provoked the callback 7789** to report an error, though the commit will have still occurred. If the 7790** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 7791** that does not correspond to any valid SQLite error code, the results 7792** are undefined. 7793** 7794** A single database handle may have at most a single write-ahead log callback 7795** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 7796** previously registered write-ahead log callback. ^Note that the 7797** [sqlite3_wal_autocheckpoint()] interface and the 7798** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 7799** overwrite any prior [sqlite3_wal_hook()] settings. 7800*/ 7801SQLITE_API void *sqlite3_wal_hook( 7802 sqlite3*, 7803 int(*)(void *,sqlite3*,const char*,int), 7804 void* 7805); 7806 7807/* 7808** CAPI3REF: Configure an auto-checkpoint 7809** METHOD: sqlite3 7810** 7811** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 7812** [sqlite3_wal_hook()] that causes any database on [database connection] D 7813** to automatically [checkpoint] 7814** after committing a transaction if there are N or 7815** more frames in the [write-ahead log] file. ^Passing zero or 7816** a negative value as the nFrame parameter disables automatic 7817** checkpoints entirely. 7818** 7819** ^The callback registered by this function replaces any existing callback 7820** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 7821** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 7822** configured by this function. 7823** 7824** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 7825** from SQL. 7826** 7827** ^Checkpoints initiated by this mechanism are 7828** [sqlite3_wal_checkpoint_v2|PASSIVE]. 7829** 7830** ^Every new [database connection] defaults to having the auto-checkpoint 7831** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 7832** pages. The use of this interface 7833** is only necessary if the default setting is found to be suboptimal 7834** for a particular application. 7835*/ 7836SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 7837 7838/* 7839** CAPI3REF: Checkpoint a database 7840** METHOD: sqlite3 7841** 7842** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 7843** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 7844** 7845** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 7846** [write-ahead log] for database X on [database connection] D to be 7847** transferred into the database file and for the write-ahead log to 7848** be reset. See the [checkpointing] documentation for addition 7849** information. 7850** 7851** This interface used to be the only way to cause a checkpoint to 7852** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 7853** interface was added. This interface is retained for backwards 7854** compatibility and as a convenience for applications that need to manually 7855** start a callback but which do not need the full power (and corresponding 7856** complication) of [sqlite3_wal_checkpoint_v2()]. 7857*/ 7858SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 7859 7860/* 7861** CAPI3REF: Checkpoint a database 7862** METHOD: sqlite3 7863** 7864** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 7865** operation on database X of [database connection] D in mode M. Status 7866** information is written back into integers pointed to by L and C.)^ 7867** ^(The M parameter must be a valid [checkpoint mode]:)^ 7868** 7869** <dl> 7870** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 7871** ^Checkpoint as many frames as possible without waiting for any database 7872** readers or writers to finish, then sync the database file if all frames 7873** in the log were checkpointed. ^The [busy-handler callback] 7874** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 7875** ^On the other hand, passive mode might leave the checkpoint unfinished 7876** if there are concurrent readers or writers. 7877** 7878** <dt>SQLITE_CHECKPOINT_FULL<dd> 7879** ^This mode blocks (it invokes the 7880** [sqlite3_busy_handler|busy-handler callback]) until there is no 7881** database writer and all readers are reading from the most recent database 7882** snapshot. ^It then checkpoints all frames in the log file and syncs the 7883** database file. ^This mode blocks new database writers while it is pending, 7884** but new database readers are allowed to continue unimpeded. 7885** 7886** <dt>SQLITE_CHECKPOINT_RESTART<dd> 7887** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 7888** that after checkpointing the log file it blocks (calls the 7889** [busy-handler callback]) 7890** until all readers are reading from the database file only. ^This ensures 7891** that the next writer will restart the log file from the beginning. 7892** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 7893** database writer attempts while it is pending, but does not impede readers. 7894** 7895** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 7896** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 7897** addition that it also truncates the log file to zero bytes just prior 7898** to a successful return. 7899** </dl> 7900** 7901** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 7902** the log file or to -1 if the checkpoint could not run because 7903** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 7904** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 7905** log file (including any that were already checkpointed before the function 7906** was called) or to -1 if the checkpoint could not run due to an error or 7907** because the database is not in WAL mode. ^Note that upon successful 7908** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 7909** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 7910** 7911** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 7912** any other process is running a checkpoint operation at the same time, the 7913** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 7914** busy-handler configured, it will not be invoked in this case. 7915** 7916** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 7917** exclusive "writer" lock on the database file. ^If the writer lock cannot be 7918** obtained immediately, and a busy-handler is configured, it is invoked and 7919** the writer lock retried until either the busy-handler returns 0 or the lock 7920** is successfully obtained. ^The busy-handler is also invoked while waiting for 7921** database readers as described above. ^If the busy-handler returns 0 before 7922** the writer lock is obtained or while waiting for database readers, the 7923** checkpoint operation proceeds from that point in the same way as 7924** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 7925** without blocking any further. ^SQLITE_BUSY is returned in this case. 7926** 7927** ^If parameter zDb is NULL or points to a zero length string, then the 7928** specified operation is attempted on all WAL databases [attached] to 7929** [database connection] db. In this case the 7930** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 7931** an SQLITE_BUSY error is encountered when processing one or more of the 7932** attached WAL databases, the operation is still attempted on any remaining 7933** attached databases and SQLITE_BUSY is returned at the end. ^If any other 7934** error occurs while processing an attached database, processing is abandoned 7935** and the error code is returned to the caller immediately. ^If no error 7936** (SQLITE_BUSY or otherwise) is encountered while processing the attached 7937** databases, SQLITE_OK is returned. 7938** 7939** ^If database zDb is the name of an attached database that is not in WAL 7940** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 7941** zDb is not NULL (or a zero length string) and is not the name of any 7942** attached database, SQLITE_ERROR is returned to the caller. 7943** 7944** ^Unless it returns SQLITE_MISUSE, 7945** the sqlite3_wal_checkpoint_v2() interface 7946** sets the error information that is queried by 7947** [sqlite3_errcode()] and [sqlite3_errmsg()]. 7948** 7949** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 7950** from SQL. 7951*/ 7952SQLITE_API int sqlite3_wal_checkpoint_v2( 7953 sqlite3 *db, /* Database handle */ 7954 const char *zDb, /* Name of attached database (or NULL) */ 7955 int eMode, /* SQLITE_CHECKPOINT_* value */ 7956 int *pnLog, /* OUT: Size of WAL log in frames */ 7957 int *pnCkpt /* OUT: Total number of frames checkpointed */ 7958); 7959 7960/* 7961** CAPI3REF: Checkpoint Mode Values 7962** KEYWORDS: {checkpoint mode} 7963** 7964** These constants define all valid values for the "checkpoint mode" passed 7965** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 7966** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 7967** meaning of each of these checkpoint modes. 7968*/ 7969#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 7970#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 7971#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 7972#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 7973 7974/* 7975** CAPI3REF: Virtual Table Interface Configuration 7976** 7977** This function may be called by either the [xConnect] or [xCreate] method 7978** of a [virtual table] implementation to configure 7979** various facets of the virtual table interface. 7980** 7981** If this interface is invoked outside the context of an xConnect or 7982** xCreate virtual table method then the behavior is undefined. 7983** 7984** At present, there is only one option that may be configured using 7985** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 7986** may be added in the future. 7987*/ 7988SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 7989 7990/* 7991** CAPI3REF: Virtual Table Configuration Options 7992** 7993** These macros define the various options to the 7994** [sqlite3_vtab_config()] interface that [virtual table] implementations 7995** can use to customize and optimize their behavior. 7996** 7997** <dl> 7998** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 7999** <dd>Calls of the form 8000** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 8001** where X is an integer. If X is zero, then the [virtual table] whose 8002** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 8003** support constraints. In this configuration (which is the default) if 8004** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 8005** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 8006** specified as part of the users SQL statement, regardless of the actual 8007** ON CONFLICT mode specified. 8008** 8009** If X is non-zero, then the virtual table implementation guarantees 8010** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 8011** any modifications to internal or persistent data structures have been made. 8012** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 8013** is able to roll back a statement or database transaction, and abandon 8014** or continue processing the current SQL statement as appropriate. 8015** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 8016** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 8017** had been ABORT. 8018** 8019** Virtual table implementations that are required to handle OR REPLACE 8020** must do so within the [xUpdate] method. If a call to the 8021** [sqlite3_vtab_on_conflict()] function indicates that the current ON 8022** CONFLICT policy is REPLACE, the virtual table implementation should 8023** silently replace the appropriate rows within the xUpdate callback and 8024** return SQLITE_OK. Or, if this is not possible, it may return 8025** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 8026** constraint handling. 8027** </dl> 8028*/ 8029#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 8030 8031/* 8032** CAPI3REF: Determine The Virtual Table Conflict Policy 8033** 8034** This function may only be called from within a call to the [xUpdate] method 8035** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 8036** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 8037** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 8038** of the SQL statement that triggered the call to the [xUpdate] method of the 8039** [virtual table]. 8040*/ 8041SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 8042 8043/* 8044** CAPI3REF: Conflict resolution modes 8045** KEYWORDS: {conflict resolution mode} 8046** 8047** These constants are returned by [sqlite3_vtab_on_conflict()] to 8048** inform a [virtual table] implementation what the [ON CONFLICT] mode 8049** is for the SQL statement being evaluated. 8050** 8051** Note that the [SQLITE_IGNORE] constant is also used as a potential 8052** return value from the [sqlite3_set_authorizer()] callback and that 8053** [SQLITE_ABORT] is also a [result code]. 8054*/ 8055#define SQLITE_ROLLBACK 1 8056/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 8057#define SQLITE_FAIL 3 8058/* #define SQLITE_ABORT 4 // Also an error code */ 8059#define SQLITE_REPLACE 5 8060 8061/* 8062** CAPI3REF: Prepared Statement Scan Status Opcodes 8063** KEYWORDS: {scanstatus options} 8064** 8065** The following constants can be used for the T parameter to the 8066** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 8067** different metric for sqlite3_stmt_scanstatus() to return. 8068** 8069** When the value returned to V is a string, space to hold that string is 8070** managed by the prepared statement S and will be automatically freed when 8071** S is finalized. 8072** 8073** <dl> 8074** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 8075** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 8076** set to the total number of times that the X-th loop has run.</dd> 8077** 8078** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 8079** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 8080** to the total number of rows examined by all iterations of the X-th loop.</dd> 8081** 8082** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 8083** <dd>^The "double" variable pointed to by the T parameter will be set to the 8084** query planner's estimate for the average number of rows output from each 8085** iteration of the X-th loop. If the query planner's estimates was accurate, 8086** then this value will approximate the quotient NVISIT/NLOOP and the 8087** product of this value for all prior loops with the same SELECTID will 8088** be the NLOOP value for the current loop. 8089** 8090** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 8091** <dd>^The "const char *" variable pointed to by the T parameter will be set 8092** to a zero-terminated UTF-8 string containing the name of the index or table 8093** used for the X-th loop. 8094** 8095** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 8096** <dd>^The "const char *" variable pointed to by the T parameter will be set 8097** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 8098** description for the X-th loop. 8099** 8100** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 8101** <dd>^The "int" variable pointed to by the T parameter will be set to the 8102** "select-id" for the X-th loop. The select-id identifies which query or 8103** subquery the loop is part of. The main query has a select-id of zero. 8104** The select-id is the same value as is output in the first column 8105** of an [EXPLAIN QUERY PLAN] query. 