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 suppose 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_STDCALL 58# define SQLITE_STDCALL 59#endif 60 61/* 62** These no-op macros are used in front of interfaces to mark those 63** interfaces as either deprecated or experimental. New applications 64** should not use deprecated interfaces - they are supported for backwards 65** compatibility only. Application writers should be aware that 66** experimental interfaces are subject to change in point releases. 67** 68** These macros used to resolve to various kinds of compiler magic that 69** would generate warning messages when they were used. But that 70** compiler magic ended up generating such a flurry of bug reports 71** that we have taken it all out and gone back to using simple 72** noop macros. 73*/ 74#define SQLITE_DEPRECATED 75#define SQLITE_EXPERIMENTAL 76 77/* 78** Ensure these symbols were not defined by some previous header file. 79*/ 80#ifdef SQLITE_VERSION 81# undef SQLITE_VERSION 82#endif 83#ifdef SQLITE_VERSION_NUMBER 84# undef SQLITE_VERSION_NUMBER 85#endif 86 87/* 88** CAPI3REF: Compile-Time Library Version Numbers 89** 90** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 91** evaluates to a string literal that is the SQLite version in the 92** format "X.Y.Z" where X is the major version number (always 3 for 93** SQLite3) and Y is the minor version number and Z is the release number.)^ 94** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 95** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 96** numbers used in [SQLITE_VERSION].)^ 97** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 98** be larger than the release from which it is derived. Either Y will 99** be held constant and Z will be incremented or else Y will be incremented 100** and Z will be reset to zero. 101** 102** Since version 3.6.18, SQLite source code has been stored in the 103** <a href="http://www.fossil-scm.org/">Fossil configuration management 104** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 105** a string which identifies a particular check-in of SQLite 106** within its configuration management system. ^The SQLITE_SOURCE_ID 107** string contains the date and time of the check-in (UTC) and an SHA1 108** hash of the entire source tree. 109** 110** See also: [sqlite3_libversion()], 111** [sqlite3_libversion_number()], [sqlite3_sourceid()], 112** [sqlite_version()] and [sqlite_source_id()]. 113*/ 114#define SQLITE_VERSION "3.8.10.2" 115#define SQLITE_VERSION_NUMBER 3008010 116#define SQLITE_SOURCE_ID "2015-05-20 18:17:19 2ef4f3a5b1d1d0c4338f8243d40a2452cc1f7fe4" 117 118/* 119** CAPI3REF: Run-Time Library Version Numbers 120** KEYWORDS: sqlite3_version, sqlite3_sourceid 121** 122** These interfaces provide the same information as the [SQLITE_VERSION], 123** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 124** but are associated with the library instead of the header file. ^(Cautious 125** programmers might include assert() statements in their application to 126** verify that values returned by these interfaces match the macros in 127** the header, and thus insure that the application is 128** compiled with matching library and header files. 129** 130** <blockquote><pre> 131** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 132** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 133** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 134** </pre></blockquote>)^ 135** 136** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 137** macro. ^The sqlite3_libversion() function returns a pointer to the 138** to the sqlite3_version[] string constant. The sqlite3_libversion() 139** function is provided for use in DLLs since DLL users usually do not have 140** direct access to string constants within the DLL. ^The 141** sqlite3_libversion_number() function returns an integer equal to 142** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 143** a pointer to a string constant whose value is the same as the 144** [SQLITE_SOURCE_ID] C preprocessor macro. 145** 146** See also: [sqlite_version()] and [sqlite_source_id()]. 147*/ 148SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 149SQLITE_API const char *SQLITE_STDCALL sqlite3_libversion(void); 150SQLITE_API const char *SQLITE_STDCALL sqlite3_sourceid(void); 151SQLITE_API int SQLITE_STDCALL sqlite3_libversion_number(void); 152 153/* 154** CAPI3REF: Run-Time Library Compilation Options Diagnostics 155** 156** ^The sqlite3_compileoption_used() function returns 0 or 1 157** indicating whether the specified option was defined at 158** compile time. ^The SQLITE_ prefix may be omitted from the 159** option name passed to sqlite3_compileoption_used(). 160** 161** ^The sqlite3_compileoption_get() function allows iterating 162** over the list of options that were defined at compile time by 163** returning the N-th compile time option string. ^If N is out of range, 164** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 165** prefix is omitted from any strings returned by 166** sqlite3_compileoption_get(). 167** 168** ^Support for the diagnostic functions sqlite3_compileoption_used() 169** and sqlite3_compileoption_get() may be omitted by specifying the 170** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 171** 172** See also: SQL functions [sqlite_compileoption_used()] and 173** [sqlite_compileoption_get()] and the [compile_options pragma]. 174*/ 175#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 176SQLITE_API int SQLITE_STDCALL sqlite3_compileoption_used(const char *zOptName); 177SQLITE_API const char *SQLITE_STDCALL sqlite3_compileoption_get(int N); 178#endif 179 180/* 181** CAPI3REF: Test To See If The Library Is Threadsafe 182** 183** ^The sqlite3_threadsafe() function returns zero if and only if 184** SQLite was compiled with mutexing code omitted due to the 185** [SQLITE_THREADSAFE] compile-time option being set to 0. 186** 187** SQLite can be compiled with or without mutexes. When 188** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 189** are enabled and SQLite is threadsafe. When the 190** [SQLITE_THREADSAFE] macro is 0, 191** the mutexes are omitted. Without the mutexes, it is not safe 192** to use SQLite concurrently from more than one thread. 193** 194** Enabling mutexes incurs a measurable performance penalty. 195** So if speed is of utmost importance, it makes sense to disable 196** the mutexes. But for maximum safety, mutexes should be enabled. 197** ^The default behavior is for mutexes to be enabled. 198** 199** This interface can be used by an application to make sure that the 200** version of SQLite that it is linking against was compiled with 201** the desired setting of the [SQLITE_THREADSAFE] macro. 202** 203** This interface only reports on the compile-time mutex setting 204** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 205** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 206** can be fully or partially disabled using a call to [sqlite3_config()] 207** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 208** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 209** sqlite3_threadsafe() function shows only the compile-time setting of 210** thread safety, not any run-time changes to that setting made by 211** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 212** is unchanged by calls to sqlite3_config().)^ 213** 214** See the [threading mode] documentation for additional information. 215*/ 216SQLITE_API int SQLITE_STDCALL sqlite3_threadsafe(void); 217 218/* 219** CAPI3REF: Database Connection Handle 220** KEYWORDS: {database connection} {database connections} 221** 222** Each open SQLite database is represented by a pointer to an instance of 223** the opaque structure named "sqlite3". It is useful to think of an sqlite3 224** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 225** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 226** and [sqlite3_close_v2()] are its destructors. There are many other 227** interfaces (such as 228** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 229** [sqlite3_busy_timeout()] to name but three) that are methods on an 230** sqlite3 object. 231*/ 232typedef struct sqlite3 sqlite3; 233 234/* 235** CAPI3REF: 64-Bit Integer Types 236** KEYWORDS: sqlite_int64 sqlite_uint64 237** 238** Because there is no cross-platform way to specify 64-bit integer types 239** SQLite includes typedefs for 64-bit signed and unsigned integers. 240** 241** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 242** The sqlite_int64 and sqlite_uint64 types are supported for backwards 243** compatibility only. 244** 245** ^The sqlite3_int64 and sqlite_int64 types can store integer values 246** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 247** sqlite3_uint64 and sqlite_uint64 types can store integer values 248** between 0 and +18446744073709551615 inclusive. 249*/ 250#ifdef SQLITE_INT64_TYPE 251 typedef SQLITE_INT64_TYPE sqlite_int64; 252 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 253#elif defined(_MSC_VER) || defined(__BORLANDC__) 254 typedef __int64 sqlite_int64; 255 typedef unsigned __int64 sqlite_uint64; 256#else 257 typedef long long int sqlite_int64; 258 typedef unsigned long long int sqlite_uint64; 259#endif 260typedef sqlite_int64 sqlite3_int64; 261typedef sqlite_uint64 sqlite3_uint64; 262 263/* 264** If compiling for a processor that lacks floating point support, 265** substitute integer for floating-point. 266*/ 267#ifdef SQLITE_OMIT_FLOATING_POINT 268# define double sqlite3_int64 269#endif 270 271/* 272** CAPI3REF: Closing A Database Connection 273** DESTRUCTOR: sqlite3 274** 275** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 276** for the [sqlite3] object. 277** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 278** the [sqlite3] object is successfully destroyed and all associated 279** resources are deallocated. 280** 281** ^If the database connection is associated with unfinalized prepared 282** statements or unfinished sqlite3_backup objects then sqlite3_close() 283** will leave the database connection open and return [SQLITE_BUSY]. 284** ^If sqlite3_close_v2() is called with unfinalized prepared statements 285** and/or unfinished sqlite3_backups, then the database connection becomes 286** an unusable "zombie" which will automatically be deallocated when the 287** last prepared statement is finalized or the last sqlite3_backup is 288** finished. The sqlite3_close_v2() interface is intended for use with 289** host languages that are garbage collected, and where the order in which 290** destructors are called is arbitrary. 291** 292** Applications should [sqlite3_finalize | finalize] all [prepared statements], 293** [sqlite3_blob_close | close] all [BLOB handles], and 294** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 295** with the [sqlite3] object prior to attempting to close the object. ^If 296** sqlite3_close_v2() is called on a [database connection] that still has 297** outstanding [prepared statements], [BLOB handles], and/or 298** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 299** of resources is deferred until all [prepared statements], [BLOB handles], 300** and [sqlite3_backup] objects are also destroyed. 301** 302** ^If an [sqlite3] object is destroyed while a transaction is open, 303** the transaction is automatically rolled back. 304** 305** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 306** must be either a NULL 307** pointer or an [sqlite3] object pointer obtained 308** from [sqlite3_open()], [sqlite3_open16()], or 309** [sqlite3_open_v2()], and not previously closed. 310** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 311** argument is a harmless no-op. 312*/ 313SQLITE_API int SQLITE_STDCALL sqlite3_close(sqlite3*); 314SQLITE_API int SQLITE_STDCALL sqlite3_close_v2(sqlite3*); 315 316/* 317** The type for a callback function. 318** This is legacy and deprecated. It is included for historical 319** compatibility and is not documented. 320*/ 321typedef int (*sqlite3_callback)(void*,int,char**, char**); 322 323/* 324** CAPI3REF: One-Step Query Execution Interface 325** METHOD: sqlite3 326** 327** The sqlite3_exec() interface is a convenience wrapper around 328** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 329** that allows an application to run multiple statements of SQL 330** without having to use a lot of C code. 331** 332** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 333** semicolon-separate SQL statements passed into its 2nd argument, 334** in the context of the [database connection] passed in as its 1st 335** argument. ^If the callback function of the 3rd argument to 336** sqlite3_exec() is not NULL, then it is invoked for each result row 337** coming out of the evaluated SQL statements. ^The 4th argument to 338** sqlite3_exec() is relayed through to the 1st argument of each 339** callback invocation. ^If the callback pointer to sqlite3_exec() 340** is NULL, then no callback is ever invoked and result rows are 341** ignored. 342** 343** ^If an error occurs while evaluating the SQL statements passed into 344** sqlite3_exec(), then execution of the current statement stops and 345** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 346** is not NULL then any error message is written into memory obtained 347** from [sqlite3_malloc()] and passed back through the 5th parameter. 348** To avoid memory leaks, the application should invoke [sqlite3_free()] 349** on error message strings returned through the 5th parameter of 350** of sqlite3_exec() after the error message string is no longer needed. 351** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 352** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 353** NULL before returning. 354** 355** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 356** routine returns SQLITE_ABORT without invoking the callback again and 357** without running any subsequent SQL statements. 358** 359** ^The 2nd argument to the sqlite3_exec() callback function is the 360** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 361** callback is an array of pointers to strings obtained as if from 362** [sqlite3_column_text()], one for each column. ^If an element of a 363** result row is NULL then the corresponding string pointer for the 364** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 365** sqlite3_exec() callback is an array of pointers to strings where each 366** entry represents the name of corresponding result column as obtained 367** from [sqlite3_column_name()]. 368** 369** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 370** to an empty string, or a pointer that contains only whitespace and/or 371** SQL comments, then no SQL statements are evaluated and the database 372** is not changed. 373** 374** Restrictions: 375** 376** <ul> 377** <li> The application must insure that the 1st parameter to sqlite3_exec() 378** is a valid and open [database connection]. 379** <li> The application must not close the [database connection] specified by 380** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 381** <li> The application must not modify the SQL statement text passed into 382** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 383** </ul> 384*/ 385SQLITE_API int SQLITE_STDCALL sqlite3_exec( 386 sqlite3*, /* An open database */ 387 const char *sql, /* SQL to be evaluated */ 388 int (*callback)(void*,int,char**,char**), /* Callback function */ 389 void *, /* 1st argument to callback */ 390 char **errmsg /* Error msg written here */ 391); 392 393/* 394** CAPI3REF: Result Codes 395** KEYWORDS: {result code definitions} 396** 397** Many SQLite functions return an integer result code from the set shown 398** here in order to indicate success or failure. 399** 400** New error codes may be added in future versions of SQLite. 401** 402** See also: [extended result code definitions] 403*/ 404#define SQLITE_OK 0 /* Successful result */ 405/* beginning-of-error-codes */ 406#define SQLITE_ERROR 1 /* SQL error or missing database */ 407#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 408#define SQLITE_PERM 3 /* Access permission denied */ 409#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 410#define SQLITE_BUSY 5 /* The database file is locked */ 411#define SQLITE_LOCKED 6 /* A table in the database is locked */ 412#define SQLITE_NOMEM 7 /* A malloc() failed */ 413#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 414#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 415#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 416#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 417#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 418#define SQLITE_FULL 13 /* Insertion failed because database is full */ 419#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 420#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 421#define SQLITE_EMPTY 16 /* Database is empty */ 422#define SQLITE_SCHEMA 17 /* The database schema changed */ 423#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 424#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 425#define SQLITE_MISMATCH 20 /* Data type mismatch */ 426#define SQLITE_MISUSE 21 /* Library used incorrectly */ 427#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 428#define SQLITE_AUTH 23 /* Authorization denied */ 429#define SQLITE_FORMAT 24 /* Auxiliary database format error */ 430#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 431#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 432#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 433#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 434#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 435#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 436/* end-of-error-codes */ 437 438/* 439** CAPI3REF: Extended Result Codes 440** KEYWORDS: {extended result code definitions} 441** 442** In its default configuration, SQLite API routines return one of 30 integer 443** [result codes]. However, experience has shown that many of 444** these result codes are too coarse-grained. They do not provide as 445** much information about problems as programmers might like. In an effort to 446** address this, newer versions of SQLite (version 3.3.8 and later) include 447** support for additional result codes that provide more detailed information 448** about errors. These [extended result codes] are enabled or disabled 449** on a per database connection basis using the 450** [sqlite3_extended_result_codes()] API. Or, the extended code for 451** the most recent error can be obtained using 452** [sqlite3_extended_errcode()]. 453*/ 454#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 455#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 456#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 457#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 458#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 459#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 460#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 461#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 462#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 463#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 464#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 465#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 466#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 467#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 468#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 469#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 470#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 471#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 472#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 473#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 474#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 475#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 476#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 477#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 478#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 479#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 480#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 481#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 482#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 483#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 484#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 485#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 486#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 487#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 488#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 489#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 490#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 491#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 492#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 493#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 494#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 495#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 496#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 497#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 498#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 499#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 500#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 501#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 502#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 503#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 504#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 505#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 506#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 507 508/* 509** CAPI3REF: Flags For File Open Operations 510** 511** These bit values are intended for use in the 512** 3rd parameter to the [sqlite3_open_v2()] interface and 513** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 514*/ 515#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 516#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 517#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 518#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 519#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 520#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 521#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 522#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 523#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 524#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 525#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 526#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 527#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 528#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 529#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 530#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 531#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 532#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 533#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 534#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 535 536/* Reserved: 0x00F00000 */ 537 538/* 539** CAPI3REF: Device Characteristics 540** 541** The xDeviceCharacteristics method of the [sqlite3_io_methods] 542** object returns an integer which is a vector of these 543** bit values expressing I/O characteristics of the mass storage 544** device that holds the file that the [sqlite3_io_methods] 545** refers to. 546** 547** The SQLITE_IOCAP_ATOMIC property means that all writes of 548** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 549** mean that writes of blocks that are nnn bytes in size and 550** are aligned to an address which is an integer multiple of 551** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 552** that when data is appended to a file, the data is appended 553** first then the size of the file is extended, never the other 554** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 555** information is written to disk in the same order as calls 556** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 557** after reboot following a crash or power loss, the only bytes in a 558** file that were written at the application level might have changed 559** and that adjacent bytes, even bytes within the same sector are 560** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 561** flag indicate that a file cannot be deleted when open. The 562** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 563** read-only media and cannot be changed even by processes with 564** elevated privileges. 565*/ 566#define SQLITE_IOCAP_ATOMIC 0x00000001 567#define SQLITE_IOCAP_ATOMIC512 0x00000002 568#define SQLITE_IOCAP_ATOMIC1K 0x00000004 569#define SQLITE_IOCAP_ATOMIC2K 0x00000008 570#define SQLITE_IOCAP_ATOMIC4K 0x00000010 571#define SQLITE_IOCAP_ATOMIC8K 0x00000020 572#define SQLITE_IOCAP_ATOMIC16K 0x00000040 573#define SQLITE_IOCAP_ATOMIC32K 0x00000080 574#define SQLITE_IOCAP_ATOMIC64K 0x00000100 575#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 576#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 577#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 578#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 579#define SQLITE_IOCAP_IMMUTABLE 0x00002000 580 581/* 582** CAPI3REF: File Locking Levels 583** 584** SQLite uses one of these integer values as the second 585** argument to calls it makes to the xLock() and xUnlock() methods 586** of an [sqlite3_io_methods] object. 587*/ 588#define SQLITE_LOCK_NONE 0 589#define SQLITE_LOCK_SHARED 1 590#define SQLITE_LOCK_RESERVED 2 591#define SQLITE_LOCK_PENDING 3 592#define SQLITE_LOCK_EXCLUSIVE 4 593 594/* 595** CAPI3REF: Synchronization Type Flags 596** 597** When SQLite invokes the xSync() method of an 598** [sqlite3_io_methods] object it uses a combination of 599** these integer values as the second argument. 600** 601** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 602** sync operation only needs to flush data to mass storage. Inode 603** information need not be flushed. If the lower four bits of the flag 604** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 605** If the lower four bits equal SQLITE_SYNC_FULL, that means 606** to use Mac OS X style fullsync instead of fsync(). 607** 608** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 609** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 610** settings. The [synchronous pragma] determines when calls to the 611** xSync VFS method occur and applies uniformly across all platforms. 612** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 613** energetic or rigorous or forceful the sync operations are and 614** only make a difference on Mac OSX for the default SQLite code. 615** (Third-party VFS implementations might also make the distinction 616** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 617** operating systems natively supported by SQLite, only Mac OSX 618** cares about the difference.) 619*/ 620#define SQLITE_SYNC_NORMAL 0x00002 621#define SQLITE_SYNC_FULL 0x00003 622#define SQLITE_SYNC_DATAONLY 0x00010 623 624/* 625** CAPI3REF: OS Interface Open File Handle 626** 627** An [sqlite3_file] object represents an open file in the 628** [sqlite3_vfs | OS interface layer]. Individual OS interface 629** implementations will 630** want to subclass this object by appending additional fields 631** for their own use. The pMethods entry is a pointer to an 632** [sqlite3_io_methods] object that defines methods for performing 633** I/O operations on the open file. 634*/ 635typedef struct sqlite3_file sqlite3_file; 636struct sqlite3_file { 637 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 638}; 639 640/* 641** CAPI3REF: OS Interface File Virtual Methods Object 642** 643** Every file opened by the [sqlite3_vfs.xOpen] method populates an 644** [sqlite3_file] object (or, more commonly, a subclass of the 645** [sqlite3_file] object) with a pointer to an instance of this object. 646** This object defines the methods used to perform various operations 647** against the open file represented by the [sqlite3_file] object. 648** 649** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 650** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 651** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 652** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 653** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 654** to NULL. 655** 656** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 657** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 658** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 659** flag may be ORed in to indicate that only the data of the file 660** and not its inode needs to be synced. 661** 662** The integer values to xLock() and xUnlock() are one of 663** <ul> 664** <li> [SQLITE_LOCK_NONE], 665** <li> [SQLITE_LOCK_SHARED], 666** <li> [SQLITE_LOCK_RESERVED], 667** <li> [SQLITE_LOCK_PENDING], or 668** <li> [SQLITE_LOCK_EXCLUSIVE]. 669** </ul> 670** xLock() increases the lock. xUnlock() decreases the lock. 671** The xCheckReservedLock() method checks whether any database connection, 672** either in this process or in some other process, is holding a RESERVED, 673** PENDING, or EXCLUSIVE lock on the file. It returns true 674** if such a lock exists and false otherwise. 675** 676** The xFileControl() method is a generic interface that allows custom 677** VFS implementations to directly control an open file using the 678** [sqlite3_file_control()] interface. The second "op" argument is an 679** integer opcode. The third argument is a generic pointer intended to 680** point to a structure that may contain arguments or space in which to 681** write return values. Potential uses for xFileControl() might be 682** functions to enable blocking locks with timeouts, to change the 683** locking strategy (for example to use dot-file locks), to inquire 684** about the status of a lock, or to break stale locks. The SQLite 685** core reserves all opcodes less than 100 for its own use. 686** A [file control opcodes | list of opcodes] less than 100 is available. 687** Applications that define a custom xFileControl method should use opcodes 688** greater than 100 to avoid conflicts. VFS implementations should 689** return [SQLITE_NOTFOUND] for file control opcodes that they do not 690** recognize. 691** 692** The xSectorSize() method returns the sector size of the 693** device that underlies the file. The sector size is the 694** minimum write that can be performed without disturbing 695** other bytes in the file. The xDeviceCharacteristics() 696** method returns a bit vector describing behaviors of the 697** underlying device: 698** 699** <ul> 700** <li> [SQLITE_IOCAP_ATOMIC] 701** <li> [SQLITE_IOCAP_ATOMIC512] 702** <li> [SQLITE_IOCAP_ATOMIC1K] 703** <li> [SQLITE_IOCAP_ATOMIC2K] 704** <li> [SQLITE_IOCAP_ATOMIC4K] 705** <li> [SQLITE_IOCAP_ATOMIC8K] 706** <li> [SQLITE_IOCAP_ATOMIC16K] 707** <li> [SQLITE_IOCAP_ATOMIC32K] 708** <li> [SQLITE_IOCAP_ATOMIC64K] 709** <li> [SQLITE_IOCAP_SAFE_APPEND] 710** <li> [SQLITE_IOCAP_SEQUENTIAL] 711** </ul> 712** 713** The SQLITE_IOCAP_ATOMIC property means that all writes of 714** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 715** mean that writes of blocks that are nnn bytes in size and 716** are aligned to an address which is an integer multiple of 717** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 718** that when data is appended to a file, the data is appended 719** first then the size of the file is extended, never the other 720** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 721** information is written to disk in the same order as calls 722** to xWrite(). 723** 724** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 725** in the unread portions of the buffer with zeros. A VFS that 726** fails to zero-fill short reads might seem to work. However, 727** failure to zero-fill short reads will eventually lead to 728** database corruption. 729*/ 730typedef struct sqlite3_io_methods sqlite3_io_methods; 731struct sqlite3_io_methods { 732 int iVersion; 733 int (*xClose)(sqlite3_file*); 734 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 735 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 736 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 737 int (*xSync)(sqlite3_file*, int flags); 738 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 739 int (*xLock)(sqlite3_file*, int); 740 int (*xUnlock)(sqlite3_file*, int); 741 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 742 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 743 int (*xSectorSize)(sqlite3_file*); 744 int (*xDeviceCharacteristics)(sqlite3_file*); 745 /* Methods above are valid for version 1 */ 746 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 747 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 748 void (*xShmBarrier)(sqlite3_file*); 749 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 750 /* Methods above are valid for version 2 */ 751 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 752 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 753 /* Methods above are valid for version 3 */ 754 /* Additional methods may be added in future releases */ 755}; 756 757/* 758** CAPI3REF: Standard File Control Opcodes 759** KEYWORDS: {file control opcodes} {file control opcode} 760** 761** These integer constants are opcodes for the xFileControl method 762** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 763** interface. 764** 765** <ul> 766** <li>[[SQLITE_FCNTL_LOCKSTATE]] 767** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 768** opcode causes the xFileControl method to write the current state of 769** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 770** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 771** into an integer that the pArg argument points to. This capability 772** is used during testing and is only available when the SQLITE_TEST 773** compile-time option is used. 774** 775** <li>[[SQLITE_FCNTL_SIZE_HINT]] 776** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 777** layer a hint of how large the database file will grow to be during the 778** current transaction. This hint is not guaranteed to be accurate but it 779** is often close. The underlying VFS might choose to preallocate database 780** file space based on this hint in order to help writes to the database 781** file run faster. 782** 783** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 784** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 785** extends and truncates the database file in chunks of a size specified 786** by the user. The fourth argument to [sqlite3_file_control()] should 787** point to an integer (type int) containing the new chunk-size to use 788** for the nominated database. Allocating database file space in large 789** chunks (say 1MB at a time), may reduce file-system fragmentation and 790** improve performance on some systems. 791** 792** <li>[[SQLITE_FCNTL_FILE_POINTER]] 793** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 794** to the [sqlite3_file] object associated with a particular database 795** connection. See the [sqlite3_file_control()] documentation for 796** additional information. 797** 798** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 799** No longer in use. 800** 801** <li>[[SQLITE_FCNTL_SYNC]] 802** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 803** sent to the VFS immediately before the xSync method is invoked on a 804** database file descriptor. Or, if the xSync method is not invoked 805** because the user has configured SQLite with 806** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 807** of the xSync method. In most cases, the pointer argument passed with 808** this file-control is NULL. However, if the database file is being synced 809** as part of a multi-database commit, the argument points to a nul-terminated 810** string containing the transactions master-journal file name. VFSes that 811** do not need this signal should silently ignore this opcode. Applications 812** should not call [sqlite3_file_control()] with this opcode as doing so may 813** disrupt the operation of the specialized VFSes that do require it. 814** 815** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 816** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 817** and sent to the VFS after a transaction has been committed immediately 818** but before the database is unlocked. VFSes that do not need this signal 819** should silently ignore this opcode. Applications should not call 820** [sqlite3_file_control()] with this opcode as doing so may disrupt the 821** operation of the specialized VFSes that do require it. 822** 823** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 824** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 825** retry counts and intervals for certain disk I/O operations for the 826** windows [VFS] in order to provide robustness in the presence of 827** anti-virus programs. By default, the windows VFS will retry file read, 828** file write, and file delete operations up to 10 times, with a delay 829** of 25 milliseconds before the first retry and with the delay increasing 830** by an additional 25 milliseconds with each subsequent retry. This 831** opcode allows these two values (10 retries and 25 milliseconds of delay) 832** to be adjusted. The values are changed for all database connections 833** within the same process. The argument is a pointer to an array of two 834** integers where the first integer i the new retry count and the second 835** integer is the delay. If either integer is negative, then the setting 836** is not changed but instead the prior value of that setting is written 837** into the array entry, allowing the current retry settings to be 838** interrogated. The zDbName parameter is ignored. 839** 840** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 841** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 842** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 843** write ahead log and shared memory files used for transaction control 844** are automatically deleted when the latest connection to the database 845** closes. Setting persistent WAL mode causes those files to persist after 846** close. Persisting the files is useful when other processes that do not 847** have write permission on the directory containing the database file want 848** to read the database file, as the WAL and shared memory files must exist 849** in order for the database to be readable. The fourth parameter to 850** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 851** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 852** WAL mode. If the integer is -1, then it is overwritten with the current 853** WAL persistence setting. 854** 855** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 856** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 857** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 858** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 859** xDeviceCharacteristics methods. The fourth parameter to 860** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 861** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 862** mode. If the integer is -1, then it is overwritten with the current 863** zero-damage mode setting. 864** 865** <li>[[SQLITE_FCNTL_OVERWRITE]] 866** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 867** a write transaction to indicate that, unless it is rolled back for some 868** reason, the entire database file will be overwritten by the current 869** transaction. This is used by VACUUM operations. 870** 871** <li>[[SQLITE_FCNTL_VFSNAME]] 872** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 873** all [VFSes] in the VFS stack. The names are of all VFS shims and the 874** final bottom-level VFS are written into memory obtained from 875** [sqlite3_malloc()] and the result is stored in the char* variable 876** that the fourth parameter of [sqlite3_file_control()] points to. 877** The caller is responsible for freeing the memory when done. As with 878** all file-control actions, there is no guarantee that this will actually 879** do anything. Callers should initialize the char* variable to a NULL 880** pointer in case this file-control is not implemented. This file-control 881** is intended for diagnostic use only. 882** 883** <li>[[SQLITE_FCNTL_PRAGMA]] 884** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 885** file control is sent to the open [sqlite3_file] object corresponding 886** to the database file to which the pragma statement refers. ^The argument 887** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 888** pointers to strings (char**) in which the second element of the array 889** is the name of the pragma and the third element is the argument to the 890** pragma or NULL if the pragma has no argument. ^The handler for an 891** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 892** of the char** argument point to a string obtained from [sqlite3_mprintf()] 893** or the equivalent and that string will become the result of the pragma or 894** the error message if the pragma fails. ^If the 895** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 896** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 897** file control returns [SQLITE_OK], then the parser assumes that the 898** VFS has handled the PRAGMA itself and the parser generates a no-op 899** prepared statement if result string is NULL, or that returns a copy 900** of the result string if the string is non-NULL. 901** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 902** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 903** that the VFS encountered an error while handling the [PRAGMA] and the 904** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 905** file control occurs at the beginning of pragma statement analysis and so 906** it is able to override built-in [PRAGMA] statements. 907** 908** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 909** ^The [SQLITE_FCNTL_BUSYHANDLER] 910** file-control may be invoked by SQLite on the database file handle 911** shortly after it is opened in order to provide a custom VFS with access 912** to the connections busy-handler callback. The argument is of type (void **) 913** - an array of two (void *) values. The first (void *) actually points 914** to a function of type (int (*)(void *)). In order to invoke the connections 915** busy-handler, this function should be invoked with the second (void *) in 916** the array as the only argument. If it returns non-zero, then the operation 917** should be retried. If it returns zero, the custom VFS should abandon the 918** current operation. 919** 920** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 921** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 922** to have SQLite generate a 923** temporary filename using the same algorithm that is followed to generate 924** temporary filenames for TEMP tables and other internal uses. The 925** argument should be a char** which will be filled with the filename 926** written into memory obtained from [sqlite3_malloc()]. The caller should 927** invoke [sqlite3_free()] on the result to avoid a memory leak. 928** 929** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 930** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 931** maximum number of bytes that will be used for memory-mapped I/O. 932** The argument is a pointer to a value of type sqlite3_int64 that 933** is an advisory maximum number of bytes in the file to memory map. The 934** pointer is overwritten with the old value. The limit is not changed if 935** the value originally pointed to is negative, and so the current limit 936** can be queried by passing in a pointer to a negative number. This 937** file-control is used internally to implement [PRAGMA mmap_size]. 938** 939** <li>[[SQLITE_FCNTL_TRACE]] 940** The [SQLITE_FCNTL_TRACE] file control provides advisory information 941** to the VFS about what the higher layers of the SQLite stack are doing. 942** This file control is used by some VFS activity tracing [shims]. 943** The argument is a zero-terminated string. Higher layers in the 944** SQLite stack may generate instances of this file control if 945** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 946** 947** <li>[[SQLITE_FCNTL_HAS_MOVED]] 948** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 949** pointer to an integer and it writes a boolean into that integer depending 950** on whether or not the file has been renamed, moved, or deleted since it 951** was first opened. 952** 953** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 954** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 955** opcode causes the xFileControl method to swap the file handle with the one 956** pointed to by the pArg argument. This capability is used during testing 957** and only needs to be supported when SQLITE_TEST is defined. 958** 959** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 960** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 961** be advantageous to block on the next WAL lock if the lock is not immediately 962** available. The WAL subsystem issues this signal during rare 963** circumstances in order to fix a problem with priority inversion. 964** Applications should <em>not</em> use this file-control. 965** 966** </ul> 967*/ 968#define SQLITE_FCNTL_LOCKSTATE 1 969#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 970#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 971#define SQLITE_FCNTL_LAST_ERRNO 4 972#define SQLITE_FCNTL_SIZE_HINT 5 973#define SQLITE_FCNTL_CHUNK_SIZE 6 974#define SQLITE_FCNTL_FILE_POINTER 7 975#define SQLITE_FCNTL_SYNC_OMITTED 8 976#define SQLITE_FCNTL_WIN32_AV_RETRY 9 977#define SQLITE_FCNTL_PERSIST_WAL 10 978#define SQLITE_FCNTL_OVERWRITE 11 979#define SQLITE_FCNTL_VFSNAME 12 980#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 981#define SQLITE_FCNTL_PRAGMA 14 982#define SQLITE_FCNTL_BUSYHANDLER 15 983#define SQLITE_FCNTL_TEMPFILENAME 16 984#define SQLITE_FCNTL_MMAP_SIZE 18 985#define SQLITE_FCNTL_TRACE 19 986#define SQLITE_FCNTL_HAS_MOVED 20 987#define SQLITE_FCNTL_SYNC 21 988#define SQLITE_FCNTL_COMMIT_PHASETWO 22 989#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 990#define SQLITE_FCNTL_WAL_BLOCK 24 991 992/* deprecated names */ 993#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 994#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 995#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 996 997 998/* 999** CAPI3REF: Mutex Handle 1000** 1001** The mutex module within SQLite defines [sqlite3_mutex] to be an 1002** abstract type for a mutex object. The SQLite core never looks 1003** at the internal representation of an [sqlite3_mutex]. It only 1004** deals with pointers to the [sqlite3_mutex] object. 1005** 1006** Mutexes are created using [sqlite3_mutex_alloc()]. 1007*/ 1008typedef struct sqlite3_mutex sqlite3_mutex; 1009 1010/* 1011** CAPI3REF: OS Interface Object 1012** 1013** An instance of the sqlite3_vfs object defines the interface between 1014** the SQLite core and the underlying operating system. The "vfs" 1015** in the name of the object stands for "virtual file system". See 1016** the [VFS | VFS documentation] for further information. 1017** 1018** The value of the iVersion field is initially 1 but may be larger in 1019** future versions of SQLite. Additional fields may be appended to this 1020** object when the iVersion value is increased. Note that the structure 1021** of the sqlite3_vfs object changes in the transaction between 1022** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 1023** modified. 1024** 1025** The szOsFile field is the size of the subclassed [sqlite3_file] 1026** structure used by this VFS. mxPathname is the maximum length of 1027** a pathname in this VFS. 1028** 1029** Registered sqlite3_vfs objects are kept on a linked list formed by 1030** the pNext pointer. The [sqlite3_vfs_register()] 1031** and [sqlite3_vfs_unregister()] interfaces manage this list 1032** in a thread-safe way. The [sqlite3_vfs_find()] interface 1033** searches the list. Neither the application code nor the VFS 1034** implementation should use the pNext pointer. 1035** 1036** The pNext field is the only field in the sqlite3_vfs 1037** structure that SQLite will ever modify. SQLite will only access 1038** or modify this field while holding a particular static mutex. 1039** The application should never modify anything within the sqlite3_vfs 1040** object once the object has been registered. 1041** 1042** The zName field holds the name of the VFS module. The name must 1043** be unique across all VFS modules. 1044** 1045** [[sqlite3_vfs.xOpen]] 1046** ^SQLite guarantees that the zFilename parameter to xOpen 1047** is either a NULL pointer or string obtained 1048** from xFullPathname() with an optional suffix added. 1049** ^If a suffix is added to the zFilename parameter, it will 1050** consist of a single "-" character followed by no more than 1051** 11 alphanumeric and/or "-" characters. 1052** ^SQLite further guarantees that 1053** the string will be valid and unchanged until xClose() is 1054** called. Because of the previous sentence, 1055** the [sqlite3_file] can safely store a pointer to the 1056** filename if it needs to remember the filename for some reason. 1057** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1058** must invent its own temporary name for the file. ^Whenever the 1059** xFilename parameter is NULL it will also be the case that the 1060** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1061** 1062** The flags argument to xOpen() includes all bits set in 1063** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1064** or [sqlite3_open16()] is used, then flags includes at least 1065** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1066** If xOpen() opens a file read-only then it sets *pOutFlags to 1067** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1068** 1069** ^(SQLite will also add one of the following flags to the xOpen() 1070** call, depending on the object being opened: 1071** 1072** <ul> 1073** <li> [SQLITE_OPEN_MAIN_DB] 1074** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1075** <li> [SQLITE_OPEN_TEMP_DB] 1076** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1077** <li> [SQLITE_OPEN_TRANSIENT_DB] 1078** <li> [SQLITE_OPEN_SUBJOURNAL] 1079** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1080** <li> [SQLITE_OPEN_WAL] 1081** </ul>)^ 1082** 1083** The file I/O implementation can use the object type flags to 1084** change the way it deals with files. For example, an application 1085** that does not care about crash recovery or rollback might make 1086** the open of a journal file a no-op. Writes to this journal would 1087** also be no-ops, and any attempt to read the journal would return 1088** SQLITE_IOERR. Or the implementation might recognize that a database 1089** file will be doing page-aligned sector reads and writes in a random 1090** order and set up its I/O subsystem accordingly. 1091** 1092** SQLite might also add one of the following flags to the xOpen method: 1093** 1094** <ul> 1095** <li> [SQLITE_OPEN_DELETEONCLOSE] 1096** <li> [SQLITE_OPEN_EXCLUSIVE] 1097** </ul> 1098** 1099** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1100** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1101** will be set for TEMP databases and their journals, transient 1102** databases, and subjournals. 1103** 1104** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1105** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1106** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1107** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1108** SQLITE_OPEN_CREATE, is used to indicate that file should always 1109** be created, and that it is an error if it already exists. 1110** It is <i>not</i> used to indicate the file should be opened 1111** for exclusive access. 1112** 1113** ^At least szOsFile bytes of memory are allocated by SQLite 1114** to hold the [sqlite3_file] structure passed as the third 1115** argument to xOpen. The xOpen method does not have to 1116** allocate the structure; it should just fill it in. Note that 1117** the xOpen method must set the sqlite3_file.pMethods to either 1118** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1119** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1120** element will be valid after xOpen returns regardless of the success 1121** or failure of the xOpen call. 1122** 1123** [[sqlite3_vfs.xAccess]] 1124** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1125** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1126** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1127** to test whether a file is at least readable. The file can be a 1128** directory. 1129** 1130** ^SQLite will always allocate at least mxPathname+1 bytes for the 1131** output buffer xFullPathname. The exact size of the output buffer 1132** is also passed as a parameter to both methods. If the output buffer 1133** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1134** handled as a fatal error by SQLite, vfs implementations should endeavor 1135** to prevent this by setting mxPathname to a sufficiently large value. 1136** 1137** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1138** interfaces are not strictly a part of the filesystem, but they are 1139** included in the VFS structure for completeness. 1140** The xRandomness() function attempts to return nBytes bytes 1141** of good-quality randomness into zOut. The return value is 1142** the actual number of bytes of randomness obtained. 1143** The xSleep() method causes the calling thread to sleep for at 1144** least the number of microseconds given. ^The xCurrentTime() 1145** method returns a Julian Day Number for the current date and time as 1146** a floating point value. 1147** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1148** Day Number multiplied by 86400000 (the number of milliseconds in 1149** a 24-hour day). 1150** ^SQLite will use the xCurrentTimeInt64() method to get the current 1151** date and time if that method is available (if iVersion is 2 or 1152** greater and the function pointer is not NULL) and will fall back 1153** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1154** 1155** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1156** are not used by the SQLite core. These optional interfaces are provided 1157** by some VFSes to facilitate testing of the VFS code. By overriding 1158** system calls with functions under its control, a test program can 1159** simulate faults and error conditions that would otherwise be difficult 1160** or impossible to induce. The set of system calls that can be overridden 1161** varies from one VFS to another, and from one version of the same VFS to the 1162** next. Applications that use these interfaces must be prepared for any 1163** or all of these interfaces to be NULL or for their behavior to change 1164** from one release to the next. Applications must not attempt to access 1165** any of these methods if the iVersion of the VFS is less than 3. 1166*/ 1167typedef struct sqlite3_vfs sqlite3_vfs; 1168typedef void (*sqlite3_syscall_ptr)(void); 1169struct sqlite3_vfs { 1170 int iVersion; /* Structure version number (currently 3) */ 1171 int szOsFile; /* Size of subclassed sqlite3_file */ 1172 int mxPathname; /* Maximum file pathname length */ 1173 sqlite3_vfs *pNext; /* Next registered VFS */ 1174 const char *zName; /* Name of this virtual file system */ 1175 void *pAppData; /* Pointer to application-specific data */ 1176 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1177 int flags, int *pOutFlags); 1178 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1179 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1180 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1181 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1182 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1183 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1184 void (*xDlClose)(sqlite3_vfs*, void*); 1185 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1186 int (*xSleep)(sqlite3_vfs*, int microseconds); 1187 int (*xCurrentTime)(sqlite3_vfs*, double*); 1188 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1189 /* 1190 ** The methods above are in version 1 of the sqlite_vfs object 1191 ** definition. Those that follow are added in version 2 or later 1192 */ 1193 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1194 /* 1195 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1196 ** Those below are for version 3 and greater. 1197 */ 1198 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1199 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1200 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1201 /* 1202 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1203 ** New fields may be appended in figure versions. The iVersion 1204 ** value will increment whenever this happens. 1205 */ 1206}; 1207 1208/* 1209** CAPI3REF: Flags for the xAccess VFS method 1210** 1211** These integer constants can be used as the third parameter to 1212** the xAccess method of an [sqlite3_vfs] object. They determine 1213** what kind of permissions the xAccess method is looking for. 1214** With SQLITE_ACCESS_EXISTS, the xAccess method 1215** simply checks whether the file exists. 1216** With SQLITE_ACCESS_READWRITE, the xAccess method 1217** checks whether the named directory is both readable and writable 1218** (in other words, if files can be added, removed, and renamed within 1219** the directory). 1220** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1221** [temp_store_directory pragma], though this could change in a future 1222** release of SQLite. 1223** With SQLITE_ACCESS_READ, the xAccess method 1224** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1225** currently unused, though it might be used in a future release of 1226** SQLite. 1227*/ 1228#define SQLITE_ACCESS_EXISTS 0 1229#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1230#define SQLITE_ACCESS_READ 2 /* Unused */ 1231 1232/* 1233** CAPI3REF: Flags for the xShmLock VFS method 1234** 1235** These integer constants define the various locking operations 1236** allowed by the xShmLock method of [sqlite3_io_methods]. The 1237** following are the only legal combinations of flags to the 1238** xShmLock method: 1239** 1240** <ul> 1241** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1242** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1243** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1244** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1245** </ul> 1246** 1247** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1248** was given on the corresponding lock. 1249** 1250** The xShmLock method can transition between unlocked and SHARED or 1251** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1252** and EXCLUSIVE. 1253*/ 1254#define SQLITE_SHM_UNLOCK 1 1255#define SQLITE_SHM_LOCK 2 1256#define SQLITE_SHM_SHARED 4 1257#define SQLITE_SHM_EXCLUSIVE 8 1258 1259/* 1260** CAPI3REF: Maximum xShmLock index 1261** 1262** The xShmLock method on [sqlite3_io_methods] may use values 1263** between 0 and this upper bound as its "offset" argument. 1264** The SQLite core will never attempt to acquire or release a 1265** lock outside of this range 1266*/ 1267#define SQLITE_SHM_NLOCK 8 1268 1269 1270/* 1271** CAPI3REF: Initialize The SQLite Library 1272** 1273** ^The sqlite3_initialize() routine initializes the 1274** SQLite library. ^The sqlite3_shutdown() routine 1275** deallocates any resources that were allocated by sqlite3_initialize(). 1276** These routines are designed to aid in process initialization and 1277** shutdown on embedded systems. Workstation applications using 1278** SQLite normally do not need to invoke either of these routines. 1279** 1280** A call to sqlite3_initialize() is an "effective" call if it is 1281** the first time sqlite3_initialize() is invoked during the lifetime of 1282** the process, or if it is the first time sqlite3_initialize() is invoked 1283** following a call to sqlite3_shutdown(). ^(Only an effective call 1284** of sqlite3_initialize() does any initialization. All other calls 1285** are harmless no-ops.)^ 1286** 1287** A call to sqlite3_shutdown() is an "effective" call if it is the first 1288** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1289** an effective call to sqlite3_shutdown() does any deinitialization. 1290** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1291** 1292** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1293** is not. The sqlite3_shutdown() interface must only be called from a 1294** single thread. All open [database connections] must be closed and all 1295** other SQLite resources must be deallocated prior to invoking 1296** sqlite3_shutdown(). 1297** 1298** Among other things, ^sqlite3_initialize() will invoke 1299** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1300** will invoke sqlite3_os_end(). 1301** 1302** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1303** ^If for some reason, sqlite3_initialize() is unable to initialize 1304** the library (perhaps it is unable to allocate a needed resource such 1305** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1306** 1307** ^The sqlite3_initialize() routine is called internally by many other 1308** SQLite interfaces so that an application usually does not need to 1309** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1310** calls sqlite3_initialize() so the SQLite library will be automatically 1311** initialized when [sqlite3_open()] is called if it has not be initialized 1312** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1313** compile-time option, then the automatic calls to sqlite3_initialize() 1314** are omitted and the application must call sqlite3_initialize() directly 1315** prior to using any other SQLite interface. For maximum portability, 1316** it is recommended that applications always invoke sqlite3_initialize() 1317** directly prior to using any other SQLite interface. Future releases 1318** of SQLite may require this. In other words, the behavior exhibited 1319** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1320** default behavior in some future release of SQLite. 1321** 1322** The sqlite3_os_init() routine does operating-system specific 1323** initialization of the SQLite library. The sqlite3_os_end() 1324** routine undoes the effect of sqlite3_os_init(). Typical tasks 1325** performed by these routines include allocation or deallocation 1326** of static resources, initialization of global variables, 1327** setting up a default [sqlite3_vfs] module, or setting up 1328** a default configuration using [sqlite3_config()]. 1329** 1330** The application should never invoke either sqlite3_os_init() 1331** or sqlite3_os_end() directly. The application should only invoke 1332** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1333** interface is called automatically by sqlite3_initialize() and 1334** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1335** implementations for sqlite3_os_init() and sqlite3_os_end() 1336** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1337** When [custom builds | built for other platforms] 1338** (using the [SQLITE_OS_OTHER=1] compile-time 1339** option) the application must supply a suitable implementation for 1340** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1341** implementation of sqlite3_os_init() or sqlite3_os_end() 1342** must return [SQLITE_OK] on success and some other [error code] upon 1343** failure. 1344*/ 1345SQLITE_API int SQLITE_STDCALL sqlite3_initialize(void); 1346SQLITE_API int SQLITE_STDCALL sqlite3_shutdown(void); 1347SQLITE_API int SQLITE_STDCALL sqlite3_os_init(void); 1348SQLITE_API int SQLITE_STDCALL sqlite3_os_end(void); 1349 1350/* 1351** CAPI3REF: Configuring The SQLite Library 1352** 1353** The sqlite3_config() interface is used to make global configuration 1354** changes to SQLite in order to tune SQLite to the specific needs of 1355** the application. The default configuration is recommended for most 1356** applications and so this routine is usually not necessary. It is 1357** provided to support rare applications with unusual needs. 1358** 1359** The sqlite3_config() interface is not threadsafe. The application 1360** must insure that no other SQLite interfaces are invoked by other 1361** threads while sqlite3_config() is running. Furthermore, sqlite3_config() 1362** may only be invoked prior to library initialization using 1363** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1364** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1365** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1366** Note, however, that ^sqlite3_config() can be called as part of the 1367** implementation of an application-defined [sqlite3_os_init()]. 1368** 1369** The first argument to sqlite3_config() is an integer 1370** [configuration option] that determines 1371** what property of SQLite is to be configured. Subsequent arguments 1372** vary depending on the [configuration option] 1373** in the first argument. 1374** 1375** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1376** ^If the option is unknown or SQLite is unable to set the option 1377** then this routine returns a non-zero [error code]. 1378*/ 1379SQLITE_API int SQLITE_CDECL sqlite3_config(int, ...); 1380 1381/* 1382** CAPI3REF: Configure database connections 1383** METHOD: sqlite3 1384** 1385** The sqlite3_db_config() interface is used to make configuration 1386** changes to a [database connection]. The interface is similar to 1387** [sqlite3_config()] except that the changes apply to a single 1388** [database connection] (specified in the first argument). 1389** 1390** The second argument to sqlite3_db_config(D,V,...) is the 1391** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1392** that indicates what aspect of the [database connection] is being configured. 1393** Subsequent arguments vary depending on the configuration verb. 1394** 1395** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1396** the call is considered successful. 1397*/ 1398SQLITE_API int SQLITE_CDECL sqlite3_db_config(sqlite3*, int op, ...); 1399 1400/* 1401** CAPI3REF: Memory Allocation Routines 1402** 1403** An instance of this object defines the interface between SQLite 1404** and low-level memory allocation routines. 1405** 1406** This object is used in only one place in the SQLite interface. 1407** A pointer to an instance of this object is the argument to 1408** [sqlite3_config()] when the configuration option is 1409** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1410** By creating an instance of this object 1411** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1412** during configuration, an application can specify an alternative 1413** memory allocation subsystem for SQLite to use for all of its 1414** dynamic memory needs. 1415** 1416** Note that SQLite comes with several [built-in memory allocators] 1417** that are perfectly adequate for the overwhelming majority of applications 1418** and that this object is only useful to a tiny minority of applications 1419** with specialized memory allocation requirements. This object is 1420** also used during testing of SQLite in order to specify an alternative 1421** memory allocator that simulates memory out-of-memory conditions in 1422** order to verify that SQLite recovers gracefully from such 1423** conditions. 1424** 1425** The xMalloc, xRealloc, and xFree methods must work like the 1426** malloc(), realloc() and free() functions from the standard C library. 1427** ^SQLite guarantees that the second argument to 1428** xRealloc is always a value returned by a prior call to xRoundup. 1429** 1430** xSize should return the allocated size of a memory allocation 1431** previously obtained from xMalloc or xRealloc. The allocated size 1432** is always at least as big as the requested size but may be larger. 1433** 1434** The xRoundup method returns what would be the allocated size of 1435** a memory allocation given a particular requested size. Most memory 1436** allocators round up memory allocations at least to the next multiple 1437** of 8. Some allocators round up to a larger multiple or to a power of 2. 1438** Every memory allocation request coming in through [sqlite3_malloc()] 1439** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1440** that causes the corresponding memory allocation to fail. 1441** 1442** The xInit method initializes the memory allocator. For example, 1443** it might allocate any require mutexes or initialize internal data 1444** structures. The xShutdown method is invoked (indirectly) by 1445** [sqlite3_shutdown()] and should deallocate any resources acquired 1446** by xInit. The pAppData pointer is used as the only parameter to 1447** xInit and xShutdown. 1448** 1449** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1450** the xInit method, so the xInit method need not be threadsafe. The 1451** xShutdown method is only called from [sqlite3_shutdown()] so it does 1452** not need to be threadsafe either. For all other methods, SQLite 1453** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1454** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1455** it is by default) and so the methods are automatically serialized. 1456** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1457** methods must be threadsafe or else make their own arrangements for 1458** serialization. 1459** 1460** SQLite will never invoke xInit() more than once without an intervening 1461** call to xShutdown(). 1462*/ 1463typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1464struct sqlite3_mem_methods { 1465 void *(*xMalloc)(int); /* Memory allocation function */ 1466 void (*xFree)(void*); /* Free a prior allocation */ 1467 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1468 int (*xSize)(void*); /* Return the size of an allocation */ 1469 int (*xRoundup)(int); /* Round up request size to allocation size */ 1470 int (*xInit)(void*); /* Initialize the memory allocator */ 1471 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1472 void *pAppData; /* Argument to xInit() and xShutdown() */ 1473}; 1474 1475/* 1476** CAPI3REF: Configuration Options 1477** KEYWORDS: {configuration option} 1478** 1479** These constants are the available integer configuration options that 1480** can be passed as the first argument to the [sqlite3_config()] interface. 1481** 1482** New configuration options may be added in future releases of SQLite. 1483** Existing configuration options might be discontinued. Applications 1484** should check the return code from [sqlite3_config()] to make sure that 1485** the call worked. The [sqlite3_config()] interface will return a 1486** non-zero [error code] if a discontinued or unsupported configuration option 1487** is invoked. 1488** 1489** <dl> 1490** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1491** <dd>There are no arguments to this option. ^This option sets the 1492** [threading mode] to Single-thread. In other words, it disables 1493** all mutexing and puts SQLite into a mode where it can only be used 1494** by a single thread. ^If SQLite is compiled with 1495** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1496** it is not possible to change the [threading mode] from its default 1497** value of Single-thread and so [sqlite3_config()] will return 1498** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1499** configuration option.</dd> 1500** 1501** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1502** <dd>There are no arguments to this option. ^This option sets the 1503** [threading mode] to Multi-thread. In other words, it disables 1504** mutexing on [database connection] and [prepared statement] objects. 1505** The application is responsible for serializing access to 1506** [database connections] and [prepared statements]. But other mutexes 1507** are enabled so that SQLite will be safe to use in a multi-threaded 1508** environment as long as no two threads attempt to use the same 1509** [database connection] at the same time. ^If SQLite is compiled with 1510** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1511** it is not possible to set the Multi-thread [threading mode] and 1512** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1513** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1514** 1515** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1516** <dd>There are no arguments to this option. ^This option sets the 1517** [threading mode] to Serialized. In other words, this option enables 1518** all mutexes including the recursive 1519** mutexes on [database connection] and [prepared statement] objects. 1520** In this mode (which is the default when SQLite is compiled with 1521** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1522** to [database connections] and [prepared statements] so that the 1523** application is free to use the same [database connection] or the 1524** same [prepared statement] in different threads at the same time. 1525** ^If SQLite is compiled with 1526** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1527** it is not possible to set the Serialized [threading mode] and 1528** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1529** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1530** 1531** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1532** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1533** a pointer to an instance of the [sqlite3_mem_methods] structure. 1534** The argument specifies 1535** alternative low-level memory allocation routines to be used in place of 1536** the memory allocation routines built into SQLite.)^ ^SQLite makes 1537** its own private copy of the content of the [sqlite3_mem_methods] structure 1538** before the [sqlite3_config()] call returns.</dd> 1539** 1540** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1541** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1542** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1543** The [sqlite3_mem_methods] 1544** structure is filled with the currently defined memory allocation routines.)^ 1545** This option can be used to overload the default memory allocation 1546** routines with a wrapper that simulations memory allocation failure or 1547** tracks memory usage, for example. </dd> 1548** 1549** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1550** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1551** interpreted as a boolean, which enables or disables the collection of 1552** memory allocation statistics. ^(When memory allocation statistics are 1553** disabled, the following SQLite interfaces become non-operational: 1554** <ul> 1555** <li> [sqlite3_memory_used()] 1556** <li> [sqlite3_memory_highwater()] 1557** <li> [sqlite3_soft_heap_limit64()] 1558** <li> [sqlite3_status64()] 1559** </ul>)^ 1560** ^Memory allocation statistics are enabled by default unless SQLite is 1561** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1562** allocation statistics are disabled by default. 1563** </dd> 1564** 1565** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1566** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer 1567** that SQLite can use for scratch memory. ^(There are three arguments 1568** to SQLITE_CONFIG_SCRATCH: A pointer an 8-byte 1569** aligned memory buffer from which the scratch allocations will be 1570** drawn, the size of each scratch allocation (sz), 1571** and the maximum number of scratch allocations (N).)^ 1572** The first argument must be a pointer to an 8-byte aligned buffer 1573** of at least sz*N bytes of memory. 1574** ^SQLite will not use more than one scratch buffers per thread. 1575** ^SQLite will never request a scratch buffer that is more than 6 1576** times the database page size. 1577** ^If SQLite needs needs additional 1578** scratch memory beyond what is provided by this configuration option, then 1579** [sqlite3_malloc()] will be used to obtain the memory needed.<p> 1580** ^When the application provides any amount of scratch memory using 1581** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large 1582** [sqlite3_malloc|heap allocations]. 1583** This can help [Robson proof|prevent memory allocation failures] due to heap 1584** fragmentation in low-memory embedded systems. 1585** </dd> 1586** 1587** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1588** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a static memory buffer 1589** that SQLite can use for the database page cache with the default page 1590** cache implementation. 1591** This configuration should not be used if an application-define page 1592** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2] 1593** configuration option. 1594** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1595** 8-byte aligned 1596** memory, the size of each page buffer (sz), and the number of pages (N). 1597** The sz argument should be the size of the largest database page 1598** (a power of two between 512 and 65536) plus some extra bytes for each 1599** page header. ^The number of extra bytes needed by the page header 1600** can be determined using the [SQLITE_CONFIG_PCACHE_HDRSZ] option 1601** to [sqlite3_config()]. 1602** ^It is harmless, apart from the wasted memory, 1603** for the sz parameter to be larger than necessary. The first 1604** argument should pointer to an 8-byte aligned block of memory that 1605** is at least sz*N bytes of memory, otherwise subsequent behavior is 1606** undefined. 1607** ^SQLite will use the memory provided by the first argument to satisfy its 1608** memory needs for the first N pages that it adds to cache. ^If additional 1609** page cache memory is needed beyond what is provided by this option, then 1610** SQLite goes to [sqlite3_malloc()] for the additional storage space.</dd> 1611** 1612** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1613** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1614** that SQLite will use for all of its dynamic memory allocation needs 1615** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and 1616** [SQLITE_CONFIG_PAGECACHE]. 1617** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1618** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1619** [SQLITE_ERROR] if invoked otherwise. 1620** ^There are three arguments to SQLITE_CONFIG_HEAP: 1621** An 8-byte aligned pointer to the memory, 1622** the number of bytes in the memory buffer, and the minimum allocation size. 1623** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1624** to using its default memory allocator (the system malloc() implementation), 1625** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1626** memory pointer is not NULL then the alternative memory 1627** allocator is engaged to handle all of SQLites memory allocation needs. 1628** The first pointer (the memory pointer) must be aligned to an 8-byte 1629** boundary or subsequent behavior of SQLite will be undefined. 1630** The minimum allocation size is capped at 2**12. Reasonable values 1631** for the minimum allocation size are 2**5 through 2**8.</dd> 1632** 1633** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1634** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1635** pointer to an instance of the [sqlite3_mutex_methods] structure. 1636** The argument specifies alternative low-level mutex routines to be used 1637** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1638** the content of the [sqlite3_mutex_methods] structure before the call to 1639** [sqlite3_config()] returns. ^If SQLite is compiled with 1640** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1641** the entire mutexing subsystem is omitted from the build and hence calls to 1642** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1643** return [SQLITE_ERROR].</dd> 1644** 1645** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1646** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1647** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1648** [sqlite3_mutex_methods] 1649** structure is filled with the currently defined mutex routines.)^ 1650** This option can be used to overload the default mutex allocation 1651** routines with a wrapper used to track mutex usage for performance 1652** profiling or testing, for example. ^If SQLite is compiled with 1653** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1654** the entire mutexing subsystem is omitted from the build and hence calls to 1655** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1656** return [SQLITE_ERROR].</dd> 1657** 1658** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1659** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1660** the default size of lookaside memory on each [database connection]. 1661** The first argument is the 1662** size of each lookaside buffer slot and the second is the number of 1663** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1664** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1665** option to [sqlite3_db_config()] can be used to change the lookaside 1666** configuration on individual connections.)^ </dd> 1667** 1668** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1669** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1670** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1671** the interface to a custom page cache implementation.)^ 1672** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1673** 1674** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1675** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1676** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1677** the current page cache implementation into that object.)^ </dd> 1678** 1679** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1680** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1681** global [error log]. 1682** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1683** function with a call signature of void(*)(void*,int,const char*), 1684** and a pointer to void. ^If the function pointer is not NULL, it is 1685** invoked by [sqlite3_log()] to process each logging event. ^If the 1686** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1687** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1688** passed through as the first parameter to the application-defined logger 1689** function whenever that function is invoked. ^The second parameter to 1690** the logger function is a copy of the first parameter to the corresponding 1691** [sqlite3_log()] call and is intended to be a [result code] or an 1692** [extended result code]. ^The third parameter passed to the logger is 1693** log message after formatting via [sqlite3_snprintf()]. 1694** The SQLite logging interface is not reentrant; the logger function 1695** supplied by the application must not invoke any SQLite interface. 1696** In a multi-threaded application, the application-defined logger 1697** function must be threadsafe. </dd> 1698** 1699** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1700** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1701** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1702** then URI handling is globally disabled.)^ ^If URI handling is globally 1703** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1704** [sqlite3_open16()] or 1705** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1706** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1707** connection is opened. ^If it is globally disabled, filenames are 1708** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1709** database connection is opened. ^(By default, URI handling is globally 1710** disabled. The default value may be changed by compiling with the 1711** [SQLITE_USE_URI] symbol defined.)^ 1712** 1713** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1714** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1715** argument which is interpreted as a boolean in order to enable or disable 1716** the use of covering indices for full table scans in the query optimizer. 1717** ^The default setting is determined 1718** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1719** if that compile-time option is omitted. 1720** The ability to disable the use of covering indices for full table scans 1721** is because some incorrectly coded legacy applications might malfunction 1722** when the optimization is enabled. Providing the ability to 1723** disable the optimization allows the older, buggy application code to work 1724** without change even with newer versions of SQLite. 1725** 1726** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1727** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1728** <dd> These options are obsolete and should not be used by new code. 1729** They are retained for backwards compatibility but are now no-ops. 1730** </dd> 1731** 1732** [[SQLITE_CONFIG_SQLLOG]] 1733** <dt>SQLITE_CONFIG_SQLLOG 1734** <dd>This option is only available if sqlite is compiled with the 1735** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1736** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1737** The second should be of type (void*). The callback is invoked by the library 1738** in three separate circumstances, identified by the value passed as the 1739** fourth parameter. If the fourth parameter is 0, then the database connection 1740** passed as the second argument has just been opened. The third argument 1741** points to a buffer containing the name of the main database file. If the 1742** fourth parameter is 1, then the SQL statement that the third parameter 1743** points to has just been executed. Or, if the fourth parameter is 2, then 1744** the connection being passed as the second parameter is being closed. The 1745** third parameter is passed NULL In this case. An example of using this 1746** configuration option can be seen in the "test_sqllog.c" source file in 1747** the canonical SQLite source tree.</dd> 1748** 1749** [[SQLITE_CONFIG_MMAP_SIZE]] 1750** <dt>SQLITE_CONFIG_MMAP_SIZE 1751** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1752** that are the default mmap size limit (the default setting for 1753** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1754** ^The default setting can be overridden by each database connection using 1755** either the [PRAGMA mmap_size] command, or by using the 1756** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1757** will be silently truncated if necessary so that it does not exceed the 1758** compile-time maximum mmap size set by the 1759** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1760** ^If either argument to this option is negative, then that argument is 1761** changed to its compile-time default. 1762** 1763** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1764** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1765** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1766** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1767** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1768** that specifies the maximum size of the created heap. 1769** 1770** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1771** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1772** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1773** is a pointer to an integer and writes into that integer the number of extra 1774** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1775** The amount of extra space required can change depending on the compiler, 1776** target platform, and SQLite version. 1777** 1778** [[SQLITE_CONFIG_PMASZ]] 1779** <dt>SQLITE_CONFIG_PMASZ 1780** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1781** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1782** sorter to that integer. The default minimum PMA Size is set by the 1783** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1784** to help with sort operations when multithreaded sorting 1785** is enabled (using the [PRAGMA threads] command) and the amount of content 1786** to be sorted exceeds the page size times the minimum of the 1787** [PRAGMA cache_size] setting and this value. 1788** </dl> 1789*/ 1790#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1791#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1792#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1793#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1794#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1795#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1796#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1797#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1798#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1799#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1800#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1801/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1802#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1803#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1804#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1805#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1806#define SQLITE_CONFIG_URI 17 /* int */ 1807#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1808#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1809#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1810#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1811#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1812#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1813#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 1814#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 1815 1816/* 1817** CAPI3REF: Database Connection Configuration Options 1818** 1819** These constants are the available integer configuration options that 1820** can be passed as the second argument to the [sqlite3_db_config()] interface. 1821** 1822** New configuration options may be added in future releases of SQLite. 1823** Existing configuration options might be discontinued. Applications 1824** should check the return code from [sqlite3_db_config()] to make sure that 1825** the call worked. ^The [sqlite3_db_config()] interface will return a 1826** non-zero [error code] if a discontinued or unsupported configuration option 1827** is invoked. 1828** 1829** <dl> 1830** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1831** <dd> ^This option takes three additional arguments that determine the 1832** [lookaside memory allocator] configuration for the [database connection]. 1833** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1834** pointer to a memory buffer to use for lookaside memory. 