8106** </dl> 8107*/ 8108#define SQLITE_SCANSTAT_NLOOP 0 8109#define SQLITE_SCANSTAT_NVISIT 1 8110#define SQLITE_SCANSTAT_EST 2 8111#define SQLITE_SCANSTAT_NAME 3 8112#define SQLITE_SCANSTAT_EXPLAIN 4 8113#define SQLITE_SCANSTAT_SELECTID 5 8114 8115/* 8116** CAPI3REF: Prepared Statement Scan Status 8117** METHOD: sqlite3_stmt 8118** 8119** This interface returns information about the predicted and measured 8120** performance for pStmt. Advanced applications can use this 8121** interface to compare the predicted and the measured performance and 8122** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 8123** 8124** Since this interface is expected to be rarely used, it is only 8125** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 8126** compile-time option. 8127** 8128** The "iScanStatusOp" parameter determines which status information to return. 8129** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 8130** of this interface is undefined. 8131** ^The requested measurement is written into a variable pointed to by 8132** the "pOut" parameter. 8133** Parameter "idx" identifies the specific loop to retrieve statistics for. 8134** Loops are numbered starting from zero. ^If idx is out of range - less than 8135** zero or greater than or equal to the total number of loops used to implement 8136** the statement - a non-zero value is returned and the variable that pOut 8137** points to is unchanged. 8138** 8139** ^Statistics might not be available for all loops in all statements. ^In cases 8140** where there exist loops with no available statistics, this function behaves 8141** as if the loop did not exist - it returns non-zero and leave the variable 8142** that pOut points to unchanged. 8143** 8144** See also: [sqlite3_stmt_scanstatus_reset()] 8145*/ 8146SQLITE_API int sqlite3_stmt_scanstatus( 8147 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 8148 int idx, /* Index of loop to report on */ 8149 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 8150 void *pOut /* Result written here */ 8151); 8152 8153/* 8154** CAPI3REF: Zero Scan-Status Counters 8155** METHOD: sqlite3_stmt 8156** 8157** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 8158** 8159** This API is only available if the library is built with pre-processor 8160** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 8161*/ 8162SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 8163 8164/* 8165** CAPI3REF: Flush caches to disk mid-transaction 8166** 8167** ^If a write-transaction is open on [database connection] D when the 8168** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 8169** pages in the pager-cache that are not currently in use are written out 8170** to disk. A dirty page may be in use if a database cursor created by an 8171** active SQL statement is reading from it, or if it is page 1 of a database 8172** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 8173** interface flushes caches for all schemas - "main", "temp", and 8174** any [attached] databases. 8175** 8176** ^If this function needs to obtain extra database locks before dirty pages 8177** can be flushed to disk, it does so. ^If those locks cannot be obtained 8178** immediately and there is a busy-handler callback configured, it is invoked 8179** in the usual manner. ^If the required lock still cannot be obtained, then 8180** the database is skipped and an attempt made to flush any dirty pages 8181** belonging to the next (if any) database. ^If any databases are skipped 8182** because locks cannot be obtained, but no other error occurs, this 8183** function returns SQLITE_BUSY. 8184** 8185** ^If any other error occurs while flushing dirty pages to disk (for 8186** example an IO error or out-of-memory condition), then processing is 8187** abandoned and an SQLite [error code] is returned to the caller immediately. 8188** 8189** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 8190** 8191** ^This function does not set the database handle error code or message 8192** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 8193*/ 8194SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 8195 8196/* 8197** CAPI3REF: The pre-update hook. 8198** 8199** ^These interfaces are only available if SQLite is compiled using the 8200** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 8201** 8202** ^The [sqlite3_preupdate_hook()] interface registers a callback function 8203** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 8204** on a database table. 8205** ^At most one preupdate hook may be registered at a time on a single 8206** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 8207** the previous setting. 8208** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 8209** with a NULL pointer as the second parameter. 8210** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 8211** the first parameter to callbacks. 8212** 8213** ^The preupdate hook only fires for changes to real database tables; the 8214** preupdate hook is not invoked for changes to [virtual tables] or to 8215** system tables like sqlite_master or sqlite_stat1. 8216** 8217** ^The second parameter to the preupdate callback is a pointer to 8218** the [database connection] that registered the preupdate hook. 8219** ^The third parameter to the preupdate callback is one of the constants 8220** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 8221** kind of update operation that is about to occur. 8222** ^(The fourth parameter to the preupdate callback is the name of the 8223** database within the database connection that is being modified. This 8224** will be "main" for the main database or "temp" for TEMP tables or 8225** the name given after the AS keyword in the [ATTACH] statement for attached 8226** databases.)^ 8227** ^The fifth parameter to the preupdate callback is the name of the 8228** table that is being modified. 8229** 8230** For an UPDATE or DELETE operation on a [rowid table], the sixth 8231** parameter passed to the preupdate callback is the initial [rowid] of the 8232** row being modified or deleted. For an INSERT operation on a rowid table, 8233** or any operation on a WITHOUT ROWID table, the value of the sixth 8234** parameter is undefined. For an INSERT or UPDATE on a rowid table the 8235** seventh parameter is the final rowid value of the row being inserted 8236** or updated. The value of the seventh parameter passed to the callback 8237** function is not defined for operations on WITHOUT ROWID tables, or for 8238** INSERT operations on rowid tables. 8239** 8240** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 8241** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 8242** provide additional information about a preupdate event. These routines 8243** may only be called from within a preupdate callback. Invoking any of 8244** these routines from outside of a preupdate callback or with a 8245** [database connection] pointer that is different from the one supplied 8246** to the preupdate callback results in undefined and probably undesirable 8247** behavior. 8248** 8249** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 8250** in the row that is being inserted, updated, or deleted. 8251** 8252** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 8253** a [protected sqlite3_value] that contains the value of the Nth column of 8254** the table row before it is updated. The N parameter must be between 0 8255** and one less than the number of columns or the behavior will be 8256** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 8257** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 8258** behavior is undefined. The [sqlite3_value] that P points to 8259** will be destroyed when the preupdate callback returns. 8260** 8261** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 8262** a [protected sqlite3_value] that contains the value of the Nth column of 8263** the table row after it is updated. The N parameter must be between 0 8264** and one less than the number of columns or the behavior will be 8265** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 8266** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 8267** behavior is undefined. The [sqlite3_value] that P points to 8268** will be destroyed when the preupdate callback returns. 8269** 8270** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 8271** callback was invoked as a result of a direct insert, update, or delete 8272** operation; or 1 for inserts, updates, or deletes invoked by top-level 8273** triggers; or 2 for changes resulting from triggers called by top-level 8274** triggers; and so forth. 8275** 8276** See also: [sqlite3_update_hook()] 8277*/ 8278#if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 8279SQLITE_API void *sqlite3_preupdate_hook( 8280 sqlite3 *db, 8281 void(*xPreUpdate)( 8282 void *pCtx, /* Copy of third arg to preupdate_hook() */ 8283 sqlite3 *db, /* Database handle */ 8284 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 8285 char const *zDb, /* Database name */ 8286 char const *zName, /* Table name */ 8287 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 8288 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 8289 ), 8290 void* 8291); 8292SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 8293SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 8294SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 8295SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 8296#endif 8297 8298/* 8299** CAPI3REF: Low-level system error code 8300** 8301** ^Attempt to return the underlying operating system error code or error 8302** number that caused the most recent I/O error or failure to open a file. 8303** The return value is OS-dependent. For example, on unix systems, after 8304** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 8305** called to get back the underlying "errno" that caused the problem, such 8306** as ENOSPC, EAUTH, EISDIR, and so forth. 8307*/ 8308SQLITE_API int sqlite3_system_errno(sqlite3*); 8309 8310/* 8311** CAPI3REF: Database Snapshot 8312** KEYWORDS: {snapshot} {sqlite3_snapshot} 8313** EXPERIMENTAL 8314** 8315** An instance of the snapshot object records the state of a [WAL mode] 8316** database for some specific point in history. 8317** 8318** In [WAL mode], multiple [database connections] that are open on the 8319** same database file can each be reading a different historical version 8320** of the database file. When a [database connection] begins a read 8321** transaction, that connection sees an unchanging copy of the database 8322** as it existed for the point in time when the transaction first started. 8323** Subsequent changes to the database from other connections are not seen 8324** by the reader until a new read transaction is started. 8325** 8326** The sqlite3_snapshot object records state information about an historical 8327** version of the database file so that it is possible to later open a new read 8328** transaction that sees that historical version of the database rather than 8329** the most recent version. 8330** 8331** The constructor for this object is [sqlite3_snapshot_get()]. The 8332** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer 8333** to an historical snapshot (if possible). The destructor for 8334** sqlite3_snapshot objects is [sqlite3_snapshot_free()]. 8335*/ 8336typedef struct sqlite3_snapshot { 8337 unsigned char hidden[48]; 8338} sqlite3_snapshot; 8339 8340/* 8341** CAPI3REF: Record A Database Snapshot 8342** EXPERIMENTAL 8343** 8344** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 8345** new [sqlite3_snapshot] object that records the current state of 8346** schema S in database connection D. ^On success, the 8347** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 8348** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 8349** If there is not already a read-transaction open on schema S when 8350** this function is called, one is opened automatically. 8351** 8352** The following must be true for this function to succeed. If any of 8353** the following statements are false when sqlite3_snapshot_get() is 8354** called, SQLITE_ERROR is returned. The final value of *P is undefined 8355** in this case. 8356** 8357** <ul> 8358** <li> The database handle must be in [autocommit mode]. 8359** 8360** <li> Schema S of [database connection] D must be a [WAL mode] database. 8361** 8362** <li> There must not be a write transaction open on schema S of database 8363** connection D. 8364** 8365** <li> One or more transactions must have been written to the current wal 8366** file since it was created on disk (by any connection). This means 8367** that a snapshot cannot be taken on a wal mode database with no wal 8368** file immediately after it is first opened. At least one transaction 8369** must be written to it first. 8370** </ul> 8371** 8372** This function may also return SQLITE_NOMEM. If it is called with the 8373** database handle in autocommit mode but fails for some other reason, 8374** whether or not a read transaction is opened on schema S is undefined. 8375** 8376** The [sqlite3_snapshot] object returned from a successful call to 8377** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 8378** to avoid a memory leak. 8379** 8380** The [sqlite3_snapshot_get()] interface is only available when the 8381** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8382*/ 8383SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 8384 sqlite3 *db, 8385 const char *zSchema, 8386 sqlite3_snapshot **ppSnapshot 8387); 8388 8389/* 8390** CAPI3REF: Start a read transaction on an historical snapshot 8391** EXPERIMENTAL 8392** 8393** ^The [sqlite3_snapshot_open(D,S,P)] interface starts a 8394** read transaction for schema S of 8395** [database connection] D such that the read transaction 8396** refers to historical [snapshot] P, rather than the most 8397** recent change to the database. 8398** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success 8399** or an appropriate [error code] if it fails. 8400** 8401** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be 8402** the first operation following the [BEGIN] that takes the schema S 8403** out of [autocommit mode]. 8404** ^In other words, schema S must not currently be in 8405** a transaction for [sqlite3_snapshot_open(D,S,P)] to work, but the 8406** database connection D must be out of [autocommit mode]. 8407** ^A [snapshot] will fail to open if it has been overwritten by a 8408** [checkpoint]. 8409** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 8410** database connection D does not know that the database file for 8411** schema S is in [WAL mode]. A database connection might not know 8412** that the database file is in [WAL mode] if there has been no prior 8413** I/O on that database connection, or if the database entered [WAL mode] 8414** after the most recent I/O on the database connection.)^ 8415** (Hint: Run "[PRAGMA application_id]" against a newly opened 8416** database connection in order to make it ready to use snapshots.) 8417** 8418** The [sqlite3_snapshot_open()] interface is only available when the 8419** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8420*/ 8421SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 8422 sqlite3 *db, 8423 const char *zSchema, 8424 sqlite3_snapshot *pSnapshot 8425); 8426 8427/* 8428** CAPI3REF: Destroy a snapshot 8429** EXPERIMENTAL 8430** 8431** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 8432** The application must eventually free every [sqlite3_snapshot] object 8433** using this routine to avoid a memory leak. 8434** 8435** The [sqlite3_snapshot_free()] interface is only available when the 8436** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8437*/ 8438SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 8439 8440/* 8441** CAPI3REF: Compare the ages of two snapshot handles. 