1835** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1836** may be NULL in which case SQLite will allocate the 1837** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1838** size of each lookaside buffer slot. ^The third argument is the number of 1839** slots. The size of the buffer in the first argument must be greater than 1840** or equal to the product of the second and third arguments. The buffer 1841** must be aligned to an 8-byte boundary. ^If the second argument to 1842** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1843** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1844** configuration for a database connection can only be changed when that 1845** connection is not currently using lookaside memory, or in other words 1846** when the "current value" returned by 1847** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1848** Any attempt to change the lookaside memory configuration when lookaside 1849** memory is in use leaves the configuration unchanged and returns 1850** [SQLITE_BUSY].)^</dd> 1851** 1852** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1853** <dd> ^This option is used to enable or disable the enforcement of 1854** [foreign key constraints]. There should be two additional arguments. 1855** The first argument is an integer which is 0 to disable FK enforcement, 1856** positive to enable FK enforcement or negative to leave FK enforcement 1857** unchanged. The second parameter is a pointer to an integer into which 1858** is written 0 or 1 to indicate whether FK enforcement is off or on 1859** following this call. The second parameter may be a NULL pointer, in 1860** which case the FK enforcement setting is not reported back. </dd> 1861** 1862** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1863** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1864** There should be two additional arguments. 1865** The first argument is an integer which is 0 to disable triggers, 1866** positive to enable triggers or negative to leave the setting unchanged. 1867** The second parameter is a pointer to an integer into which 1868** is written 0 or 1 to indicate whether triggers are disabled or enabled 1869** following this call. The second parameter may be a NULL pointer, in 1870** which case the trigger setting is not reported back. </dd> 1871** 1872** </dl> 1873*/ 1874#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1875#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1876#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1877 1878 1879/* 1880** CAPI3REF: Enable Or Disable Extended Result Codes 1881** METHOD: sqlite3 1882** 1883** ^The sqlite3_extended_result_codes() routine enables or disables the 1884** [extended result codes] feature of SQLite. ^The extended result 1885** codes are disabled by default for historical compatibility. 1886*/ 1887SQLITE_API int SQLITE_STDCALL sqlite3_extended_result_codes(sqlite3*, int onoff); 1888 1889/* 1890** CAPI3REF: Last Insert Rowid 1891** METHOD: sqlite3 1892** 1893** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 1894** has a unique 64-bit signed 1895** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1896** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1897** names are not also used by explicitly declared columns. ^If 1898** the table has a column of type [INTEGER PRIMARY KEY] then that column 1899** is another alias for the rowid. 1900** 1901** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the 1902** most recent successful [INSERT] into a rowid table or [virtual table] 1903** on database connection D. 1904** ^Inserts into [WITHOUT ROWID] tables are not recorded. 1905** ^If no successful [INSERT]s into rowid tables 1906** have ever occurred on the database connection D, 1907** then sqlite3_last_insert_rowid(D) returns zero. 1908** 1909** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 1910** method, then this routine will return the [rowid] of the inserted 1911** row as long as the trigger or virtual table method is running. 1912** But once the trigger or virtual table method ends, the value returned 1913** by this routine reverts to what it was before the trigger or virtual 1914** table method began.)^ 1915** 1916** ^An [INSERT] that fails due to a constraint violation is not a 1917** successful [INSERT] and does not change the value returned by this 1918** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1919** and INSERT OR ABORT make no changes to the return value of this 1920** routine when their insertion fails. ^(When INSERT OR REPLACE 1921** encounters a constraint violation, it does not fail. The 1922** INSERT continues to completion after deleting rows that caused 1923** the constraint problem so INSERT OR REPLACE will always change 1924** the return value of this interface.)^ 1925** 1926** ^For the purposes of this routine, an [INSERT] is considered to 1927** be successful even if it is subsequently rolled back. 1928** 1929** This function is accessible to SQL statements via the 1930** [last_insert_rowid() SQL function]. 1931** 1932** If a separate thread performs a new [INSERT] on the same 1933** database connection while the [sqlite3_last_insert_rowid()] 1934** function is running and thus changes the last insert [rowid], 1935** then the value returned by [sqlite3_last_insert_rowid()] is 1936** unpredictable and might not equal either the old or the new 1937** last insert [rowid]. 1938*/ 1939SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_last_insert_rowid(sqlite3*); 1940 1941/* 1942** CAPI3REF: Count The Number Of Rows Modified 1943** METHOD: sqlite3 1944** 1945** ^This function returns the number of rows modified, inserted or 1946** deleted by the most recently completed INSERT, UPDATE or DELETE 1947** statement on the database connection specified by the only parameter. 1948** ^Executing any other type of SQL statement does not modify the value 1949** returned by this function. 1950** 1951** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 1952** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 1953** [foreign key actions] or [REPLACE] constraint resolution are not counted. 1954** 1955** Changes to a view that are intercepted by 1956** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 1957** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 1958** DELETE statement run on a view is always zero. Only changes made to real 1959** tables are counted. 1960** 1961** Things are more complicated if the sqlite3_changes() function is 1962** executed while a trigger program is running. This may happen if the 1963** program uses the [changes() SQL function], or if some other callback 1964** function invokes sqlite3_changes() directly. Essentially: 1965** 1966** <ul> 1967** <li> ^(Before entering a trigger program the value returned by 1968** sqlite3_changes() function is saved. After the trigger program 1969** has finished, the original value is restored.)^ 1970** 1971** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 1972** statement sets the value returned by sqlite3_changes() 1973** upon completion as normal. Of course, this value will not include 1974** any changes performed by sub-triggers, as the sqlite3_changes() 1975** value will be saved and restored after each sub-trigger has run.)^ 1976** </ul> 1977** 1978** ^This means that if the changes() SQL function (or similar) is used 1979** by the first INSERT, UPDATE or DELETE statement within a trigger, it 1980** returns the value as set when the calling statement began executing. 1981** ^If it is used by the second or subsequent such statement within a trigger 1982** program, the value returned reflects the number of rows modified by the 1983** previous INSERT, UPDATE or DELETE statement within the same trigger. 1984** 1985** See also the [sqlite3_total_changes()] interface, the 1986** [count_changes pragma], and the [changes() SQL function]. 1987** 1988** If a separate thread makes changes on the same database connection 1989** while [sqlite3_changes()] is running then the value returned 1990** is unpredictable and not meaningful. 1991*/ 1992SQLITE_API int SQLITE_STDCALL sqlite3_changes(sqlite3*); 1993 1994/* 1995** CAPI3REF: Total Number Of Rows Modified 1996** METHOD: sqlite3 1997** 1998** ^This function returns the total number of rows inserted, modified or 1999** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2000** since the database connection was opened, including those executed as 2001** part of trigger programs. ^Executing any other type of SQL statement 2002** does not affect the value returned by sqlite3_total_changes(). 2003** 2004** ^Changes made as part of [foreign key actions] are included in the 2005** count, but those made as part of REPLACE constraint resolution are 2006** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2007** are not counted. 2008** 2009** See also the [sqlite3_changes()] interface, the 2010** [count_changes pragma], and the [total_changes() SQL function]. 2011** 2012** If a separate thread makes changes on the same database connection 2013** while [sqlite3_total_changes()] is running then the value 2014** returned is unpredictable and not meaningful. 2015*/ 2016SQLITE_API int SQLITE_STDCALL sqlite3_total_changes(sqlite3*); 2017 2018/* 2019** CAPI3REF: Interrupt A Long-Running Query 2020** METHOD: sqlite3 2021** 2022** ^This function causes any pending database operation to abort and 2023** return at its earliest opportunity. This routine is typically 2024** called in response to a user action such as pressing "Cancel" 2025** or Ctrl-C where the user wants a long query operation to halt 2026** immediately. 2027** 2028** ^It is safe to call this routine from a thread different from the 2029** thread that is currently running the database operation. But it 2030** is not safe to call this routine with a [database connection] that 2031** is closed or might close before sqlite3_interrupt() returns. 2032** 2033** ^If an SQL operation is very nearly finished at the time when 2034** sqlite3_interrupt() is called, then it might not have an opportunity 2035** to be interrupted and might continue to completion. 2036** 2037** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2038** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2039** that is inside an explicit transaction, then the entire transaction 2040** will be rolled back automatically. 2041** 2042** ^The sqlite3_interrupt(D) call is in effect until all currently running 2043** SQL statements on [database connection] D complete. ^Any new SQL statements 2044** that are started after the sqlite3_interrupt() call and before the 2045** running statements reaches zero are interrupted as if they had been 2046** running prior to the sqlite3_interrupt() call. ^New SQL statements 2047** that are started after the running statement count reaches zero are 2048** not effected by the sqlite3_interrupt(). 2049** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2050** SQL statements is a no-op and has no effect on SQL statements 2051** that are started after the sqlite3_interrupt() call returns. 2052** 2053** If the database connection closes while [sqlite3_interrupt()] 2054** is running then bad things will likely happen. 2055*/ 2056SQLITE_API void SQLITE_STDCALL sqlite3_interrupt(sqlite3*); 2057 2058/* 2059** CAPI3REF: Determine If An SQL Statement Is Complete 2060** 2061** These routines are useful during command-line input to determine if the 2062** currently entered text seems to form a complete SQL statement or 2063** if additional input is needed before sending the text into 2064** SQLite for parsing. ^These routines return 1 if the input string 2065** appears to be a complete SQL statement. ^A statement is judged to be 2066** complete if it ends with a semicolon token and is not a prefix of a 2067** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2068** string literals or quoted identifier names or comments are not 2069** independent tokens (they are part of the token in which they are 2070** embedded) and thus do not count as a statement terminator. ^Whitespace 2071** and comments that follow the final semicolon are ignored. 2072** 2073** ^These routines return 0 if the statement is incomplete. ^If a 2074** memory allocation fails, then SQLITE_NOMEM is returned. 2075** 2076** ^These routines do not parse the SQL statements thus 2077** will not detect syntactically incorrect SQL. 2078** 2079** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2080** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2081** automatically by sqlite3_complete16(). If that initialization fails, 2082** then the return value from sqlite3_complete16() will be non-zero 2083** regardless of whether or not the input SQL is complete.)^ 2084** 2085** The input to [sqlite3_complete()] must be a zero-terminated 2086** UTF-8 string. 2087** 2088** The input to [sqlite3_complete16()] must be a zero-terminated 2089** UTF-16 string in native byte order. 2090*/ 2091SQLITE_API int SQLITE_STDCALL sqlite3_complete(const char *sql); 2092SQLITE_API int SQLITE_STDCALL sqlite3_complete16(const void *sql); 2093 2094/* 2095** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2096** KEYWORDS: {busy-handler callback} {busy handler} 2097** METHOD: sqlite3 2098** 2099** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2100** that might be invoked with argument P whenever 2101** an attempt is made to access a database table associated with 2102** [database connection] D when another thread 2103** or process has the table locked. 2104** The sqlite3_busy_handler() interface is used to implement 2105** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2106** 2107** ^If the busy callback is NULL, then [SQLITE_BUSY] 2108** is returned immediately upon encountering the lock. ^If the busy callback 2109** is not NULL, then the callback might be invoked with two arguments. 2110** 2111** ^The first argument to the busy handler is a copy of the void* pointer which 2112** is the third argument to sqlite3_busy_handler(). ^The second argument to 2113** the busy handler callback is the number of times that the busy handler has 2114** been invoked previously for the same locking event. ^If the 2115** busy callback returns 0, then no additional attempts are made to 2116** access the database and [SQLITE_BUSY] is returned 2117** to the application. 2118** ^If the callback returns non-zero, then another attempt 2119** is made to access the database and the cycle repeats. 2120** 2121** The presence of a busy handler does not guarantee that it will be invoked 2122** when there is lock contention. ^If SQLite determines that invoking the busy 2123** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2124** to the application instead of invoking the 2125** busy handler. 2126** Consider a scenario where one process is holding a read lock that 2127** it is trying to promote to a reserved lock and 2128** a second process is holding a reserved lock that it is trying 2129** to promote to an exclusive lock. The first process cannot proceed 2130** because it is blocked by the second and the second process cannot 2131** proceed because it is blocked by the first. If both processes 2132** invoke the busy handlers, neither will make any progress. Therefore, 2133** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2134** will induce the first process to release its read lock and allow 2135** the second process to proceed. 2136** 2137** ^The default busy callback is NULL. 2138** 2139** ^(There can only be a single busy handler defined for each 2140** [database connection]. Setting a new busy handler clears any 2141** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2142** or evaluating [PRAGMA busy_timeout=N] will change the 2143** busy handler and thus clear any previously set busy handler. 2144** 2145** The busy callback should not take any actions which modify the 2146** database connection that invoked the busy handler. In other words, 2147** the busy handler is not reentrant. Any such actions 2148** result in undefined behavior. 2149** 2150** A busy handler must not close the database connection 2151** or [prepared statement] that invoked the busy handler. 2152*/ 2153SQLITE_API int SQLITE_STDCALL sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 2154 2155/* 2156** CAPI3REF: Set A Busy Timeout 2157** METHOD: sqlite3 2158** 2159** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2160** for a specified amount of time when a table is locked. ^The handler 2161** will sleep multiple times until at least "ms" milliseconds of sleeping 2162** have accumulated. ^After at least "ms" milliseconds of sleeping, 2163** the handler returns 0 which causes [sqlite3_step()] to return 2164** [SQLITE_BUSY]. 2165** 2166** ^Calling this routine with an argument less than or equal to zero 2167** turns off all busy handlers. 2168** 2169** ^(There can only be a single busy handler for a particular 2170** [database connection] at any given moment. If another busy handler 2171** was defined (using [sqlite3_busy_handler()]) prior to calling 2172** this routine, that other busy handler is cleared.)^ 2173** 2174** See also: [PRAGMA busy_timeout] 2175*/ 2176SQLITE_API int SQLITE_STDCALL sqlite3_busy_timeout(sqlite3*, int ms); 2177 2178/* 2179** CAPI3REF: Convenience Routines For Running Queries 2180** METHOD: sqlite3 2181** 2182** This is a legacy interface that is preserved for backwards compatibility. 2183** Use of this interface is not recommended. 2184** 2185** Definition: A <b>result table</b> is memory data structure created by the 2186** [sqlite3_get_table()] interface. A result table records the 2187** complete query results from one or more queries. 2188** 2189** The table conceptually has a number of rows and columns. But 2190** these numbers are not part of the result table itself. These 2191** numbers are obtained separately. Let N be the number of rows 2192** and M be the number of columns. 2193** 2194** A result table is an array of pointers to zero-terminated UTF-8 strings. 2195** There are (N+1)*M elements in the array. The first M pointers point 2196** to zero-terminated strings that contain the names of the columns. 2197** The remaining entries all point to query results. NULL values result 2198** in NULL pointers. All other values are in their UTF-8 zero-terminated 2199** string representation as returned by [sqlite3_column_text()]. 2200** 2201** A result table might consist of one or more memory allocations. 2202** It is not safe to pass a result table directly to [sqlite3_free()]. 2203** A result table should be deallocated using [sqlite3_free_table()]. 2204** 2205** ^(As an example of the result table format, suppose a query result 2206** is as follows: 2207** 2208** <blockquote><pre> 2209** Name | Age 2210** ----------------------- 2211** Alice | 43 2212** Bob | 28 2213** Cindy | 21 2214** </pre></blockquote> 2215** 2216** There are two column (M==2) and three rows (N==3). Thus the 2217** result table has 8 entries. Suppose the result table is stored 2218** in an array names azResult. Then azResult holds this content: 2219** 2220** <blockquote><pre> 2221** azResult[0] = "Name"; 2222** azResult[1] = "Age"; 2223** azResult[2] = "Alice"; 2224** azResult[3] = "43"; 2225** azResult[4] = "Bob"; 2226** azResult[5] = "28"; 2227** azResult[6] = "Cindy"; 2228** azResult[7] = "21"; 2229** </pre></blockquote>)^ 2230** 2231** ^The sqlite3_get_table() function evaluates one or more 2232** semicolon-separated SQL statements in the zero-terminated UTF-8 2233** string of its 2nd parameter and returns a result table to the 2234** pointer given in its 3rd parameter. 2235** 2236** After the application has finished with the result from sqlite3_get_table(), 2237** it must pass the result table pointer to sqlite3_free_table() in order to 2238** release the memory that was malloced. Because of the way the 2239** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2240** function must not try to call [sqlite3_free()] directly. Only 2241** [sqlite3_free_table()] is able to release the memory properly and safely. 2242** 2243** The sqlite3_get_table() interface is implemented as a wrapper around 2244** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2245** to any internal data structures of SQLite. It uses only the public 2246** interface defined here. As a consequence, errors that occur in the 2247** wrapper layer outside of the internal [sqlite3_exec()] call are not 2248** reflected in subsequent calls to [sqlite3_errcode()] or 2249** [sqlite3_errmsg()]. 2250*/ 2251SQLITE_API int SQLITE_STDCALL sqlite3_get_table( 2252 sqlite3 *db, /* An open database */ 2253 const char *zSql, /* SQL to be evaluated */ 2254 char ***pazResult, /* Results of the query */ 2255 int *pnRow, /* Number of result rows written here */ 2256 int *pnColumn, /* Number of result columns written here */ 2257 char **pzErrmsg /* Error msg written here */ 2258); 2259SQLITE_API void SQLITE_STDCALL sqlite3_free_table(char **result); 2260 2261/* 2262** CAPI3REF: Formatted String Printing Functions 2263** 2264** These routines are work-alikes of the "printf()" family of functions 2265** from the standard C library. 2266** These routines understand most of the common K&R formatting options, 2267** plus some additional non-standard formats, detailed below. 2268** Note that some of the more obscure formatting options from recent 2269** C-library standards are omitted from this implementation. 2270** 2271** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2272** results into memory obtained from [sqlite3_malloc()]. 2273** The strings returned by these two routines should be 2274** released by [sqlite3_free()]. ^Both routines return a 2275** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2276** memory to hold the resulting string. 2277** 2278** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2279** the standard C library. The result is written into the 2280** buffer supplied as the second parameter whose size is given by 2281** the first parameter. Note that the order of the 2282** first two parameters is reversed from snprintf().)^ This is an 2283** historical accident that cannot be fixed without breaking 2284** backwards compatibility. ^(Note also that sqlite3_snprintf() 2285** returns a pointer to its buffer instead of the number of 2286** characters actually written into the buffer.)^ We admit that 2287** the number of characters written would be a more useful return 2288** value but we cannot change the implementation of sqlite3_snprintf() 2289** now without breaking compatibility. 2290** 2291** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2292** guarantees that the buffer is always zero-terminated. ^The first 2293** parameter "n" is the total size of the buffer, including space for 2294** the zero terminator. So the longest string that can be completely 2295** written will be n-1 characters. 2296** 2297** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2298** 2299** These routines all implement some additional formatting 2300** options that are useful for constructing SQL statements. 2301** All of the usual printf() formatting options apply. In addition, there 2302** is are "%q", "%Q", "%w" and "%z" options. 2303** 2304** ^(The %q option works like %s in that it substitutes a nul-terminated 2305** string from the argument list. But %q also doubles every '\'' character. 2306** %q is designed for use inside a string literal.)^ By doubling each '\'' 2307** character it escapes that character and allows it to be inserted into 2308** the string. 2309** 2310** For example, assume the string variable zText contains text as follows: 2311** 2312** <blockquote><pre> 2313** char *zText = "It's a happy day!"; 2314** </pre></blockquote> 2315** 2316** One can use this text in an SQL statement as follows: 2317** 2318** <blockquote><pre> 2319** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2320** sqlite3_exec(db, zSQL, 0, 0, 0); 2321** sqlite3_free(zSQL); 2322** </pre></blockquote> 2323** 2324** Because the %q format string is used, the '\'' character in zText 2325** is escaped and the SQL generated is as follows: 2326** 2327** <blockquote><pre> 2328** INSERT INTO table1 VALUES('It''s a happy day!') 2329** </pre></blockquote> 2330** 2331** This is correct. Had we used %s instead of %q, the generated SQL 2332** would have looked like this: 2333** 2334** <blockquote><pre> 2335** INSERT INTO table1 VALUES('It's a happy day!'); 2336** </pre></blockquote> 2337** 2338** This second example is an SQL syntax error. As a general rule you should 2339** always use %q instead of %s when inserting text into a string literal. 2340** 2341** ^(The %Q option works like %q except it also adds single quotes around 2342** the outside of the total string. Additionally, if the parameter in the 2343** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2344** single quotes).)^ So, for example, one could say: 2345** 2346** <blockquote><pre> 2347** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2348** sqlite3_exec(db, zSQL, 0, 0, 0); 2349** sqlite3_free(zSQL); 2350** </pre></blockquote> 2351** 2352** The code above will render a correct SQL statement in the zSQL 2353** variable even if the zText variable is a NULL pointer. 2354** 2355** ^(The "%w" formatting option is like "%q" except that it expects to 2356** be contained within double-quotes instead of single quotes, and it 2357** escapes the double-quote character instead of the single-quote 2358** character.)^ The "%w" formatting option is intended for safely inserting 2359** table and column names into a constructed SQL statement. 2360** 2361** ^(The "%z" formatting option works like "%s" but with the 2362** addition that after the string has been read and copied into 2363** the result, [sqlite3_free()] is called on the input string.)^ 2364*/ 2365SQLITE_API char *SQLITE_CDECL sqlite3_mprintf(const char*,...); 2366SQLITE_API char *SQLITE_STDCALL sqlite3_vmprintf(const char*, va_list); 2367SQLITE_API char *SQLITE_CDECL sqlite3_snprintf(int,char*,const char*, ...); 2368SQLITE_API char *SQLITE_STDCALL sqlite3_vsnprintf(int,char*,const char*, va_list); 2369 2370/* 2371** CAPI3REF: Memory Allocation Subsystem 2372** 2373** The SQLite core uses these three routines for all of its own 2374** internal memory allocation needs. "Core" in the previous sentence 2375** does not include operating-system specific VFS implementation. The 2376** Windows VFS uses native malloc() and free() for some operations. 2377** 2378** ^The sqlite3_malloc() routine returns a pointer to a block 2379** of memory at least N bytes in length, where N is the parameter. 2380** ^If sqlite3_malloc() is unable to obtain sufficient free 2381** memory, it returns a NULL pointer. ^If the parameter N to 2382** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2383** a NULL pointer. 2384** 2385** ^The sqlite3_malloc64(N) routine works just like 2386** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2387** of a signed 32-bit integer. 2388** 2389** ^Calling sqlite3_free() with a pointer previously returned 2390** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2391** that it might be reused. ^The sqlite3_free() routine is 2392** a no-op if is called with a NULL pointer. Passing a NULL pointer 2393** to sqlite3_free() is harmless. After being freed, memory 2394** should neither be read nor written. Even reading previously freed 2395** memory might result in a segmentation fault or other severe error. 2396** Memory corruption, a segmentation fault, or other severe error 2397** might result if sqlite3_free() is called with a non-NULL pointer that 2398** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2399** 2400** ^The sqlite3_realloc(X,N) interface attempts to resize a 2401** prior memory allocation X to be at least N bytes. 2402** ^If the X parameter to sqlite3_realloc(X,N) 2403** is a NULL pointer then its behavior is identical to calling 2404** sqlite3_malloc(N). 2405** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2406** negative then the behavior is exactly the same as calling 2407** sqlite3_free(X). 2408** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2409** of at least N bytes in size or NULL if insufficient memory is available. 2410** ^If M is the size of the prior allocation, then min(N,M) bytes 2411** of the prior allocation are copied into the beginning of buffer returned 2412** by sqlite3_realloc(X,N) and the prior allocation is freed. 2413** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2414** prior allocation is not freed. 2415** 2416** ^The sqlite3_realloc64(X,N) interfaces works the same as 2417** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2418** of a 32-bit signed integer. 2419** 2420** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2421** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2422** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2423** ^The value returned by sqlite3_msize(X) might be larger than the number 2424** of bytes requested when X was allocated. ^If X is a NULL pointer then 2425** sqlite3_msize(X) returns zero. If X points to something that is not 2426** the beginning of memory allocation, or if it points to a formerly 2427** valid memory allocation that has now been freed, then the behavior 2428** of sqlite3_msize(X) is undefined and possibly harmful. 2429** 2430** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2431** sqlite3_malloc64(), and sqlite3_realloc64() 2432** is always aligned to at least an 8 byte boundary, or to a 2433** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2434** option is used. 2435** 2436** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2437** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2438** implementation of these routines to be omitted. That capability 2439** is no longer provided. Only built-in memory allocators can be used. 2440** 2441** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2442** the system malloc() and free() directly when converting 2443** filenames between the UTF-8 encoding used by SQLite 2444** and whatever filename encoding is used by the particular Windows 2445** installation. Memory allocation errors were detected, but 2446** they were reported back as [SQLITE_CANTOPEN] or 2447** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2448** 2449** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2450** must be either NULL or else pointers obtained from a prior 2451** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2452** not yet been released. 2453** 2454** The application must not read or write any part of 2455** a block of memory after it has been released using 2456** [sqlite3_free()] or [sqlite3_realloc()]. 2457*/ 2458SQLITE_API void *SQLITE_STDCALL sqlite3_malloc(int); 2459SQLITE_API void *SQLITE_STDCALL sqlite3_malloc64(sqlite3_uint64); 2460SQLITE_API void *SQLITE_STDCALL sqlite3_realloc(void*, int); 2461SQLITE_API void *SQLITE_STDCALL sqlite3_realloc64(void*, sqlite3_uint64); 2462SQLITE_API void SQLITE_STDCALL sqlite3_free(void*); 2463SQLITE_API sqlite3_uint64 SQLITE_STDCALL sqlite3_msize(void*); 2464 2465/* 2466** CAPI3REF: Memory Allocator Statistics 2467** 2468** SQLite provides these two interfaces for reporting on the status 2469** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2470** routines, which form the built-in memory allocation subsystem. 2471** 2472** ^The [sqlite3_memory_used()] routine returns the number of bytes 2473** of memory currently outstanding (malloced but not freed). 2474** ^The [sqlite3_memory_highwater()] routine returns the maximum 2475** value of [sqlite3_memory_used()] since the high-water mark 2476** was last reset. ^The values returned by [sqlite3_memory_used()] and 2477** [sqlite3_memory_highwater()] include any overhead 2478** added by SQLite in its implementation of [sqlite3_malloc()], 2479** but not overhead added by the any underlying system library 2480** routines that [sqlite3_malloc()] may call. 2481** 2482** ^The memory high-water mark is reset to the current value of 2483** [sqlite3_memory_used()] if and only if the parameter to 2484** [sqlite3_memory_highwater()] is true. ^The value returned 2485** by [sqlite3_memory_highwater(1)] is the high-water mark 2486** prior to the reset. 2487*/ 2488SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_used(void); 2489SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_highwater(int resetFlag); 2490 2491/* 2492** CAPI3REF: Pseudo-Random Number Generator 2493** 2494** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2495** select random [ROWID | ROWIDs] when inserting new records into a table that 2496** already uses the largest possible [ROWID]. The PRNG is also used for 2497** the build-in random() and randomblob() SQL functions. This interface allows 2498** applications to access the same PRNG for other purposes. 2499** 2500** ^A call to this routine stores N bytes of randomness into buffer P. 2501** ^The P parameter can be a NULL pointer. 2502** 2503** ^If this routine has not been previously called or if the previous 2504** call had N less than one or a NULL pointer for P, then the PRNG is 2505** seeded using randomness obtained from the xRandomness method of 2506** the default [sqlite3_vfs] object. 2507** ^If the previous call to this routine had an N of 1 or more and a 2508** non-NULL P then the pseudo-randomness is generated 2509** internally and without recourse to the [sqlite3_vfs] xRandomness 2510** method. 2511*/ 2512SQLITE_API void SQLITE_STDCALL sqlite3_randomness(int N, void *P); 2513 2514/* 2515** CAPI3REF: Compile-Time Authorization Callbacks 2516** METHOD: sqlite3 2517** 2518** ^This routine registers an authorizer callback with a particular 2519** [database connection], supplied in the first argument. 2520** ^The authorizer callback is invoked as SQL statements are being compiled 2521** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2522** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2523** points during the compilation process, as logic is being created 2524** to perform various actions, the authorizer callback is invoked to 2525** see if those actions are allowed. ^The authorizer callback should 2526** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2527** specific action but allow the SQL statement to continue to be 2528** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2529** rejected with an error. ^If the authorizer callback returns 2530** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2531** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2532** the authorizer will fail with an error message. 2533** 2534** When the callback returns [SQLITE_OK], that means the operation 2535** requested is ok. ^When the callback returns [SQLITE_DENY], the 2536** [sqlite3_prepare_v2()] or equivalent call that triggered the 2537** authorizer will fail with an error message explaining that 2538** access is denied. 2539** 2540** ^The first parameter to the authorizer callback is a copy of the third 2541** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2542** to the callback is an integer [SQLITE_COPY | action code] that specifies 2543** the particular action to be authorized. ^The third through sixth parameters 2544** to the callback are zero-terminated strings that contain additional 2545** details about the action to be authorized. 2546** 2547** ^If the action code is [SQLITE_READ] 2548** and the callback returns [SQLITE_IGNORE] then the 2549** [prepared statement] statement is constructed to substitute 2550** a NULL value in place of the table column that would have 2551** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2552** return can be used to deny an untrusted user access to individual 2553** columns of a table. 2554** ^If the action code is [SQLITE_DELETE] and the callback returns 2555** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2556** [truncate optimization] is disabled and all rows are deleted individually. 2557** 2558** An authorizer is used when [sqlite3_prepare | preparing] 2559** SQL statements from an untrusted source, to ensure that the SQL statements 2560** do not try to access data they are not allowed to see, or that they do not 2561** try to execute malicious statements that damage the database. For 2562** example, an application may allow a user to enter arbitrary 2563** SQL queries for evaluation by a database. But the application does 2564** not want the user to be able to make arbitrary changes to the 2565** database. An authorizer could then be put in place while the 2566** user-entered SQL is being [sqlite3_prepare | prepared] that 2567** disallows everything except [SELECT] statements. 2568** 2569** Applications that need to process SQL from untrusted sources 2570** might also consider lowering resource limits using [sqlite3_limit()] 2571** and limiting database size using the [max_page_count] [PRAGMA] 2572** in addition to using an authorizer. 2573** 2574** ^(Only a single authorizer can be in place on a database connection 2575** at a time. Each call to sqlite3_set_authorizer overrides the 2576** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2577** The authorizer is disabled by default. 2578** 2579** The authorizer callback must not do anything that will modify 2580** the database connection that invoked the authorizer callback. 2581** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2582** database connections for the meaning of "modify" in this paragraph. 2583** 2584** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2585** statement might be re-prepared during [sqlite3_step()] due to a 2586** schema change. Hence, the application should ensure that the 2587** correct authorizer callback remains in place during the [sqlite3_step()]. 2588** 2589** ^Note that the authorizer callback is invoked only during 2590** [sqlite3_prepare()] or its variants. Authorization is not 2591** performed during statement evaluation in [sqlite3_step()], unless 2592** as stated in the previous paragraph, sqlite3_step() invokes 2593** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2594*/ 2595SQLITE_API int SQLITE_STDCALL sqlite3_set_authorizer( 2596 sqlite3*, 2597 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2598 void *pUserData 2599); 2600 2601/* 2602** CAPI3REF: Authorizer Return Codes 2603** 2604** The [sqlite3_set_authorizer | authorizer callback function] must 2605** return either [SQLITE_OK] or one of these two constants in order 2606** to signal SQLite whether or not the action is permitted. See the 2607** [sqlite3_set_authorizer | authorizer documentation] for additional 2608** information. 2609** 2610** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2611** returned from the [sqlite3_vtab_on_conflict()] interface. 2612*/ 2613#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2614#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2615 2616/* 2617** CAPI3REF: Authorizer Action Codes 2618** 2619** The [sqlite3_set_authorizer()] interface registers a callback function 2620** that is invoked to authorize certain SQL statement actions. The 2621** second parameter to the callback is an integer code that specifies 2622** what action is being authorized. These are the integer action codes that 2623** the authorizer callback may be passed. 2624** 2625** These action code values signify what kind of operation is to be 2626** authorized. The 3rd and 4th parameters to the authorization 2627** callback function will be parameters or NULL depending on which of these 2628** codes is used as the second parameter. ^(The 5th parameter to the 2629** authorizer callback is the name of the database ("main", "temp", 2630** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2631** is the name of the inner-most trigger or view that is responsible for 2632** the access attempt or NULL if this access attempt is directly from 2633** top-level SQL code. 2634*/ 2635/******************************************* 3rd ************ 4th ***********/ 2636#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2637#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2638#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2639#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2640#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2641#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2642#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2643#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2644#define SQLITE_DELETE 9 /* Table Name NULL */ 2645#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2646#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2647#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2648#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2649#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2650#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2651#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2652#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2653#define SQLITE_INSERT 18 /* Table Name NULL */ 2654#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2655#define SQLITE_READ 20 /* Table Name Column Name */ 2656#define SQLITE_SELECT 21 /* NULL NULL */ 2657#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2658#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2659#define SQLITE_ATTACH 24 /* Filename NULL */ 2660#define SQLITE_DETACH 25 /* Database Name NULL */ 2661#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2662#define SQLITE_REINDEX 27 /* Index Name NULL */ 2663#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2664#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2665#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2666#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2667#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2668#define SQLITE_COPY 0 /* No longer used */ 2669#define SQLITE_RECURSIVE 33 /* NULL NULL */ 2670 2671/* 2672** CAPI3REF: Tracing And Profiling Functions 2673** METHOD: sqlite3 2674** 2675** These routines register callback functions that can be used for 2676** tracing and profiling the execution of SQL statements. 2677** 2678** ^The callback function registered by sqlite3_trace() is invoked at 2679** various times when an SQL statement is being run by [sqlite3_step()]. 2680** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2681** SQL statement text as the statement first begins executing. 2682** ^(Additional sqlite3_trace() callbacks might occur 2683** as each triggered subprogram is entered. The callbacks for triggers 2684** contain a UTF-8 SQL comment that identifies the trigger.)^ 2685** 2686** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2687** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2688** 2689** ^The callback function registered by sqlite3_profile() is invoked 2690** as each SQL statement finishes. ^The profile callback contains 2691** the original statement text and an estimate of wall-clock time 2692** of how long that statement took to run. ^The profile callback 2693** time is in units of nanoseconds, however the current implementation 2694** is only capable of millisecond resolution so the six least significant 2695** digits in the time are meaningless. Future versions of SQLite 2696** might provide greater resolution on the profiler callback. The 2697** sqlite3_profile() function is considered experimental and is 2698** subject to change in future versions of SQLite. 2699*/ 2700SQLITE_API void *SQLITE_STDCALL sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 2701SQLITE_API SQLITE_EXPERIMENTAL void *SQLITE_STDCALL sqlite3_profile(sqlite3*, 2702 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2703 2704/* 2705** CAPI3REF: Query Progress Callbacks 2706** METHOD: sqlite3 2707** 2708** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2709** function X to be invoked periodically during long running calls to 2710** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2711** database connection D. An example use for this 2712** interface is to keep a GUI updated during a large query. 2713** 2714** ^The parameter P is passed through as the only parameter to the 2715** callback function X. ^The parameter N is the approximate number of 2716** [virtual machine instructions] that are evaluated between successive 2717** invocations of the callback X. ^If N is less than one then the progress 2718** handler is disabled. 2719** 2720** ^Only a single progress handler may be defined at one time per 2721** [database connection]; setting a new progress handler cancels the 2722** old one. ^Setting parameter X to NULL disables the progress handler. 2723** ^The progress handler is also disabled by setting N to a value less 2724** than 1. 2725** 2726** ^If the progress callback returns non-zero, the operation is 2727** interrupted. This feature can be used to implement a 2728** "Cancel" button on a GUI progress dialog box. 2729** 2730** The progress handler callback must not do anything that will modify 2731** the database connection that invoked the progress handler. 2732** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2733** database connections for the meaning of "modify" in this paragraph. 2734** 2735*/ 2736SQLITE_API void SQLITE_STDCALL sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2737 2738/* 2739** CAPI3REF: Opening A New Database Connection 2740** CONSTRUCTOR: sqlite3 2741** 2742** ^These routines open an SQLite database file as specified by the 2743** filename argument. ^The filename argument is interpreted as UTF-8 for 2744** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2745** order for sqlite3_open16(). ^(A [database connection] handle is usually 2746** returned in *ppDb, even if an error occurs. The only exception is that 2747** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2748** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2749** object.)