8442** EXPERIMENTAL 8443** 8444** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 8445** of two valid snapshot handles. 8446** 8447** If the two snapshot handles are not associated with the same database 8448** file, the result of the comparison is undefined. 8449** 8450** Additionally, the result of the comparison is only valid if both of the 8451** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 8452** last time the wal file was deleted. The wal file is deleted when the 8453** database is changed back to rollback mode or when the number of database 8454** clients drops to zero. If either snapshot handle was obtained before the 8455** wal file was last deleted, the value returned by this function 8456** is undefined. 8457** 8458** Otherwise, this API returns a negative value if P1 refers to an older 8459** snapshot than P2, zero if the two handles refer to the same database 8460** snapshot, and a positive value if P1 is a newer snapshot than P2. 8461*/ 8462SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 8463 sqlite3_snapshot *p1, 8464 sqlite3_snapshot *p2 8465); 8466 8467/* 8468** CAPI3REF: Recover snapshots from a wal file 8469** EXPERIMENTAL 8470** 8471** If all connections disconnect from a database file but do not perform 8472** a checkpoint, the existing wal file is opened along with the database 8473** file the next time the database is opened. At this point it is only 8474** possible to successfully call sqlite3_snapshot_open() to open the most 8475** recent snapshot of the database (the one at the head of the wal file), 8476** even though the wal file may contain other valid snapshots for which 8477** clients have sqlite3_snapshot handles. 8478** 8479** This function attempts to scan the wal file associated with database zDb 8480** of database handle db and make all valid snapshots available to 8481** sqlite3_snapshot_open(). It is an error if there is already a read 8482** transaction open on the database, or if the database is not a wal mode 8483** database. 8484** 8485** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 8486*/ 8487SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 8488 8489/* 8490** Undo the hack that converts floating point types to integer for 8491** builds on processors without floating point support. 8492*/ 8493#ifdef SQLITE_OMIT_FLOATING_POINT 8494# undef double 8495#endif 8496 8497#ifdef __cplusplus 8498} /* End of the 'extern "C"' block */ 8499#endif 8500#endif /* SQLITE3_H */ 8501 8502/******** Begin file sqlite3rtree.h *********/ 8503/* 8504** 2010 August 30 8505** 8506** The author disclaims copyright to this source code. In place of 8507** a legal notice, here is a blessing: 8508** 8509** May you do good and not evil. 8510** May you find forgiveness for yourself and forgive others. 8511** May you share freely, never taking more than you give. 8512** 8513************************************************************************* 8514*/ 8515 8516#ifndef _SQLITE3RTREE_H_ 8517#define _SQLITE3RTREE_H_ 8518 8519 8520#ifdef __cplusplus 8521extern "C" { 8522#endif 8523 8524typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 8525typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 8526 8527/* The double-precision datatype used by RTree depends on the 8528** SQLITE_RTREE_INT_ONLY compile-time option. 8529*/ 8530#ifdef SQLITE_RTREE_INT_ONLY 8531 typedef sqlite3_int64 sqlite3_rtree_dbl; 8532#else 8533 typedef double sqlite3_rtree_dbl; 8534#endif 8535 8536/* 8537** Register a geometry callback named zGeom that can be used as part of an 8538** R-Tree geometry query as follows: 8539** 8540** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 8541*/ 8542SQLITE_API int sqlite3_rtree_geometry_callback( 8543 sqlite3 *db, 8544 const char *zGeom, 8545 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 8546 void *pContext 8547); 8548 8549 8550/* 8551** A pointer to a structure of the following type is passed as the first 8552** argument to callbacks registered using rtree_geometry_callback(). 8553*/ 8554struct sqlite3_rtree_geometry { 8555 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 8556 int nParam; /* Size of array aParam[] */ 8557 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 8558 void *pUser; /* Callback implementation user data */ 8559 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 8560}; 8561 8562/* 8563** Register a 2nd-generation geometry callback named zScore that can be 8564** used as part of an R-Tree geometry query as follows: 8565** 8566** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 8567*/ 8568SQLITE_API int sqlite3_rtree_query_callback( 8569 sqlite3 *db, 8570 const char *zQueryFunc, 8571 int (*xQueryFunc)(sqlite3_rtree_query_info*), 8572 void *pContext, 8573 void (*xDestructor)(void*) 8574); 8575 8576 8577/* 8578** A pointer to a structure of the following type is passed as the 8579** argument to scored geometry callback registered using 8580** sqlite3_rtree_query_callback(). 8581** 8582** Note that the first 5 fields of this structure are identical to 8583** sqlite3_rtree_geometry. This structure is a subclass of 8584** sqlite3_rtree_geometry. 8585*/ 8586struct sqlite3_rtree_query_info { 8587 void *pContext; /* pContext from when function registered */ 8588 int nParam; /* Number of function parameters */ 8589 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 8590 void *pUser; /* callback can use this, if desired */ 8591 void (*xDelUser)(void*); /* function to free pUser */ 8592 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 8593 unsigned int *anQueue; /* Number of pending entries in the queue */ 8594 int nCoord; /* Number of coordinates */ 8595 int iLevel; /* Level of current node or entry */ 8596 int mxLevel; /* The largest iLevel value in the tree */ 8597 sqlite3_int64 iRowid; /* Rowid for current entry */ 8598 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 8599 int eParentWithin; /* Visibility of parent node */ 8600 int eWithin; /* OUT: Visiblity */ 8601 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 8602 /* The following fields are only available in 3.8.11 and later */ 8603 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 8604}; 8605 8606/* 8607** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 8608*/ 8609#define NOT_WITHIN 0 /* Object completely outside of query region */ 8610#define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 8611#define FULLY_WITHIN 2 /* Object fully contained within query region */ 8612 8613 8614#ifdef __cplusplus 8615} /* end of the 'extern "C"' block */ 8616#endif 8617 8618#endif /* ifndef _SQLITE3RTREE_H_ */ 8619 8620/******** End of sqlite3rtree.h *********/ 8621/******** Begin file sqlite3session.h *********/ 8622 8623#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 8624#define __SQLITESESSION_H_ 1 8625 8626/* 8627** Make sure we can call this stuff from C++. 8628*/ 8629#ifdef __cplusplus 8630extern "C" { 8631#endif 8632 8633 8634/* 8635** CAPI3REF: Session Object Handle 8636*/ 8637typedef struct sqlite3_session sqlite3_session; 8638 8639/* 8640** CAPI3REF: Changeset Iterator Handle 8641*/ 8642typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 8643 8644/* 8645** CAPI3REF: Create A New Session Object 8646** 8647** Create a new session object attached to database handle db. If successful, 8648** a pointer to the new object is written to *ppSession and SQLITE_OK is 8649** returned. If an error occurs, *ppSession is set to NULL and an SQLite 8650** error code (e.g. SQLITE_NOMEM) is returned. 8651** 8652** It is possible to create multiple session objects attached to a single 8653** database handle. 8654** 8655** Session objects created using this function should be deleted using the 8656** [sqlite3session_delete()] function before the database handle that they 8657** are attached to is itself closed. If the database handle is closed before 8658** the session object is deleted, then the results of calling any session 8659** module function, including [sqlite3session_delete()] on the session object 8660** are undefined. 8661** 8662** Because the session module uses the [sqlite3_preupdate_hook()] API, it 8663** is not possible for an application to register a pre-update hook on a 8664** database handle that has one or more session objects attached. Nor is 8665** it possible to create a session object attached to a database handle for 8666** which a pre-update hook is already defined. The results of attempting 8667** either of these things are undefined. 8668** 8669** The session object will be used to create changesets for tables in 8670** database zDb, where zDb is either "main", or "temp", or the name of an 8671** attached database. It is not an error if database zDb is not attached 8672** to the database when the session object is created. 8673*/ 8674SQLITE_API int sqlite3session_create( 8675 sqlite3 *db, /* Database handle */ 8676 const char *zDb, /* Name of db (e.g. "main") */ 8677 sqlite3_session **ppSession /* OUT: New session object */ 8678); 8679 8680/* 8681** CAPI3REF: Delete A Session Object 8682** 8683** Delete a session object previously allocated using 8684** [sqlite3session_create()]. Once a session object has been deleted, the 8685** results of attempting to use pSession with any other session module 8686** function are undefined. 8687** 8688** Session objects must be deleted before the database handle to which they 8689** are attached is closed. Refer to the documentation for 8690** [sqlite3session_create()] for details. 8691*/ 8692SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 8693 8694 8695/* 8696** CAPI3REF: Enable Or Disable A Session Object 8697** 8698** Enable or disable the recording of changes by a session object. When 8699** enabled, a session object records changes made to the database. When 8700** disabled - it does not. A newly created session object is enabled. 8701** Refer to the documentation for [sqlite3session_changeset()] for further 8702** details regarding how enabling and disabling a session object affects 8703** the eventual changesets. 8704** 8705** Passing zero to this function disables the session. Passing a value 8706** greater than zero enables it. Passing a value less than zero is a 8707** no-op, and may be used to query the current state of the session. 8708** 8709** The return value indicates the final state of the session object: 0 if 8710** the session is disabled, or 1 if it is enabled. 8711*/ 8712SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 8713 8714/* 8715** CAPI3REF: Set Or Clear the Indirect Change Flag 8716** 8717** Each change recorded by a session object is marked as either direct or 8718** indirect. A change is marked as indirect if either: 8719** 8720** <ul> 8721** <li> The session object "indirect" flag is set when the change is 8722** made, or 8723** <li> The change is made by an SQL trigger or foreign key action 8724** instead of directly as a result of a users SQL statement. 8725** </ul> 8726** 8727** If a single row is affected by more than one operation within a session, 8728** then the change is considered indirect if all operations meet the criteria 8729** for an indirect change above, or direct otherwise. 8730** 8731** This function is used to set, clear or query the session object indirect 8732** flag. If the second argument passed to this function is zero, then the 8733** indirect flag is cleared. If it is greater than zero, the indirect flag 8734** is set. Passing a value less than zero does not modify the current value 8735** of the indirect flag, and may be used to query the current state of the 8736** indirect flag for the specified session object. 8737** 8738** The return value indicates the final state of the indirect flag: 0 if 8739** it is clear, or 1 if it is set. 8740*/ 8741SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 8742 8743/* 8744** CAPI3REF: Attach A Table To A Session Object 8745** 8746** If argument zTab is not NULL, then it is the name of a table to attach 8747** to the session object passed as the first argument. All subsequent changes 8748** made to the table while the session object is enabled will be recorded. See 8749** documentation for [sqlite3session_changeset()] for further details. 8750** 8751** Or, if argument zTab is NULL, then changes are recorded for all tables 8752** in the database. If additional tables are added to the database (by 8753** executing "CREATE TABLE" statements) after this call is made, changes for 8754** the new tables are also recorded. 8755** 8756** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 8757** defined as part of their CREATE TABLE statement. It does not matter if the 8758** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 8759** KEY may consist of a single column, or may be a composite key. 8760** 8761** It is not an error if the named table does not exist in the database. Nor 8762** is it an error if the named table does not have a PRIMARY KEY. However, 8763** no changes will be recorded in either of these scenarios. 8764** 8765** Changes are not recorded for individual rows that have NULL values stored 8766** in one or more of their PRIMARY KEY columns. 8767** 8768** SQLITE_OK is returned if the call completes without error. Or, if an error 8769** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 8770*/ 8771SQLITE_API int sqlite3session_attach( 8772 sqlite3_session *pSession, /* Session object */ 8773 const char *zTab /* Table name */ 8774); 8775 8776/* 8777** CAPI3REF: Set a table filter on a Session Object. 8778** 8779** The second argument (xFilter) is the "filter callback". For changes to rows 8780** in tables that are not attached to the Session object, the filter is called 8781** to determine whether changes to the table's rows should be tracked or not. 8782** If xFilter returns 0, changes is not tracked. Note that once a table is 8783** attached, xFilter will not be called again. 8784*/ 8785SQLITE_API void sqlite3session_table_filter( 8786 sqlite3_session *pSession, /* Session object */ 8787 int(*xFilter)( 8788 void *pCtx, /* Copy of third arg to _filter_table() */ 8789 const char *zTab /* Table name */ 8790 ), 8791 void *pCtx /* First argument passed to xFilter */ 8792); 8793 8794/* 8795** CAPI3REF: Generate A Changeset From A Session Object 8796** 8797** Obtain a changeset containing changes to the tables attached to the 8798** session object passed as the first argument. If successful, 8799** set *ppChangeset to point to a buffer containing the changeset 8800** and *pnChangeset to the size of the changeset in bytes before returning 8801** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 8802** zero and return an SQLite error code. 8803** 8804** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 8805** each representing a change to a single row of an attached table. An INSERT 8806** change contains the values of each field of a new database row. A DELETE 8807** contains the original values of each field of a deleted database row. An 8808** UPDATE change contains the original values of each field of an updated 8809** database row along with the updated values for each updated non-primary-key 8810** column. It is not possible for an UPDATE change to represent a change that 8811** modifies the values of primary key columns. If such a change is made, it 8812** is represented in a changeset as a DELETE followed by an INSERT. 