^ ^(If the database is opened (and/or created) successfully, then 2750** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2751** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2752** an English language description of the error following a failure of any 2753** of the sqlite3_open() routines. 2754** 2755** ^The default encoding will be UTF-8 for databases created using 2756** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 2757** created using sqlite3_open16() will be UTF-16 in the native byte order. 2758** 2759** Whether or not an error occurs when it is opened, resources 2760** associated with the [database connection] handle should be released by 2761** passing it to [sqlite3_close()] when it is no longer required. 2762** 2763** The sqlite3_open_v2() interface works like sqlite3_open() 2764** except that it accepts two additional parameters for additional control 2765** over the new database connection. ^(The flags parameter to 2766** sqlite3_open_v2() can take one of 2767** the following three values, optionally combined with the 2768** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2769** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 2770** 2771** <dl> 2772** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2773** <dd>The database is opened in read-only mode. If the database does not 2774** already exist, an error is returned.</dd>)^ 2775** 2776** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2777** <dd>The database is opened for reading and writing if possible, or reading 2778** only if the file is write protected by the operating system. In either 2779** case the database must already exist, otherwise an error is returned.</dd>)^ 2780** 2781** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2782** <dd>The database is opened for reading and writing, and is created if 2783** it does not already exist. This is the behavior that is always used for 2784** sqlite3_open() and sqlite3_open16().</dd>)^ 2785** </dl> 2786** 2787** If the 3rd parameter to sqlite3_open_v2() is not one of the 2788** combinations shown above optionally combined with other 2789** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 2790** then the behavior is undefined. 2791** 2792** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2793** opens in the multi-thread [threading mode] as long as the single-thread 2794** mode has not been set at compile-time or start-time. ^If the 2795** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2796** in the serialized [threading mode] unless single-thread was 2797** previously selected at compile-time or start-time. 2798** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 2799** eligible to use [shared cache mode], regardless of whether or not shared 2800** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 2801** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 2802** participate in [shared cache mode] even if it is enabled. 2803** 2804** ^The fourth parameter to sqlite3_open_v2() is the name of the 2805** [sqlite3_vfs] object that defines the operating system interface that 2806** the new database connection should use. ^If the fourth parameter is 2807** a NULL pointer then the default [sqlite3_vfs] object is used. 2808** 2809** ^If the filename is ":memory:", then a private, temporary in-memory database 2810** is created for the connection. ^This in-memory database will vanish when 2811** the database connection is closed. Future versions of SQLite might 2812** make use of additional special filenames that begin with the ":" character. 2813** It is recommended that when a database filename actually does begin with 2814** a ":" character you should prefix the filename with a pathname such as 2815** "./" to avoid ambiguity. 2816** 2817** ^If the filename is an empty string, then a private, temporary 2818** on-disk database will be created. ^This private database will be 2819** automatically deleted as soon as the database connection is closed. 2820** 2821** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 2822** 2823** ^If [URI filename] interpretation is enabled, and the filename argument 2824** begins with "file:", then the filename is interpreted as a URI. ^URI 2825** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 2826** set in the fourth argument to sqlite3_open_v2(), or if it has 2827** been enabled globally using the [SQLITE_CONFIG_URI] option with the 2828** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 2829** As of SQLite version 3.7.7, URI filename interpretation is turned off 2830** by default, but future releases of SQLite might enable URI filename 2831** interpretation by default. See "[URI filenames]" for additional 2832** information. 2833** 2834** URI filenames are parsed according to RFC 3986. ^If the URI contains an 2835** authority, then it must be either an empty string or the string 2836** "localhost". ^If the authority is not an empty string or "localhost", an 2837** error is returned to the caller. ^The fragment component of a URI, if 2838** present, is ignored. 2839** 2840** ^SQLite uses the path component of the URI as the name of the disk file 2841** which contains the database. ^If the path begins with a '/' character, 2842** then it is interpreted as an absolute path. ^If the path does not begin 2843** with a '/' (meaning that the authority section is omitted from the URI) 2844** then the path is interpreted as a relative path. 2845** ^(On windows, the first component of an absolute path 2846** is a drive specification (e.g. "C:").)^ 2847** 2848** [[core URI query parameters]] 2849** The query component of a URI may contain parameters that are interpreted 2850** either by SQLite itself, or by a [VFS | custom VFS implementation]. 2851** SQLite and its built-in [VFSes] interpret the 2852** following query parameters: 2853** 2854** <ul> 2855** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 2856** a VFS object that provides the operating system interface that should 2857** be used to access the database file on disk. ^If this option is set to 2858** an empty string the default VFS object is used. ^Specifying an unknown 2859** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 2860** present, then the VFS specified by the option takes precedence over 2861** the value passed as the fourth parameter to sqlite3_open_v2(). 2862** 2863** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 2864** "rwc", or "memory". Attempting to set it to any other value is 2865** an error)^. 2866** ^If "ro" is specified, then the database is opened for read-only 2867** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 2868** third argument to sqlite3_open_v2(). ^If the mode option is set to 2869** "rw", then the database is opened for read-write (but not create) 2870** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 2871** been set. ^Value "rwc" is equivalent to setting both 2872** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 2873** set to "memory" then a pure [in-memory database] that never reads 2874** or writes from disk is used. ^It is an error to specify a value for 2875** the mode parameter that is less restrictive than that specified by 2876** the flags passed in the third parameter to sqlite3_open_v2(). 2877** 2878** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 2879** "private". ^Setting it to "shared" is equivalent to setting the 2880** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 2881** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 2882** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 2883** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 2884** a URI filename, its value overrides any behavior requested by setting 2885** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 2886** 2887** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 2888** [powersafe overwrite] property does or does not apply to the 2889** storage media on which the database file resides. 2890** 2891** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 2892** which if set disables file locking in rollback journal modes. This 2893** is useful for accessing a database on a filesystem that does not 2894** support locking. Caution: Database corruption might result if two 2895** or more processes write to the same database and any one of those 2896** processes uses nolock=1. 2897** 2898** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 2899** parameter that indicates that the database file is stored on 2900** read-only media. ^When immutable is set, SQLite assumes that the 2901** database file cannot be changed, even by a process with higher 2902** privilege, and so the database is opened read-only and all locking 2903** and change detection is disabled. Caution: Setting the immutable 2904** property on a database file that does in fact change can result 2905** in incorrect query results and/or [SQLITE_CORRUPT] errors. 2906** See also: [SQLITE_IOCAP_IMMUTABLE]. 2907** 2908** </ul> 2909** 2910** ^Specifying an unknown parameter in the query component of a URI is not an 2911** error. Future versions of SQLite might understand additional query 2912** parameters. See "[query parameters with special meaning to SQLite]" for 2913** additional information. 2914** 2915** [[URI filename examples]] <h3>URI filename examples</h3> 2916** 2917** <table border="1" align=center cellpadding=5> 2918** <tr><th> URI filenames <th> Results 2919** <tr><td> file:data.db <td> 2920** Open the file "data.db" in the current directory. 2921** <tr><td> file:/home/fred/data.db<br> 2922** file:///home/fred/data.db <br> 2923** file://localhost/home/fred/data.db <br> <td> 2924** Open the database file "/home/fred/data.db". 2925** <tr><td> file://darkstar/home/fred/data.db <td> 2926** An error. "darkstar" is not a recognized authority. 2927** <tr><td style="white-space:nowrap"> 2928** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 2929** <td> Windows only: Open the file "data.db" on fred's desktop on drive 2930** C:. Note that the %20 escaping in this example is not strictly 2931** necessary - space characters can be used literally 2932** in URI filenames. 2933** <tr><td> file:data.db?mode=ro&cache=private <td> 2934** Open file "data.db" in the current directory for read-only access. 2935** Regardless of whether or not shared-cache mode is enabled by 2936** default, use a private cache. 2937** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 2938** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 2939** that uses dot-files in place of posix advisory locking. 2940** <tr><td> file:data.db?mode=readonly <td> 2941** An error. "readonly" is not a valid option for the "mode" parameter. 2942** </table> 2943** 2944** ^URI hexadecimal escape sequences (%HH) are supported within the path and 2945** query components of a URI. A hexadecimal escape sequence consists of a 2946** percent sign - "%" - followed by exactly two hexadecimal digits 2947** specifying an octet value. ^Before the path or query components of a 2948** URI filename are interpreted, they are encoded using UTF-8 and all 2949** hexadecimal escape sequences replaced by a single byte containing the 2950** corresponding octet. If this process generates an invalid UTF-8 encoding, 2951** the results are undefined. 2952** 2953** <b>Note to Windows users:</b> The encoding used for the filename argument 2954** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 2955** codepage is currently defined. Filenames containing international 2956** characters must be converted to UTF-8 prior to passing them into 2957** sqlite3_open() or sqlite3_open_v2(). 2958** 2959** <b>Note to Windows Runtime users:</b> The temporary directory must be set 2960** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 2961** features that require the use of temporary files may fail. 2962** 2963** See also: [sqlite3_temp_directory] 2964*/ 2965SQLITE_API int SQLITE_STDCALL sqlite3_open( 2966 const char *filename, /* Database filename (UTF-8) */ 2967 sqlite3 **ppDb /* OUT: SQLite db handle */ 2968); 2969SQLITE_API int SQLITE_STDCALL sqlite3_open16( 2970 const void *filename, /* Database filename (UTF-16) */ 2971 sqlite3 **ppDb /* OUT: SQLite db handle */ 2972); 2973SQLITE_API int SQLITE_STDCALL sqlite3_open_v2( 2974 const char *filename, /* Database filename (UTF-8) */ 2975 sqlite3 **ppDb, /* OUT: SQLite db handle */ 2976 int flags, /* Flags */ 2977 const char *zVfs /* Name of VFS module to use */ 2978); 2979 2980/* 2981** CAPI3REF: Obtain Values For URI Parameters 2982** 2983** These are utility routines, useful to VFS implementations, that check 2984** to see if a database file was a URI that contained a specific query 2985** parameter, and if so obtains the value of that query parameter. 2986** 2987** If F is the database filename pointer passed into the xOpen() method of 2988** a VFS implementation when the flags parameter to xOpen() has one or 2989** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 2990** P is the name of the query parameter, then 2991** sqlite3_uri_parameter(F,P) returns the value of the P 2992** parameter if it exists or a NULL pointer if P does not appear as a 2993** query parameter on F. If P is a query parameter of F 2994** has no explicit value, then sqlite3_uri_parameter(F,P) returns 2995** a pointer to an empty string. 2996** 2997** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 2998** parameter and returns true (1) or false (0) according to the value 2999** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3000** value of query parameter P is one of "yes", "true", or "on" in any 3001** case or if the value begins with a non-zero number. The 3002** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3003** query parameter P is one of "no", "false", or "off" in any case or 3004** if the value begins with a numeric zero. If P is not a query 3005** parameter on F or if the value of P is does not match any of the 3006** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3007** 3008** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3009** 64-bit signed integer and returns that integer, or D if P does not 3010** exist. If the value of P is something other than an integer, then 3011** zero is returned. 3012** 3013** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3014** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3015** is not a database file pathname pointer that SQLite passed into the xOpen 3016** VFS method, then the behavior of this routine is undefined and probably 3017** undesirable. 3018*/ 3019SQLITE_API const char *SQLITE_STDCALL sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3020SQLITE_API int SQLITE_STDCALL sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3021SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3022 3023 3024/* 3025** CAPI3REF: Error Codes And Messages 3026** METHOD: sqlite3 3027** 3028** ^If the most recent sqlite3_* API call associated with 3029** [database connection] D failed, then the sqlite3_errcode(D) interface 3030** returns the numeric [result code] or [extended result code] for that 3031** API call. 3032** If the most recent API call was successful, 3033** then the return value from sqlite3_errcode() is undefined. 3034** ^The sqlite3_extended_errcode() 3035** interface is the same except that it always returns the 3036** [extended result code] even when extended result codes are 3037** disabled. 3038** 3039** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3040** text that describes the error, as either UTF-8 or UTF-16 respectively. 3041** ^(Memory to hold the error message string is managed internally. 3042** The application does not need to worry about freeing the result. 3043** However, the error string might be overwritten or deallocated by 3044** subsequent calls to other SQLite interface functions.)^ 3045** 3046** ^The sqlite3_errstr() interface returns the English-language text 3047** that describes the [result code], as UTF-8. 3048** ^(Memory to hold the error message string is managed internally 3049** and must not be freed by the application)^. 3050** 3051** When the serialized [threading mode] is in use, it might be the 3052** case that a second error occurs on a separate thread in between 3053** the time of the first error and the call to these interfaces. 3054** When that happens, the second error will be reported since these 3055** interfaces always report the most recent result. To avoid 3056** this, each thread can obtain exclusive use of the [database connection] D 3057** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3058** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3059** all calls to the interfaces listed here are completed. 3060** 3061** If an interface fails with SQLITE_MISUSE, that means the interface 3062** was invoked incorrectly by the application. In that case, the 3063** error code and message may or may not be set. 3064*/ 3065SQLITE_API int SQLITE_STDCALL sqlite3_errcode(sqlite3 *db); 3066SQLITE_API int SQLITE_STDCALL sqlite3_extended_errcode(sqlite3 *db); 3067SQLITE_API const char *SQLITE_STDCALL sqlite3_errmsg(sqlite3*); 3068SQLITE_API const void *SQLITE_STDCALL sqlite3_errmsg16(sqlite3*); 3069SQLITE_API const char *SQLITE_STDCALL sqlite3_errstr(int); 3070 3071/* 3072** CAPI3REF: Prepared Statement Object 3073** KEYWORDS: {prepared statement} {prepared statements} 3074** 3075** An instance of this object represents a single SQL statement that 3076** has been compiled into binary form and is ready to be evaluated. 3077** 3078** Think of each SQL statement as a separate computer program. The 3079** original SQL text is source code. A prepared statement object 3080** is the compiled object code. All SQL must be converted into a 3081** prepared statement before it can be run. 3082** 3083** The life-cycle of a prepared statement object usually goes like this: 3084** 3085** <ol> 3086** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3087** <li> Bind values to [parameters] using the sqlite3_bind_*() 3088** interfaces. 3089** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3090** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3091** to step 2. Do this zero or more times. 3092** <li> Destroy the object using [sqlite3_finalize()]. 3093** </ol> 3094*/ 3095typedef struct sqlite3_stmt sqlite3_stmt; 3096 3097/* 3098** CAPI3REF: Run-time Limits 3099** METHOD: sqlite3 3100** 3101** ^(This interface allows the size of various constructs to be limited 3102** on a connection by connection basis. The first parameter is the 3103** [database connection] whose limit is to be set or queried. The 3104** second parameter is one of the [limit categories] that define a 3105** class of constructs to be size limited. The third parameter is the 3106** new limit for that construct.)^ 3107** 3108** ^If the new limit is a negative number, the limit is unchanged. 3109** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3110** [limits | hard upper bound] 3111** set at compile-time by a C preprocessor macro called 3112** [limits | SQLITE_MAX_<i>NAME</i>]. 3113** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3114** ^Attempts to increase a limit above its hard upper bound are 3115** silently truncated to the hard upper bound. 3116** 3117** ^Regardless of whether or not the limit was changed, the 3118** [sqlite3_limit()] interface returns the prior value of the limit. 3119** ^Hence, to find the current value of a limit without changing it, 3120** simply invoke this interface with the third parameter set to -1. 3121** 3122** Run-time limits are intended for use in applications that manage 3123** both their own internal database and also databases that are controlled 3124** by untrusted external sources. An example application might be a 3125** web browser that has its own databases for storing history and 3126** separate databases controlled by JavaScript applications downloaded 3127** off the Internet. The internal databases can be given the 3128** large, default limits. Databases managed by external sources can 3129** be given much smaller limits designed to prevent a denial of service 3130** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3131** interface to further control untrusted SQL. The size of the database 3132** created by an untrusted script can be contained using the 3133** [max_page_count] [PRAGMA]. 3134** 3135** New run-time limit categories may be added in future releases. 3136*/ 3137SQLITE_API int SQLITE_STDCALL sqlite3_limit(sqlite3*, int id, int newVal); 3138 3139/* 3140** CAPI3REF: Run-Time Limit Categories 3141** KEYWORDS: {limit category} {*limit categories} 3142** 3143** These constants define various performance limits 3144** that can be lowered at run-time using [sqlite3_limit()]. 3145** The synopsis of the meanings of the various limits is shown below. 3146** Additional information is available at [limits | Limits in SQLite]. 3147** 3148** <dl> 3149** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3150** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3151** 3152** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3153** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3154** 3155** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3156** <dd>The maximum number of columns in a table definition or in the 3157** result set of a [SELECT] or the maximum number of columns in an index 3158** or in an ORDER BY or GROUP BY clause.</dd>)^ 3159** 3160** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3161** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3162** 3163** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3164** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3165** 3166** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3167** <dd>The maximum number of instructions in a virtual machine program 3168** used to implement an SQL statement. This limit is not currently 3169** enforced, though that might be added in some future release of 3170** SQLite.</dd>)^ 3171** 3172** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3173** <dd>The maximum number of arguments on a function.</dd>)^ 3174** 3175** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3176** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3177** 3178** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3179** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3180** <dd>The maximum length of the pattern argument to the [LIKE] or 3181** [GLOB] operators.</dd>)^ 3182** 3183** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3184** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3185** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3186** 3187** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3188** <dd>The maximum depth of recursion for triggers.</dd>)^ 3189** 3190** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3191** <dd>The maximum number of auxiliary worker threads that a single 3192** [prepared statement] may start.</dd>)^ 3193** </dl> 3194*/ 3195#define SQLITE_LIMIT_LENGTH 0 3196#define SQLITE_LIMIT_SQL_LENGTH 1 3197#define SQLITE_LIMIT_COLUMN 2 3198#define SQLITE_LIMIT_EXPR_DEPTH 3 3199#define SQLITE_LIMIT_COMPOUND_SELECT 4 3200#define SQLITE_LIMIT_VDBE_OP 5 3201#define SQLITE_LIMIT_FUNCTION_ARG 6 3202#define SQLITE_LIMIT_ATTACHED 7 3203#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3204#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3205#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3206#define SQLITE_LIMIT_WORKER_THREADS 11 3207 3208/* 3209** CAPI3REF: Compiling An SQL Statement 3210** KEYWORDS: {SQL statement compiler} 3211** METHOD: sqlite3 3212** CONSTRUCTOR: sqlite3_stmt 3213** 3214** To execute an SQL query, it must first be compiled into a byte-code 3215** program using one of these routines. 3216** 3217** The first argument, "db", is a [database connection] obtained from a 3218** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3219** [sqlite3_open16()]. The database connection must not have been closed. 3220** 3221** The second argument, "zSql", is the statement to be compiled, encoded 3222** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 3223** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 3224** use UTF-16. 3225** 3226** ^If the nByte argument is negative, then zSql is read up to the 3227** first zero terminator. ^If nByte is positive, then it is the 3228** number of bytes read from zSql. ^If nByte is zero, then no prepared 3229** statement is generated. 3230** If the caller knows that the supplied string is nul-terminated, then 3231** there is a small performance advantage to passing an nByte parameter that 3232** is the number of bytes in the input string <i>including</i> 3233** the nul-terminator. 3234** 3235** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3236** past the end of the first SQL statement in zSql. These routines only 3237** compile the first statement in zSql, so *pzTail is left pointing to 3238** what remains uncompiled. 3239** 3240** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3241** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3242** to NULL. ^If the input text contains no SQL (if the input is an empty 3243** string or a comment) then *ppStmt is set to NULL. 3244** The calling procedure is responsible for deleting the compiled 3245** SQL statement using [sqlite3_finalize()] after it has finished with it. 3246** ppStmt may not be NULL. 3247** 3248** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3249** otherwise an [error code] is returned. 3250** 3251** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 3252** recommended for all new programs. The two older interfaces are retained 3253** for backwards compatibility, but their use is discouraged. 3254** ^In the "v2" interfaces, the prepared statement 3255** that is returned (the [sqlite3_stmt] object) contains a copy of the 3256** original SQL text. This causes the [sqlite3_step()] interface to 3257** behave differently in three ways: 3258** 3259** <ol> 3260** <li> 3261** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3262** always used to do, [sqlite3_step()] will automatically recompile the SQL 3263** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3264** retries will occur before sqlite3_step() gives up and returns an error. 3265** </li> 3266** 3267** <li> 3268** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3269** [error codes] or [extended error codes]. ^The legacy behavior was that 3270** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3271** and the application would have to make a second call to [sqlite3_reset()] 3272** in order to find the underlying cause of the problem. With the "v2" prepare 3273** interfaces, the underlying reason for the error is returned immediately. 3274** </li> 3275** 3276** <li> 3277** ^If the specific value bound to [parameter | host parameter] in the 3278** WHERE clause might influence the choice of query plan for a statement, 3279** then the statement will be automatically recompiled, as if there had been 3280** a schema change, on the first [sqlite3_step()] call following any change 3281** to the [sqlite3_bind_text | bindings] of that [parameter]. 3282** ^The specific value of WHERE-clause [parameter] might influence the 3283** choice of query plan if the parameter is the left-hand side of a [LIKE] 3284** or [GLOB] operator or if the parameter is compared to an indexed column 3285** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3286** </li> 3287** </ol> 3288*/ 3289SQLITE_API int SQLITE_STDCALL sqlite3_prepare( 3290 sqlite3 *db, /* Database handle */ 3291 const char *zSql, /* SQL statement, UTF-8 encoded */ 3292 int nByte, /* Maximum length of zSql in bytes. */ 3293 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3294 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3295); 3296SQLITE_API int SQLITE_STDCALL sqlite3_prepare_v2( 3297 sqlite3 *db, /* Database handle */ 3298 const char *zSql, /* SQL statement, UTF-8 encoded */ 3299 int nByte, /* Maximum length of zSql in bytes. */ 3300 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3301 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3302); 3303SQLITE_API int SQLITE_STDCALL sqlite3_prepare16( 3304 sqlite3 *db, /* Database handle */ 3305 const void *zSql, /* SQL statement, UTF-16 encoded */ 3306 int nByte, /* Maximum length of zSql in bytes. */ 3307 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3308 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3309); 3310SQLITE_API int SQLITE_STDCALL sqlite3_prepare16_v2( 3311 sqlite3 *db, /* Database handle */ 3312 const void *zSql, /* SQL statement, UTF-16 encoded */ 3313 int nByte, /* Maximum length of zSql in bytes. */ 3314 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3315 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3316); 3317 3318/* 3319** CAPI3REF: Retrieving Statement SQL 3320** METHOD: sqlite3_stmt 3321** 3322** ^This interface can be used to retrieve a saved copy of the original 3323** SQL text used to create a [prepared statement] if that statement was 3324** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3325*/ 3326SQLITE_API const char *SQLITE_STDCALL sqlite3_sql(sqlite3_stmt *pStmt); 3327 3328/* 3329** CAPI3REF: Determine If An SQL Statement Writes The Database 3330** METHOD: sqlite3_stmt 3331** 3332** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3333** and only if the [prepared statement] X makes no direct changes to 3334** the content of the database file. 3335** 3336** Note that [application-defined SQL functions] or 3337** [virtual tables] might change the database indirectly as a side effect. 3338** ^(For example, if an application defines a function "eval()" that 3339** calls [sqlite3_exec()], then the following SQL statement would 3340** change the database file through side-effects: 3341** 3342** <blockquote><pre> 3343** SELECT eval('DELETE FROM t1') FROM t2; 3344** </pre></blockquote> 3345** 3346** But because the [SELECT] statement does not change the database file 3347** directly, sqlite3_stmt_readonly() would still return true.)^ 3348** 3349** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3350** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3351** since the statements themselves do not actually modify the database but 3352** rather they control the timing of when other statements modify the 3353** database. ^The [ATTACH] and [DETACH] statements also cause 3354** sqlite3_stmt_readonly() to return true since, while those statements 3355** change the configuration of a database connection, they do not make 3356** changes to the content of the database files on disk. 3357*/ 3358SQLITE_API int SQLITE_STDCALL sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3359 3360/* 3361** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3362** METHOD: sqlite3_stmt 3363** 3364** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3365** [prepared statement] S has been stepped at least once using 3366** [sqlite3_step(S)] but has not run to completion and/or has not 3367** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3368** interface returns false if S is a NULL pointer. If S is not a 3369** NULL pointer and is not a pointer to a valid [prepared statement] 3370** object, then the behavior is undefined and probably undesirable. 3371** 3372** This interface can be used in combination [sqlite3_next_stmt()] 3373** to locate all prepared statements associated with a database 3374** connection that are in need of being reset. This can be used, 3375** for example, in diagnostic routines to search for prepared 3376** statements that are holding a transaction open. 3377*/ 3378SQLITE_API int SQLITE_STDCALL sqlite3_stmt_busy(sqlite3_stmt*); 3379 3380/* 3381** CAPI3REF: Dynamically Typed Value Object 3382** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3383** 3384** SQLite uses the sqlite3_value object to represent all values 3385** that can be stored in a database table. SQLite uses dynamic typing 3386** for the values it stores. ^Values stored in sqlite3_value objects 3387** can be integers, floating point values, strings, BLOBs, or NULL. 3388** 3389** An sqlite3_value object may be either "protected" or "unprotected". 3390** Some interfaces require a protected sqlite3_value. Other interfaces 3391** will accept either a protected or an unprotected sqlite3_value. 3392** Every interface that accepts sqlite3_value arguments specifies 3393** whether or not it requires a protected sqlite3_value. 3394** 3395** The terms "protected" and "unprotected" refer to whether or not 3396** a mutex is held. An internal mutex is held for a protected 3397** sqlite3_value object but no mutex is held for an unprotected 3398** sqlite3_value object. If SQLite is compiled to be single-threaded 3399** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3400** or if SQLite is run in one of reduced mutex modes 3401** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3402** then there is no distinction between protected and unprotected 3403** sqlite3_value objects and they can be used interchangeably. However, 3404** for maximum code portability it is recommended that applications 3405** still make the distinction between protected and unprotected 3406** sqlite3_value objects even when not strictly required. 3407** 3408** ^The sqlite3_value objects that are passed as parameters into the 3409** implementation of [application-defined SQL functions] are protected. 3410** ^The sqlite3_value object returned by 3411** [sqlite3_column_value()] is unprotected. 3412** Unprotected sqlite3_value objects may only be used with 3413** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3414** The [sqlite3_value_blob | sqlite3_value_type()] family of 3415** interfaces require protected sqlite3_value objects. 3416*/ 3417typedef struct Mem sqlite3_value; 3418 3419/* 3420** CAPI3REF: SQL Function Context Object 3421** 3422** The context in which an SQL function executes is stored in an 3423** sqlite3_context object. ^A pointer to an sqlite3_context object 3424** is always first parameter to [application-defined SQL functions]. 3425** The application-defined SQL function implementation will pass this 3426** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3427** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3428** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3429** and/or [sqlite3_set_auxdata()]. 3430*/ 3431typedef struct sqlite3_context sqlite3_context; 3432 3433/* 3434** CAPI3REF: Binding Values To Prepared Statements 3435** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3436** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3437** METHOD: sqlite3_stmt 3438** 3439** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3440** literals may be replaced by a [parameter] that matches one of following 3441** templates: 3442** 3443** <ul> 3444** <li> ? 3445** <li> ?NNN 3446** <li> :VVV 3447** <li> @VVV 3448** <li> $VVV 3449** </ul> 3450** 3451** In the templates above, NNN represents an integer literal, 3452** and VVV represents an alphanumeric identifier.)^ ^The values of these 3453** parameters (also called "host parameter names" or "SQL parameters") 3454** can be set using the sqlite3_bind_*() routines defined here. 3455** 3456** ^The first argument to the sqlite3_bind_*() routines is always 3457** a pointer to the [sqlite3_stmt] object returned from 3458** [sqlite3_prepare_v2()] or its variants. 3459** 3460** ^The second argument is the index of the SQL parameter to be set. 3461** ^The leftmost SQL parameter has an index of 1. ^When the same named 3462** SQL parameter is used more than once, second and subsequent 3463** occurrences have the same index as the first occurrence. 3464** ^The index for named parameters can be looked up using the 3465** [sqlite3_bind_parameter_index()] API if desired. ^The index 3466** for "?NNN" parameters is the value of NNN. 3467** ^The NNN value must be between 1 and the [sqlite3_limit()] 3468** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3469** 3470** ^The third argument is the value to bind to the parameter. 3471** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3472** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3473** is ignored and the end result is the same as sqlite3_bind_null(). 3474** 3475** ^(In those routines that have a fourth argument, its value is the 3476** number of bytes in the parameter. To be clear: the value is the 3477** number of <u>bytes</u> in the value, not the number of characters.)^ 3478** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3479** is negative, then the length of the string is 3480** the number of bytes up to the first zero terminator. 3481** If the fourth parameter to sqlite3_bind_blob() is negative, then 3482** the behavior is undefined. 3483** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3484** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3485** that parameter must be the byte offset 3486** where the NUL terminator would occur assuming the string were NUL 3487** terminated. If any NUL characters occur at byte offsets less than 3488** the value of the fourth parameter then the resulting string value will 3489** contain embedded NULs. The result of expressions involving strings 3490** with embedded NULs is undefined. 3491** 3492** ^The fifth argument to the BLOB and string binding interfaces 3493** is a destructor used to dispose of the BLOB or 3494** string after SQLite has finished with it. ^The destructor is called 3495** to dispose of the BLOB or string even if the call to bind API fails. 3496** ^If the fifth argument is 3497** the special value [SQLITE_STATIC], then SQLite assumes that the 3498** information is in static, unmanaged space and does not need to be freed. 3499** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3500** SQLite makes its own private copy of the data immediately, before 3501** the sqlite3_bind_*() routine returns. 3502** 3503** ^The sixth argument to sqlite3_bind_text64() must be one of 3504** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 3505** to specify the encoding of the text in the third parameter. If 3506** the sixth argument to sqlite3_bind_text64() is not one of the 3507** allowed values shown above, or if the text encoding is different 3508** from the encoding specified by the sixth parameter, then the behavior 3509** is undefined. 3510** 3511** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3512** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3513** (just an integer to hold its size) while it is being processed. 3514** Zeroblobs are intended to serve as placeholders for BLOBs whose 3515** content is later written using 3516** [sqlite3_blob_open | incremental BLOB I/O] routines. 3517** ^A negative value for the zeroblob results in a zero-length BLOB. 3518** 3519** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3520** for the [prepared statement] or with a prepared statement for which 3521** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3522** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3523** routine is passed a [prepared statement] that has been finalized, the 3524** result is undefined and probably harmful. 3525** 3526** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3527** ^Unbound parameters are interpreted as NULL. 3528** 3529** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3530** [error code] if anything goes wrong. 3531** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 3532** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 3533** [SQLITE_MAX_LENGTH]. 3534** ^[SQLITE_RANGE] is returned if the parameter 3535** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3536** 3537** See also: [sqlite3_bind_parameter_count()], 3538** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3539*/ 3540SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3541SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 3542 void(*)(void*)); 3543SQLITE_API int SQLITE_STDCALL sqlite3_bind_double(sqlite3_stmt*, int, double); 3544SQLITE_API int SQLITE_STDCALL sqlite3_bind_int(sqlite3_stmt*, int, int); 3545SQLITE_API int SQLITE_STDCALL sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3546SQLITE_API int SQLITE_STDCALL sqlite3_bind_null(sqlite3_stmt*, int); 3547SQLITE_API int SQLITE_STDCALL sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 3548SQLITE_API int SQLITE_STDCALL sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3549SQLITE_API int SQLITE_STDCALL sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 3550 void(*)(void*), unsigned char encoding); 3551SQLITE_API int SQLITE_STDCALL sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3552SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3553 3554/* 3555** CAPI3REF: Number Of SQL Parameters 3556** METHOD: sqlite3_stmt 3557** 3558** ^This routine can be used to find the number of [SQL parameters] 3559** in a [prepared statement]. SQL parameters are tokens of the 3560** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3561** placeholders for values that are [sqlite3_bind_blob | bound] 3562** to the parameters at a later time. 3563** 3564** ^(This routine actually returns the index of the largest (rightmost) 3565** parameter. For all forms except ?NNN, this will correspond to the 3566** number of unique parameters. If parameters of the ?NNN form are used, 3567** there may be gaps in the list.)^ 3568** 3569** See also: [sqlite3_bind_blob|sqlite3_bind()], 3570** [sqlite3_bind_parameter_name()], and 3571** [sqlite3_bind_parameter_index()]. 3572*/ 3573SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_count(sqlite3_stmt*); 3574 3575/* 3576** CAPI3REF: Name Of A Host Parameter 3577** METHOD: sqlite3_stmt 3578** 3579** ^The sqlite3_bind_parameter_name(P,N) interface returns 3580** the name of the N-th [SQL parameter] in the [prepared statement] P. 3581** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3582** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3583** respectively. 3584** In other words, the initial ":" or "$" or "@" or "?" 3585** is included as part of the name.)^ 3586** ^Parameters of the form "?" without a following integer have no name 3587** and are referred to as "nameless" or "anonymous parameters". 3588** 3589** ^The first host parameter has an index of 1, not 0. 3590** 3591** ^If the value N is out of range or if the N-th parameter is 3592** nameless, then NULL is returned. ^The returned string is 3593** always in UTF-8 encoding even if the named parameter was 3594** originally specified as UTF-16 in [sqlite3_prepare16()] or 3595** [sqlite3_prepare16_v2()]. 3596** 3597** See also: [sqlite3_bind_blob|sqlite3_bind()], 3598** [sqlite3_bind_parameter_count()], and 3599** [sqlite3_bind_parameter_index()]. 3600*/ 3601SQLITE_API const char *SQLITE_STDCALL sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3602 3603/* 3604** CAPI3REF: Index Of A Parameter With A Given Name 3605** METHOD: sqlite3_stmt 3606** 3607** ^Return the index of an SQL parameter given its name. ^The 3608** index value returned is suitable for use as the second 3609** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3610** is returned if no matching parameter is found. ^The parameter 3611** name must be given in UTF-8 even if the original statement 3612** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3613** 3614** See also: [sqlite3_bind_blob|sqlite3_bind()], 3615** [sqlite3_bind_parameter_count()], and 3616** [sqlite3_bind_parameter_index()]. 3617*/ 3618SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3619 3620/* 3621** CAPI3REF: Reset All Bindings On A Prepared Statement 3622** METHOD: sqlite3_stmt 3623** 3624** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3625** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3626** ^Use this routine to reset all host parameters to NULL. 3627*/ 3628SQLITE_API int SQLITE_STDCALL sqlite3_clear_bindings(sqlite3_stmt*); 3629 3630/* 3631** CAPI3REF: Number Of Columns In A Result Set 3632** METHOD: sqlite3_stmt 3633** 3634** ^Return the number of columns in the result set returned by the 3635** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 3636** statement that does not return data (for example an [UPDATE]). 3637** 3638** See also: [sqlite3_data_count()] 3639*/ 3640SQLITE_API int SQLITE_STDCALL sqlite3_column_count(sqlite3_stmt *pStmt); 3641 3642/* 3643** CAPI3REF: Column Names In A Result Set 3644** METHOD: sqlite3_stmt 3645** 3646** ^These routines return the name assigned to a particular column 3647** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3648** interface returns a pointer to a zero-terminated UTF-8 string 3649** and sqlite3_column_name16() returns a pointer to a zero-terminated 3650** UTF-16 string. ^The first parameter is the [prepared statement] 3651** that implements the [SELECT] statement. ^The second parameter is the 3652** column number. ^The leftmost column is number 0. 3653** 3654** ^The returned string pointer is valid until either the [prepared statement] 3655** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3656** reprepared by the first call to [sqlite3_step()] for a particular run 3657** or until the next call to 3658** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3659** 3660** ^If sqlite3_malloc() fails during the processing of either routine 3661** (for example during a conversion from UTF-8 to UTF-16) then a 3662** NULL pointer is returned. 3663** 3664** ^The name of a result column is the value of the "AS" clause for 3665** that column, if there is an AS clause. If there is no AS clause 3666** then the name of the column is unspecified and may change from 3667** one release of SQLite to the next. 3668*/ 3669SQLITE_API const char *SQLITE_STDCALL sqlite3_column_name(sqlite3_stmt*, int N); 3670SQLITE_API const void *SQLITE_STDCALL sqlite3_column_name16(sqlite3_stmt*, int N); 3671 3672/* 3673** CAPI3REF: Source Of Data In A Query Result 3674** METHOD: sqlite3_stmt 3675** 3676** ^These routines provide a means to determine the database, table, and 3677** table column that is the origin of a particular result column in 3678** [SELECT] statement. 3679** ^The name of the database or table or column can be returned as 3680** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3681** the database name, the _table_ routines return the table name, and 3682** the origin_ routines return the column name. 3683** ^The returned string is valid until the [prepared statement] is destroyed 3684** using [sqlite3_finalize()] or until the statement is automatically 3685** reprepared by the first call to [sqlite3_step()] for a particular run 3686** or until the same information is requested 3687** again in a different encoding. 3688** 3689** ^The names returned are the original un-aliased names of the 3690** database, table, and column. 3691** 3692** ^The first argument to these interfaces is a [prepared statement]. 3693** ^These functions return information about the Nth result column returned by 3694** the statement, where N is the second function argument. 3695** ^The left-most column is column 0 for these routines. 3696** 3697** ^If the Nth column returned by the statement is an expression or 3698** subquery and is not a column value, then all of these functions return 3699** NULL. ^These routine might also return NULL if a memory allocation error 3700** occurs. ^Otherwise, they return the name of the attached database, table, 3701** or column that query result column was extracted from. 3702** 3703** ^As with all other SQLite APIs, those whose names end with "16" return 3704** UTF-16 encoded strings and the other functions return UTF-8. 3705** 3706** ^These APIs are only available if the library was compiled with the 3707** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3708** 3709** If two or more threads call one or more of these routines against the same 3710** prepared statement and column at the same time then the results are 3711** undefined. 3712** 3713** If two or more threads call one or more 3714** [sqlite3_column_database_name | column metadata interfaces] 3715** for the same [prepared statement] and result column 3716** at the same time then the results are undefined. 3717*/ 3718SQLITE_API const char *SQLITE_STDCALL sqlite3_column_database_name(sqlite3_stmt*,int); 3719SQLITE_API const void *SQLITE_STDCALL sqlite3_column_database_name16(sqlite3_stmt*,int); 3720SQLITE_API const char *SQLITE_STDCALL sqlite3_column_table_name(sqlite3_stmt*,int); 3721SQLITE_API const void *SQLITE_STDCALL sqlite3_column_table_name16(sqlite3_stmt*,int); 3722SQLITE_API const char *SQLITE_STDCALL sqlite3_column_origin_name(sqlite3_stmt*,int); 3723SQLITE_API const void *SQLITE_STDCALL sqlite3_column_origin_name16(sqlite3_stmt*,int); 3724 3725/* 3726** CAPI3REF: Declared Datatype Of A Query Result 3727** METHOD: sqlite3_stmt 3728** 3729** ^(The first parameter is a [prepared statement]. 3730** If this statement is a [SELECT] statement and the Nth column of the 3731** returned result set of that [SELECT] is a table column (not an 3732** expression or subquery) then the declared type of the table 3733** column is returned.)^ ^If the Nth column of the result set is an 3734** expression or subquery, then a NULL pointer is returned. 3735** ^The returned string is always UTF-8 encoded. 3736** 3737** ^(For example, given the database schema: 3738** 3739** CREATE TABLE t1(c1 VARIANT); 3740** 3741** and the following statement to be compiled: 3742** 3743** SELECT c1 + 1, c1 FROM t1; 3744** 3745** this routine would return the string "VARIANT" for the second result 3746** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3747** 3748** ^SQLite uses dynamic run-time typing. ^So just because a column 3749** is declared to contain a particular type does not mean that the 3750** data stored in that column is of the declared type. SQLite is 3751** strongly typed, but the typing is dynamic not static. ^Type 3752** is associated with individual values, not with the containers 3753** used to hold those values. 3754*/ 3755SQLITE_API const char *SQLITE_STDCALL sqlite3_column_decltype(sqlite3_stmt*,int); 3756SQLITE_API const void *SQLITE_STDCALL sqlite3_column_decltype16(sqlite3_stmt*,int); 3757 3758/* 3759** CAPI3REF: Evaluate An SQL Statement 3760** METHOD: sqlite3_stmt 3761** 3762** After a [prepared statement] has been prepared using either 3763** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3764** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3765** must be called one or more times to evaluate the statement. 3766** 3767** The details of the behavior of the sqlite3_step() interface depend 3768** on whether the statement was prepared using the newer "v2" interface 3769** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3770** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3771** new "v2" interface is recommended for new applications but the legacy 3772** interface will continue to be supported. 3773** 3774** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 3775** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 3776** ^With the "v2" interface, any of the other [result codes] or 3777** [extended result codes] might be returned as well. 3778** 3779** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 3780** database locks it needs to do its job. ^If the statement is a [COMMIT] 3781** or occurs outside of an explicit transaction, then you can retry the 3782** statement. If the statement is not a [COMMIT] and occurs within an 3783** explicit transaction then you should rollback the transaction before 3784** continuing. 3785** 3786** ^[SQLITE_DONE] means that the statement has finished executing 3787** successfully. sqlite3_step() should not be called again on this virtual 3788** machine without first calling [sqlite3_reset()] to reset the virtual 3789** machine back to its initial state. 3790** 3791** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 3792** is returned each time a new row of data is ready for processing by the 3793** caller. The values may be accessed using the [column access functions]. 3794** sqlite3_step() is called again to retrieve the next row of data. 3795** 3796** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 3797** violation) has occurred. sqlite3_step() should not be called again on 3798** the VM. More information may be found by calling [sqlite3_errmsg()]. 3799** ^With the legacy interface, a more specific error code (for example, 3800** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 3801** can be obtained by calling [sqlite3_reset()] on the 3802** [prepared statement]. ^In the "v2" interface, 3803** the more specific error code is returned directly by sqlite3_step(). 3804** 3805** [SQLITE_MISUSE] means that the this routine was called inappropriately. 3806** Perhaps it was called on a [prepared statement] that has 3807** already been [sqlite3_finalize | finalized] or on one that had 3808** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 3809** be the case that the same database connection is being used by two or 3810** more threads at the same moment in time. 3811** 3812** For all versions of SQLite up to and including 3.6.23.1, a call to 3813** [sqlite3_reset()] was required after sqlite3_step() returned anything 3814** other than [SQLITE_ROW] before any subsequent invocation of 3815** sqlite3_step(). Failure to reset the prepared statement using 3816** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 3817** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 3818** calling [sqlite3_reset()] automatically in this circumstance rather 3819** than returning [SQLITE_MISUSE]. This is not considered a compatibility 3820** break because any application that ever receives an SQLITE_MISUSE error 3821** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 3822** can be used to restore the legacy behavior. 3823** 3824** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 3825** API always returns a generic error code, [SQLITE_ERROR], following any 3826** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 3827** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 3828** specific [error codes] that better describes the error. 3829** We admit that this is a goofy design. The problem has been fixed 3830** with the "v2" interface. If you prepare all of your SQL statements 3831** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 3832** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 3833** then the more specific [error codes] are returned directly 3834** by sqlite3_step(). The use of the "v2" interface is recommended. 3835*/ 3836SQLITE_API int SQLITE_STDCALL sqlite3_step(sqlite3_stmt*); 3837 3838/* 3839** CAPI3REF: Number of columns in a result set 3840** METHOD: sqlite3_stmt 3841** 3842** ^The sqlite3_data_count(P) interface returns the number of columns in the 3843** current row of the result set of [prepared statement] P. 3844** ^If prepared statement P does not have results ready to return 3845** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 3846** interfaces) then sqlite3_data_count(P) returns 0. 3847** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 3848** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 3849** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 3850** will return non-zero if previous call to [sqlite3_step](P) returned 3851** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 3852** where it always returns zero since each step of that multi-step 3853** pragma returns 0 columns of data. 3854** 3855** See also: [sqlite3_column_count()] 3856*/ 3857SQLITE_API int SQLITE_STDCALL sqlite3_data_count(sqlite3_stmt *pStmt); 3858 3859/* 3860** CAPI3REF: Fundamental Datatypes 3861** KEYWORDS: SQLITE_TEXT 3862** 3863** ^(Every value in SQLite has one of five fundamental datatypes: 3864** 3865** <ul> 3866** <li> 64-bit signed integer 3867** <li> 64-bit IEEE floating point number 3868** <li> string 3869** <li> BLOB 3870** <li> NULL 3871** </ul>)^ 3872** 3873** These constants are codes for each of those types. 3874** 3875** Note that the SQLITE_TEXT constant was also used in SQLite version 2 3876** for a completely different meaning. Software that links against both 3877** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 3878** SQLITE_TEXT. 3879*/ 3880#define SQLITE_INTEGER 1 3881#define SQLITE_FLOAT 2 3882#define SQLITE_BLOB 4 3883#define SQLITE_NULL 5 3884#ifdef SQLITE_TEXT 3885# undef SQLITE_TEXT 3886#else 3887# define SQLITE_TEXT 3 3888#endif 3889#define SQLITE3_TEXT 3 3890 3891/* 3892** CAPI3REF: Result Values From A Query 3893** KEYWORDS: {column access functions} 3894** METHOD: sqlite3_stmt 3895** 3896** These routines form the "result set" interface. 3897** 3898** ^These routines return information about a single column of the current 3899** result row of a query. ^In every case the first argument is a pointer 3900** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 3901** that was returned from [sqlite3_prepare_v2()] or one of its variants) 3902** and the second argument is the index of the column for which information 3903** should be returned. ^The leftmost column of the result set has the index 0. 3904** ^The number of columns in the result can be determined using 3905** [sqlite3_column_count()]. 3906** 3907** If the SQL statement does not currently point to a valid row, or if the 3908** column index is out of range, the result is undefined. 3909** These routines may only be called when the most recent call to 3910** [sqlite3_step()] has returned [SQLITE_ROW] and neither 3911** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 3912** If any of these routines are called after [sqlite3_reset()] or 3913** [sqlite3_finalize()] or after [sqlite3_step()] has returned 3914** something other than [SQLITE_ROW], the results are undefined. 3915** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 3916** are called from a different thread while any of these routines 3917** are pending, then the results are undefined. 3918** 3919** ^The sqlite3_column_type() routine returns the 3920** [SQLITE_INTEGER | datatype code] for the initial data type 3921** of the result column. ^The returned value is one of [SQLITE_INTEGER], 3922** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 3923** returned by sqlite3_column_type() is only meaningful if no type 3924** conversions have occurred as described below. After a type conversion, 3925** the value returned by sqlite3_column_type() is undefined. Future 3926** versions of SQLite may change the behavior of sqlite3_column_type() 3927** following a type conversion. 3928** 3929** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 3930** routine returns the number of bytes in that BLOB or string. 3931** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 3932** the string to UTF-8 and then returns the number of bytes. 3933** ^If the result is a numeric value then sqlite3_column_bytes() uses 3934** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 3935** the number of bytes in that string. 3936** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 3937** 3938** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 3939** routine returns the number of bytes in that BLOB or string. 3940** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 3941** the string to UTF-16 and then returns the number of bytes. 3942** ^If the result is a numeric value then sqlite3_column_bytes16() uses 3943** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 3944** the number of bytes in that string. 3945** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 3946** 3947** ^The values returned by [sqlite3_column_bytes()] and 3948** [sqlite3_column_bytes16()] do not include the zero terminators at the end 3949** of the string. ^For clarity: the values returned by 3950** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 3951** bytes in the string, not the number of characters. 3952** 3953** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 3954** even empty strings, are always zero-terminated. ^The return 3955** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 3956** 3957** ^The object returned by [sqlite3_column_value()] is an 3958** [unprotected sqlite3_value] object. An unprotected sqlite3_value object 3959** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. 3960** If the [unprotected sqlite3_value] object returned by 3961** [sqlite3_column_value()] is used in any other way, including calls 3962** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 3963** or [sqlite3_value_bytes()], then the behavior is undefined. 3964** 3965** These routines attempt to convert the value where appropriate. ^For 3966** example, if the internal representation is FLOAT and a text result 3967** is requested, [sqlite3_snprintf()] is used internally to perform the 3968** conversion automatically. ^(The following table details the conversions 3969** that are applied: 3970** 3971** <blockquote> 3972** <table border="1"> 3973** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 3974** 3975** <tr><td> NULL <td> INTEGER <td> Result is 0 3976** <tr><td> NULL <td> FLOAT <td> Result is 0.0 3977** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 3978** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 3979** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 3980** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 3981** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 3982** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 3983** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 3984** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 3985** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 3986** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 3987** <tr><td> TEXT <td> BLOB <td> No change 3988** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 3989** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 3990** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 3991** </table> 3992** </blockquote>)^ 3993** 3994** The table above makes reference to standard C library functions atoi() 3995** and atof(). SQLite does not really use these functions. It has its 3996** own equivalent internal routines. The atoi() and atof() names are 3997** used in the table for brevity and because they are familiar to most 3998** C programmers. 3999** 4000** Note that when type conversions occur, pointers returned by prior 4001** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4002** sqlite3_column_text16() may be invalidated. 4003** Type conversions and pointer invalidations might occur 4004** in the following cases: 4005** 4006** <ul> 4007** <li> The initial content is a BLOB and sqlite3_column_text() or 4008** sqlite3_column_text16() is called. A zero-terminator might 4009** need to be added to the string.</li> 4010** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4011** sqlite3_column_text16() is called. The content must be converted 4012** to UTF-16.</li> 4013** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4014** sqlite3_column_text() is called. The content must be converted 4015** to UTF-8.</li> 4016** </ul> 4017** 4018** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4019** not invalidate a prior pointer, though of course the content of the buffer 4020** that the prior pointer references will have been modified. Other kinds 4021** of conversion are done in place when it is possible, but sometimes they 4022** are not possible and in those cases prior pointers are invalidated. 4023** 4024** The safest and easiest to remember policy is to invoke these routines 4025** in one of the following ways: 4026** 4027** <ul> 4028** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4029** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4030** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4031** </ul> 4032** 4033** In other words, you should call sqlite3_column_text(), 4034** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4035** into the desired format, then invoke sqlite3_column_bytes() or 4036** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4037** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4038** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4039** with calls to sqlite3_column_bytes(). 4040** 4041** ^The pointers returned are valid until a type conversion occurs as 4042** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4043** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4044** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned 4045** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4046** [sqlite3_free()]. 4047** 4048** ^(If a memory allocation error occurs during the evaluation of any 4049** of these routines, a default value is returned. The default value 4050** is either the integer 0, the floating point number 0.0, or a NULL 4051** pointer. Subsequent calls to [sqlite3_errcode()] will return 4052** [SQLITE_NOMEM].)^ 4053*/ 4054SQLITE_API const void *SQLITE_STDCALL sqlite3_column_blob(sqlite3_stmt*, int iCol); 4055SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4056SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4057SQLITE_API double SQLITE_STDCALL sqlite3_column_double(sqlite3_stmt*, int iCol); 4058SQLITE_API int SQLITE_STDCALL sqlite3_column_int(sqlite3_stmt*, int iCol); 4059SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_column_int64(sqlite3_stmt*, int iCol); 4060SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_column_text(sqlite3_stmt*, int iCol); 4061SQLITE_API const void *SQLITE_STDCALL sqlite3_column_text16(sqlite3_stmt*, int iCol); 4062SQLITE_API int SQLITE_STDCALL sqlite3_column_type(sqlite3_stmt*, int iCol); 4063SQLITE_API sqlite3_value *SQLITE_STDCALL sqlite3_column_value(sqlite3_stmt*, int iCol); 4064 4065/* 4066** CAPI3REF: Destroy A Prepared Statement Object 4067** DESTRUCTOR: sqlite3_stmt 4068** 4069** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4070** ^If the most recent evaluation of the statement encountered no errors 4071** or if the statement is never been evaluated, then sqlite3_finalize() returns 4072** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4073** sqlite3_finalize(S) returns the appropriate [error code] or 4074** [extended error code]. 4075** 4076** ^The sqlite3_finalize(S) routine can be called at any point during 4077** the life cycle of [prepared statement] S: 4078** before statement S is ever evaluated, after 4079** one or more calls to [sqlite3_reset()], or after any call 4080** to [sqlite3_step()] regardless of whether or not the statement has 4081** completed execution. 4082** 4083** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4084** 4085** The application must finalize every [prepared statement] in order to avoid 4086** resource leaks. It is a grievous error for the application to try to use 4087** a prepared statement after it has been finalized. Any use of a prepared 4088** statement after it has been finalized can result in undefined and 4089** undesirable behavior such as segfaults and heap corruption. 4090*/ 4091SQLITE_API int SQLITE_STDCALL sqlite3_finalize(sqlite3_stmt *pStmt); 4092 4093/* 4094** CAPI3REF: Reset A Prepared Statement Object 4095** METHOD: sqlite3_stmt 4096** 4097** The sqlite3_reset() function is called to reset a [prepared statement] 4098** object back to its initial state, ready to be re-executed. 4099** ^Any SQL statement variables that had values bound to them using 4100** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4101** Use [sqlite3_clear_bindings()] to reset the bindings. 4102** 4103** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4104** back to the beginning of its program. 4105** 4106** ^If the most recent call to [sqlite3_step(S)] for the 4107** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4108** or if [sqlite3_step(S)] has never before been called on S, 4109** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4110** 4111** ^If the most recent call to [sqlite3_step(S)] for the 4112** [prepared statement] S indicated an error, then 4113** [sqlite3_reset(S)] returns an appropriate [error code]. 4114** 4115** ^The [sqlite3_reset(S)] interface does not change the values 4116** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4117*/ 4118SQLITE_API int SQLITE_STDCALL sqlite3_reset(sqlite3_stmt *pStmt); 4119 4120/* 4121** CAPI3REF: Create Or Redefine SQL Functions 4122** KEYWORDS: {function creation routines} 4123** KEYWORDS: {application-defined SQL function} 4124** KEYWORDS: {application-defined SQL functions} 4125** METHOD: sqlite3 4126** 4127** ^These functions (collectively known as "function creation routines") 4128** are used to add SQL functions or aggregates or to redefine the behavior 4129** of existing SQL functions or aggregates. The only differences between 4130** these routines are the text encoding expected for 4131** the second parameter (the name of the function being created) 4132** and the presence or absence of a destructor callback for 4133** the application data pointer. 4134** 4135** ^The first parameter is the [database connection] to which the SQL 4136** function is to be added. ^If an application uses more than one database 4137** connection then application-defined SQL functions must be added 4138** to each database connection separately. 4139** 4140** ^The second parameter is the name of the SQL function to be created or 4141** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4142** representation, exclusive of the zero-terminator. ^Note that the name 4143** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4144** ^Any attempt to create a function with a longer name 4145** will result in [SQLITE_MISUSE] being returned. 4146** 4147** ^The third parameter (nArg) 4148** is the number of arguments that the SQL function or 4149** aggregate takes. ^If this parameter is -1, then the SQL function or 4150** aggregate may take any number of arguments between 0 and the limit 4151** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4152** parameter is less than -1 or greater than 127 then the behavior is 4153** undefined. 4154** 4155** ^The fourth parameter, eTextRep, specifies what 4156** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4157** its parameters. The application should set this parameter to 4158** [SQLITE_UTF16LE] if the function implementation invokes 4159** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4160** implementation invokes [sqlite3_value_text16be()] on an input, or 4161** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4162** otherwise. ^The same SQL function may be registered multiple times using 4163** different preferred text encodings, with different implementations for 4164** each encoding. 4165** ^When multiple implementations of the same function are available, SQLite 4166** will pick the one that involves the least amount of data conversion. 4167** 4168** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4169** to signal that the function will always return the same result given 4170** the same inputs within a single SQL statement. Most SQL functions are 4171** deterministic. The built-in [random()] SQL function is an example of a 4172** function that is not deterministic. The SQLite query planner is able to 4173** perform additional optimizations on deterministic functions, so use 4174** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4175** 4176** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4177** function can gain access to this pointer using [sqlite3_user_data()].)^ 4178** 4179** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4180** pointers to C-language functions that implement the SQL function or 4181** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4182** callback only; NULL pointers must be passed as the xStep and xFinal 4183** parameters. ^An aggregate SQL function requires an implementation of xStep 4184** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4185** SQL function or aggregate, pass NULL pointers for all three function 4186** callbacks. 4187** 4188** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4189** then it is destructor for the application data pointer. 4190** The destructor is invoked when the function is deleted, either by being 4191** overloaded or when the database connection closes.)^ 4192** ^The destructor is also invoked if the call to 4193** sqlite3_create_function_v2() fails. 4194** ^When the destructor callback of the tenth parameter is invoked, it 4195** is passed a single argument which is a copy of the application data 4196** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4197** 4198** ^It is permitted to register multiple implementations of the same 4199** functions with the same name but with either differing numbers of 4200** arguments or differing preferred text encodings. ^SQLite will use 4201** the implementation that most closely matches the way in which the 4202** SQL function is used. ^A function implementation with a non-negative 4203** nArg parameter is a better match than a function implementation with 4204** a negative nArg. ^A function where the preferred text encoding 4205** matches the database encoding is a better 4206** match than a function where the encoding is different. 4207** ^A function where the encoding difference is between UTF16le and UTF16be 4208** is a closer match than a function where the encoding difference is 4209** between UTF8 and UTF16. 4210** 4211** ^Built-in functions may be overloaded by new application-defined functions. 4212** 4213** ^An application-defined function is permitted to call other 4214** SQLite interfaces. However, such calls must not 4215** close the database connection nor finalize or reset the prepared 4216** statement in which the function is running. 4217*/ 4218SQLITE_API int SQLITE_STDCALL sqlite3_create_function( 4219 sqlite3 *db, 4220 const char *zFunctionName, 4221 int nArg, 4222 int eTextRep, 4223 void *pApp, 4224 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4225 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4226 void (*xFinal)(sqlite3_context*) 4227); 4228SQLITE_API int SQLITE_STDCALL sqlite3_create_function16( 4229 sqlite3 *db, 4230 const void *zFunctionName, 4231 int nArg, 4232 int eTextRep, 4233 void *pApp, 4234 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4235 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4236 void (*xFinal)(sqlite3_context*) 4237); 4238SQLITE_API int SQLITE_STDCALL sqlite3_create_function_v2( 4239 sqlite3 *db, 4240 const char *zFunctionName, 4241 int nArg, 4242 int eTextRep, 4243 void *pApp, 4244 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4245 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4246 void (*xFinal)(sqlite3_context*), 4247 void(*xDestroy)(void*) 4248); 4249 4250/* 4251** CAPI3REF: Text Encodings 4252** 4253** These constant define integer codes that represent the various 4254** text encodings supported by SQLite. 4255*/ 4256#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4257#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4258#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4259#define SQLITE_UTF16 4 /* Use native byte order */ 4260#define SQLITE_ANY 5 /* Deprecated */ 4261#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4262 4263/* 4264** CAPI3REF: Function Flags 4265** 4266** These constants may be ORed together with the 4267** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4268** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4269** [sqlite3_create_function_v2()]. 4270*/ 4271#define SQLITE_DETERMINISTIC 0x800 4272 4273/* 4274** CAPI3REF: Deprecated Functions 4275** DEPRECATED 4276** 4277** These functions are [deprecated]. In order to maintain 4278** backwards compatibility with older code, these functions continue 4279** to be supported. However, new applications should avoid 4280** the use of these functions. To encourage programmers to avoid 4281** these functions, we will not explain what they do. 4282*/ 4283#ifndef SQLITE_OMIT_DEPRECATED 4284SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_aggregate_count(sqlite3_context*); 4285SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_expired(sqlite3_stmt*); 4286SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4287SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_global_recover(void); 4288SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_thread_cleanup(void); 4289SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4290 void*,sqlite3_int64); 4291#endif 4292 4293/* 4294** CAPI3REF: Obtaining SQL Function Parameter Values 4295** METHOD: sqlite3_value 4296** 4297** The C-language implementation of SQL functions and aggregates uses 4298** this set of interface routines to access the parameter values on 4299** the function or aggregate. 4300** 4301** The xFunc (for scalar functions) or xStep (for aggregates) parameters 4302** to [sqlite3_create_function()] and [sqlite3_create_function16()] 4303** define callbacks that implement the SQL functions and aggregates. 4304** The 3rd parameter to these callbacks is an array of pointers to 4305** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 4306** each parameter to the SQL function. These routines are used to 4307** extract values from the [sqlite3_value] objects. 4308** 4309** These routines work only with [protected sqlite3_value] objects. 4310** Any attempt to use these routines on an [unprotected sqlite3_value] 4311** object results in undefined behavior. 4312** 4313** ^These routines work just like the corresponding [column access functions] 4314** except that these routines take a single [protected sqlite3_value] object 4315** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4316** 4317** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4318** in the native byte-order of the host machine. ^The 4319** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4320** extract UTF-16 strings as big-endian and little-endian respectively. 4321** 4322** ^(The sqlite3_value_numeric_type() interface attempts to apply 4323** numeric affinity to the value. This means that an attempt is 4324** made to convert the value to an integer or floating point. If 4325** such a conversion is possible without loss of information (in other 4326** words, if the value is a string that looks like a number) 4327** then the conversion is performed. Otherwise no conversion occurs. 4328** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4329** 4330** Please pay particular attention to the fact that the pointer returned 4331** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4332** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4333** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4334** or [sqlite3_value_text16()]. 4335** 4336** These routines must be called from the same thread as 4337** the SQL function that supplied the [sqlite3_value*] parameters. 4338*/ 4339SQLITE_API const void *SQLITE_STDCALL sqlite3_value_blob(sqlite3_value*); 4340SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes(sqlite3_value*); 4341SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes16(sqlite3_value*); 4342SQLITE_API double SQLITE_STDCALL sqlite3_value_double(sqlite3_value*); 4343SQLITE_API int SQLITE_STDCALL sqlite3_value_int(sqlite3_value*); 4344SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_value_int64(sqlite3_value*); 4345SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_value_text(sqlite3_value*); 4346SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16(sqlite3_value*); 4347SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16le(sqlite3_value*); 4348SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16be(sqlite3_value*); 4349SQLITE_API int SQLITE_STDCALL sqlite3_value_type(sqlite3_value*); 4350SQLITE_API int SQLITE_STDCALL sqlite3_value_numeric_type(sqlite3_value*); 4351 4352/* 4353** CAPI3REF: Obtain Aggregate Function Context 4354** METHOD: sqlite3_context 4355** 4356** Implementations of aggregate SQL functions use this 4357** routine to allocate memory for storing their state. 4358** 4359** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4360** for a particular aggregate function, SQLite 4361** allocates N of memory, zeroes out that memory, and returns a pointer 4362** to the new memory. ^On second and subsequent calls to 4363** sqlite3_aggregate_context() for the same aggregate function instance, 4364** the same buffer is returned. Sqlite3_aggregate_context() is normally 4365** called once for each invocation of the xStep callback and then one 4366** last time when the xFinal callback is invoked. ^(When no rows match 4367** an aggregate query, the xStep() callback of the aggregate function 4368** implementation is never called and xFinal() is called exactly once. 4369** In those cases, sqlite3_aggregate_context() might be called for the 4370** first time from within xFinal().)^ 4371** 4372** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4373** when first called if N is less than or equal to zero or if a memory 4374** allocate error occurs. 4375** 4376** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4377** determined by the N parameter on first successful call. Changing the 4378** value of N in subsequent call to sqlite3_aggregate_context() within 4379** the same aggregate function instance will not resize the memory 4380** allocation.)^ Within the xFinal callback, it is customary to set 4381** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4382** pointless memory allocations occur. 4383** 4384** ^SQLite automatically frees the memory allocated by 4385** sqlite3_aggregate_context() when the aggregate query concludes. 4386** 4387** The first parameter must be a copy of the 4388** [sqlite3_context | SQL function context] that is the first parameter 4389** to the xStep or xFinal callback routine that implements the aggregate 4390** function. 4391** 4392** This routine must be called from the same thread in which 4393** the aggregate SQL function is running. 4394*/ 4395SQLITE_API void *SQLITE_STDCALL sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4396 4397/* 4398** CAPI3REF: User Data For Functions 4399** METHOD: sqlite3_context 4400** 4401** ^The sqlite3_user_data() interface returns a copy of 4402** the pointer that was the pUserData parameter (the 5th parameter) 4403** of the [sqlite3_create_function()] 4404** and [sqlite3_create_function16()] routines that originally 4405** registered the application defined function. 4406** 4407** This routine must be called from the same thread in which 4408** the application-defined function is running. 4409*/ 4410SQLITE_API void *SQLITE_STDCALL sqlite3_user_data(sqlite3_context*); 4411 4412/* 4413** CAPI3REF: Database Connection For Functions 4414** METHOD: sqlite3_context 4415** 4416** ^The sqlite3_context_db_handle() interface returns a copy of 4417** the pointer to the [database connection] (the 1st parameter) 4418** of the [sqlite3_create_function()] 4419** and [sqlite3_create_function16()] routines that originally 4420** registered the application defined function. 4421*/ 4422SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_context_db_handle(sqlite3_context*); 4423 4424/* 4425** CAPI3REF: Function Auxiliary Data 4426** METHOD: sqlite3_context 4427** 4428** These functions may be used by (non-aggregate) SQL functions to 4429** associate metadata with argument values. If the same value is passed to 4430** multiple invocations of the same SQL function during query execution, under 4431** some circumstances the associated metadata may be preserved. An example 4432** of where this might be useful is in a regular-expression matching 4433** function. The compiled version of the regular expression can be stored as 4434** metadata associated with the pattern string. 4435** Then as long as the pattern string remains the same, 4436** the compiled regular expression can be reused on multiple 4437** invocations of the same function. 4438** 4439** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4440** associated by the sqlite3_set_auxdata() function with the Nth argument 4441** value to the application-defined function. ^If there is no metadata 4442** associated with the function argument, this sqlite3_get_auxdata() interface 4443** returns a NULL pointer. 4444** 4445** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 4446** argument of the application-defined function. ^Subsequent 4447** calls to sqlite3_get_auxdata(C,N) return P from the most recent 4448** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 4449** NULL if the metadata has been discarded. 4450** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 4451** SQLite will invoke the destructor function X with parameter P exactly 4452** once, when the metadata is discarded. 4453** SQLite is free to discard the metadata at any time, including: <ul> 4454** <li> when the corresponding function parameter changes, or 4455** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 4456** SQL statement, or 4457** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or 4458** <li> during the original sqlite3_set_auxdata() call when a memory 4459** allocation error occurs. </ul>)^ 4460** 4461** Note the last bullet in particular. The destructor X in 4462** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 4463** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 4464** should be called near the end of the function implementation and the 4465** function implementation should not make any use of P after 4466** sqlite3_set_auxdata() has been called. 4467** 4468** ^(In practice, metadata is preserved between function calls for 4469** function parameters that are compile-time constants, including literal 4470** values and [parameters] and expressions composed from the same.)^ 4471** 4472** These routines must be called from the same thread in which 4473** the SQL function is running. 4474*/ 4475SQLITE_API void *SQLITE_STDCALL sqlite3_get_auxdata(sqlite3_context*, int N); 4476SQLITE_API void SQLITE_STDCALL sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4477 4478 4479/* 4480** CAPI3REF: Constants Defining Special Destructor Behavior 4481** 4482** These are special values for the destructor that is passed in as the 4483** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4484** argument is SQLITE_STATIC, it means that the content pointer is constant 4485** and will never change. It does not need to be destroyed. ^The 4486** SQLITE_TRANSIENT value means that the content will likely change in 4487** the near future and that SQLite should make its own private copy of 4488** the content before returning. 4489** 4490** The typedef is necessary to work around problems in certain 4491** C++ compilers. 4492*/ 4493typedef void (*sqlite3_destructor_type)(void*); 4494#define SQLITE_STATIC ((sqlite3_destructor_type)0) 4495#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4496 4497/* 4498** CAPI3REF: Setting The Result Of An SQL Function 4499** METHOD: sqlite3_context 4500** 4501** These routines are used by the xFunc or xFinal callbacks that 4502** implement SQL functions and aggregates. See 4503** [sqlite3_create_function()] and [sqlite3_create_function16()] 4504** for additional information. 4505** 4506** These functions work very much like the [parameter binding] family of 4507** functions used to bind values to host parameters in prepared statements. 4508** Refer to the [SQL parameter] documentation for additional information. 4509** 4510** ^The sqlite3_result_blob() interface sets the result from 4511** an application-defined function to be the BLOB whose content is pointed 4512** to by the second parameter and which is N bytes long where N is the 4513** third parameter. 4514** 4515** ^The sqlite3_result_zeroblob() interfaces set the result of 4516** the application-defined function to be a BLOB containing all zero 4517** bytes and N bytes in size, where N is the value of the 2nd parameter. 4518** 4519** ^The sqlite3_result_double() interface sets the result from 4520** an application-defined function to be a floating point value specified 4521** by its 2nd argument. 4522** 4523** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4524** cause the implemented SQL function to throw an exception. 4525** ^SQLite uses the string pointed to by the 4526** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4527** as the text of an error message. ^SQLite interprets the error 4528** message string from sqlite3_result_error() as UTF-8. ^SQLite 4529** interprets the string from sqlite3_result_error16() as UTF-16 in native 4530** byte order. ^If the third parameter to sqlite3_result_error() 4531** or sqlite3_result_error16() is negative then SQLite takes as the error 4532** message all text up through the first zero character. 4533** ^If the third parameter to sqlite3_result_error() or 4534** sqlite3_result_error16() is non-negative then SQLite takes that many 4535** bytes (not characters) from the 2nd parameter as the error message. 4536** ^The sqlite3_result_error() and sqlite3_result_error16() 4537** routines make a private copy of the error message text before 4538** they return. Hence, the calling function can deallocate or 4539** modify the text after they return without harm. 4540** ^The sqlite3_result_error_code() function changes the error code 4541** returned by SQLite as a result of an error in a function. ^By default, 4542** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4543** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4544** 4545** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4546** error indicating that a string or BLOB is too long to represent. 4547** 4548** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4549** error indicating that a memory allocation failed. 4550** 4551** ^The sqlite3_result_int() interface sets the return value 4552** of the application-defined function to be the 32-bit signed integer 4553** value given in the 2nd argument. 4554** ^The sqlite3_result_int64() interface sets the return value 4555** of the application-defined function to be the 64-bit signed integer 4556** value given in the 2nd argument. 4557** 4558** ^The sqlite3_result_null() interface sets the return value 4559** of the application-defined function to be NULL. 4560** 4561** ^The sqlite3_result_text(), sqlite3_result_text16(), 4562** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4563** set the return value of the application-defined function to be 4564** a text string which is represented as UTF-8, UTF-16 native byte order, 4565** UTF-16 little endian, or UTF-16 big endian, respectively. 