8813** 8814** Changes are not recorded for rows that have NULL values stored in one or 8815** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 8816** no corresponding change is present in the changesets returned by this 8817** function. If an existing row with one or more NULL values stored in 8818** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 8819** only an INSERT is appears in the changeset. Similarly, if an existing row 8820** with non-NULL PRIMARY KEY values is updated so that one or more of its 8821** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 8822** DELETE change only. 8823** 8824** The contents of a changeset may be traversed using an iterator created 8825** using the [sqlite3changeset_start()] API. A changeset may be applied to 8826** a database with a compatible schema using the [sqlite3changeset_apply()] 8827** API. 8828** 8829** Within a changeset generated by this function, all changes related to a 8830** single table are grouped together. In other words, when iterating through 8831** a changeset or when applying a changeset to a database, all changes related 8832** to a single table are processed before moving on to the next table. Tables 8833** are sorted in the same order in which they were attached (or auto-attached) 8834** to the sqlite3_session object. The order in which the changes related to 8835** a single table are stored is undefined. 8836** 8837** Following a successful call to this function, it is the responsibility of 8838** the caller to eventually free the buffer that *ppChangeset points to using 8839** [sqlite3_free()]. 8840** 8841** <h3>Changeset Generation</h3> 8842** 8843** Once a table has been attached to a session object, the session object 8844** records the primary key values of all new rows inserted into the table. 8845** It also records the original primary key and other column values of any 8846** deleted or updated rows. For each unique primary key value, data is only 8847** recorded once - the first time a row with said primary key is inserted, 8848** updated or deleted in the lifetime of the session. 8849** 8850** There is one exception to the previous paragraph: when a row is inserted, 8851** updated or deleted, if one or more of its primary key columns contain a 8852** NULL value, no record of the change is made. 8853** 8854** The session object therefore accumulates two types of records - those 8855** that consist of primary key values only (created when the user inserts 8856** a new record) and those that consist of the primary key values and the 8857** original values of other table columns (created when the users deletes 8858** or updates a record). 8859** 8860** When this function is called, the requested changeset is created using 8861** both the accumulated records and the current contents of the database 8862** file. Specifically: 8863** 8864** <ul> 8865** <li> For each record generated by an insert, the database is queried 8866** for a row with a matching primary key. If one is found, an INSERT 8867** change is added to the changeset. If no such row is found, no change 8868** is added to the changeset. 8869** 8870** <li> For each record generated by an update or delete, the database is 8871** queried for a row with a matching primary key. If such a row is 8872** found and one or more of the non-primary key fields have been 8873** modified from their original values, an UPDATE change is added to 8874** the changeset. Or, if no such row is found in the table, a DELETE 8875** change is added to the changeset. If there is a row with a matching 8876** primary key in the database, but all fields contain their original 8877** values, no change is added to the changeset. 8878** </ul> 8879** 8880** This means, amongst other things, that if a row is inserted and then later 8881** deleted while a session object is active, neither the insert nor the delete 8882** will be present in the changeset. Or if a row is deleted and then later a 8883** row with the same primary key values inserted while a session object is 8884** active, the resulting changeset will contain an UPDATE change instead of 8885** a DELETE and an INSERT. 8886** 8887** When a session object is disabled (see the [sqlite3session_enable()] API), 8888** it does not accumulate records when rows are inserted, updated or deleted. 8889** This may appear to have some counter-intuitive effects if a single row 8890** is written to more than once during a session. For example, if a row 8891** is inserted while a session object is enabled, then later deleted while 8892** the same session object is disabled, no INSERT record will appear in the 8893** changeset, even though the delete took place while the session was disabled. 8894** Or, if one field of a row is updated while a session is disabled, and 8895** another field of the same row is updated while the session is enabled, the 8896** resulting changeset will contain an UPDATE change that updates both fields. 8897*/ 8898SQLITE_API int sqlite3session_changeset( 8899 sqlite3_session *pSession, /* Session object */ 8900 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 8901 void **ppChangeset /* OUT: Buffer containing changeset */ 8902); 8903 8904/* 8905** CAPI3REF: Load The Difference Between Tables Into A Session 8906** 8907** If it is not already attached to the session object passed as the first 8908** argument, this function attaches table zTbl in the same manner as the 8909** [sqlite3session_attach()] function. If zTbl does not exist, or if it 8910** does not have a primary key, this function is a no-op (but does not return 8911** an error). 8912** 8913** Argument zFromDb must be the name of a database ("main", "temp" etc.) 8914** attached to the same database handle as the session object that contains 8915** a table compatible with the table attached to the session by this function. 8916** A table is considered compatible if it: 8917** 8918** <ul> 8919** <li> Has the same name, 8920** <li> Has the same set of columns declared in the same order, and 8921** <li> Has the same PRIMARY KEY definition. 8922** </ul> 8923** 8924** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 8925** are compatible but do not have any PRIMARY KEY columns, it is not an error 8926** but no changes are added to the session object. As with other session 8927** APIs, tables without PRIMARY KEYs are simply ignored. 8928** 8929** This function adds a set of changes to the session object that could be 8930** used to update the table in database zFrom (call this the "from-table") 8931** so that its content is the same as the table attached to the session 8932** object (call this the "to-table"). Specifically: 8933** 8934** <ul> 8935** <li> For each row (primary key) that exists in the to-table but not in 8936** the from-table, an INSERT record is added to the session object. 8937** 8938** <li> For each row (primary key) that exists in the to-table but not in 8939** the from-table, a DELETE record is added to the session object. 8940** 8941** <li> For each row (primary key) that exists in both tables, but features 8942** different non-PK values in each, an UPDATE record is added to the 8943** session. 8944** </ul> 8945** 8946** To clarify, if this function is called and then a changeset constructed 8947** using [sqlite3session_changeset()], then after applying that changeset to 8948** database zFrom the contents of the two compatible tables would be 8949** identical. 8950** 8951** It an error if database zFrom does not exist or does not contain the 8952** required compatible table. 8953** 8954** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite 8955** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 8956** may be set to point to a buffer containing an English language error 8957** message. It is the responsibility of the caller to free this buffer using 8958** sqlite3_free(). 8959*/ 8960SQLITE_API int sqlite3session_diff( 8961 sqlite3_session *pSession, 8962 const char *zFromDb, 8963 const char *zTbl, 8964 char **pzErrMsg 8965); 8966 8967 8968/* 8969** CAPI3REF: Generate A Patchset From A Session Object 8970** 8971** The differences between a patchset and a changeset are that: 8972** 8973** <ul> 8974** <li> DELETE records consist of the primary key fields only. The 8975** original values of other fields are omitted. 8976** <li> The original values of any modified fields are omitted from 8977** UPDATE records. 8978** </ul> 8979** 8980** A patchset blob may be used with up to date versions of all 8981** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 8982** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 8983** attempting to use a patchset blob with old versions of the 8984** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 8985** 8986** Because the non-primary key "old.*" fields are omitted, no 8987** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 8988** is passed to the sqlite3changeset_apply() API. Other conflict types work 8989** in the same way as for changesets. 8990** 8991** Changes within a patchset are ordered in the same way as for changesets 8992** generated by the sqlite3session_changeset() function (i.e. all changes for 8993** a single table are grouped together, tables appear in the order in which 8994** they were attached to the session object). 8995*/ 8996SQLITE_API int sqlite3session_patchset( 8997 sqlite3_session *pSession, /* Session object */ 8998 int *pnPatchset, /* OUT: Size of buffer at *ppChangeset */ 8999 void **ppPatchset /* OUT: Buffer containing changeset */ 9000); 9001 9002/* 9003** CAPI3REF: Test if a changeset has recorded any changes. 9004** 9005** Return non-zero if no changes to attached tables have been recorded by 9006** the session object passed as the first argument. Otherwise, if one or 9007** more changes have been recorded, return zero. 9008** 9009** Even if this function returns zero, it is possible that calling 9010** [sqlite3session_changeset()] on the session handle may still return a 9011** changeset that contains no changes. This can happen when a row in 9012** an attached table is modified and then later on the original values 9013** are restored. However, if this function returns non-zero, then it is 9014** guaranteed that a call to sqlite3session_changeset() will return a 9015** changeset containing zero changes. 9016*/ 9017SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 9018 9019/* 9020** CAPI3REF: Create An Iterator To Traverse A Changeset 9021** 9022** Create an iterator used to iterate through the contents of a changeset. 9023** If successful, *pp is set to point to the iterator handle and SQLITE_OK 9024** is returned. Otherwise, if an error occurs, *pp is set to zero and an 9025** SQLite error code is returned. 9026** 9027** The following functions can be used to advance and query a changeset 9028** iterator created by this function: 9029** 9030** <ul> 9031** <li> [sqlite3changeset_next()] 9032** <li> [sqlite3changeset_op()] 9033** <li> [sqlite3changeset_new()] 9034** <li> [sqlite3changeset_old()] 9035** </ul> 9036** 9037** It is the responsibility of the caller to eventually destroy the iterator 9038** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 9039** changeset (pChangeset) must remain valid until after the iterator is 9040** destroyed. 9041** 9042** Assuming the changeset blob was created by one of the 9043** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 9044** [sqlite3changeset_invert()] functions, all changes within the changeset 9045** that apply to a single table are grouped together. This means that when 9046** an application iterates through a changeset using an iterator created by 9047** this function, all changes that relate to a single table are visited 9048** consecutively. There is no chance that the iterator will visit a change 9049** the applies to table X, then one for table Y, and then later on visit 9050** another change for table X. 9051*/ 9052SQLITE_API int sqlite3changeset_start( 9053 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 9054 int nChangeset, /* Size of changeset blob in bytes */ 9055 void *pChangeset /* Pointer to blob containing changeset */ 9056); 9057 9058 9059/* 9060** CAPI3REF: Advance A Changeset Iterator 9061** 9062** This function may only be used with iterators created by function 9063** [sqlite3changeset_start()]. If it is called on an iterator passed to 9064** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 9065** is returned and the call has no effect. 9066** 9067** Immediately after an iterator is created by sqlite3changeset_start(), it 9068** does not point to any change in the changeset. Assuming the changeset 9069** is not empty, the first call to this function advances the iterator to 9070** point to the first change in the changeset. Each subsequent call advances 9071** the iterator to point to the next change in the changeset (if any). If 9072** no error occurs and the iterator points to a valid change after a call 9073** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 9074** Otherwise, if all changes in the changeset have already been visited, 9075** SQLITE_DONE is returned. 9076** 9077** If an error occurs, an SQLite error code is returned. Possible error 9078** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 9079** SQLITE_NOMEM. 9080*/ 9081SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 9082 9083/* 9084** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 9085** 9086** The pIter argument passed to this function may either be an iterator 9087** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9088** created by [sqlite3changeset_start()]. In the latter case, the most recent 9089** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 9090** is not the case, this function returns [SQLITE_MISUSE]. 9091** 9092** If argument pzTab is not NULL, then *pzTab is set to point to a 9093** nul-terminated utf-8 encoded string containing the name of the table 9094** affected by the current change. The buffer remains valid until either 9095** sqlite3changeset_next() is called on the iterator or until the 9096** conflict-handler function returns. If pnCol is not NULL, then *pnCol is 9097** set to the number of columns in the table affected by the change. If 9098** pbIncorrect is not NULL, then *pbIndirect is set to true (1) if the change 9099** is an indirect change, or false (0) otherwise. See the documentation for 9100** [sqlite3session_indirect()] for a description of direct and indirect 9101** changes. Finally, if pOp is not NULL, then *pOp is set to one of 9102** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the 9103** type of change that the iterator currently points to. 9104** 9105** If no error occurs, SQLITE_OK is returned. If an error does occur, an 9106** SQLite error code is returned. The values of the output variables may not 9107** be trusted in this case. 9108*/ 9109SQLITE_API int sqlite3changeset_op( 9110 sqlite3_changeset_iter *pIter, /* Iterator object */ 9111 const char **pzTab, /* OUT: Pointer to table name */ 9112 int *pnCol, /* OUT: Number of columns in table */ 9113 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 9114 int *pbIndirect /* OUT: True for an 'indirect' change */ 9115); 9116 9117/* 9118** CAPI3REF: Obtain The Primary Key Definition Of A Table 9119** 9120** For each modified table, a changeset includes the following: 9121** 9122** <ul> 9123** <li> The number of columns in the table, and 9124** <li> Which of those columns make up the tables PRIMARY KEY. 9125** </ul> 9126** 9127** This function is used to find which columns comprise the PRIMARY KEY of 9128** the table modified by the change that iterator pIter currently points to. 9129** If successful, *pabPK is set to point to an array of nCol entries, where 9130** nCol is the number of columns in the table. Elements of *pabPK are set to 9131** 0x01 if the corresponding column is part of the tables primary key, or 9132** 0x00 if it is not. 9133** 9134** If argument pnCol is not NULL, then *pnCol is set to the number of columns 9135** in the table. 9136** 9137** If this function is called when the iterator does not point to a valid 9138** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 9139** SQLITE_OK is returned and the output variables populated as described 9140** above. 9141*/ 9142SQLITE_API int sqlite3changeset_pk( 9143 sqlite3_changeset_iter *pIter, /* Iterator object */ 9144 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 9145 int *pnCol /* OUT: Number of entries in output array */ 9146); 9147 9148/* 9149** CAPI3REF: Obtain old.* Values From A Changeset Iterator 9150** 9151** The pIter argument passed to this function may either be an iterator 9152** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9153** created by [sqlite3changeset_start()]. In the latter case, the most recent 9154** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 9155** Furthermore, it may only be called if the type of change that the iterator 9156** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 9157** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 9158** 9159** Argument iVal must be greater than or equal to 0, and less than the number 9160** of columns in the table affected by the current change. Otherwise, 9161** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9162** 9163** If successful, this function sets *ppValue to point to a protected 9164** sqlite3_value object containing the iVal'th value from the vector of 9165** original row values stored as part of the UPDATE or DELETE change and 9166** returns SQLITE_OK. The name of the function comes from the fact that this 9167** is similar to the "old.*" columns available to update or delete triggers. 9168** 9169** If some other error occurs (e.g. an OOM condition), an SQLite error code 9170** is returned and *ppValue is set to NULL. 9171*/ 9172SQLITE_API int sqlite3changeset_old( 9173 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9174 int iVal, /* Column number */ 9175 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 9176); 9177 9178/* 9179** CAPI3REF: Obtain new.* Values From A Changeset Iterator 9180** 9181** The pIter argument passed to this function may either be an iterator 9182** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9183** created by [sqlite3changeset_start()]. In the latter case, the most recent 9184** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 9185** Furthermore, it may only be called if the type of change that the iterator 9186** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 9187** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 9188** 9189** Argument iVal must be greater than or equal to 0, and less than the number 9190** of columns in the table affected by the current change. Otherwise, 9191** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9192** 9193** If successful, this function sets *ppValue to point to a protected 9194** sqlite3_value object containing the iVal'th value from the vector of 9195** new row values stored as part of the UPDATE or INSERT change and 9196** returns SQLITE_OK. If the change is an UPDATE and does not include 9197** a new value for the requested column, *ppValue is set to NULL and 9198** SQLITE_OK returned. The name of the function comes from the fact that 9199** this is similar to the "new.*" columns available to update or delete 9200** triggers. 9201** 9202** If some other error occurs (e.g. an OOM condition), an SQLite error code 9203** is returned and *ppValue is set to NULL. 9204*/ 9205SQLITE_API int sqlite3changeset_new( 9206 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9207 int iVal, /* Column number */ 9208 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 9209); 9210 9211/* 9212** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 9213** 9214** This function should only be used with iterator objects passed to a 9215** conflict-handler callback by [sqlite3changeset_apply()] with either 9216** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 9217** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 9218** is set to NULL. 9219** 9220** Argument iVal must be greater than or equal to 0, and less than the number 9221** of columns in the table affected by the current change. Otherwise, 9222** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9223** 9224** If successful, this function sets *ppValue to point to a protected 9225** sqlite3_value object containing the iVal'th value from the 9226** "conflicting row" associated with the current conflict-handler callback 9227** and returns SQLITE_OK. 9228** 9229** If some other error occurs (e.g. an OOM condition), an SQLite error code 9230** is returned and *ppValue is set to NULL. 9231*/ 9232SQLITE_API int sqlite3changeset_conflict( 9233 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9234 int iVal, /* Column number */ 9235 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 9236); 9237 9238/* 9239** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 9240** 9241** This function may only be called with an iterator passed to an 9242** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 9243** it sets the output variable to the total number of known foreign key 9244** violations in the destination database and returns SQLITE_OK. 9245** 9246** In all other cases this function returns SQLITE_MISUSE. 9247*/ 9248SQLITE_API int sqlite3changeset_fk_conflicts( 9249 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9250 int *pnOut /* OUT: Number of FK violations */ 9251); 9252 9253 9254/* 9255** CAPI3REF: Finalize A Changeset Iterator 9256** 9257** This function is used to finalize an iterator allocated with 9258** [sqlite3changeset_start()]. 9259** 9260** This function should only be called on iterators created using the 9261** [sqlite3changeset_start()] function. If an application calls this 9262** function with an iterator passed to a conflict-handler by 9263** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 9264** call has no effect. 9265** 9266** If an error was encountered within a call to an sqlite3changeset_xxx() 9267** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 9268** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 9269** to that error is returned by this function. Otherwise, SQLITE_OK is 9270** returned. This is to allow the following pattern (pseudo-code): 9271** 9272** sqlite3changeset_start(); 9273** while( SQLITE_ROW==sqlite3changeset_next() ){ 9274** // Do something with change. 9275** } 9276** rc = sqlite3changeset_finalize(); 9277** if( rc!=SQLITE_OK ){ 9278** // An error has occurred 9279** } 9280*/ 9281SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 9282 9283/* 9284** CAPI3REF: Invert A Changeset 9285** 9286** This function is used to "invert" a changeset object. Applying an inverted 9287** changeset to a database reverses the effects of applying the uninverted 9288** changeset. Specifically: 9289** 9290** <ul> 9291** <li> Each DELETE change is changed to an INSERT, and 9292** <li> Each INSERT change is changed to a DELETE, and 9293** <li> For each UPDATE change, the old.* and new.* values are exchanged. 9294** </ul> 9295** 9296** This function does not change the order in which changes appear within 9297** the changeset. It merely reverses the sense of each individual change. 9298** 9299** If successful, a pointer to a buffer containing the inverted changeset 9300** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 9301** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 9302** zeroed and an SQLite error code returned. 9303** 9304** It is the responsibility of the caller to eventually call sqlite3_free() 9305** on the *ppOut pointer to free the buffer allocation following a successful 9306** call to this function. 9307** 9308** WARNING/TODO: This function currently assumes that the input is a valid 9309** changeset. If it is not, the results are undefined. 9310*/ 9311SQLITE_API int sqlite3changeset_invert( 9312 int nIn, const void *pIn, /* Input changeset */ 9313 int *pnOut, void **ppOut /* OUT: Inverse of input */ 9314); 9315 9316/* 9317** CAPI3REF: Concatenate Two Changeset Objects 9318** 9319** This function is used to concatenate two changesets, A and B, into a 9320** single changeset. The result is a changeset equivalent to applying 9321** changeset A followed by changeset B. 9322** 9323** This function combines the two input changesets using an 9324** sqlite3_changegroup object. Calling it produces similar results as the 9325** following code fragment: 9326** 9327** sqlite3_changegroup *pGrp; 9328** rc = sqlite3_changegroup_new(&pGrp); 9329** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 9330** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 9331** if( rc==SQLITE_OK ){ 9332** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 9333** }else{ 9334** *ppOut = 0; 9335** *pnOut = 0; 9336** } 9337** 9338** Refer to the sqlite3_changegroup documentation below for details. 9339*/ 9340SQLITE_API int sqlite3changeset_concat( 9341 int nA, /* Number of bytes in buffer pA */ 9342 void *pA, /* Pointer to buffer containing changeset A */ 9343 int nB, /* Number of bytes in buffer pB */ 9344 void *pB, /* Pointer to buffer containing changeset B */ 9345 int *pnOut, /* OUT: Number of bytes in output changeset */ 9346 void **ppOut /* OUT: Buffer containing output changeset */ 9347); 9348 9349 9350/* 9351** CAPI3REF: Changegroup Handle 9352*/ 9353typedef struct sqlite3_changegroup sqlite3_changegroup; 9354 9355/* 9356** CAPI3REF: Create A New Changegroup Object 9357** 9358** An sqlite3_changegroup object is used to combine two or more changesets 9359** (or patchsets) into a single changeset (or patchset). A single changegroup 9360** object may combine changesets or patchsets, but not both. The output is 9361** always in the same format as the input. 9362** 9363** If successful, this function returns SQLITE_OK and populates (*pp) with 9364** a pointer to a new sqlite3_changegroup object before returning. The caller 9365** should eventually free the returned object using a call to 9366** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 9367** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 9368** 9369** The usual usage pattern for an sqlite3_changegroup object is as follows: 9370** 9371** <ul> 9372** <li> It is created using a call to sqlite3changegroup_new(). 9373** 9374** <li> Zero or more changesets (or patchsets) are added to the object 9375** by calling sqlite3changegroup_add(). 9376** 9377** <li> The result of combining all input changesets together is obtained 9378** by the application via a call to sqlite3changegroup_output(). 9379** 9380** <li> The object is deleted using a call to sqlite3changegroup_delete(). 9381** </ul> 9382** 9383** Any number of calls to add() and output() may be made between the calls to 9384** new() and delete(), and in any order. 9385** 9386** As well as the regular sqlite3changegroup_add() and 9387** sqlite3changegroup_output() functions, also available are the streaming 9388** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 9389*/ 9390int sqlite3changegroup_new(sqlite3_changegroup **pp); 9391 9392/* 9393** CAPI3REF: Add A Changeset To A Changegroup 9394** 9395** Add all changes within the changeset (or patchset) in buffer pData (size 9396** nData bytes) to the changegroup. 9397** 9398** If the buffer contains a patchset, then all prior calls to this function 9399** on the same changegroup object must also have specified patchsets. Or, if 9400** the buffer contains a changeset, so must have the earlier calls to this 9401** function. Otherwise, SQLITE_ERROR is returned and no changes are added 9402** to the changegroup. 9403** 9404** Rows within the changeset and changegroup are identified by the values in 9405** their PRIMARY KEY columns. A change in the changeset is considered to 9406** apply to the same row as a change already present in the changegroup if 9407** the two rows have the same primary key. 9408** 9409** Changes to rows that do not already appear in the changegroup are 9410** simply copied into it. Or, if both the new changeset and the changegroup 9411** contain changes that apply to a single row, the final contents of the 9412** changegroup depends on the type of each change, as follows: 9413** 9414** <table border=1 style="margin-left:8ex;margin-right:8ex"> 9415** <tr><th style="white-space:pre">Existing Change </th> 9416** <th style="white-space:pre">New Change </th> 9417** <th>Output Change 9418** <tr><td>INSERT <td>INSERT <td> 9419** The new change is ignored. This case does not occur if the new 9420** changeset was recorded immediately after the changesets already 9421** added to the changegroup. 9422** <tr><td>INSERT <td>UPDATE <td> 9423** The INSERT change remains in the changegroup. The values in the 9424** INSERT change are modified as if the row was inserted by the 9425** existing change and then updated according to the new change. 9426** <tr><td>INSERT <td>DELETE <td> 9427** The existing INSERT is removed from the changegroup. The DELETE is 9428** not added. 9429** <tr><td>UPDATE <td>INSERT <td> 9430** The new change is ignored. This case does not occur if the new 9431** changeset was recorded immediately after the changesets already 9432** added to the changegroup. 9433** <tr><td>UPDATE <td>UPDATE <td> 9434** The existing UPDATE remains within the changegroup. It is amended 9435** so that the accompanying values are as if the row was updated once 9436** by the existing change and then again by the new change. 9437** <tr><td>UPDATE <td>DELETE <td> 9438** The existing UPDATE is replaced by the new DELETE within the 9439** changegroup. 9440** <tr><td>DELETE <td>INSERT <td> 9441** If one or more of the column values in the row inserted by the 9442** new change differ from those in the row deleted by the existing 9443** change, the existing DELETE is replaced by an UPDATE within the 9444** changegroup. Otherwise, if the inserted row is exactly the same 9445** as the deleted row, the existing DELETE is simply discarded. 9446** <tr><td>DELETE <td>UPDATE <td> 9447** The new change is ignored. This case does not occur if the new 9448** changeset was recorded immediately after the changesets already 9449** added to the changegroup. 9450** <tr><td>DELETE <td>DELETE <td> 9451** The new change is ignored. This case does not occur if the new 9452** changeset was recorded immediately after the changesets already 9453** added to the changegroup. 9454** </table> 9455** 9456** If the new changeset contains changes to a table that is already present 9457** in the changegroup, then the number of columns and the position of the 9458** primary key columns for the table must be consistent. If this is not the 9459** case, this function fails with SQLITE_SCHEMA. If the input changeset 9460** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 9461** returned. Or, if an out-of-memory condition occurs during processing, this 9462** function returns SQLITE_NOMEM. In all cases, if an error occurs the 9463** final contents of the changegroup is undefined. 9464** 9465** If no error occurs, SQLITE_OK is returned. 