4566** ^The sqlite3_result_text64() interface sets the return value of an 4567** application-defined function to be a text string in an encoding 4568** specified by the fifth (and last) parameter, which must be one 4569** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 4570** ^SQLite takes the text result from the application from 4571** the 2nd parameter of the sqlite3_result_text* interfaces. 4572** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4573** is negative, then SQLite takes result text from the 2nd parameter 4574** through the first zero character. 4575** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4576** is non-negative, then as many bytes (not characters) of the text 4577** pointed to by the 2nd parameter are taken as the application-defined 4578** function result. If the 3rd parameter is non-negative, then it 4579** must be the byte offset into the string where the NUL terminator would 4580** appear if the string where NUL terminated. If any NUL characters occur 4581** in the string at a byte offset that is less than the value of the 3rd 4582** parameter, then the resulting string will contain embedded NULs and the 4583** result of expressions operating on strings with embedded NULs is undefined. 4584** ^If the 4th parameter to the sqlite3_result_text* interfaces 4585** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4586** function as the destructor on the text or BLOB result when it has 4587** finished using that result. 4588** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4589** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4590** assumes that the text or BLOB result is in constant space and does not 4591** copy the content of the parameter nor call a destructor on the content 4592** when it has finished using that result. 4593** ^If the 4th parameter to the sqlite3_result_text* interfaces 4594** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4595** then SQLite makes a copy of the result into space obtained from 4596** from [sqlite3_malloc()] before it returns. 4597** 4598** ^The sqlite3_result_value() interface sets the result of 4599** the application-defined function to be a copy the 4600** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4601** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4602** so that the [sqlite3_value] specified in the parameter may change or 4603** be deallocated after sqlite3_result_value() returns without harm. 4604** ^A [protected sqlite3_value] object may always be used where an 4605** [unprotected sqlite3_value] object is required, so either 4606** kind of [sqlite3_value] object can be used with this interface. 4607** 4608** If these routines are called from within the different thread 4609** than the one containing the application-defined function that received 4610** the [sqlite3_context] pointer, the results are undefined. 4611*/ 4612SQLITE_API void SQLITE_STDCALL sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4613SQLITE_API void SQLITE_STDCALL sqlite3_result_blob64(sqlite3_context*,const void*, 4614 sqlite3_uint64,void(*)(void*)); 4615SQLITE_API void SQLITE_STDCALL sqlite3_result_double(sqlite3_context*, double); 4616SQLITE_API void SQLITE_STDCALL sqlite3_result_error(sqlite3_context*, const char*, int); 4617SQLITE_API void SQLITE_STDCALL sqlite3_result_error16(sqlite3_context*, const void*, int); 4618SQLITE_API void SQLITE_STDCALL sqlite3_result_error_toobig(sqlite3_context*); 4619SQLITE_API void SQLITE_STDCALL sqlite3_result_error_nomem(sqlite3_context*); 4620SQLITE_API void SQLITE_STDCALL sqlite3_result_error_code(sqlite3_context*, int); 4621SQLITE_API void SQLITE_STDCALL sqlite3_result_int(sqlite3_context*, int); 4622SQLITE_API void SQLITE_STDCALL sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4623SQLITE_API void SQLITE_STDCALL sqlite3_result_null(sqlite3_context*); 4624SQLITE_API void SQLITE_STDCALL sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4625SQLITE_API void SQLITE_STDCALL sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 4626 void(*)(void*), unsigned char encoding); 4627SQLITE_API void SQLITE_STDCALL sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4628SQLITE_API void SQLITE_STDCALL sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4629SQLITE_API void SQLITE_STDCALL sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4630SQLITE_API void SQLITE_STDCALL sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4631SQLITE_API void SQLITE_STDCALL sqlite3_result_zeroblob(sqlite3_context*, int n); 4632 4633/* 4634** CAPI3REF: Define New Collating Sequences 4635** METHOD: sqlite3 4636** 4637** ^These functions add, remove, or modify a [collation] associated 4638** with the [database connection] specified as the first argument. 4639** 4640** ^The name of the collation is a UTF-8 string 4641** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4642** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4643** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4644** considered to be the same name. 4645** 4646** ^(The third argument (eTextRep) must be one of the constants: 4647** <ul> 4648** <li> [SQLITE_UTF8], 4649** <li> [SQLITE_UTF16LE], 4650** <li> [SQLITE_UTF16BE], 4651** <li> [SQLITE_UTF16], or 4652** <li> [SQLITE_UTF16_ALIGNED]. 4653** </ul>)^ 4654** ^The eTextRep argument determines the encoding of strings passed 4655** to the collating function callback, xCallback. 4656** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4657** force strings to be UTF16 with native byte order. 4658** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4659** on an even byte address. 4660** 4661** ^The fourth argument, pArg, is an application data pointer that is passed 4662** through as the first argument to the collating function callback. 4663** 4664** ^The fifth argument, xCallback, is a pointer to the collating function. 4665** ^Multiple collating functions can be registered using the same name but 4666** with different eTextRep parameters and SQLite will use whichever 4667** function requires the least amount of data transformation. 4668** ^If the xCallback argument is NULL then the collating function is 4669** deleted. ^When all collating functions having the same name are deleted, 4670** that collation is no longer usable. 4671** 4672** ^The collating function callback is invoked with a copy of the pArg 4673** application data pointer and with two strings in the encoding specified 4674** by the eTextRep argument. The collating function must return an 4675** integer that is negative, zero, or positive 4676** if the first string is less than, equal to, or greater than the second, 4677** respectively. A collating function must always return the same answer 4678** given the same inputs. If two or more collating functions are registered 4679** to the same collation name (using different eTextRep values) then all 4680** must give an equivalent answer when invoked with equivalent strings. 4681** The collating function must obey the following properties for all 4682** strings A, B, and C: 4683** 4684** <ol> 4685** <li> If A==B then B==A. 4686** <li> If A==B and B==C then A==C. 4687** <li> If A<B THEN B>A. 4688** <li> If A<B and B<C then A<C. 4689** </ol> 4690** 4691** If a collating function fails any of the above constraints and that 4692** collating function is registered and used, then the behavior of SQLite 4693** is undefined. 4694** 4695** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4696** with the addition that the xDestroy callback is invoked on pArg when 4697** the collating function is deleted. 4698** ^Collating functions are deleted when they are overridden by later 4699** calls to the collation creation functions or when the 4700** [database connection] is closed using [sqlite3_close()]. 4701** 4702** ^The xDestroy callback is <u>not</u> called if the 4703** sqlite3_create_collation_v2() function fails. Applications that invoke 4704** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 4705** check the return code and dispose of the application data pointer 4706** themselves rather than expecting SQLite to deal with it for them. 4707** This is different from every other SQLite interface. The inconsistency 4708** is unfortunate but cannot be changed without breaking backwards 4709** compatibility. 4710** 4711** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 4712*/ 4713SQLITE_API int SQLITE_STDCALL sqlite3_create_collation( 4714 sqlite3*, 4715 const char *zName, 4716 int eTextRep, 4717 void *pArg, 4718 int(*xCompare)(void*,int,const void*,int,const void*) 4719); 4720SQLITE_API int SQLITE_STDCALL sqlite3_create_collation_v2( 4721 sqlite3*, 4722 const char *zName, 4723 int eTextRep, 4724 void *pArg, 4725 int(*xCompare)(void*,int,const void*,int,const void*), 4726 void(*xDestroy)(void*) 4727); 4728SQLITE_API int SQLITE_STDCALL sqlite3_create_collation16( 4729 sqlite3*, 4730 const void *zName, 4731 int eTextRep, 4732 void *pArg, 4733 int(*xCompare)(void*,int,const void*,int,const void*) 4734); 4735 4736/* 4737** CAPI3REF: Collation Needed Callbacks 4738** METHOD: sqlite3 4739** 4740** ^To avoid having to register all collation sequences before a database 4741** can be used, a single callback function may be registered with the 4742** [database connection] to be invoked whenever an undefined collation 4743** sequence is required. 4744** 4745** ^If the function is registered using the sqlite3_collation_needed() API, 4746** then it is passed the names of undefined collation sequences as strings 4747** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 4748** the names are passed as UTF-16 in machine native byte order. 4749** ^A call to either function replaces the existing collation-needed callback. 4750** 4751** ^(When the callback is invoked, the first argument passed is a copy 4752** of the second argument to sqlite3_collation_needed() or 4753** sqlite3_collation_needed16(). The second argument is the database 4754** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 4755** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 4756** sequence function required. The fourth parameter is the name of the 4757** required collation sequence.)^ 4758** 4759** The callback function should register the desired collation using 4760** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 4761** [sqlite3_create_collation_v2()]. 4762*/ 4763SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed( 4764 sqlite3*, 4765 void*, 4766 void(*)(void*,sqlite3*,int eTextRep,const char*) 4767); 4768SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed16( 4769 sqlite3*, 4770 void*, 4771 void(*)(void*,sqlite3*,int eTextRep,const void*) 4772); 4773 4774#ifdef SQLITE_HAS_CODEC 4775/* 4776** Specify the key for an encrypted database. This routine should be 4777** called right after sqlite3_open(). 4778** 4779** The code to implement this API is not available in the public release 4780** of SQLite. 4781*/ 4782SQLITE_API int SQLITE_STDCALL sqlite3_key( 4783 sqlite3 *db, /* Database to be rekeyed */ 4784 const void *pKey, int nKey /* The key */ 4785); 4786SQLITE_API int SQLITE_STDCALL sqlite3_key_v2( 4787 sqlite3 *db, /* Database to be rekeyed */ 4788 const char *zDbName, /* Name of the database */ 4789 const void *pKey, int nKey /* The key */ 4790); 4791 4792/* 4793** Change the key on an open database. If the current database is not 4794** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 4795** database is decrypted. 4796** 4797** The code to implement this API is not available in the public release 4798** of SQLite. 4799*/ 4800SQLITE_API int SQLITE_STDCALL sqlite3_rekey( 4801 sqlite3 *db, /* Database to be rekeyed */ 4802 const void *pKey, int nKey /* The new key */ 4803); 4804SQLITE_API int SQLITE_STDCALL sqlite3_rekey_v2( 4805 sqlite3 *db, /* Database to be rekeyed */ 4806 const char *zDbName, /* Name of the database */ 4807 const void *pKey, int nKey /* The new key */ 4808); 4809 4810/* 4811** Specify the activation key for a SEE database. Unless 4812** activated, none of the SEE routines will work. 4813*/ 4814SQLITE_API void SQLITE_STDCALL sqlite3_activate_see( 4815 const char *zPassPhrase /* Activation phrase */ 4816); 4817#endif 4818 4819#ifdef SQLITE_ENABLE_CEROD 4820/* 4821** Specify the activation key for a CEROD database. Unless 4822** activated, none of the CEROD routines will work. 4823*/ 4824SQLITE_API void SQLITE_STDCALL sqlite3_activate_cerod( 4825 const char *zPassPhrase /* Activation phrase */ 4826); 4827#endif 4828 4829/* 4830** CAPI3REF: Suspend Execution For A Short Time 4831** 4832** The sqlite3_sleep() function causes the current thread to suspend execution 4833** for at least a number of milliseconds specified in its parameter. 4834** 4835** If the operating system does not support sleep requests with 4836** millisecond time resolution, then the time will be rounded up to 4837** the nearest second. The number of milliseconds of sleep actually 4838** requested from the operating system is returned. 4839** 4840** ^SQLite implements this interface by calling the xSleep() 4841** method of the default [sqlite3_vfs] object. If the xSleep() method 4842** of the default VFS is not implemented correctly, or not implemented at 4843** all, then the behavior of sqlite3_sleep() may deviate from the description 4844** in the previous paragraphs. 4845*/ 4846SQLITE_API int SQLITE_STDCALL sqlite3_sleep(int); 4847 4848/* 4849** CAPI3REF: Name Of The Folder Holding Temporary Files 4850** 4851** ^(If this global variable is made to point to a string which is 4852** the name of a folder (a.k.a. directory), then all temporary files 4853** created by SQLite when using a built-in [sqlite3_vfs | VFS] 4854** will be placed in that directory.)^ ^If this variable 4855** is a NULL pointer, then SQLite performs a search for an appropriate 4856** temporary file directory. 4857** 4858** Applications are strongly discouraged from using this global variable. 4859** It is required to set a temporary folder on Windows Runtime (WinRT). 4860** But for all other platforms, it is highly recommended that applications 4861** neither read nor write this variable. This global variable is a relic 4862** that exists for backwards compatibility of legacy applications and should 4863** be avoided in new projects. 4864** 4865** It is not safe to read or modify this variable in more than one 4866** thread at a time. It is not safe to read or modify this variable 4867** if a [database connection] is being used at the same time in a separate 4868** thread. 4869** It is intended that this variable be set once 4870** as part of process initialization and before any SQLite interface 4871** routines have been called and that this variable remain unchanged 4872** thereafter. 4873** 4874** ^The [temp_store_directory pragma] may modify this variable and cause 4875** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4876** the [temp_store_directory pragma] always assumes that any string 4877** that this variable points to is held in memory obtained from 4878** [sqlite3_malloc] and the pragma may attempt to free that memory 4879** using [sqlite3_free]. 4880** Hence, if this variable is modified directly, either it should be 4881** made NULL or made to point to memory obtained from [sqlite3_malloc] 4882** or else the use of the [temp_store_directory pragma] should be avoided. 4883** Except when requested by the [temp_store_directory pragma], SQLite 4884** does not free the memory that sqlite3_temp_directory points to. If 4885** the application wants that memory to be freed, it must do 4886** so itself, taking care to only do so after all [database connection] 4887** objects have been destroyed. 4888** 4889** <b>Note to Windows Runtime users:</b> The temporary directory must be set 4890** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 4891** features that require the use of temporary files may fail. Here is an 4892** example of how to do this using C++ with the Windows Runtime: 4893** 4894** <blockquote><pre> 4895** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 4896** TemporaryFolder->Path->Data(); 4897** char zPathBuf[MAX_PATH + 1]; 4898** memset(zPathBuf, 0, sizeof(zPathBuf)); 4899** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 4900** NULL, NULL); 4901** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 4902** </pre></blockquote> 4903*/ 4904SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 4905 4906/* 4907** CAPI3REF: Name Of The Folder Holding Database Files 4908** 4909** ^(If this global variable is made to point to a string which is 4910** the name of a folder (a.k.a. directory), then all database files 4911** specified with a relative pathname and created or accessed by 4912** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 4913** to be relative to that directory.)^ ^If this variable is a NULL 4914** pointer, then SQLite assumes that all database files specified 4915** with a relative pathname are relative to the current directory 4916** for the process. Only the windows VFS makes use of this global 4917** variable; it is ignored by the unix VFS. 4918** 4919** Changing the value of this variable while a database connection is 4920** open can result in a corrupt database. 4921** 4922** It is not safe to read or modify this variable in more than one 4923** thread at a time. It is not safe to read or modify this variable 4924** if a [database connection] is being used at the same time in a separate 4925** thread. 4926** It is intended that this variable be set once 4927** as part of process initialization and before any SQLite interface 4928** routines have been called and that this variable remain unchanged 4929** thereafter. 4930** 4931** ^The [data_store_directory pragma] may modify this variable and cause 4932** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4933** the [data_store_directory pragma] always assumes that any string 4934** that this variable points to is held in memory obtained from 4935** [sqlite3_malloc] and the pragma may attempt to free that memory 4936** using [sqlite3_free]. 4937** Hence, if this variable is modified directly, either it should be 4938** made NULL or made to point to memory obtained from [sqlite3_malloc] 4939** or else the use of the [data_store_directory pragma] should be avoided. 4940*/ 4941SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 4942 4943/* 4944** CAPI3REF: Test For Auto-Commit Mode 4945** KEYWORDS: {autocommit mode} 4946** METHOD: sqlite3 4947** 4948** ^The sqlite3_get_autocommit() interface returns non-zero or 4949** zero if the given database connection is or is not in autocommit mode, 4950** respectively. ^Autocommit mode is on by default. 4951** ^Autocommit mode is disabled by a [BEGIN] statement. 4952** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 4953** 4954** If certain kinds of errors occur on a statement within a multi-statement 4955** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 4956** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 4957** transaction might be rolled back automatically. The only way to 4958** find out whether SQLite automatically rolled back the transaction after 4959** an error is to use this function. 4960** 4961** If another thread changes the autocommit status of the database 4962** connection while this routine is running, then the return value 4963** is undefined. 4964*/ 4965SQLITE_API int SQLITE_STDCALL sqlite3_get_autocommit(sqlite3*); 4966 4967/* 4968** CAPI3REF: Find The Database Handle Of A Prepared Statement 4969** METHOD: sqlite3_stmt 4970** 4971** ^The sqlite3_db_handle interface returns the [database connection] handle 4972** to which a [prepared statement] belongs. ^The [database connection] 4973** returned by sqlite3_db_handle is the same [database connection] 4974** that was the first argument 4975** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 4976** create the statement in the first place. 4977*/ 4978SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_db_handle(sqlite3_stmt*); 4979 4980/* 4981** CAPI3REF: Return The Filename For A Database Connection 4982** METHOD: sqlite3 4983** 4984** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 4985** associated with database N of connection D. ^The main database file 4986** has the name "main". If there is no attached database N on the database 4987** connection D, or if database N is a temporary or in-memory database, then 4988** a NULL pointer is returned. 4989** 4990** ^The filename returned by this function is the output of the 4991** xFullPathname method of the [VFS]. ^In other words, the filename 4992** will be an absolute pathname, even if the filename used 4993** to open the database originally was a URI or relative pathname. 4994*/ 4995SQLITE_API const char *SQLITE_STDCALL sqlite3_db_filename(sqlite3 *db, const char *zDbName); 4996 4997/* 4998** CAPI3REF: Determine if a database is read-only 4999** METHOD: sqlite3 5000** 5001** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5002** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5003** the name of a database on connection D. 5004*/ 5005SQLITE_API int SQLITE_STDCALL sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5006 5007/* 5008** CAPI3REF: Find the next prepared statement 5009** METHOD: sqlite3 5010** 5011** ^This interface returns a pointer to the next [prepared statement] after 5012** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5013** then this interface returns a pointer to the first prepared statement 5014** associated with the database connection pDb. ^If no prepared statement 5015** satisfies the conditions of this routine, it returns NULL. 5016** 5017** The [database connection] pointer D in a call to 5018** [sqlite3_next_stmt(D,S)] must refer to an open database 5019** connection and in particular must not be a NULL pointer. 5020*/ 5021SQLITE_API sqlite3_stmt *SQLITE_STDCALL sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5022 5023/* 5024** CAPI3REF: Commit And Rollback Notification Callbacks 5025** METHOD: sqlite3 5026** 5027** ^The sqlite3_commit_hook() interface registers a callback 5028** function to be invoked whenever a transaction is [COMMIT | committed]. 5029** ^Any callback set by a previous call to sqlite3_commit_hook() 5030** for the same database connection is overridden. 5031** ^The sqlite3_rollback_hook() interface registers a callback 5032** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5033** ^Any callback set by a previous call to sqlite3_rollback_hook() 5034** for the same database connection is overridden. 5035** ^The pArg argument is passed through to the callback. 5036** ^If the callback on a commit hook function returns non-zero, 5037** then the commit is converted into a rollback. 5038** 5039** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5040** return the P argument from the previous call of the same function 5041** on the same [database connection] D, or NULL for 5042** the first call for each function on D. 5043** 5044** The commit and rollback hook callbacks are not reentrant. 5045** The callback implementation must not do anything that will modify 5046** the database connection that invoked the callback. Any actions 5047** to modify the database connection must be deferred until after the 5048** completion of the [sqlite3_step()] call that triggered the commit 5049** or rollback hook in the first place. 5050** Note that running any other SQL statements, including SELECT statements, 5051** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5052** the database connections for the meaning of "modify" in this paragraph. 5053** 5054** ^Registering a NULL function disables the callback. 5055** 5056** ^When the commit hook callback routine returns zero, the [COMMIT] 5057** operation is allowed to continue normally. ^If the commit hook 5058** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5059** ^The rollback hook is invoked on a rollback that results from a commit 5060** hook returning non-zero, just as it would be with any other rollback. 5061** 5062** ^For the purposes of this API, a transaction is said to have been 5063** rolled back if an explicit "ROLLBACK" statement is executed, or 5064** an error or constraint causes an implicit rollback to occur. 5065** ^The rollback callback is not invoked if a transaction is 5066** automatically rolled back because the database connection is closed. 5067** 5068** See also the [sqlite3_update_hook()] interface. 5069*/ 5070SQLITE_API void *SQLITE_STDCALL sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5071SQLITE_API void *SQLITE_STDCALL sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5072 5073/* 5074** CAPI3REF: Data Change Notification Callbacks 5075** METHOD: sqlite3 5076** 5077** ^The sqlite3_update_hook() interface registers a callback function 5078** with the [database connection] identified by the first argument 5079** to be invoked whenever a row is updated, inserted or deleted in 5080** a rowid table. 5081** ^Any callback set by a previous call to this function 5082** for the same database connection is overridden. 5083** 5084** ^The second argument is a pointer to the function to invoke when a 5085** row is updated, inserted or deleted in a rowid table. 5086** ^The first argument to the callback is a copy of the third argument 5087** to sqlite3_update_hook(). 5088** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5089** or [SQLITE_UPDATE], depending on the operation that caused the callback 5090** to be invoked. 5091** ^The third and fourth arguments to the callback contain pointers to the 5092** database and table name containing the affected row. 5093** ^The final callback parameter is the [rowid] of the row. 5094** ^In the case of an update, this is the [rowid] after the update takes place. 5095** 5096** ^(The update hook is not invoked when internal system tables are 5097** modified (i.e. sqlite_master and sqlite_sequence).)^ 5098** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5099** 5100** ^In the current implementation, the update hook 5101** is not invoked when duplication rows are deleted because of an 5102** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5103** invoked when rows are deleted using the [truncate optimization]. 5104** The exceptions defined in this paragraph might change in a future 5105** release of SQLite. 5106** 5107** The update hook implementation must not do anything that will modify 5108** the database connection that invoked the update hook. Any actions 5109** to modify the database connection must be deferred until after the 5110** completion of the [sqlite3_step()] call that triggered the update hook. 5111** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5112** database connections for the meaning of "modify" in this paragraph. 5113** 5114** ^The sqlite3_update_hook(D,C,P) function 5115** returns the P argument from the previous call 5116** on the same [database connection] D, or NULL for 5117** the first call on D. 5118** 5119** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] 5120** interfaces. 5121*/ 5122SQLITE_API void *SQLITE_STDCALL sqlite3_update_hook( 5123 sqlite3*, 5124 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5125 void* 5126); 5127 5128/* 5129** CAPI3REF: Enable Or Disable Shared Pager Cache 5130** 5131** ^(This routine enables or disables the sharing of the database cache 5132** and schema data structures between [database connection | connections] 5133** to the same database. Sharing is enabled if the argument is true 5134** and disabled if the argument is false.)^ 5135** 5136** ^Cache sharing is enabled and disabled for an entire process. 5137** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 5138** sharing was enabled or disabled for each thread separately. 5139** 5140** ^(The cache sharing mode set by this interface effects all subsequent 5141** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5142** Existing database connections continue use the sharing mode 5143** that was in effect at the time they were opened.)^ 5144** 5145** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5146** successfully. An [error code] is returned otherwise.)^ 5147** 5148** ^Shared cache is disabled by default. But this might change in 5149** future releases of SQLite. Applications that care about shared 5150** cache setting should set it explicitly. 5151** 5152** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5153** and will always return SQLITE_MISUSE. On those systems, 5154** shared cache mode should be enabled per-database connection via 5155** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5156** 5157** This interface is threadsafe on processors where writing a 5158** 32-bit integer is atomic. 5159** 5160** See Also: [SQLite Shared-Cache Mode] 5161*/ 5162SQLITE_API int SQLITE_STDCALL sqlite3_enable_shared_cache(int); 5163 5164/* 5165** CAPI3REF: Attempt To Free Heap Memory 5166** 5167** ^The sqlite3_release_memory() interface attempts to free N bytes 5168** of heap memory by deallocating non-essential memory allocations 5169** held by the database library. Memory used to cache database 5170** pages to improve performance is an example of non-essential memory. 5171** ^sqlite3_release_memory() returns the number of bytes actually freed, 5172** which might be more or less than the amount requested. 5173** ^The sqlite3_release_memory() routine is a no-op returning zero 5174** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5175** 5176** See also: [sqlite3_db_release_memory()] 5177*/ 5178SQLITE_API int SQLITE_STDCALL sqlite3_release_memory(int); 5179 5180/* 5181** CAPI3REF: Free Memory Used By A Database Connection 5182** METHOD: sqlite3 5183** 5184** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5185** memory as possible from database connection D. Unlike the 5186** [sqlite3_release_memory()] interface, this interface is in effect even 5187** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5188** omitted. 5189** 5190** See also: [sqlite3_release_memory()] 5191*/ 5192SQLITE_API int SQLITE_STDCALL sqlite3_db_release_memory(sqlite3*); 5193 5194/* 5195** CAPI3REF: Impose A Limit On Heap Size 5196** 5197** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5198** soft limit on the amount of heap memory that may be allocated by SQLite. 5199** ^SQLite strives to keep heap memory utilization below the soft heap 5200** limit by reducing the number of pages held in the page cache 5201** as heap memory usages approaches the limit. 5202** ^The soft heap limit is "soft" because even though SQLite strives to stay 5203** below the limit, it will exceed the limit rather than generate 5204** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5205** is advisory only. 5206** 5207** ^The return value from sqlite3_soft_heap_limit64() is the size of 5208** the soft heap limit prior to the call, or negative in the case of an 5209** error. ^If the argument N is negative 5210** then no change is made to the soft heap limit. Hence, the current 5211** size of the soft heap limit can be determined by invoking 5212** sqlite3_soft_heap_limit64() with a negative argument. 5213** 5214** ^If the argument N is zero then the soft heap limit is disabled. 5215** 5216** ^(The soft heap limit is not enforced in the current implementation 5217** if one or more of following conditions are true: 5218** 5219** <ul> 5220** <li> The soft heap limit is set to zero. 5221** <li> Memory accounting is disabled using a combination of the 5222** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5223** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5224** <li> An alternative page cache implementation is specified using 5225** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5226** <li> The page cache allocates from its own memory pool supplied 5227** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5228** from the heap. 5229** </ul>)^ 5230** 5231** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 5232** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5233** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5234** the soft heap limit is enforced on every memory allocation. Without 5235** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5236** when memory is allocated by the page cache. Testing suggests that because 5237** the page cache is the predominate memory user in SQLite, most 5238** applications will achieve adequate soft heap limit enforcement without 5239** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5240** 5241** The circumstances under which SQLite will enforce the soft heap limit may 5242** changes in future releases of SQLite. 5243*/ 5244SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_soft_heap_limit64(sqlite3_int64 N); 5245 5246/* 5247** CAPI3REF: Deprecated Soft Heap Limit Interface 5248** DEPRECATED 5249** 5250** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5251** interface. This routine is provided for historical compatibility 5252** only. All new applications should use the 5253** [sqlite3_soft_heap_limit64()] interface rather than this one. 5254*/ 5255SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_soft_heap_limit(int N); 5256 5257 5258/* 5259** CAPI3REF: Extract Metadata About A Column Of A Table 5260** METHOD: sqlite3 5261** 5262** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 5263** information about column C of table T in database D 5264** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 5265** interface returns SQLITE_OK and fills in the non-NULL pointers in 5266** the final five arguments with appropriate values if the specified 5267** column exists. ^The sqlite3_table_column_metadata() interface returns 5268** SQLITE_ERROR and if the specified column does not exist. 5269** ^If the column-name parameter to sqlite3_table_column_metadata() is a 5270** NULL pointer, then this routine simply checks for the existance of the 5271** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 5272** does not. 5273** 5274** ^The column is identified by the second, third and fourth parameters to 5275** this function. ^(The second parameter is either the name of the database 5276** (i.e. "main", "temp", or an attached database) containing the specified 5277** table or NULL.)^ ^If it is NULL, then all attached databases are searched 5278** for the table using the same algorithm used by the database engine to 5279** resolve unqualified table references. 5280** 5281** ^The third and fourth parameters to this function are the table and column 5282** name of the desired column, respectively. 5283** 5284** ^Metadata is returned by writing to the memory locations passed as the 5th 5285** and subsequent parameters to this function. ^Any of these arguments may be 5286** NULL, in which case the corresponding element of metadata is omitted. 5287** 5288** ^(<blockquote> 5289** <table border="1"> 5290** <tr><th> Parameter <th> Output<br>Type <th> Description 5291** 5292** <tr><td> 5th <td> const char* <td> Data type 5293** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5294** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5295** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5296** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5297** </table> 5298** </blockquote>)^ 5299** 5300** ^The memory pointed to by the character pointers returned for the 5301** declaration type and collation sequence is valid until the next 5302** call to any SQLite API function. 5303** 5304** ^If the specified table is actually a view, an [error code] is returned. 5305** 5306** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 5307** is not a [WITHOUT ROWID] table and an 5308** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5309** parameters are set for the explicitly declared column. ^(If there is no 5310** [INTEGER PRIMARY KEY] column, then the outputs 5311** for the [rowid] are set as follows: 5312** 5313** <pre> 5314** data type: "INTEGER" 5315** collation sequence: "BINARY" 5316** not null: 0 5317** primary key: 1 5318** auto increment: 0 5319** </pre>)^ 5320** 5321** ^This function causes all database schemas to be read from disk and 5322** parsed, if that has not already been done, and returns an error if 5323** any errors are encountered while loading the schema. 5324*/ 5325SQLITE_API int SQLITE_STDCALL sqlite3_table_column_metadata( 5326 sqlite3 *db, /* Connection handle */ 5327 const char *zDbName, /* Database name or NULL */ 5328 const char *zTableName, /* Table name */ 5329 const char *zColumnName, /* Column name */ 5330 char const **pzDataType, /* OUTPUT: Declared data type */ 5331 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5332 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5333 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5334 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5335); 5336 5337/* 5338** CAPI3REF: Load An Extension 5339** METHOD: sqlite3 5340** 5341** ^This interface loads an SQLite extension library from the named file. 5342** 5343** ^The sqlite3_load_extension() interface attempts to load an 5344** [SQLite extension] library contained in the file zFile. If 5345** the file cannot be loaded directly, attempts are made to load 5346** with various operating-system specific extensions added. 5347** So for example, if "samplelib" cannot be loaded, then names like 5348** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5349** be tried also. 5350** 5351** ^The entry point is zProc. 5352** ^(zProc may be 0, in which case SQLite will try to come up with an 5353** entry point name on its own. It first tries "sqlite3_extension_init". 5354** If that does not work, it constructs a name "sqlite3_X_init" where the 5355** X is consists of the lower-case equivalent of all ASCII alphabetic 5356** characters in the filename from the last "/" to the first following 5357** "." and omitting any initial "lib".)^ 5358** ^The sqlite3_load_extension() interface returns 5359** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5360** ^If an error occurs and pzErrMsg is not 0, then the 5361** [sqlite3_load_extension()] interface shall attempt to 5362** fill *pzErrMsg with error message text stored in memory 5363** obtained from [sqlite3_malloc()]. The calling function 5364** should free this memory by calling [sqlite3_free()]. 5365** 5366** ^Extension loading must be enabled using 5367** [sqlite3_enable_load_extension()] prior to calling this API, 5368** otherwise an error will be returned. 5369** 5370** See also the [load_extension() SQL function]. 5371*/ 5372SQLITE_API int SQLITE_STDCALL sqlite3_load_extension( 5373 sqlite3 *db, /* Load the extension into this database connection */ 5374 const char *zFile, /* Name of the shared library containing extension */ 5375 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5376 char **pzErrMsg /* Put error message here if not 0 */ 5377); 5378 5379/* 5380** CAPI3REF: Enable Or Disable Extension Loading 5381** METHOD: sqlite3 5382** 5383** ^So as not to open security holes in older applications that are 5384** unprepared to deal with [extension loading], and as a means of disabling 5385** [extension loading] while evaluating user-entered SQL, the following API 5386** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5387** 5388** ^Extension loading is off by default. 5389** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5390** to turn extension loading on and call it with onoff==0 to turn 5391** it back off again. 5392*/ 5393SQLITE_API int SQLITE_STDCALL sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5394 5395/* 5396** CAPI3REF: Automatically Load Statically Linked Extensions 5397** 5398** ^This interface causes the xEntryPoint() function to be invoked for 5399** each new [database connection] that is created. The idea here is that 5400** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5401** that is to be automatically loaded into all new database connections. 5402** 5403** ^(Even though the function prototype shows that xEntryPoint() takes 5404** no arguments and returns void, SQLite invokes xEntryPoint() with three 5405** arguments and expects and integer result as if the signature of the 5406** entry point where as follows: 5407** 5408** <blockquote><pre> 5409** int xEntryPoint( 5410** sqlite3 *db, 5411** const char **pzErrMsg, 5412** const struct sqlite3_api_routines *pThunk 5413** ); 5414** </pre></blockquote>)^ 5415** 5416** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5417** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5418** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5419** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5420** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5421** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5422** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5423** 5424** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5425** on the list of automatic extensions is a harmless no-op. ^No entry point 5426** will be called more than once for each database connection that is opened. 5427** 5428** See also: [sqlite3_reset_auto_extension()] 5429** and [sqlite3_cancel_auto_extension()] 5430*/ 5431SQLITE_API int SQLITE_STDCALL sqlite3_auto_extension(void (*xEntryPoint)(void)); 5432 5433/* 5434** CAPI3REF: Cancel Automatic Extension Loading 5435** 5436** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 5437** initialization routine X that was registered using a prior call to 5438** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 5439** routine returns 1 if initialization routine X was successfully 5440** unregistered and it returns 0 if X was not on the list of initialization 5441** routines. 5442*/ 5443SQLITE_API int SQLITE_STDCALL sqlite3_cancel_auto_extension(void (*xEntryPoint)(void)); 5444 5445/* 5446** CAPI3REF: Reset Automatic Extension Loading 5447** 5448** ^This interface disables all automatic extensions previously 5449** registered using [sqlite3_auto_extension()]. 5450*/ 5451SQLITE_API void SQLITE_STDCALL sqlite3_reset_auto_extension(void); 5452 5453/* 5454** The interface to the virtual-table mechanism is currently considered 5455** to be experimental. The interface might change in incompatible ways. 5456** If this is a problem for you, do not use the interface at this time. 5457** 5458** When the virtual-table mechanism stabilizes, we will declare the 5459** interface fixed, support it indefinitely, and remove this comment. 5460*/ 5461 5462/* 5463** Structures used by the virtual table interface 5464*/ 5465typedef struct sqlite3_vtab sqlite3_vtab; 5466typedef struct sqlite3_index_info sqlite3_index_info; 5467typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5468typedef struct sqlite3_module sqlite3_module; 5469 5470/* 5471** CAPI3REF: Virtual Table Object 5472** KEYWORDS: sqlite3_module {virtual table module} 5473** 5474** This structure, sometimes called a "virtual table module", 5475** defines the implementation of a [virtual tables]. 5476** This structure consists mostly of methods for the module. 5477** 5478** ^A virtual table module is created by filling in a persistent 5479** instance of this structure and passing a pointer to that instance 5480** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5481** ^The registration remains valid until it is replaced by a different 5482** module or until the [database connection] closes. The content 5483** of this structure must not change while it is registered with 5484** any database connection. 5485*/ 5486struct sqlite3_module { 5487 int iVersion; 5488 int (*xCreate)(sqlite3*, void *pAux, 5489 int argc, const char *const*argv, 5490 sqlite3_vtab **ppVTab, char**); 5491 int (*xConnect)(sqlite3*, void *pAux, 5492 int argc, const char *const*argv, 5493 sqlite3_vtab **ppVTab, char**); 5494 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5495 int (*xDisconnect)(sqlite3_vtab *pVTab); 5496 int (*xDestroy)(sqlite3_vtab *pVTab); 5497 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5498 int (*xClose)(sqlite3_vtab_cursor*); 5499 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5500 int argc, sqlite3_value **argv); 5501 int (*xNext)(sqlite3_vtab_cursor*); 5502 int (*xEof)(sqlite3_vtab_cursor*); 5503 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5504 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5505 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5506 int (*xBegin)(sqlite3_vtab *pVTab); 5507 int (*xSync)(sqlite3_vtab *pVTab); 5508 int (*xCommit)(sqlite3_vtab *pVTab); 5509 int (*xRollback)(sqlite3_vtab *pVTab); 5510 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5511 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5512 void **ppArg); 5513 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5514 /* The methods above are in version 1 of the sqlite_module object. Those 5515 ** below are for version 2 and greater. */ 5516 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5517 int (*xRelease)(sqlite3_vtab *pVTab, int); 5518 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5519}; 5520 5521/* 5522** CAPI3REF: Virtual Table Indexing Information 5523** KEYWORDS: sqlite3_index_info 5524** 5525** The sqlite3_index_info structure and its substructures is used as part 5526** of the [virtual table] interface to 5527** pass information into and receive the reply from the [xBestIndex] 5528** method of a [virtual table module]. The fields under **Inputs** are the 5529** inputs to xBestIndex and are read-only. xBestIndex inserts its 5530** results into the **Outputs** fields. 