9466*/ 9467int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 9468 9469/* 9470** CAPI3REF: Obtain A Composite Changeset From A Changegroup 9471** 9472** Obtain a buffer containing a changeset (or patchset) representing the 9473** current contents of the changegroup. If the inputs to the changegroup 9474** were themselves changesets, the output is a changeset. Or, if the 9475** inputs were patchsets, the output is also a patchset. 9476** 9477** As with the output of the sqlite3session_changeset() and 9478** sqlite3session_patchset() functions, all changes related to a single 9479** table are grouped together in the output of this function. Tables appear 9480** in the same order as for the very first changeset added to the changegroup. 9481** If the second or subsequent changesets added to the changegroup contain 9482** changes for tables that do not appear in the first changeset, they are 9483** appended onto the end of the output changeset, again in the order in 9484** which they are first encountered. 9485** 9486** If an error occurs, an SQLite error code is returned and the output 9487** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 9488** is returned and the output variables are set to the size of and a 9489** pointer to the output buffer, respectively. In this case it is the 9490** responsibility of the caller to eventually free the buffer using a 9491** call to sqlite3_free(). 9492*/ 9493int sqlite3changegroup_output( 9494 sqlite3_changegroup*, 9495 int *pnData, /* OUT: Size of output buffer in bytes */ 9496 void **ppData /* OUT: Pointer to output buffer */ 9497); 9498 9499/* 9500** CAPI3REF: Delete A Changegroup Object 9501*/ 9502void sqlite3changegroup_delete(sqlite3_changegroup*); 9503 9504/* 9505** CAPI3REF: Apply A Changeset To A Database 9506** 9507** Apply a changeset to a database. This function attempts to update the 9508** "main" database attached to handle db with the changes found in the 9509** changeset passed via the second and third arguments. 9510** 9511** The fourth argument (xFilter) passed to this function is the "filter 9512** callback". If it is not NULL, then for each table affected by at least one 9513** change in the changeset, the filter callback is invoked with 9514** the table name as the second argument, and a copy of the context pointer 9515** passed as the sixth argument to this function as the first. If the "filter 9516** callback" returns zero, then no attempt is made to apply any changes to 9517** the table. Otherwise, if the return value is non-zero or the xFilter 9518** argument to this function is NULL, all changes related to the table are 9519** attempted. 9520** 9521** For each table that is not excluded by the filter callback, this function 9522** tests that the target database contains a compatible table. A table is 9523** considered compatible if all of the following are true: 9524** 9525** <ul> 9526** <li> The table has the same name as the name recorded in the 9527** changeset, and 9528** <li> The table has at least as many columns as recorded in the 9529** changeset, and 9530** <li> The table has primary key columns in the same position as 9531** recorded in the changeset. 9532** </ul> 9533** 9534** If there is no compatible table, it is not an error, but none of the 9535** changes associated with the table are applied. A warning message is issued 9536** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 9537** one such warning is issued for each table in the changeset. 9538** 9539** For each change for which there is a compatible table, an attempt is made 9540** to modify the table contents according to the UPDATE, INSERT or DELETE 9541** change. If a change cannot be applied cleanly, the conflict handler 9542** function passed as the fifth argument to sqlite3changeset_apply() may be 9543** invoked. A description of exactly when the conflict handler is invoked for 9544** each type of change is below. 9545** 9546** Unlike the xFilter argument, xConflict may not be passed NULL. The results 9547** of passing anything other than a valid function pointer as the xConflict 9548** argument are undefined. 9549** 9550** Each time the conflict handler function is invoked, it must return one 9551** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 9552** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 9553** if the second argument passed to the conflict handler is either 9554** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 9555** returns an illegal value, any changes already made are rolled back and 9556** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 9557** actions are taken by sqlite3changeset_apply() depending on the value 9558** returned by each invocation of the conflict-handler function. Refer to 9559** the documentation for the three 9560** [SQLITE_CHANGESET_OMIT|available return values] for details. 9561** 9562** <dl> 9563** <dt>DELETE Changes<dd> 9564** For each DELETE change, this function checks if the target database 9565** contains a row with the same primary key value (or values) as the 9566** original row values stored in the changeset. If it does, and the values 9567** stored in all non-primary key columns also match the values stored in 9568** the changeset the row is deleted from the target database. 9569** 9570** If a row with matching primary key values is found, but one or more of 9571** the non-primary key fields contains a value different from the original 9572** row value stored in the changeset, the conflict-handler function is 9573** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 9574** database table has more columns than are recorded in the changeset, 9575** only the values of those non-primary key fields are compared against 9576** the current database contents - any trailing database table columns 9577** are ignored. 9578** 9579** If no row with matching primary key values is found in the database, 9580** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 9581** passed as the second argument. 9582** 9583** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 9584** (which can only happen if a foreign key constraint is violated), the 9585** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 9586** passed as the second argument. This includes the case where the DELETE 9587** operation is attempted because an earlier call to the conflict handler 9588** function returned [SQLITE_CHANGESET_REPLACE]. 9589** 9590** <dt>INSERT Changes<dd> 9591** For each INSERT change, an attempt is made to insert the new row into 9592** the database. If the changeset row contains fewer fields than the 9593** database table, the trailing fields are populated with their default 9594** values. 9595** 9596** If the attempt to insert the row fails because the database already 9597** contains a row with the same primary key values, the conflict handler 9598** function is invoked with the second argument set to 9599** [SQLITE_CHANGESET_CONFLICT]. 9600** 9601** If the attempt to insert the row fails because of some other constraint 9602** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 9603** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 9604** This includes the case where the INSERT operation is re-attempted because 9605** an earlier call to the conflict handler function returned 9606** [SQLITE_CHANGESET_REPLACE]. 9607** 9608** <dt>UPDATE Changes<dd> 9609** For each UPDATE change, this function checks if the target database 9610** contains a row with the same primary key value (or values) as the 9611** original row values stored in the changeset. If it does, and the values 9612** stored in all modified non-primary key columns also match the values 9613** stored in the changeset the row is updated within the target database. 9614** 9615** If a row with matching primary key values is found, but one or more of 9616** the modified non-primary key fields contains a value different from an 9617** original row value stored in the changeset, the conflict-handler function 9618** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 9619** UPDATE changes only contain values for non-primary key fields that are 9620** to be modified, only those fields need to match the original values to 9621** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 9622** 9623** If no row with matching primary key values is found in the database, 9624** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 9625** passed as the second argument. 9626** 9627** If the UPDATE operation is attempted, but SQLite returns 9628** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 9629** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 9630** This includes the case where the UPDATE operation is attempted after 9631** an earlier call to the conflict handler function returned 9632** [SQLITE_CHANGESET_REPLACE]. 9633** </dl> 9634** 9635** It is safe to execute SQL statements, including those that write to the 9636** table that the callback related to, from within the xConflict callback. 9637** This can be used to further customize the applications conflict 9638** resolution strategy. 9639** 9640** All changes made by this function are enclosed in a savepoint transaction. 9641** If any other error (aside from a constraint failure when attempting to 9642** write to the target database) occurs, then the savepoint transaction is 9643** rolled back, restoring the target database to its original state, and an 9644** SQLite error code returned. 9645*/ 9646SQLITE_API int sqlite3changeset_apply( 9647 sqlite3 *db, /* Apply change to "main" db of this handle */ 9648 int nChangeset, /* Size of changeset in bytes */ 9649 void *pChangeset, /* Changeset blob */ 9650 int(*xFilter)( 9651 void *pCtx, /* Copy of sixth arg to _apply() */ 9652 const char *zTab /* Table name */ 9653 ), 9654 int(*xConflict)( 9655 void *pCtx, /* Copy of sixth arg to _apply() */ 9656 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 9657 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 9658 ), 9659 void *pCtx /* First argument passed to xConflict */ 9660); 9661 9662/* 9663** CAPI3REF: Constants Passed To The Conflict Handler 9664** 9665** Values that may be passed as the second argument to a conflict-handler. 9666** 9667** <dl> 9668** <dt>SQLITE_CHANGESET_DATA<dd> 9669** The conflict handler is invoked with CHANGESET_DATA as the second argument 9670** when processing a DELETE or UPDATE change if a row with the required 9671** PRIMARY KEY fields is present in the database, but one or more other 9672** (non primary-key) fields modified by the update do not contain the 9673** expected "before" values. 9674** 9675** The conflicting row, in this case, is the database row with the matching 9676** primary key. 9677** 9678** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 9679** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 9680** argument when processing a DELETE or UPDATE change if a row with the 9681** required PRIMARY KEY fields is not present in the database. 9682** 9683** There is no conflicting row in this case. The results of invoking the 9684** sqlite3changeset_conflict() API are undefined. 9685** 9686** <dt>SQLITE_CHANGESET_CONFLICT<dd> 9687** CHANGESET_CONFLICT is passed as the second argument to the conflict 9688** handler while processing an INSERT change if the operation would result 9689** in duplicate primary key values. 9690** 9691** The conflicting row in this case is the database row with the matching 9692** primary key. 9693** 9694** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 9695** If foreign key handling is enabled, and applying a changeset leaves the 9696** database in a state containing foreign key violations, the conflict 9697** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 9698** exactly once before the changeset is committed. If the conflict handler 9699** returns CHANGESET_OMIT, the changes, including those that caused the 9700** foreign key constraint violation, are committed. Or, if it returns 9701** CHANGESET_ABORT, the changeset is rolled back. 9702** 9703** No current or conflicting row information is provided. The only function 9704** it is possible to call on the supplied sqlite3_changeset_iter handle 9705** is sqlite3changeset_fk_conflicts(). 9706** 9707** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 9708** If any other constraint violation occurs while applying a change (i.e. 9709** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 9710** invoked with CHANGESET_CONSTRAINT as the second argument. 9711** 9712** There is no conflicting row in this case. The results of invoking the 9713** sqlite3changeset_conflict() API are undefined. 9714** 9715** </dl> 9716*/ 9717#define SQLITE_CHANGESET_DATA 1 9718#define SQLITE_CHANGESET_NOTFOUND 2 9719#define SQLITE_CHANGESET_CONFLICT 3 9720#define SQLITE_CHANGESET_CONSTRAINT 4 9721#define SQLITE_CHANGESET_FOREIGN_KEY 5 9722 9723/* 9724** CAPI3REF: Constants Returned By The Conflict Handler 9725** 9726** A conflict handler callback must return one of the following three values. 9727** 9728** <dl> 9729** <dt>SQLITE_CHANGESET_OMIT<dd> 9730** If a conflict handler returns this value no special action is taken. The 9731** change that caused the conflict is not applied. The session module 9732** continues to the next change in the changeset. 9733** 9734** <dt>SQLITE_CHANGESET_REPLACE<dd> 9735** This value may only be returned if the second argument to the conflict 9736** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 9737** is not the case, any changes applied so far are rolled back and the 9738** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 9739** 9740** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 9741** handler, then the conflicting row is either updated or deleted, depending 9742** on the type of change. 9743** 9744** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 9745** handler, then the conflicting row is removed from the database and a 9746** second attempt to apply the change is made. If this second attempt fails, 9747** the original row is restored to the database before continuing. 9748** 9749** <dt>SQLITE_CHANGESET_ABORT<dd> 9750** If this value is returned, any changes applied so far are rolled back 9751** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 9752** </dl> 9753*/ 9754#define SQLITE_CHANGESET_OMIT 0 9755#define SQLITE_CHANGESET_REPLACE 1 9756#define SQLITE_CHANGESET_ABORT 2 9757 9758/* 9759** CAPI3REF: Streaming Versions of API functions. 9760** 9761** The six streaming API xxx_strm() functions serve similar purposes to the 9762** corresponding non-streaming API functions: 9763** 9764** <table border=1 style="margin-left:8ex;margin-right:8ex"> 9765** <tr><th>Streaming function<th>Non-streaming equivalent</th> 9766** <tr><td>sqlite3changeset_apply_str<td>[sqlite3changeset_apply] 9767** <tr><td>sqlite3changeset_concat_str<td>[sqlite3changeset_concat] 9768** <tr><td>sqlite3changeset_invert_str<td>[sqlite3changeset_invert] 9769** <tr><td>sqlite3changeset_start_str<td>[sqlite3changeset_start] 9770** <tr><td>sqlite3session_changeset_str<td>[sqlite3session_changeset] 9771** <tr><td>sqlite3session_patchset_str<td>[sqlite3session_patchset] 9772** </table> 9773** 9774** Non-streaming functions that accept changesets (or patchsets) as input 9775** require that the entire changeset be stored in a single buffer in memory. 9776** Similarly, those that return a changeset or patchset do so by returning 9777** a pointer to a single large buffer allocated using sqlite3_malloc(). 9778** Normally this is convenient. However, if an application running in a 9779** low-memory environment is required to handle very large changesets, the 9780** large contiguous memory allocations required can become onerous. 