5531** 5532** ^(The aConstraint[] array records WHERE clause constraints of the form: 5533** 5534** <blockquote>column OP expr</blockquote> 5535** 5536** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5537** stored in aConstraint[].op using one of the 5538** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5539** ^(The index of the column is stored in 5540** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5541** expr on the right-hand side can be evaluated (and thus the constraint 5542** is usable) and false if it cannot.)^ 5543** 5544** ^The optimizer automatically inverts terms of the form "expr OP column" 5545** and makes other simplifications to the WHERE clause in an attempt to 5546** get as many WHERE clause terms into the form shown above as possible. 5547** ^The aConstraint[] array only reports WHERE clause terms that are 5548** relevant to the particular virtual table being queried. 5549** 5550** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5551** ^Each term of aOrderBy records a column of the ORDER BY clause. 5552** 5553** The [xBestIndex] method must fill aConstraintUsage[] with information 5554** about what parameters to pass to xFilter. ^If argvIndex>0 then 5555** the right-hand side of the corresponding aConstraint[] is evaluated 5556** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5557** is true, then the constraint is assumed to be fully handled by the 5558** virtual table and is not checked again by SQLite.)^ 5559** 5560** ^The idxNum and idxPtr values are recorded and passed into the 5561** [xFilter] method. 5562** ^[sqlite3_free()] is used to free idxPtr if and only if 5563** needToFreeIdxPtr is true. 5564** 5565** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5566** the correct order to satisfy the ORDER BY clause so that no separate 5567** sorting step is required. 5568** 5569** ^The estimatedCost value is an estimate of the cost of a particular 5570** strategy. A cost of N indicates that the cost of the strategy is similar 5571** to a linear scan of an SQLite table with N rows. A cost of log(N) 5572** indicates that the expense of the operation is similar to that of a 5573** binary search on a unique indexed field of an SQLite table with N rows. 5574** 5575** ^The estimatedRows value is an estimate of the number of rows that 5576** will be returned by the strategy. 5577** 5578** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 5579** structure for SQLite version 3.8.2. If a virtual table extension is 5580** used with an SQLite version earlier than 3.8.2, the results of attempting 5581** to read or write the estimatedRows field are undefined (but are likely 5582** to included crashing the application). The estimatedRows field should 5583** therefore only be used if [sqlite3_libversion_number()] returns a 5584** value greater than or equal to 3008002. 5585*/ 5586struct sqlite3_index_info { 5587 /* Inputs */ 5588 int nConstraint; /* Number of entries in aConstraint */ 5589 struct sqlite3_index_constraint { 5590 int iColumn; /* Column on left-hand side of constraint */ 5591 unsigned char op; /* Constraint operator */ 5592 unsigned char usable; /* True if this constraint is usable */ 5593 int iTermOffset; /* Used internally - xBestIndex should ignore */ 5594 } *aConstraint; /* Table of WHERE clause constraints */ 5595 int nOrderBy; /* Number of terms in the ORDER BY clause */ 5596 struct sqlite3_index_orderby { 5597 int iColumn; /* Column number */ 5598 unsigned char desc; /* True for DESC. False for ASC. */ 5599 } *aOrderBy; /* The ORDER BY clause */ 5600 /* Outputs */ 5601 struct sqlite3_index_constraint_usage { 5602 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5603 unsigned char omit; /* Do not code a test for this constraint */ 5604 } *aConstraintUsage; 5605 int idxNum; /* Number used to identify the index */ 5606 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5607 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5608 int orderByConsumed; /* True if output is already ordered */ 5609 double estimatedCost; /* Estimated cost of using this index */ 5610 /* Fields below are only available in SQLite 3.8.2 and later */ 5611 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 5612}; 5613 5614/* 5615** CAPI3REF: Virtual Table Constraint Operator Codes 5616** 5617** These macros defined the allowed values for the 5618** [sqlite3_index_info].aConstraint[].op field. Each value represents 5619** an operator that is part of a constraint term in the wHERE clause of 5620** a query that uses a [virtual table]. 5621*/ 5622#define SQLITE_INDEX_CONSTRAINT_EQ 2 5623#define SQLITE_INDEX_CONSTRAINT_GT 4 5624#define SQLITE_INDEX_CONSTRAINT_LE 8 5625#define SQLITE_INDEX_CONSTRAINT_LT 16 5626#define SQLITE_INDEX_CONSTRAINT_GE 32 5627#define SQLITE_INDEX_CONSTRAINT_MATCH 64 5628 5629/* 5630** CAPI3REF: Register A Virtual Table Implementation 5631** METHOD: sqlite3 5632** 5633** ^These routines are used to register a new [virtual table module] name. 5634** ^Module names must be registered before 5635** creating a new [virtual table] using the module and before using a 5636** preexisting [virtual table] for the module. 5637** 5638** ^The module name is registered on the [database connection] specified 5639** by the first parameter. ^The name of the module is given by the 5640** second parameter. ^The third parameter is a pointer to 5641** the implementation of the [virtual table module]. ^The fourth 5642** parameter is an arbitrary client data pointer that is passed through 5643** into the [xCreate] and [xConnect] methods of the virtual table module 5644** when a new virtual table is be being created or reinitialized. 5645** 5646** ^The sqlite3_create_module_v2() interface has a fifth parameter which 5647** is a pointer to a destructor for the pClientData. ^SQLite will 5648** invoke the destructor function (if it is not NULL) when SQLite 5649** no longer needs the pClientData pointer. ^The destructor will also 5650** be invoked if the call to sqlite3_create_module_v2() fails. 5651** ^The sqlite3_create_module() 5652** interface is equivalent to sqlite3_create_module_v2() with a NULL 5653** destructor. 5654*/ 5655SQLITE_API int SQLITE_STDCALL sqlite3_create_module( 5656 sqlite3 *db, /* SQLite connection to register module with */ 5657 const char *zName, /* Name of the module */ 5658 const sqlite3_module *p, /* Methods for the module */ 5659 void *pClientData /* Client data for xCreate/xConnect */ 5660); 5661SQLITE_API int SQLITE_STDCALL sqlite3_create_module_v2( 5662 sqlite3 *db, /* SQLite connection to register module with */ 5663 const char *zName, /* Name of the module */ 5664 const sqlite3_module *p, /* Methods for the module */ 5665 void *pClientData, /* Client data for xCreate/xConnect */ 5666 void(*xDestroy)(void*) /* Module destructor function */ 5667); 5668 5669/* 5670** CAPI3REF: Virtual Table Instance Object 5671** KEYWORDS: sqlite3_vtab 5672** 5673** Every [virtual table module] implementation uses a subclass 5674** of this object to describe a particular instance 5675** of the [virtual table]. Each subclass will 5676** be tailored to the specific needs of the module implementation. 5677** The purpose of this superclass is to define certain fields that are 5678** common to all module implementations. 5679** 5680** ^Virtual tables methods can set an error message by assigning a 5681** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 5682** take care that any prior string is freed by a call to [sqlite3_free()] 5683** prior to assigning a new string to zErrMsg. ^After the error message 5684** is delivered up to the client application, the string will be automatically 5685** freed by sqlite3_free() and the zErrMsg field will be zeroed. 5686*/ 5687struct sqlite3_vtab { 5688 const sqlite3_module *pModule; /* The module for this virtual table */ 5689 int nRef; /* Number of open cursors */ 5690 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 5691 /* Virtual table implementations will typically add additional fields */ 5692}; 5693 5694/* 5695** CAPI3REF: Virtual Table Cursor Object 5696** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 5697** 5698** Every [virtual table module] implementation uses a subclass of the 5699** following structure to describe cursors that point into the 5700** [virtual table] and are used 5701** to loop through the virtual table. Cursors are created using the 5702** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 5703** by the [sqlite3_module.xClose | xClose] method. Cursors are used 5704** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 5705** of the module. Each module implementation will define 5706** the content of a cursor structure to suit its own needs. 5707** 5708** This superclass exists in order to define fields of the cursor that 5709** are common to all implementations. 5710*/ 5711struct sqlite3_vtab_cursor { 5712 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 5713 /* Virtual table implementations will typically add additional fields */ 5714}; 5715 5716/* 5717** CAPI3REF: Declare The Schema Of A Virtual Table 5718** 5719** ^The [xCreate] and [xConnect] methods of a 5720** [virtual table module] call this interface 5721** to declare the format (the names and datatypes of the columns) of 5722** the virtual tables they implement. 5723*/ 5724SQLITE_API int SQLITE_STDCALL sqlite3_declare_vtab(sqlite3*, const char *zSQL); 5725 5726/* 5727** CAPI3REF: Overload A Function For A Virtual Table 5728** METHOD: sqlite3 5729** 5730** ^(Virtual tables can provide alternative implementations of functions 5731** using the [xFindFunction] method of the [virtual table module]. 5732** But global versions of those functions 5733** must exist in order to be overloaded.)^ 5734** 5735** ^(This API makes sure a global version of a function with a particular 5736** name and number of parameters exists. If no such function exists 5737** before this API is called, a new function is created.)^ ^The implementation 5738** of the new function always causes an exception to be thrown. So 5739** the new function is not good for anything by itself. Its only 5740** purpose is to be a placeholder function that can be overloaded 5741** by a [virtual table]. 5742*/ 5743SQLITE_API int SQLITE_STDCALL sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 5744 5745/* 5746** The interface to the virtual-table mechanism defined above (back up 5747** to a comment remarkably similar to this one) is currently considered 5748** to be experimental. The interface might change in incompatible ways. 5749** If this is a problem for you, do not use the interface at this time. 5750** 5751** When the virtual-table mechanism stabilizes, we will declare the 5752** interface fixed, support it indefinitely, and remove this comment. 5753*/ 5754 5755/* 5756** CAPI3REF: A Handle To An Open BLOB 5757** KEYWORDS: {BLOB handle} {BLOB handles} 5758** 5759** An instance of this object represents an open BLOB on which 5760** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 5761** ^Objects of this type are created by [sqlite3_blob_open()] 5762** and destroyed by [sqlite3_blob_close()]. 5763** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 5764** can be used to read or write small subsections of the BLOB. 5765** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 5766*/ 5767typedef struct sqlite3_blob sqlite3_blob; 5768 5769/* 5770** CAPI3REF: Open A BLOB For Incremental I/O 5771** METHOD: sqlite3 5772** CONSTRUCTOR: sqlite3_blob 5773** 5774** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 5775** in row iRow, column zColumn, table zTable in database zDb; 5776** in other words, the same BLOB that would be selected by: 5777** 5778** <pre> 5779** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 5780** </pre>)^ 5781** 5782** ^(Parameter zDb is not the filename that contains the database, but 5783** rather the symbolic name of the database. For attached databases, this is 5784** the name that appears after the AS keyword in the [ATTACH] statement. 5785** For the main database file, the database name is "main". For TEMP 5786** tables, the database name is "temp".)^ 5787** 5788** ^If the flags parameter is non-zero, then the BLOB is opened for read 5789** and write access. ^If the flags parameter is zero, the BLOB is opened for 5790** read-only access. 5791** 5792** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 5793** in *ppBlob. Otherwise an [error code] is returned and, unless the error 5794** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 5795** the API is not misused, it is always safe to call [sqlite3_blob_close()] 5796** on *ppBlob after this function it returns. 5797** 5798** This function fails with SQLITE_ERROR if any of the following are true: 5799** <ul> 5800** <li> ^(Database zDb does not exist)^, 5801** <li> ^(Table zTable does not exist within database zDb)^, 5802** <li> ^(Table zTable is a WITHOUT ROWID table)^, 5803** <li> ^(Column zColumn does not exist)^, 5804** <li> ^(Row iRow is not present in the table)^, 5805** <li> ^(The specified column of row iRow contains a value that is not 5806** a TEXT or BLOB value)^, 5807** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 5808** constraint and the blob is being opened for read/write access)^, 5809** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 5810** column zColumn is part of a [child key] definition and the blob is 5811** being opened for read/write access)^. 5812** </ul> 5813** 5814** ^Unless it returns SQLITE_MISUSE, this function sets the 5815** [database connection] error code and message accessible via 5816** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 5817** 5818** 5819** ^(If the row that a BLOB handle points to is modified by an 5820** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 5821** then the BLOB handle is marked as "expired". 5822** This is true if any column of the row is changed, even a column 5823** other than the one the BLOB handle is open on.)^ 5824** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 5825** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 5826** ^(Changes written into a BLOB prior to the BLOB expiring are not 5827** rolled back by the expiration of the BLOB. Such changes will eventually 5828** commit if the transaction continues to completion.)^ 5829** 5830** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 5831** the opened blob. ^The size of a blob may not be changed by this 5832** interface. Use the [UPDATE] SQL command to change the size of a 5833** blob. 5834** 5835** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 5836** and the built-in [zeroblob] SQL function may be used to create a 5837** zero-filled blob to read or write using the incremental-blob interface. 5838** 5839** To avoid a resource leak, every open [BLOB handle] should eventually 5840** be released by a call to [sqlite3_blob_close()]. 5841*/ 5842SQLITE_API int SQLITE_STDCALL sqlite3_blob_open( 5843 sqlite3*, 5844 const char *zDb, 5845 const char *zTable, 5846 const char *zColumn, 5847 sqlite3_int64 iRow, 5848 int flags, 5849 sqlite3_blob **ppBlob 5850); 5851 5852/* 5853** CAPI3REF: Move a BLOB Handle to a New Row 5854** METHOD: sqlite3_blob 5855** 5856** ^This function is used to move an existing blob handle so that it points 5857** to a different row of the same database table. ^The new row is identified 5858** by the rowid value passed as the second argument. Only the row can be 5859** changed. ^The database, table and column on which the blob handle is open 5860** remain the same. Moving an existing blob handle to a new row can be 5861** faster than closing the existing handle and opening a new one. 5862** 5863** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 5864** it must exist and there must be either a blob or text value stored in 5865** the nominated column.)^ ^If the new row is not present in the table, or if 5866** it does not contain a blob or text value, or if another error occurs, an 5867** SQLite error code is returned and the blob handle is considered aborted. 5868** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 5869** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 5870** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 5871** always returns zero. 5872** 5873** ^This function sets the database handle error code and message. 5874*/ 5875SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 5876 5877/* 5878** CAPI3REF: Close A BLOB Handle 5879** DESTRUCTOR: sqlite3_blob 5880** 5881** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 5882** unconditionally. Even if this routine returns an error code, the 5883** handle is still closed.)^ 5884** 5885** ^If the blob handle being closed was opened for read-write access, and if 5886** the database is in auto-commit mode and there are no other open read-write 5887** blob handles or active write statements, the current transaction is 5888** committed. ^If an error occurs while committing the transaction, an error 5889** code is returned and the transaction rolled back. 5890** 5891** Calling this function with an argument that is not a NULL pointer or an 5892** open blob handle results in undefined behaviour. ^Calling this routine 5893** with a null pointer (such as would be returned by a failed call to 5894** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 5895** is passed a valid open blob handle, the values returned by the 5896** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 5897*/ 5898SQLITE_API int SQLITE_STDCALL sqlite3_blob_close(sqlite3_blob *); 5899 5900/* 5901** CAPI3REF: Return The Size Of An Open BLOB 5902** METHOD: sqlite3_blob 5903** 5904** ^Returns the size in bytes of the BLOB accessible via the 5905** successfully opened [BLOB handle] in its only argument. ^The 5906** incremental blob I/O routines can only read or overwriting existing 5907** blob content; they cannot change the size of a blob. 5908** 5909** This routine only works on a [BLOB handle] which has been created 5910** by a prior successful call to [sqlite3_blob_open()] and which has not 5911** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5912** to this routine results in undefined and probably undesirable behavior. 5913*/ 5914SQLITE_API int SQLITE_STDCALL sqlite3_blob_bytes(sqlite3_blob *); 5915 5916/* 5917** CAPI3REF: Read Data From A BLOB Incrementally 5918** METHOD: sqlite3_blob 5919** 5920** ^(This function is used to read data from an open [BLOB handle] into a 5921** caller-supplied buffer. N bytes of data are copied into buffer Z 5922** from the open BLOB, starting at offset iOffset.)^ 5923** 5924** ^If offset iOffset is less than N bytes from the end of the BLOB, 5925** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 5926** less than zero, [SQLITE_ERROR] is returned and no data is read. 5927** ^The size of the blob (and hence the maximum value of N+iOffset) 5928** can be determined using the [sqlite3_blob_bytes()] interface. 5929** 5930** ^An attempt to read from an expired [BLOB handle] fails with an 5931** error code of [SQLITE_ABORT]. 5932** 5933** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 5934** Otherwise, an [error code] or an [extended error code] is returned.)^ 5935** 5936** This routine only works on a [BLOB handle] which has been created 5937** by a prior successful call to [sqlite3_blob_open()] and which has not 5938** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5939** to this routine results in undefined and probably undesirable behavior. 5940** 5941** See also: [sqlite3_blob_write()]. 5942*/ 5943SQLITE_API int SQLITE_STDCALL sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 5944 5945/* 5946** CAPI3REF: Write Data Into A BLOB Incrementally 5947** METHOD: sqlite3_blob 5948** 5949** ^(This function is used to write data into an open [BLOB handle] from a 5950** caller-supplied buffer. N bytes of data are copied from the buffer Z 5951** into the open BLOB, starting at offset iOffset.)^ 5952** 5953** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 5954** Otherwise, an [error code] or an [extended error code] is returned.)^ 5955** ^Unless SQLITE_MISUSE is returned, this function sets the 5956** [database connection] error code and message accessible via 5957** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 5958** 5959** ^If the [BLOB handle] passed as the first argument was not opened for 5960** writing (the flags parameter to [sqlite3_blob_open()] was zero), 5961** this function returns [SQLITE_READONLY]. 5962** 5963** This function may only modify the contents of the BLOB; it is 5964** not possible to increase the size of a BLOB using this API. 5965** ^If offset iOffset is less than N bytes from the end of the BLOB, 5966** [SQLITE_ERROR] is returned and no data is written. The size of the 5967** BLOB (and hence the maximum value of N+iOffset) can be determined 5968** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 5969** than zero [SQLITE_ERROR] is returned and no data is written. 5970** 5971** ^An attempt to write to an expired [BLOB handle] fails with an 5972** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 5973** before the [BLOB handle] expired are not rolled back by the 5974** expiration of the handle, though of course those changes might 5975** have been overwritten by the statement that expired the BLOB handle 5976** or by other independent statements. 5977** 5978** This routine only works on a [BLOB handle] which has been created 5979** by a prior successful call to [sqlite3_blob_open()] and which has not 5980** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5981** to this routine results in undefined and probably undesirable behavior. 5982** 5983** See also: [sqlite3_blob_read()]. 5984*/ 5985SQLITE_API int SQLITE_STDCALL sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 5986 5987/* 5988** CAPI3REF: Virtual File System Objects 5989** 5990** A virtual filesystem (VFS) is an [sqlite3_vfs] object 5991** that SQLite uses to interact 5992** with the underlying operating system. Most SQLite builds come with a 5993** single default VFS that is appropriate for the host computer. 5994** New VFSes can be registered and existing VFSes can be unregistered. 5995** The following interfaces are provided. 5996** 5997** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 5998** ^Names are case sensitive. 5999** ^Names are zero-terminated UTF-8 strings. 6000** ^If there is no match, a NULL pointer is returned. 6001** ^If zVfsName is NULL then the default VFS is returned. 6002** 6003** ^New VFSes are registered with sqlite3_vfs_register(). 6004** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6005** ^The same VFS can be registered multiple times without injury. 6006** ^To make an existing VFS into the default VFS, register it again 6007** with the makeDflt flag set. If two different VFSes with the 6008** same name are registered, the behavior is undefined. If a 6009** VFS is registered with a name that is NULL or an empty string, 6010** then the behavior is undefined. 6011** 6012** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6013** ^(If the default VFS is unregistered, another VFS is chosen as 6014** the default. The choice for the new VFS is arbitrary.)^ 6015*/ 6016SQLITE_API sqlite3_vfs *SQLITE_STDCALL sqlite3_vfs_find(const char *zVfsName); 6017SQLITE_API int SQLITE_STDCALL sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6018SQLITE_API int SQLITE_STDCALL sqlite3_vfs_unregister(sqlite3_vfs*); 6019 6020/* 6021** CAPI3REF: Mutexes 6022** 6023** The SQLite core uses these routines for thread 6024** synchronization. Though they are intended for internal 6025** use by SQLite, code that links against SQLite is 6026** permitted to use any of these routines. 6027** 6028** The SQLite source code contains multiple implementations 6029** of these mutex routines. An appropriate implementation 6030** is selected automatically at compile-time. The following 6031** implementations are available in the SQLite core: 6032** 6033** <ul> 6034** <li> SQLITE_MUTEX_PTHREADS 6035** <li> SQLITE_MUTEX_W32 6036** <li> SQLITE_MUTEX_NOOP 6037** </ul> 6038** 6039** The SQLITE_MUTEX_NOOP implementation is a set of routines 6040** that does no real locking and is appropriate for use in 6041** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6042** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6043** and Windows. 6044** 6045** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6046** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6047** implementation is included with the library. In this case the 6048** application must supply a custom mutex implementation using the 6049** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6050** before calling sqlite3_initialize() or any other public sqlite3_ 6051** function that calls sqlite3_initialize(). 6052** 6053** ^The sqlite3_mutex_alloc() routine allocates a new 6054** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6055** routine returns NULL if it is unable to allocate the requested 6056** mutex. The argument to sqlite3_mutex_alloc() must one of these 6057** integer constants: 6058** 6059** <ul> 6060** <li> SQLITE_MUTEX_FAST 6061** <li> SQLITE_MUTEX_RECURSIVE 6062** <li> SQLITE_MUTEX_STATIC_MASTER 6063** <li> SQLITE_MUTEX_STATIC_MEM 6064** <li> SQLITE_MUTEX_STATIC_OPEN 6065** <li> SQLITE_MUTEX_STATIC_PRNG 6066** <li> SQLITE_MUTEX_STATIC_LRU 6067** <li> SQLITE_MUTEX_STATIC_PMEM 6068** <li> SQLITE_MUTEX_STATIC_APP1 6069** <li> SQLITE_MUTEX_STATIC_APP2 6070** <li> SQLITE_MUTEX_STATIC_APP3 6071** </ul> 6072** 6073** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6074** cause sqlite3_mutex_alloc() to create 6075** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6076** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6077** The mutex implementation does not need to make a distinction 6078** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6079** not want to. SQLite will only request a recursive mutex in 6080** cases where it really needs one. If a faster non-recursive mutex 6081** implementation is available on the host platform, the mutex subsystem 6082** might return such a mutex in response to SQLITE_MUTEX_FAST. 6083** 6084** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6085** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6086** a pointer to a static preexisting mutex. ^Nine static mutexes are 6087** used by the current version of SQLite. Future versions of SQLite 6088** may add additional static mutexes. Static mutexes are for internal 6089** use by SQLite only. Applications that use SQLite mutexes should 6090** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6091** SQLITE_MUTEX_RECURSIVE. 6092** 6093** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6094** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6095** returns a different mutex on every call. ^For the static 6096** mutex types, the same mutex is returned on every call that has 6097** the same type number. 6098** 6099** ^The sqlite3_mutex_free() routine deallocates a previously 6100** allocated dynamic mutex. Attempting to deallocate a static 6101** mutex results in undefined behavior. 6102** 6103** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6104** to enter a mutex. ^If another thread is already within the mutex, 6105** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6106** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6107** upon successful entry. ^(Mutexes created using 6108** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6109** In such cases, the 6110** mutex must be exited an equal number of times before another thread 6111** can enter.)^ If the same thread tries to enter any mutex other 6112** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6113** 6114** ^(Some systems (for example, Windows 95) do not support the operation 6115** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6116** will always return SQLITE_BUSY. The SQLite core only ever uses 6117** sqlite3_mutex_try() as an optimization so this is acceptable 6118** behavior.)^ 6119** 6120** ^The sqlite3_mutex_leave() routine exits a mutex that was 6121** previously entered by the same thread. The behavior 6122** is undefined if the mutex is not currently entered by the 6123** calling thread or is not currently allocated. 6124** 6125** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6126** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6127** behave as no-ops. 6128** 6129** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6130*/ 6131SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_mutex_alloc(int); 6132SQLITE_API void SQLITE_STDCALL sqlite3_mutex_free(sqlite3_mutex*); 6133SQLITE_API void SQLITE_STDCALL sqlite3_mutex_enter(sqlite3_mutex*); 6134SQLITE_API int SQLITE_STDCALL sqlite3_mutex_try(sqlite3_mutex*); 6135SQLITE_API void SQLITE_STDCALL sqlite3_mutex_leave(sqlite3_mutex*); 6136 6137/* 6138** CAPI3REF: Mutex Methods Object 6139** 6140** An instance of this structure defines the low-level routines 6141** used to allocate and use mutexes. 6142** 6143** Usually, the default mutex implementations provided by SQLite are 6144** sufficient, however the application has the option of substituting a custom 6145** implementation for specialized deployments or systems for which SQLite 6146** does not provide a suitable implementation. In this case, the application 6147** creates and populates an instance of this structure to pass 6148** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6149** Additionally, an instance of this structure can be used as an 6150** output variable when querying the system for the current mutex 6151** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6152** 6153** ^The xMutexInit method defined by this structure is invoked as 6154** part of system initialization by the sqlite3_initialize() function. 6155** ^The xMutexInit routine is called by SQLite exactly once for each 6156** effective call to [sqlite3_initialize()]. 6157** 6158** ^The xMutexEnd method defined by this structure is invoked as 6159** part of system shutdown by the sqlite3_shutdown() function. The 6160** implementation of this method is expected to release all outstanding 6161** resources obtained by the mutex methods implementation, especially 6162** those obtained by the xMutexInit method. ^The xMutexEnd() 6163** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6164** 6165** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6166** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6167** xMutexNotheld) implement the following interfaces (respectively): 6168** 6169** <ul> 6170** <li> [sqlite3_mutex_alloc()] </li> 6171** <li> [sqlite3_mutex_free()] </li> 6172** <li> [sqlite3_mutex_enter()] </li> 6173** <li> [sqlite3_mutex_try()] </li> 6174** <li> [sqlite3_mutex_leave()] </li> 6175** <li> [sqlite3_mutex_held()] </li> 6176** <li> [sqlite3_mutex_notheld()] </li> 6177** </ul>)^ 6178** 6179** The only difference is that the public sqlite3_XXX functions enumerated 6180** above silently ignore any invocations that pass a NULL pointer instead 6181** of a valid mutex handle. The implementations of the methods defined 6182** by this structure are not required to handle this case, the results 6183** of passing a NULL pointer instead of a valid mutex handle are undefined 6184** (i.e. it is acceptable to provide an implementation that segfaults if 6185** it is passed a NULL pointer). 6186** 6187** The xMutexInit() method must be threadsafe. It must be harmless to 6188** invoke xMutexInit() multiple times within the same process and without 6189** intervening calls to xMutexEnd(). Second and subsequent calls to 6190** xMutexInit() must be no-ops. 6191** 6192** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 6193** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 6194** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 6195** memory allocation for a fast or recursive mutex. 6196** 6197** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 6198** called, but only if the prior call to xMutexInit returned SQLITE_OK. 6199** If xMutexInit fails in any way, it is expected to clean up after itself 6200** prior to returning. 6201*/ 6202typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6203struct sqlite3_mutex_methods { 6204 int (*xMutexInit)(void); 6205 int (*xMutexEnd)(void); 6206 sqlite3_mutex *(*xMutexAlloc)(int); 6207 void (*xMutexFree)(sqlite3_mutex *); 6208 void (*xMutexEnter)(sqlite3_mutex *); 6209 int (*xMutexTry)(sqlite3_mutex *); 6210 void (*xMutexLeave)(sqlite3_mutex *); 6211 int (*xMutexHeld)(sqlite3_mutex *); 6212 int (*xMutexNotheld)(sqlite3_mutex *); 6213}; 6214 6215/* 6216** CAPI3REF: Mutex Verification Routines 6217** 6218** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 6219** are intended for use inside assert() statements. The SQLite core 6220** never uses these routines except inside an assert() and applications 6221** are advised to follow the lead of the core. The SQLite core only 6222** provides implementations for these routines when it is compiled 6223** with the SQLITE_DEBUG flag. External mutex implementations 6224** are only required to provide these routines if SQLITE_DEBUG is 6225** defined and if NDEBUG is not defined. 6226** 6227** These routines should return true if the mutex in their argument 6228** is held or not held, respectively, by the calling thread. 6229** 6230** The implementation is not required to provide versions of these 6231** routines that actually work. If the implementation does not provide working 6232** versions of these routines, it should at least provide stubs that always 6233** return true so that one does not get spurious assertion failures. 6234** 6235** If the argument to sqlite3_mutex_held() is a NULL pointer then 6236** the routine should return 1. This seems counter-intuitive since 6237** clearly the mutex cannot be held if it does not exist. But 6238** the reason the mutex does not exist is because the build is not 6239** using mutexes. And we do not want the assert() containing the 6240** call to sqlite3_mutex_held() to fail, so a non-zero return is 6241** the appropriate thing to do. The sqlite3_mutex_notheld() 6242** interface should also return 1 when given a NULL pointer. 6243*/ 6244#ifndef NDEBUG 6245SQLITE_API int SQLITE_STDCALL sqlite3_mutex_held(sqlite3_mutex*); 6246SQLITE_API int SQLITE_STDCALL sqlite3_mutex_notheld(sqlite3_mutex*); 6247#endif 6248 6249/* 6250** CAPI3REF: Mutex Types 6251** 6252** The [sqlite3_mutex_alloc()] interface takes a single argument 6253** which is one of these integer constants. 6254** 6255** The set of static mutexes may change from one SQLite release to the 6256** next. Applications that override the built-in mutex logic must be 6257** prepared to accommodate additional static mutexes. 6258*/ 6259#define SQLITE_MUTEX_FAST 0 6260#define SQLITE_MUTEX_RECURSIVE 1 6261#define SQLITE_MUTEX_STATIC_MASTER 2 6262#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6263#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6264#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6265#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 6266#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6267#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6268#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6269#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 6270#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 6271#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 6272 6273/* 6274** CAPI3REF: Retrieve the mutex for a database connection 6275** METHOD: sqlite3 6276** 6277** ^This interface returns a pointer the [sqlite3_mutex] object that 6278** serializes access to the [database connection] given in the argument 6279** when the [threading mode] is Serialized. 6280** ^If the [threading mode] is Single-thread or Multi-thread then this 6281** routine returns a NULL pointer. 6282*/ 6283SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_db_mutex(sqlite3*); 6284 6285/* 6286** CAPI3REF: Low-Level Control Of Database Files 6287** METHOD: sqlite3 6288** 6289** ^The [sqlite3_file_control()] interface makes a direct call to the 6290** xFileControl method for the [sqlite3_io_methods] object associated 6291** with a particular database identified by the second argument. ^The 6292** name of the database is "main" for the main database or "temp" for the 6293** TEMP database, or the name that appears after the AS keyword for 6294** databases that are added using the [ATTACH] SQL command. 6295** ^A NULL pointer can be used in place of "main" to refer to the 6296** main database file. 6297** ^The third and fourth parameters to this routine 6298** are passed directly through to the second and third parameters of 6299** the xFileControl method. ^The return value of the xFileControl 6300** method becomes the return value of this routine. 6301** 6302** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 6303** a pointer to the underlying [sqlite3_file] object to be written into 6304** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 6305** case is a short-circuit path which does not actually invoke the 6306** underlying sqlite3_io_methods.xFileControl method. 6307** 6308** ^If the second parameter (zDbName) does not match the name of any 6309** open database file, then SQLITE_ERROR is returned. ^This error 6310** code is not remembered and will not be recalled by [sqlite3_errcode()] 6311** or [sqlite3_errmsg()]. The underlying xFileControl method might 6312** also return SQLITE_ERROR. There is no way to distinguish between 6313** an incorrect zDbName and an SQLITE_ERROR return from the underlying 6314** xFileControl method. 6315** 6316** See also: [SQLITE_FCNTL_LOCKSTATE] 6317*/ 6318SQLITE_API int SQLITE_STDCALL sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 6319 6320/* 6321** CAPI3REF: Testing Interface 6322** 6323** ^The sqlite3_test_control() interface is used to read out internal 6324** state of SQLite and to inject faults into SQLite for testing 6325** purposes. ^The first parameter is an operation code that determines 6326** the number, meaning, and operation of all subsequent parameters. 6327** 6328** This interface is not for use by applications. It exists solely 6329** for verifying the correct operation of the SQLite library. Depending 6330** on how the SQLite library is compiled, this interface might not exist. 6331** 6332** The details of the operation codes, their meanings, the parameters 6333** they take, and what they do are all subject to change without notice. 6334** Unlike most of the SQLite API, this function is not guaranteed to 6335** operate consistently from one release to the next. 6336*/ 6337SQLITE_API int SQLITE_CDECL sqlite3_test_control(int op, ...); 6338 6339/* 6340** CAPI3REF: Testing Interface Operation Codes 6341** 6342** These constants are the valid operation code parameters used 6343** as the first argument to [sqlite3_test_control()]. 6344** 6345** These parameters and their meanings are subject to change 6346** without notice. These values are for testing purposes only. 6347** Applications should not use any of these parameters or the 6348** [sqlite3_test_control()] interface. 6349*/ 6350#define SQLITE_TESTCTRL_FIRST 5 6351#define SQLITE_TESTCTRL_PRNG_SAVE 5 6352#define SQLITE_TESTCTRL_PRNG_RESTORE 6 6353#define SQLITE_TESTCTRL_PRNG_RESET 7 6354#define SQLITE_TESTCTRL_BITVEC_TEST 8 6355#define SQLITE_TESTCTRL_FAULT_INSTALL 9 6356#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 6357#define SQLITE_TESTCTRL_PENDING_BYTE 11 6358#define SQLITE_TESTCTRL_ASSERT 12 6359#define SQLITE_TESTCTRL_ALWAYS 13 6360#define SQLITE_TESTCTRL_RESERVE 14 6361#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 6362#define SQLITE_TESTCTRL_ISKEYWORD 16 6363#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 6364#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 6365#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 6366#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 6367#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 6368#define SQLITE_TESTCTRL_BYTEORDER 22 6369#define SQLITE_TESTCTRL_ISINIT 23 6370#define SQLITE_TESTCTRL_SORTER_MMAP 24 6371#define SQLITE_TESTCTRL_IMPOSTER 25 6372#define SQLITE_TESTCTRL_LAST 25 6373 6374/* 6375** CAPI3REF: SQLite Runtime Status 6376** 6377** ^These interfaces are used to retrieve runtime status information 6378** about the performance of SQLite, and optionally to reset various 6379** highwater marks. ^The first argument is an integer code for 6380** the specific parameter to measure. ^(Recognized integer codes 6381** are of the form [status parameters | SQLITE_STATUS_...].)^ 6382** ^The current value of the parameter is returned into *pCurrent. 6383** ^The highest recorded value is returned in *pHighwater. ^If the 6384** resetFlag is true, then the highest record value is reset after 6385** *pHighwater is written. ^(Some parameters do not record the highest 6386** value. For those parameters 6387** nothing is written into *pHighwater and the resetFlag is ignored.)^ 6388** ^(Other parameters record only the highwater mark and not the current 6389** value. For these latter parameters nothing is written into *pCurrent.)^ 6390** 6391** ^The sqlite3_status() and sqlite3_status64() routines return 6392** SQLITE_OK on success and a non-zero [error code] on failure. 6393** 6394** If either the current value or the highwater mark is too large to 6395** be represented by a 32-bit integer, then the values returned by 6396** sqlite3_status() are undefined. 6397** 6398** See also: [sqlite3_db_status()] 6399*/ 6400SQLITE_API int SQLITE_STDCALL sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 6401SQLITE_API int SQLITE_STDCALL sqlite3_status64( 6402 int op, 6403 sqlite3_int64 *pCurrent, 6404 sqlite3_int64 *pHighwater, 6405 int resetFlag 6406); 6407 6408 6409/* 6410** CAPI3REF: Status Parameters 6411** KEYWORDS: {status parameters} 6412** 6413** These integer constants designate various run-time status parameters 6414** that can be returned by [sqlite3_status()]. 6415** 6416** <dl> 6417** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 6418** <dd>This parameter is the current amount of memory checked out 6419** using [sqlite3_malloc()], either directly or indirectly. The 6420** figure includes calls made to [sqlite3_malloc()] by the application 6421** and internal memory usage by the SQLite library. Scratch memory 6422** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 6423** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 6424** this parameter. The amount returned is the sum of the allocation 6425** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 6426** 6427** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 6428** <dd>This parameter records the largest memory allocation request 6429** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 6430** internal equivalents). Only the value returned in the 6431** *pHighwater parameter to [sqlite3_status()] is of interest. 6432** The value written into the *pCurrent parameter is undefined.</dd>)^ 6433** 6434** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 6435** <dd>This parameter records the number of separate memory allocations 6436** currently checked out.</dd>)^ 6437** 6438** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 6439** <dd>This parameter returns the number of pages used out of the 6440** [pagecache memory allocator] that was configured using 6441** [SQLITE_CONFIG_PAGECACHE]. The 6442** value returned is in pages, not in bytes.</dd>)^ 6443** 6444** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 6445** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6446** <dd>This parameter returns the number of bytes of page cache 6447** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 6448** buffer and where forced to overflow to [sqlite3_malloc()]. The 6449** returned value includes allocations that overflowed because they 6450** where too large (they were larger than the "sz" parameter to 6451** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 6452** no space was left in the page cache.</dd>)^ 6453** 6454** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 6455** <dd>This parameter records the largest memory allocation request 6456** handed to [pagecache memory allocator]. Only the value returned in the 6457** *pHighwater parameter to [sqlite3_status()] is of interest. 6458** The value written into the *pCurrent parameter is undefined.</dd>)^ 6459** 6460** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 6461** <dd>This parameter returns the number of allocations used out of the 6462** [scratch memory allocator] configured using 6463** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6464** in bytes. Since a single thread may only have one scratch allocation 6465** outstanding at time, this parameter also reports the number of threads 6466** using scratch memory at the same time.</dd>)^ 6467** 6468** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6469** <dd>This parameter returns the number of bytes of scratch memory 6470** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 6471** buffer and where forced to overflow to [sqlite3_malloc()]. The values 6472** returned include overflows because the requested allocation was too 6473** larger (that is, because the requested allocation was larger than the 6474** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 6475** slots were available. 