9781** 9782** In order to avoid this problem, instead of a single large buffer, input 9783** is passed to a streaming API functions by way of a callback function that 9784** the sessions module invokes to incrementally request input data as it is 9785** required. In all cases, a pair of API function parameters such as 9786** 9787** <pre> 9788** int nChangeset, 9789** void *pChangeset, 9790** </pre> 9791** 9792** Is replaced by: 9793** 9794** <pre> 9795** int (*xInput)(void *pIn, void *pData, int *pnData), 9796** void *pIn, 9797** </pre> 9798** 9799** Each time the xInput callback is invoked by the sessions module, the first 9800** argument passed is a copy of the supplied pIn context pointer. The second 9801** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 9802** error occurs the xInput method should copy up to (*pnData) bytes of data 9803** into the buffer and set (*pnData) to the actual number of bytes copied 9804** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 9805** should be set to zero to indicate this. Or, if an error occurs, an SQLite 9806** error code should be returned. In all cases, if an xInput callback returns 9807** an error, all processing is abandoned and the streaming API function 9808** returns a copy of the error code to the caller. 9809** 9810** In the case of sqlite3changeset_start_strm(), the xInput callback may be 9811** invoked by the sessions module at any point during the lifetime of the 9812** iterator. If such an xInput callback returns an error, the iterator enters 9813** an error state, whereby all subsequent calls to iterator functions 9814** immediately fail with the same error code as returned by xInput. 9815** 9816** Similarly, streaming API functions that return changesets (or patchsets) 9817** return them in chunks by way of a callback function instead of via a 9818** pointer to a single large buffer. In this case, a pair of parameters such 9819** as: 9820** 9821** <pre> 9822** int *pnChangeset, 9823** void **ppChangeset, 9824** </pre> 9825** 9826** Is replaced by: 9827** 9828** <pre> 9829** int (*xOutput)(void *pOut, const void *pData, int nData), 9830** void *pOut 9831** </pre> 9832** 9833** The xOutput callback is invoked zero or more times to return data to 9834** the application. The first parameter passed to each call is a copy of the 9835** pOut pointer supplied by the application. The second parameter, pData, 9836** points to a buffer nData bytes in size containing the chunk of output 9837** data being returned. If the xOutput callback successfully processes the 9838** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 9839** it should return some other SQLite error code. In this case processing 9840** is immediately abandoned and the streaming API function returns a copy 9841** of the xOutput error code to the application. 9842** 9843** The sessions module never invokes an xOutput callback with the third 9844** parameter set to a value less than or equal to zero. Other than this, 9845** no guarantees are made as to the size of the chunks of data returned. 9846*/ 9847SQLITE_API int sqlite3changeset_apply_strm( 9848 sqlite3 *db, /* Apply change to "main" db of this handle */ 9849 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 9850 void *pIn, /* First arg for xInput */ 9851 int(*xFilter)( 9852 void *pCtx, /* Copy of sixth arg to _apply() */ 9853 const char *zTab /* Table name */ 9854 ), 9855 int(*xConflict)( 9856 void *pCtx, /* Copy of sixth arg to _apply() */ 9857 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 9858 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 9859 ), 9860 void *pCtx /* First argument passed to xConflict */ 9861); 9862SQLITE_API int sqlite3changeset_concat_strm( 9863 int (*xInputA)(void *pIn, void *pData, int *pnData), 9864 void *pInA, 9865 int (*xInputB)(void *pIn, void *pData, int *pnData), 9866 void *pInB, 9867 int (*xOutput)(void *pOut, const void *pData, int nData), 9868 void *pOut 9869); 9870SQLITE_API int sqlite3changeset_invert_strm( 9871 int (*xInput)(void *pIn, void *pData, int *pnData), 9872 void *pIn, 9873 int (*xOutput)(void *pOut, const void *pData, int nData), 9874 void *pOut 9875); 9876SQLITE_API int sqlite3changeset_start_strm( 9877 sqlite3_changeset_iter **pp, 9878 int (*xInput)(void *pIn, void *pData, int *pnData), 9879 void *pIn 9880); 9881SQLITE_API int sqlite3session_changeset_strm( 9882 sqlite3_session *pSession, 9883 int (*xOutput)(void *pOut, const void *pData, int nData), 9884 void *pOut 9885); 9886SQLITE_API int sqlite3session_patchset_strm( 9887 sqlite3_session *pSession, 9888 int (*xOutput)(void *pOut, const void *pData, int nData), 9889 void *pOut 9890); 9891int sqlite3changegroup_add_strm(sqlite3_changegroup*, 9892 int (*xInput)(void *pIn, void *pData, int *pnData), 9893 void *pIn 9894); 9895int sqlite3changegroup_output_strm(sqlite3_changegroup*, 9896 int (*xOutput)(void *pOut, const void *pData, int nData), 9897 void *pOut 9898); 9899 9900 9901/* 9902** Make sure we can call this stuff from C++. 9903*/ 9904#ifdef __cplusplus 9905} 9906#endif 9907 9908#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 9909 9910/******** End of sqlite3session.h *********/ 9911/******** Begin file fts5.h *********/ 9912/* 9913** 2014 May 31 9914** 9915** The author disclaims copyright to this source code. In place of 9916** a legal notice, here is a blessing: 9917** 9918** May you do good and not evil. 9919** May you find forgiveness for yourself and forgive others. 9920** May you share freely, never taking more than you give. 9921** 9922****************************************************************************** 9923** 9924** Interfaces to extend FTS5. Using the interfaces defined in this file, 9925** FTS5 may be extended with: 9926** 9927** * custom tokenizers, and 9928** * custom auxiliary functions. 9929*/ 9930 9931 9932#ifndef _FTS5_H 9933#define _FTS5_H 9934 9935 9936#ifdef __cplusplus 9937extern "C" { 9938#endif 9939 9940/************************************************************************* 9941** CUSTOM AUXILIARY FUNCTIONS 9942** 9943** Virtual table implementations may overload SQL functions by implementing 9944** the sqlite3_module.xFindFunction() method. 9945*/ 9946 9947typedef struct Fts5ExtensionApi Fts5ExtensionApi; 9948typedef struct Fts5Context Fts5Context; 9949typedef struct Fts5PhraseIter Fts5PhraseIter; 9950 9951typedef void (*fts5_extension_function)( 9952 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 9953 Fts5Context *pFts, /* First arg to pass to pApi functions */ 9954 sqlite3_context *pCtx, /* Context for returning result/error */ 9955 int nVal, /* Number of values in apVal[] array */ 9956 sqlite3_value **apVal /* Array of trailing arguments */ 9957); 9958 9959struct Fts5PhraseIter { 9960 const unsigned char *a; 9961 const unsigned char *b; 9962}; 9963 9964/* 9965** EXTENSION API FUNCTIONS 9966** 9967** xUserData(pFts): 9968** Return a copy of the context pointer the extension function was 9969** registered with. 9970** 9971** xColumnTotalSize(pFts, iCol, pnToken): 9972** If parameter iCol is less than zero, set output variable *pnToken 9973** to the total number of tokens in the FTS5 table. Or, if iCol is 9974** non-negative but less than the number of columns in the table, return 9975** the total number of tokens in column iCol, considering all rows in 9976** the FTS5 table. 9977** 9978** If parameter iCol is greater than or equal to the number of columns 9979** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 9980** an OOM condition or IO error), an appropriate SQLite error code is 9981** returned. 9982** 9983** xColumnCount(pFts): 9984** Return the number of columns in the table. 9985** 9986** xColumnSize(pFts, iCol, pnToken): 9987** If parameter iCol is less than zero, set output variable *pnToken 9988** to the total number of tokens in the current row. Or, if iCol is 9989** non-negative but less than the number of columns in the table, set 9990** *pnToken to the number of tokens in column iCol of the current row. 9991** 9992** If parameter iCol is greater than or equal to the number of columns 9993** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 9994** an OOM condition or IO error), an appropriate SQLite error code is 9995** returned. 9996** 9997** This function may be quite inefficient if used with an FTS5 table 9998** created with the "columnsize=0" option. 9999** 10000** xColumnText: 10001** This function attempts to retrieve the text of column iCol of the 10002** current document. If successful, (*pz) is set to point to a buffer 10003** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 10004** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 10005** if an error occurs, an SQLite error code is returned and the final values 10006** of (*pz) and (*pn) are undefined. 10007** 10008** xPhraseCount: 10009** Returns the number of phrases in the current query expression. 10010** 10011** xPhraseSize: 10012** Returns the number of tokens in phrase iPhrase of the query. Phrases 10013** are numbered starting from zero. 10014** 10015** xInstCount: 10016** Set *pnInst to the total number of occurrences of all phrases within 10017** the query within the current row. Return SQLITE_OK if successful, or 10018** an error code (i.e. SQLITE_NOMEM) if an error occurs. 10019** 10020** This API can be quite slow if used with an FTS5 table created with the 10021** "detail=none" or "detail=column" option. If the FTS5 table is created 10022** with either "detail=none" or "detail=column" and "content=" option 10023** (i.e. if it is a contentless table), then this API always returns 0. 10024** 10025** xInst: 10026** Query for the details of phrase match iIdx within the current row. 10027** Phrase matches are numbered starting from zero, so the iIdx argument 10028** should be greater than or equal to zero and smaller than the value 10029** output by xInstCount(). 10030** 10031** Usually, output parameter *piPhrase is set to the phrase number, *piCol 10032** to the column in which it occurs and *piOff the token offset of the 10033** first token of the phrase. The exception is if the table was created 10034** with the offsets=0 option specified. In this case *piOff is always 10035** set to -1. 10036** 10037** Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM) 10038** if an error occurs. 10039** 10040** This API can be quite slow if used with an FTS5 table created with the 10041** "detail=none" or "detail=column" option. 10042** 10043** xRowid: 10044** Returns the rowid of the current row. 10045** 10046** xTokenize: 10047** Tokenize text using the tokenizer belonging to the FTS5 table. 10048** 10049** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 10050** This API function is used to query the FTS table for phrase iPhrase 10051** of the current query. Specifically, a query equivalent to: 10052** 10053** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 10054** 10055** with $p set to a phrase equivalent to the phrase iPhrase of the 10056** current query is executed. Any column filter that applies to 10057** phrase iPhrase of the current query is included in $p. For each 10058** row visited, the callback function passed as the fourth argument 10059** is invoked. The context and API objects passed to the callback 10060** function may be used to access the properties of each matched row. 10061** Invoking Api.xUserData() returns a copy of the pointer passed as 10062** the third argument to pUserData. 10063** 10064** If the callback function returns any value other than SQLITE_OK, the 10065** query is abandoned and the xQueryPhrase function returns immediately. 10066** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 10067** Otherwise, the error code is propagated upwards. 10068** 10069** If the query runs to completion without incident, SQLITE_OK is returned. 10070** Or, if some error occurs before the query completes or is aborted by 10071** the callback, an SQLite error code is returned. 10072** 10073** 10074** xSetAuxdata(pFts5, pAux, xDelete) 10075** 10076** Save the pointer passed as the second argument as the extension functions 10077** "auxiliary data". The pointer may then be retrieved by the current or any 10078** future invocation of the same fts5 extension function made as part of 10079** of the same MATCH query using the xGetAuxdata() API. 10080** 10081** Each extension function is allocated a single auxiliary data slot for 10082** each FTS query (MATCH expression). If the extension function is invoked 10083** more than once for a single FTS query, then all invocations share a 10084** single auxiliary data context. 10085** 10086** If there is already an auxiliary data pointer when this function is 10087** invoked, then it is replaced by the new pointer. If an xDelete callback 10088** was specified along with the original pointer, it is invoked at this 10089** point. 10090** 10091** The xDelete callback, if one is specified, is also invoked on the 10092** auxiliary data pointer after the FTS5 query has finished. 10093** 10094** If an error (e.g. an OOM condition) occurs within this function, an 10095** the auxiliary data is set to NULL and an error code returned. If the 10096** xDelete parameter was not NULL, it is invoked on the auxiliary data 10097** pointer before returning. 10098** 10099** 10100** xGetAuxdata(pFts5, bClear) 10101** 10102** Returns the current auxiliary data pointer for the fts5 extension 10103** function. See the xSetAuxdata() method for details. 10104** 10105** If the bClear argument is non-zero, then the auxiliary data is cleared 10106** (set to NULL) before this function returns. In this case the xDelete, 10107** if any, is not invoked. 10108** 10109** 10110** xRowCount(pFts5, pnRow) 10111** 10112** This function is used to retrieve the total number of rows in the table. 10113** In other words, the same value that would be returned by: 10114** 10115** SELECT count(*) FROM ftstable; 10116** 10117** xPhraseFirst() 10118** This function is used, along with type Fts5PhraseIter and the xPhraseNext 10119** method, to iterate through all instances of a single query phrase within 10120** the current row. This is the same information as is accessible via the 10121** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 10122** to use, this API may be faster under some circumstances. To iterate 10123** through instances of phrase iPhrase, use the following code: 10124** 10125** Fts5PhraseIter iter; 10126** int iCol, iOff; 10127** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 10128** iCol>=0; 10129** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 10130** ){ 10131** // An instance of phrase iPhrase at offset iOff of column iCol 10132** } 10133** 10134** The Fts5PhraseIter structure is defined above. Applications should not 10135** modify this structure directly - it should only be used as shown above 10136** with the xPhraseFirst() and xPhraseNext() API methods (and by 10137** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 10138** 10139** This API can be quite slow if used with an FTS5 table created with the 10140** "detail=none" or "detail=column" option. If the FTS5 table is created 10141** with either "detail=none" or "detail=column" and "content=" option 10142** (i.e. if it is a contentless table), then this API always iterates 10143** through an empty set (all calls to xPhraseFirst() set iCol to -1). 10144** 10145** xPhraseNext() 10146** See xPhraseFirst above. 10147** 10148** xPhraseFirstColumn() 10149** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 10150** and xPhraseNext() APIs described above. The difference is that instead 10151** of iterating through all instances of a phrase in the current row, these 10152** APIs are used to iterate through the set of columns in the current row 10153** that contain one or more instances of a specified phrase. For example: 10154** 10155** Fts5PhraseIter iter; 10156** int iCol; 10157** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 10158** iCol>=0; 10159** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 10160** ){ 10161** // Column iCol contains at least one instance of phrase iPhrase 10162** } 10163** 10164** This API can be quite slow if used with an FTS5 table created with the 10165** "detail=none" option. If the FTS5 table is created with either 10166** "detail=none" "content=" option (i.e. if it is a contentless table), 10167** then this API always iterates through an empty set (all calls to 10168** xPhraseFirstColumn() set iCol to -1). 10169** 10170** The information accessed using this API and its companion 10171** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 10172** (or xInst/xInstCount). The chief advantage of this API is that it is 10173** significantly more efficient than those alternatives when used with 10174** "detail=column" tables. 10175** 10176** xPhraseNextColumn() 10177** See xPhraseFirstColumn above. 10178*/ 10179struct Fts5ExtensionApi { 10180 int iVersion; /* Currently always set to 3 */ 10181 10182 void *(*xUserData)(Fts5Context*); 10183 10184 int (*xColumnCount)(Fts5Context*); 10185 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 10186 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 10187 10188 int (*xTokenize)(Fts5Context*, 10189 const char *pText, int nText, /* Text to tokenize */ 10190 void *pCtx, /* Context passed to xToken() */ 10191 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 10192 ); 10193 10194 int (*xPhraseCount)(Fts5Context*); 10195 int (*xPhraseSize)(Fts5Context*, int iPhrase); 10196 10197 int (*xInstCount)(Fts5Context*, int *pnInst); 10198 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 10199 10200 sqlite3_int64 (*xRowid)(Fts5Context*); 10201 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 10202 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 10203 10204 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 10205 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 10206 ); 10207 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 10208 void *(*xGetAuxdata)(Fts5Context*, int bClear); 10209 10210 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 10211 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 10212 10213 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 10214 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 10215}; 10216 10217/* 10218** CUSTOM AUXILIARY FUNCTIONS 10219*************************************************************************/ 10220 10221/************************************************************************* 10222** CUSTOM TOKENIZERS 10223** 10224** Applications may also register custom tokenizer types. A tokenizer 10225** is registered by providing fts5 with a populated instance of the 10226** following structure. All structure methods must be defined, setting 10227** any member of the fts5_tokenizer struct to NULL leads to undefined 10228** behaviour. The structure methods are expected to function as follows: 10229** 10230** xCreate: 10231** This function is used to allocate and initialize a tokenizer instance. 10232** A tokenizer instance is required to actually tokenize text. 10233** 10234** The first argument passed to this function is a copy of the (void*) 10235** pointer provided by the application when the fts5_tokenizer object 10236** was registered with FTS5 (the third argument to xCreateTokenizer()). 10237** The second and third arguments are an array of nul-terminated strings 10238** containing the tokenizer arguments, if any, specified following the 10239** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 10240** to create the FTS5 table. 10241** 10242** The final argument is an output variable. If successful, (*ppOut) 10243** should be set to point to the new tokenizer handle and SQLITE_OK 10244** returned. If an error occurs, some value other than SQLITE_OK should 10245** be returned. In this case, fts5 assumes that the final value of *ppOut 10246** is undefined. 10247** 10248** xDelete: 10249** This function is invoked to delete a tokenizer handle previously 10250** allocated using xCreate(). Fts5 guarantees that this function will 10251** be invoked exactly once for each successful call to xCreate(). 10252** 10253** xTokenize: 10254** This function is expected to tokenize the nText byte string indicated 10255** by argument pText. pText may or may not be nul-terminated. The first 10256** argument passed to this function is a pointer to an Fts5Tokenizer object 10257** returned by an earlier call to xCreate(). 10258** 10259** The second argument indicates the reason that FTS5 is requesting 10260** tokenization of the supplied text. This is always one of the following 10261** four values: 10262** 10263** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 10264** or removed from the FTS table. The tokenizer is being invoked to 10265** determine the set of tokens to add to (or delete from) the 10266** FTS index. 10267** 10268** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 10269** against the FTS index. The tokenizer is being called to tokenize 10270** a bareword or quoted string specified as part of the query. 10271** 10272** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 10273** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 10274** followed by a "*" character, indicating that the last token 10275** returned by the tokenizer will be treated as a token prefix. 10276** 10277** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 10278** satisfy an fts5_api.xTokenize() request made by an auxiliary 10279** function. Or an fts5_api.xColumnSize() request made by the same 10280** on a columnsize=0 database. 10281** </ul> 10282** 10283** For each token in the input string, the supplied callback xToken() must 10284** be invoked. The first argument to it should be a copy of the pointer 10285** passed as the second argument to xTokenize(). The third and fourth 10286** arguments are a pointer to a buffer containing the token text, and the 10287** size of the token in bytes. The 4th and 5th arguments are the byte offsets 10288** of the first byte of and first byte immediately following the text from 10289** which the token is derived within the input. 10290** 10291** The second argument passed to the xToken() callback ("tflags") should 10292** normally be set to 0. The exception is if the tokenizer supports 10293** synonyms. In this case see the discussion below for details. 10294** 10295** FTS5 assumes the xToken() callback is invoked for each token in the 10296** order that they occur within the input text. 10297** 10298** If an xToken() callback returns any value other than SQLITE_OK, then 10299** the tokenization should be abandoned and the xTokenize() method should 10300** immediately return a copy of the xToken() return value. Or, if the 10301** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 10302** if an error occurs with the xTokenize() implementation itself, it 10303** may abandon the tokenization and return any error code other than 10304** SQLITE_OK or SQLITE_DONE. 10305** 10306** SYNONYM SUPPORT 10307** 10308** Custom tokenizers may also support synonyms. Consider a case in which a 10309** user wishes to query for a phrase such as "first place". Using the 10310** built-in tokenizers, the FTS5 query 'first + place' will match instances 10311** of "first place" within the document set, but not alternative forms 10312** such as "1st place". In some applications, it would be better to match 10313** all instances of "first place" or "1st place" regardless of which form 10314** the user specified in the MATCH query text. 10315** 10316** There are several ways to approach this in FTS5: 10317** 10318** <ol><li> By mapping all synonyms to a single token. In this case, the 10319** In the above example, this means that the tokenizer returns the 10320** same token for inputs "first" and "1st". Say that token is in 10321** fact "first", so that when the user inserts the document "I won 10322** 1st place" entries are added to the index for tokens "i", "won", 10323** "first" and "place". If the user then queries for '1st + place', 10324** the tokenizer substitutes "first" for "1st" and the query works 10325** as expected. 10326** 10327** <li> By adding multiple synonyms for a single term to the FTS index. 10328** In this case, when tokenizing query text, the tokenizer may 10329** provide multiple synonyms for a single term within the document. 10330** FTS5 then queries the index for each synonym individually. For 10331** example, faced with the query: 10332** 10333** <codeblock> 10334** ... MATCH 'first place'</codeblock> 10335** 10336** the tokenizer offers both "1st" and "first" as synonyms for the 10337** first token in the MATCH query and FTS5 effectively runs a query 10338** similar to: 10339** 10340** <codeblock> 10341** ... MATCH '(first OR 1st) place'</codeblock> 10342** 10343** except that, for the purposes of auxiliary functions, the query 10344** still appears to contain just two phrases - "(first OR 1st)" 10345** being treated as a single phrase. 10346** 10347** <li> By adding multiple synonyms for a single term to the FTS index. 10348** Using this method, when tokenizing document text, the tokenizer 10349** provides multiple synonyms for each token. So that when a 10350** document such as "I won first place" is tokenized, entries are 10351** added to the FTS index for "i", "won", "first", "1st" and 10352** "place". 10353** 10354** This way, even if the tokenizer does not provide synonyms 10355** when tokenizing query text (it should not - to do would be 10356** inefficient), it doesn't matter if the user queries for 10357** 'first + place' or '1st + place', as there are entires in the 10358** FTS index corresponding to both forms of the first token. 10359** </ol> 10360** 10361** Whether it is parsing document or query text, any call to xToken that 10362** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 10363** is considered to supply a synonym for the previous token. For example, 10364** when parsing the document "I won first place", a tokenizer that supports 10365** synonyms would call xToken() 5 times, as follows: 10366** 10367** <codeblock> 10368** xToken(pCtx, 0, "i", 1, 0, 1); 10369** xToken(pCtx, 0, "won", 3, 2, 5); 10370** xToken(pCtx, 0, "first", 5, 6, 11); 10371** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 10372** xToken(pCtx, 0, "place", 5, 12, 17); 10373**</codeblock> 10374** 10375** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 10376** xToken() is called. Multiple synonyms may be specified for a single token 10377** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 10378** There is no limit to the number of synonyms that may be provided for a 10379** single token. 10380** 10381** In many cases, method (1) above is the best approach. It does not add 10382** extra data to the FTS index or require FTS5 to query for multiple terms, 10383** so it is efficient in terms of disk space and query speed. However, it 10384** does not support prefix queries very well. If, as suggested above, the 10385** token "first" is subsituted for "1st" by the tokenizer, then the query: 10386** 10387** <codeblock> 10388** ... MATCH '1s*'</codeblock> 10389** 10390** will not match documents that contain the token "1st" (as the tokenizer 10391** will probably not map "1s" to any prefix of "first"). 10392** 10393** For full prefix support, method (3) may be preferred. In this case, 10394** because the index contains entries for both "first" and "1st", prefix 10395** queries such as 'fi*' or '1s*' will match correctly. However, because 10396** extra entries are added to the FTS index, this method uses more space 10397** within the database. 10398** 10399** Method (2) offers a midpoint between (1) and (3). Using this method, 10400** a query such as '1s*' will match documents that contain the literal 10401** token "1st", but not "first" (assuming the tokenizer is not able to 10402** provide synonyms for prefixes). However, a non-prefix query like '1st' 10403** will match against "1st" and "first". This method does not require 10404** extra disk space, as no extra entries are added to the FTS index. 10405** On the other hand, it may require more CPU cycles to run MATCH queries, 10406** as separate queries of the FTS index are required for each synonym. 10407** 10408** When using methods (2) or (3), it is important that the tokenizer only 10409** provide synonyms when tokenizing document text (method (2)) or query 10410** text (method (3)), not both. Doing so will not cause any errors, but is 10411** inefficient. 10412*/ 10413typedef struct Fts5Tokenizer Fts5Tokenizer; 10414typedef struct fts5_tokenizer fts5_tokenizer; 10415struct fts5_tokenizer { 10416 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 10417 void (*xDelete)(Fts5Tokenizer*); 10418 int (*xTokenize)(Fts5Tokenizer*, 10419 void *pCtx, 10420 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 10421 const char *pText, int nText, 10422 int (*xToken)( 10423 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 10424 int tflags, /* Mask of FTS5_TOKEN_* flags */ 10425 const char *pToken, /* Pointer to buffer containing token */ 10426 int nToken, /* Size of token in bytes */ 10427 int iStart, /* Byte offset of token within input text */ 10428 int iEnd /* Byte offset of end of token within input text */ 10429 ) 10430 ); 10431}; 10432 10433/* Flags that may be passed as the third argument to xTokenize() */ 10434#define FTS5_TOKENIZE_QUERY 0x0001 10435#define FTS5_TOKENIZE_PREFIX 0x0002 10436#define FTS5_TOKENIZE_DOCUMENT 0x0004 10437#define FTS5_TOKENIZE_AUX 0x0008 10438 10439/* Flags that may be passed by the tokenizer implementation back to FTS5 10440** as the third argument to the supplied xToken callback. */ 10441#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 10442 10443/* 10444** END OF CUSTOM TOKENIZERS 10445*************************************************************************/ 10446 10447/************************************************************************* 10448** FTS5 EXTENSION REGISTRATION API 10449*/ 10450typedef struct fts5_api fts5_api; 10451struct fts5_api { 10452 int iVersion; /* Currently always set to 2 */ 10453 10454 /* Create a new tokenizer */ 10455 int (*xCreateTokenizer)( 10456 fts5_api *pApi, 10457 const char *zName, 10458 void *pContext, 10459 fts5_tokenizer *pTokenizer, 10460 void (*xDestroy)(void*) 10461 ); 10462 10463 /* Find an existing tokenizer */ 10464 int (*xFindTokenizer)( 10465 fts5_api *pApi, 10466 const char *zName, 10467 void **ppContext, 10468 fts5_tokenizer *pTokenizer 10469 ); 10470 10471 /* Create a new auxiliary function */ 10472 int (*xCreateFunction)( 10473 fts5_api *pApi, 10474 const char *zName, 10475 void *pContext, 10476 fts5_extension_function xFunction, 10477 void (*xDestroy)(void*) 10478 ); 10479}; 10480 10481/* 10482** END OF REGISTRATION API 10483*************************************************************************/ 10484 10485#ifdef __cplusplus 10486} /* end of the 'extern "C"' block */ 10487#endif 10488 10489#endif /* _FTS5_H */ 10490 10491/******** End of fts5.h *********/ 10492