6476** </dd>)^ 6477** 6478** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6479** <dd>This parameter records the largest memory allocation request 6480** handed to [scratch memory allocator]. Only the value returned in the 6481** *pHighwater parameter to [sqlite3_status()] is of interest. 6482** The value written into the *pCurrent parameter is undefined.</dd>)^ 6483** 6484** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6485** <dd>This parameter records the deepest parser stack. It is only 6486** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6487** </dl> 6488** 6489** New status parameters may be added from time to time. 6490*/ 6491#define SQLITE_STATUS_MEMORY_USED 0 6492#define SQLITE_STATUS_PAGECACHE_USED 1 6493#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6494#define SQLITE_STATUS_SCRATCH_USED 3 6495#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6496#define SQLITE_STATUS_MALLOC_SIZE 5 6497#define SQLITE_STATUS_PARSER_STACK 6 6498#define SQLITE_STATUS_PAGECACHE_SIZE 7 6499#define SQLITE_STATUS_SCRATCH_SIZE 8 6500#define SQLITE_STATUS_MALLOC_COUNT 9 6501 6502/* 6503** CAPI3REF: Database Connection Status 6504** METHOD: sqlite3 6505** 6506** ^This interface is used to retrieve runtime status information 6507** about a single [database connection]. ^The first argument is the 6508** database connection object to be interrogated. ^The second argument 6509** is an integer constant, taken from the set of 6510** [SQLITE_DBSTATUS options], that 6511** determines the parameter to interrogate. The set of 6512** [SQLITE_DBSTATUS options] is likely 6513** to grow in future releases of SQLite. 6514** 6515** ^The current value of the requested parameter is written into *pCur 6516** and the highest instantaneous value is written into *pHiwtr. ^If 6517** the resetFlg is true, then the highest instantaneous value is 6518** reset back down to the current value. 6519** 6520** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 6521** non-zero [error code] on failure. 6522** 6523** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 6524*/ 6525SQLITE_API int SQLITE_STDCALL sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 6526 6527/* 6528** CAPI3REF: Status Parameters for database connections 6529** KEYWORDS: {SQLITE_DBSTATUS options} 6530** 6531** These constants are the available integer "verbs" that can be passed as 6532** the second argument to the [sqlite3_db_status()] interface. 6533** 6534** New verbs may be added in future releases of SQLite. Existing verbs 6535** might be discontinued. Applications should check the return code from 6536** [sqlite3_db_status()] to make sure that the call worked. 6537** The [sqlite3_db_status()] interface will return a non-zero error code 6538** if a discontinued or unsupported verb is invoked. 6539** 6540** <dl> 6541** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6542** <dd>This parameter returns the number of lookaside memory slots currently 6543** checked out.</dd>)^ 6544** 6545** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6546** <dd>This parameter returns the number malloc attempts that were 6547** satisfied using lookaside memory. Only the high-water value is meaningful; 6548** the current value is always zero.)^ 6549** 6550** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6551** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6552** <dd>This parameter returns the number malloc attempts that might have 6553** been satisfied using lookaside memory but failed due to the amount of 6554** memory requested being larger than the lookaside slot size. 6555** Only the high-water value is meaningful; 6556** the current value is always zero.)^ 6557** 6558** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6559** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6560** <dd>This parameter returns the number malloc attempts that might have 6561** been satisfied using lookaside memory but failed due to all lookaside 6562** memory already being in use. 6563** Only the high-water value is meaningful; 6564** the current value is always zero.)^ 6565** 6566** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6567** <dd>This parameter returns the approximate number of bytes of heap 6568** memory used by all pager caches associated with the database connection.)^ 6569** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6570** 6571** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 6572** <dd>This parameter returns the approximate number of bytes of heap 6573** memory used to store the schema for all databases associated 6574** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 6575** ^The full amount of memory used by the schemas is reported, even if the 6576** schema memory is shared with other database connections due to 6577** [shared cache mode] being enabled. 6578** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 6579** 6580** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 6581** <dd>This parameter returns the approximate number of bytes of heap 6582** and lookaside memory used by all prepared statements associated with 6583** the database connection.)^ 6584** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 6585** </dd> 6586** 6587** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 6588** <dd>This parameter returns the number of pager cache hits that have 6589** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 6590** is always 0. 6591** </dd> 6592** 6593** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 6594** <dd>This parameter returns the number of pager cache misses that have 6595** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 6596** is always 0. 6597** </dd> 6598** 6599** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 6600** <dd>This parameter returns the number of dirty cache entries that have 6601** been written to disk. Specifically, the number of pages written to the 6602** wal file in wal mode databases, or the number of pages written to the 6603** database file in rollback mode databases. Any pages written as part of 6604** transaction rollback or database recovery operations are not included. 6605** If an IO or other error occurs while writing a page to disk, the effect 6606** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 6607** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 6608** </dd> 6609** 6610** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 6611** <dd>This parameter returns zero for the current value if and only if 6612** all foreign key constraints (deferred or immediate) have been 6613** resolved.)^ ^The highwater mark is always 0. 6614** </dd> 6615** </dl> 6616*/ 6617#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 6618#define SQLITE_DBSTATUS_CACHE_USED 1 6619#define SQLITE_DBSTATUS_SCHEMA_USED 2 6620#define SQLITE_DBSTATUS_STMT_USED 3 6621#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 6622#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 6623#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 6624#define SQLITE_DBSTATUS_CACHE_HIT 7 6625#define SQLITE_DBSTATUS_CACHE_MISS 8 6626#define SQLITE_DBSTATUS_CACHE_WRITE 9 6627#define SQLITE_DBSTATUS_DEFERRED_FKS 10 6628#define SQLITE_DBSTATUS_MAX 10 /* Largest defined DBSTATUS */ 6629 6630 6631/* 6632** CAPI3REF: Prepared Statement Status 6633** METHOD: sqlite3_stmt 6634** 6635** ^(Each prepared statement maintains various 6636** [SQLITE_STMTSTATUS counters] that measure the number 6637** of times it has performed specific operations.)^ These counters can 6638** be used to monitor the performance characteristics of the prepared 6639** statements. For example, if the number of table steps greatly exceeds 6640** the number of table searches or result rows, that would tend to indicate 6641** that the prepared statement is using a full table scan rather than 6642** an index. 6643** 6644** ^(This interface is used to retrieve and reset counter values from 6645** a [prepared statement]. The first argument is the prepared statement 6646** object to be interrogated. The second argument 6647** is an integer code for a specific [SQLITE_STMTSTATUS counter] 6648** to be interrogated.)^ 6649** ^The current value of the requested counter is returned. 6650** ^If the resetFlg is true, then the counter is reset to zero after this 6651** interface call returns. 6652** 6653** See also: [sqlite3_status()] and [sqlite3_db_status()]. 6654*/ 6655SQLITE_API int SQLITE_STDCALL sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 6656 6657/* 6658** CAPI3REF: Status Parameters for prepared statements 6659** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 6660** 6661** These preprocessor macros define integer codes that name counter 6662** values associated with the [sqlite3_stmt_status()] interface. 6663** The meanings of the various counters are as follows: 6664** 6665** <dl> 6666** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 6667** <dd>^This is the number of times that SQLite has stepped forward in 6668** a table as part of a full table scan. Large numbers for this counter 6669** may indicate opportunities for performance improvement through 6670** careful use of indices.</dd> 6671** 6672** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 6673** <dd>^This is the number of sort operations that have occurred. 6674** A non-zero value in this counter may indicate an opportunity to 6675** improvement performance through careful use of indices.</dd> 6676** 6677** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 6678** <dd>^This is the number of rows inserted into transient indices that 6679** were created automatically in order to help joins run faster. 6680** A non-zero value in this counter may indicate an opportunity to 6681** improvement performance by adding permanent indices that do not 6682** need to be reinitialized each time the statement is run.</dd> 6683** 6684** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 6685** <dd>^This is the number of virtual machine operations executed 6686** by the prepared statement if that number is less than or equal 6687** to 2147483647. The number of virtual machine operations can be 6688** used as a proxy for the total work done by the prepared statement. 6689** If the number of virtual machine operations exceeds 2147483647 6690** then the value returned by this statement status code is undefined. 6691** </dd> 6692** </dl> 6693*/ 6694#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 6695#define SQLITE_STMTSTATUS_SORT 2 6696#define SQLITE_STMTSTATUS_AUTOINDEX 3 6697#define SQLITE_STMTSTATUS_VM_STEP 4 6698 6699/* 6700** CAPI3REF: Custom Page Cache Object 6701** 6702** The sqlite3_pcache type is opaque. It is implemented by 6703** the pluggable module. The SQLite core has no knowledge of 6704** its size or internal structure and never deals with the 6705** sqlite3_pcache object except by holding and passing pointers 6706** to the object. 6707** 6708** See [sqlite3_pcache_methods2] for additional information. 6709*/ 6710typedef struct sqlite3_pcache sqlite3_pcache; 6711 6712/* 6713** CAPI3REF: Custom Page Cache Object 6714** 6715** The sqlite3_pcache_page object represents a single page in the 6716** page cache. The page cache will allocate instances of this 6717** object. Various methods of the page cache use pointers to instances 6718** of this object as parameters or as their return value. 6719** 6720** See [sqlite3_pcache_methods2] for additional information. 6721*/ 6722typedef struct sqlite3_pcache_page sqlite3_pcache_page; 6723struct sqlite3_pcache_page { 6724 void *pBuf; /* The content of the page */ 6725 void *pExtra; /* Extra information associated with the page */ 6726}; 6727 6728/* 6729** CAPI3REF: Application Defined Page Cache. 6730** KEYWORDS: {page cache} 6731** 6732** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 6733** register an alternative page cache implementation by passing in an 6734** instance of the sqlite3_pcache_methods2 structure.)^ 6735** In many applications, most of the heap memory allocated by 6736** SQLite is used for the page cache. 6737** By implementing a 6738** custom page cache using this API, an application can better control 6739** the amount of memory consumed by SQLite, the way in which 6740** that memory is allocated and released, and the policies used to 6741** determine exactly which parts of a database file are cached and for 6742** how long. 6743** 6744** The alternative page cache mechanism is an 6745** extreme measure that is only needed by the most demanding applications. 6746** The built-in page cache is recommended for most uses. 6747** 6748** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 6749** internal buffer by SQLite within the call to [sqlite3_config]. Hence 6750** the application may discard the parameter after the call to 6751** [sqlite3_config()] returns.)^ 6752** 6753** [[the xInit() page cache method]] 6754** ^(The xInit() method is called once for each effective 6755** call to [sqlite3_initialize()])^ 6756** (usually only once during the lifetime of the process). ^(The xInit() 6757** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 6758** The intent of the xInit() method is to set up global data structures 6759** required by the custom page cache implementation. 6760** ^(If the xInit() method is NULL, then the 6761** built-in default page cache is used instead of the application defined 6762** page cache.)^ 6763** 6764** [[the xShutdown() page cache method]] 6765** ^The xShutdown() method is called by [sqlite3_shutdown()]. 6766** It can be used to clean up 6767** any outstanding resources before process shutdown, if required. 6768** ^The xShutdown() method may be NULL. 6769** 6770** ^SQLite automatically serializes calls to the xInit method, 6771** so the xInit method need not be threadsafe. ^The 6772** xShutdown method is only called from [sqlite3_shutdown()] so it does 6773** not need to be threadsafe either. All other methods must be threadsafe 6774** in multithreaded applications. 6775** 6776** ^SQLite will never invoke xInit() more than once without an intervening 6777** call to xShutdown(). 6778** 6779** [[the xCreate() page cache methods]] 6780** ^SQLite invokes the xCreate() method to construct a new cache instance. 6781** SQLite will typically create one cache instance for each open database file, 6782** though this is not guaranteed. ^The 6783** first parameter, szPage, is the size in bytes of the pages that must 6784** be allocated by the cache. ^szPage will always a power of two. ^The 6785** second parameter szExtra is a number of bytes of extra storage 6786** associated with each page cache entry. ^The szExtra parameter will 6787** a number less than 250. SQLite will use the 6788** extra szExtra bytes on each page to store metadata about the underlying 6789** database page on disk. The value passed into szExtra depends 6790** on the SQLite version, the target platform, and how SQLite was compiled. 6791** ^The third argument to xCreate(), bPurgeable, is true if the cache being 6792** created will be used to cache database pages of a file stored on disk, or 6793** false if it is used for an in-memory database. The cache implementation 6794** does not have to do anything special based with the value of bPurgeable; 6795** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 6796** never invoke xUnpin() except to deliberately delete a page. 6797** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 6798** false will always have the "discard" flag set to true. 6799** ^Hence, a cache created with bPurgeable false will 6800** never contain any unpinned pages. 6801** 6802** [[the xCachesize() page cache method]] 6803** ^(The xCachesize() method may be called at any time by SQLite to set the 6804** suggested maximum cache-size (number of pages stored by) the cache 6805** instance passed as the first argument. This is the value configured using 6806** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 6807** parameter, the implementation is not required to do anything with this 6808** value; it is advisory only. 6809** 6810** [[the xPagecount() page cache methods]] 6811** The xPagecount() method must return the number of pages currently 6812** stored in the cache, both pinned and unpinned. 6813** 6814** [[the xFetch() page cache methods]] 6815** The xFetch() method locates a page in the cache and returns a pointer to 6816** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 6817** The pBuf element of the returned sqlite3_pcache_page object will be a 6818** pointer to a buffer of szPage bytes used to store the content of a 6819** single database page. The pExtra element of sqlite3_pcache_page will be 6820** a pointer to the szExtra bytes of extra storage that SQLite has requested 6821** for each entry in the page cache. 6822** 6823** The page to be fetched is determined by the key. ^The minimum key value 6824** is 1. After it has been retrieved using xFetch, the page is considered 6825** to be "pinned". 6826** 6827** If the requested page is already in the page cache, then the page cache 6828** implementation must return a pointer to the page buffer with its content 6829** intact. If the requested page is not already in the cache, then the 6830** cache implementation should use the value of the createFlag 6831** parameter to help it determined what action to take: 6832** 6833** <table border=1 width=85% align=center> 6834** <tr><th> createFlag <th> Behavior when page is not already in cache 6835** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 6836** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 6837** Otherwise return NULL. 6838** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 6839** NULL if allocating a new page is effectively impossible. 6840** </table> 6841** 6842** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 6843** will only use a createFlag of 2 after a prior call with a createFlag of 1 6844** failed.)^ In between the to xFetch() calls, SQLite may 6845** attempt to unpin one or more cache pages by spilling the content of 6846** pinned pages to disk and synching the operating system disk cache. 6847** 6848** [[the xUnpin() page cache method]] 6849** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 6850** as its second argument. If the third parameter, discard, is non-zero, 6851** then the page must be evicted from the cache. 6852** ^If the discard parameter is 6853** zero, then the page may be discarded or retained at the discretion of 6854** page cache implementation. ^The page cache implementation 6855** may choose to evict unpinned pages at any time. 6856** 6857** The cache must not perform any reference counting. A single 6858** call to xUnpin() unpins the page regardless of the number of prior calls 6859** to xFetch(). 6860** 6861** [[the xRekey() page cache methods]] 6862** The xRekey() method is used to change the key value associated with the 6863** page passed as the second argument. If the cache 6864** previously contains an entry associated with newKey, it must be 6865** discarded. ^Any prior cache entry associated with newKey is guaranteed not 6866** to be pinned. 6867** 6868** When SQLite calls the xTruncate() method, the cache must discard all 6869** existing cache entries with page numbers (keys) greater than or equal 6870** to the value of the iLimit parameter passed to xTruncate(). If any 6871** of these pages are pinned, they are implicitly unpinned, meaning that 6872** they can be safely discarded. 6873** 6874** [[the xDestroy() page cache method]] 6875** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 6876** All resources associated with the specified cache should be freed. ^After 6877** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 6878** handle invalid, and will not use it with any other sqlite3_pcache_methods2 6879** functions. 6880** 6881** [[the xShrink() page cache method]] 6882** ^SQLite invokes the xShrink() method when it wants the page cache to 6883** free up as much of heap memory as possible. The page cache implementation 6884** is not obligated to free any memory, but well-behaved implementations should 6885** do their best. 6886*/ 6887typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 6888struct sqlite3_pcache_methods2 { 6889 int iVersion; 6890 void *pArg; 6891 int (*xInit)(void*); 6892 void (*xShutdown)(void*); 6893 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 6894 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6895 int (*xPagecount)(sqlite3_pcache*); 6896 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6897 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 6898 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 6899 unsigned oldKey, unsigned newKey); 6900 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6901 void (*xDestroy)(sqlite3_pcache*); 6902 void (*xShrink)(sqlite3_pcache*); 6903}; 6904 6905/* 6906** This is the obsolete pcache_methods object that has now been replaced 6907** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 6908** retained in the header file for backwards compatibility only. 6909*/ 6910typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 6911struct sqlite3_pcache_methods { 6912 void *pArg; 6913 int (*xInit)(void*); 6914 void (*xShutdown)(void*); 6915 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 6916 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6917 int (*xPagecount)(sqlite3_pcache*); 6918 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6919 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 6920 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 6921 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6922 void (*xDestroy)(sqlite3_pcache*); 6923}; 6924 6925 6926/* 6927** CAPI3REF: Online Backup Object 6928** 6929** The sqlite3_backup object records state information about an ongoing 6930** online backup operation. ^The sqlite3_backup object is created by 6931** a call to [sqlite3_backup_init()] and is destroyed by a call to 6932** [sqlite3_backup_finish()]. 6933** 6934** See Also: [Using the SQLite Online Backup API] 6935*/ 6936typedef struct sqlite3_backup sqlite3_backup; 6937 6938/* 6939** CAPI3REF: Online Backup API. 6940** 6941** The backup API copies the content of one database into another. 6942** It is useful either for creating backups of databases or 6943** for copying in-memory databases to or from persistent files. 6944** 6945** See Also: [Using the SQLite Online Backup API] 6946** 6947** ^SQLite holds a write transaction open on the destination database file 6948** for the duration of the backup operation. 6949** ^The source database is read-locked only while it is being read; 6950** it is not locked continuously for the entire backup operation. 6951** ^Thus, the backup may be performed on a live source database without 6952** preventing other database connections from 6953** reading or writing to the source database while the backup is underway. 6954** 6955** ^(To perform a backup operation: 6956** <ol> 6957** <li><b>sqlite3_backup_init()</b> is called once to initialize the 6958** backup, 6959** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 6960** the data between the two databases, and finally 6961** <li><b>sqlite3_backup_finish()</b> is called to release all resources 6962** associated with the backup operation. 6963** </ol>)^ 6964** There should be exactly one call to sqlite3_backup_finish() for each 6965** successful call to sqlite3_backup_init(). 6966** 6967** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 6968** 6969** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 6970** [database connection] associated with the destination database 6971** and the database name, respectively. 6972** ^The database name is "main" for the main database, "temp" for the 6973** temporary database, or the name specified after the AS keyword in 6974** an [ATTACH] statement for an attached database. 6975** ^The S and M arguments passed to 6976** sqlite3_backup_init(D,N,S,M) identify the [database connection] 6977** and database name of the source database, respectively. 6978** ^The source and destination [database connections] (parameters S and D) 6979** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 6980** an error. 6981** 6982** ^A call to sqlite3_backup_init() will fail, returning SQLITE_ERROR, if 6983** there is already a read or read-write transaction open on the 6984** destination database. 6985** 6986** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 6987** returned and an error code and error message are stored in the 6988** destination [database connection] D. 6989** ^The error code and message for the failed call to sqlite3_backup_init() 6990** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 6991** [sqlite3_errmsg16()] functions. 6992** ^A successful call to sqlite3_backup_init() returns a pointer to an 6993** [sqlite3_backup] object. 6994** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 6995** sqlite3_backup_finish() functions to perform the specified backup 6996** operation. 6997** 6998** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 6999** 7000** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 7001** the source and destination databases specified by [sqlite3_backup] object B. 7002** ^If N is negative, all remaining source pages are copied. 7003** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 7004** are still more pages to be copied, then the function returns [SQLITE_OK]. 7005** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 7006** from source to destination, then it returns [SQLITE_DONE]. 7007** ^If an error occurs while running sqlite3_backup_step(B,N), 7008** then an [error code] is returned. ^As well as [SQLITE_OK] and 7009** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 7010** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 7011** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 7012** 7013** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 7014** <ol> 7015** <li> the destination database was opened read-only, or 7016** <li> the destination database is using write-ahead-log journaling 7017** and the destination and source page sizes differ, or 7018** <li> the destination database is an in-memory database and the 7019** destination and source page sizes differ. 7020** </ol>)^ 7021** 7022** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 7023** the [sqlite3_busy_handler | busy-handler function] 7024** is invoked (if one is specified). ^If the 7025** busy-handler returns non-zero before the lock is available, then 7026** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 7027** sqlite3_backup_step() can be retried later. ^If the source 7028** [database connection] 7029** is being used to write to the source database when sqlite3_backup_step() 7030** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 7031** case the call to sqlite3_backup_step() can be retried later on. ^(If 7032** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 7033** [SQLITE_READONLY] is returned, then 7034** there is no point in retrying the call to sqlite3_backup_step(). These 7035** errors are considered fatal.)^ The application must accept 7036** that the backup operation has failed and pass the backup operation handle 7037** to the sqlite3_backup_finish() to release associated resources. 7038** 7039** ^The first call to sqlite3_backup_step() obtains an exclusive lock 7040** on the destination file. ^The exclusive lock is not released until either 7041** sqlite3_backup_finish() is called or the backup operation is complete 7042** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 7043** sqlite3_backup_step() obtains a [shared lock] on the source database that 7044** lasts for the duration of the sqlite3_backup_step() call. 7045** ^Because the source database is not locked between calls to 7046** sqlite3_backup_step(), the source database may be modified mid-way 7047** through the backup process. ^If the source database is modified by an 7048** external process or via a database connection other than the one being 7049** used by the backup operation, then the backup will be automatically 7050** restarted by the next call to sqlite3_backup_step(). ^If the source 7051** database is modified by the using the same database connection as is used 7052** by the backup operation, then the backup database is automatically 7053** updated at the same time. 7054** 7055** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 7056** 7057** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 7058** application wishes to abandon the backup operation, the application 7059** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 7060** ^The sqlite3_backup_finish() interfaces releases all 7061** resources associated with the [sqlite3_backup] object. 7062** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 7063** active write-transaction on the destination database is rolled back. 7064** The [sqlite3_backup] object is invalid 7065** and may not be used following a call to sqlite3_backup_finish(). 7066** 7067** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 7068** sqlite3_backup_step() errors occurred, regardless or whether or not 7069** sqlite3_backup_step() completed. 7070** ^If an out-of-memory condition or IO error occurred during any prior 7071** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 7072** sqlite3_backup_finish() returns the corresponding [error code]. 7073** 7074** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 7075** is not a permanent error and does not affect the return value of 7076** sqlite3_backup_finish(). 7077** 7078** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 7079** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 7080** 7081** ^The sqlite3_backup_remaining() routine returns the number of pages still 7082** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 7083** ^The sqlite3_backup_pagecount() routine returns the total number of pages 7084** in the source database at the conclusion of the most recent 7085** sqlite3_backup_step(). 7086** ^(The values returned by these functions are only updated by 7087** sqlite3_backup_step(). If the source database is modified in a way that 7088** changes the size of the source database or the number of pages remaining, 7089** those changes are not reflected in the output of sqlite3_backup_pagecount() 7090** and sqlite3_backup_remaining() until after the next 7091** sqlite3_backup_step().)^ 7092** 7093** <b>Concurrent Usage of Database Handles</b> 7094** 7095** ^The source [database connection] may be used by the application for other 7096** purposes while a backup operation is underway or being initialized. 7097** ^If SQLite is compiled and configured to support threadsafe database 7098** connections, then the source database connection may be used concurrently 7099** from within other threads. 7100** 7101** However, the application must guarantee that the destination 7102** [database connection] is not passed to any other API (by any thread) after 7103** sqlite3_backup_init() is called and before the corresponding call to 7104** sqlite3_backup_finish(). SQLite does not currently check to see 7105** if the application incorrectly accesses the destination [database connection] 7106** and so no error code is reported, but the operations may malfunction 7107** nevertheless. Use of the destination database connection while a 7108** backup is in progress might also also cause a mutex deadlock. 7109** 7110** If running in [shared cache mode], the application must 7111** guarantee that the shared cache used by the destination database 7112** is not accessed while the backup is running. In practice this means 7113** that the application must guarantee that the disk file being 7114** backed up to is not accessed by any connection within the process, 7115** not just the specific connection that was passed to sqlite3_backup_init(). 7116** 7117** The [sqlite3_backup] object itself is partially threadsafe. Multiple 7118** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 7119** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 7120** APIs are not strictly speaking threadsafe. If they are invoked at the 7121** same time as another thread is invoking sqlite3_backup_step() it is 7122** possible that they return invalid values. 7123*/ 7124SQLITE_API sqlite3_backup *SQLITE_STDCALL sqlite3_backup_init( 7125 sqlite3 *pDest, /* Destination database handle */ 7126 const char *zDestName, /* Destination database name */ 7127 sqlite3 *pSource, /* Source database handle */ 7128 const char *zSourceName /* Source database name */ 7129); 7130SQLITE_API int SQLITE_STDCALL sqlite3_backup_step(sqlite3_backup *p, int nPage); 7131SQLITE_API int SQLITE_STDCALL sqlite3_backup_finish(sqlite3_backup *p); 7132SQLITE_API int SQLITE_STDCALL sqlite3_backup_remaining(sqlite3_backup *p); 7133SQLITE_API int SQLITE_STDCALL sqlite3_backup_pagecount(sqlite3_backup *p); 7134 7135/* 7136** CAPI3REF: Unlock Notification 7137** METHOD: sqlite3 7138** 7139** ^When running in shared-cache mode, a database operation may fail with 7140** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 7141** individual tables within the shared-cache cannot be obtained. See 7142** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 7143** ^This API may be used to register a callback that SQLite will invoke 7144** when the connection currently holding the required lock relinquishes it. 7145** ^This API is only available if the library was compiled with the 7146** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 7147** 7148** See Also: [Using the SQLite Unlock Notification Feature]. 7149** 7150** ^Shared-cache locks are released when a database connection concludes 7151** its current transaction, either by committing it or rolling it back. 7152** 7153** ^When a connection (known as the blocked connection) fails to obtain a 7154** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 7155** identity of the database connection (the blocking connection) that 7156** has locked the required resource is stored internally. ^After an 7157** application receives an SQLITE_LOCKED error, it may call the 7158** sqlite3_unlock_notify() method with the blocked connection handle as 7159** the first argument to register for a callback that will be invoked 7160** when the blocking connections current transaction is concluded. ^The 7161** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 7162** call that concludes the blocking connections transaction. 7163** 7164** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 7165** there is a chance that the blocking connection will have already 7166** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 7167** If this happens, then the specified callback is invoked immediately, 7168** from within the call to sqlite3_unlock_notify().)^ 7169** 7170** ^If the blocked connection is attempting to obtain a write-lock on a 7171** shared-cache table, and more than one other connection currently holds 7172** a read-lock on the same table, then SQLite arbitrarily selects one of 7173** the other connections to use as the blocking connection. 7174** 7175** ^(There may be at most one unlock-notify callback registered by a 7176** blocked connection. If sqlite3_unlock_notify() is called when the 7177** blocked connection already has a registered unlock-notify callback, 7178** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 7179** called with a NULL pointer as its second argument, then any existing 7180** unlock-notify callback is canceled. ^The blocked connections 7181** unlock-notify callback may also be canceled by closing the blocked 7182** connection using [sqlite3_close()]. 7183** 7184** The unlock-notify callback is not reentrant. If an application invokes 7185** any sqlite3_xxx API functions from within an unlock-notify callback, a 7186** crash or deadlock may be the result. 7187** 7188** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 7189** returns SQLITE_OK. 7190** 7191** <b>Callback Invocation Details</b> 7192** 7193** When an unlock-notify callback is registered, the application provides a 7194** single void* pointer that is passed to the callback when it is invoked. 7195** However, the signature of the callback function allows SQLite to pass 7196** it an array of void* context pointers. The first argument passed to 7197** an unlock-notify callback is a pointer to an array of void* pointers, 7198** and the second is the number of entries in the array. 7199** 7200** When a blocking connections transaction is concluded, there may be 7201** more than one blocked connection that has registered for an unlock-notify 7202** callback. ^If two or more such blocked connections have specified the 7203** same callback function, then instead of invoking the callback function 7204** multiple times, it is invoked once with the set of void* context pointers 7205** specified by the blocked connections bundled together into an array. 7206** This gives the application an opportunity to prioritize any actions 7207** related to the set of unblocked database connections. 7208** 7209** <b>Deadlock Detection</b> 7210** 7211** Assuming that after registering for an unlock-notify callback a 7212** database waits for the callback to be issued before taking any further 7213** action (a reasonable assumption), then using this API may cause the 7214** application to deadlock. For example, if connection X is waiting for 7215** connection Y's transaction to be concluded, and similarly connection 7216** Y is waiting on connection X's transaction, then neither connection 7217** will proceed and the system may remain deadlocked indefinitely. 7218** 7219** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 7220** detection. ^If a given call to sqlite3_unlock_notify() would put the 7221** system in a deadlocked state, then SQLITE_LOCKED is returned and no 7222** unlock-notify callback is registered. The system is said to be in 7223** a deadlocked state if connection A has registered for an unlock-notify 7224** callback on the conclusion of connection B's transaction, and connection 7225** B has itself registered for an unlock-notify callback when connection 7226** A's transaction is concluded. ^Indirect deadlock is also detected, so 7227** the system is also considered to be deadlocked if connection B has 7228** registered for an unlock-notify callback on the conclusion of connection 7229** C's transaction, where connection C is waiting on connection A. ^Any 7230** number of levels of indirection are allowed. 7231** 7232** <b>The "DROP TABLE" Exception</b> 7233** 7234** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 7235** always appropriate to call sqlite3_unlock_notify(). There is however, 7236** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 7237** SQLite checks if there are any currently executing SELECT statements 7238** that belong to the same connection. If there are, SQLITE_LOCKED is 7239** returned. In this case there is no "blocking connection", so invoking 7240** sqlite3_unlock_notify() results in the unlock-notify callback being 7241** invoked immediately. If the application then re-attempts the "DROP TABLE" 7242** or "DROP INDEX" query, an infinite loop might be the result. 7243** 7244** One way around this problem is to check the extended error code returned 7245** by an sqlite3_step() call. ^(If there is a blocking connection, then the 7246** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 7247** the special "DROP TABLE/INDEX" case, the extended error code is just 7248** SQLITE_LOCKED.)^ 7249*/ 7250SQLITE_API int SQLITE_STDCALL sqlite3_unlock_notify( 7251 sqlite3 *pBlocked, /* Waiting connection */ 7252 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 7253 void *pNotifyArg /* Argument to pass to xNotify */ 7254); 7255 7256 7257/* 7258** CAPI3REF: String Comparison 7259** 7260** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 7261** and extensions to compare the contents of two buffers containing UTF-8 7262** strings in a case-independent fashion, using the same definition of "case 7263** independence" that SQLite uses internally when comparing identifiers. 7264*/ 7265SQLITE_API int SQLITE_STDCALL sqlite3_stricmp(const char *, const char *); 7266SQLITE_API int SQLITE_STDCALL sqlite3_strnicmp(const char *, const char *, int); 7267 7268/* 7269** CAPI3REF: String Globbing 7270* 7271** ^The [sqlite3_strglob(P,X)] interface returns zero if string X matches 7272** the glob pattern P, and it returns non-zero if string X does not match 7273** the glob pattern P. ^The definition of glob pattern matching used in 7274** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 7275** SQL dialect used by SQLite. ^The sqlite3_strglob(P,X) function is case 7276** sensitive. 7277** 7278** Note that this routine returns zero on a match and non-zero if the strings 7279** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7280*/ 7281SQLITE_API int SQLITE_STDCALL sqlite3_strglob(const char *zGlob, const char *zStr); 7282 7283/* 7284** CAPI3REF: Error Logging Interface 7285** 7286** ^The [sqlite3_log()] interface writes a message into the [error log] 7287** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 7288** ^If logging is enabled, the zFormat string and subsequent arguments are 7289** used with [sqlite3_snprintf()] to generate the final output string. 7290** 7291** The sqlite3_log() interface is intended for use by extensions such as 7292** virtual tables, collating functions, and SQL functions. While there is 7293** nothing to prevent an application from calling sqlite3_log(), doing so 7294** is considered bad form. 7295** 7296** The zFormat string must not be NULL. 7297** 7298** To avoid deadlocks and other threading problems, the sqlite3_log() routine 7299** will not use dynamically allocated memory. The log message is stored in 7300** a fixed-length buffer on the stack. If the log message is longer than 7301** a few hundred characters, it will be truncated to the length of the 7302** buffer. 7303*/ 7304SQLITE_API void SQLITE_CDECL sqlite3_log(int iErrCode, const char *zFormat, ...); 7305 7306/* 7307** CAPI3REF: Write-Ahead Log Commit Hook 7308** METHOD: sqlite3 7309** 7310** ^The [sqlite3_wal_hook()] function is used to register a callback that 7311** is invoked each time data is committed to a database in wal mode. 7312** 7313** ^(The callback is invoked by SQLite after the commit has taken place and 7314** the associated write-lock on the database released)^, so the implementation 7315** may read, write or [checkpoint] the database as required. 7316** 7317** ^The first parameter passed to the callback function when it is invoked 7318** is a copy of the third parameter passed to sqlite3_wal_hook() when 7319** registering the callback. ^The second is a copy of the database handle. 7320** ^The third parameter is the name of the database that was written to - 7321** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 7322** is the number of pages currently in the write-ahead log file, 7323** including those that were just committed. 7324** 7325** The callback function should normally return [SQLITE_OK]. ^If an error 7326** code is returned, that error will propagate back up through the 7327** SQLite code base to cause the statement that provoked the callback 7328** to report an error, though the commit will have still occurred. If the 7329** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 7330** that does not correspond to any valid SQLite error code, the results 7331** are undefined. 7332** 7333** A single database handle may have at most a single write-ahead log callback 7334** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 7335** previously registered write-ahead log callback. ^Note that the 7336** [sqlite3_wal_autocheckpoint()] interface and the 7337** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 7338** those overwrite any prior [sqlite3_wal_hook()] settings. 7339*/ 7340SQLITE_API void *SQLITE_STDCALL sqlite3_wal_hook( 7341 sqlite3*, 7342 int(*)(void *,sqlite3*,const char*,int), 7343 void* 7344); 7345 7346/* 7347** CAPI3REF: Configure an auto-checkpoint 7348** METHOD: sqlite3 7349** 7350** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 7351** [sqlite3_wal_hook()] that causes any database on [database connection] D 7352** to automatically [checkpoint] 7353** after committing a transaction if there are N or 7354** more frames in the [write-ahead log] file. ^Passing zero or 7355** a negative value as the nFrame parameter disables automatic 7356** checkpoints entirely. 7357** 7358** ^The callback registered by this function replaces any existing callback 7359** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 7360** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 7361** configured by this function. 7362** 7363** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 7364** from SQL. 7365** 7366** ^Checkpoints initiated by this mechanism are 7367** [sqlite3_wal_checkpoint_v2|PASSIVE]. 7368** 7369** ^Every new [database connection] defaults to having the auto-checkpoint 7370** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 7371** pages. The use of this interface 7372** is only necessary if the default setting is found to be suboptimal 7373** for a particular application. 7374*/ 7375SQLITE_API int SQLITE_STDCALL sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 7376 7377/* 7378** CAPI3REF: Checkpoint a database 7379** METHOD: sqlite3 7380** 7381** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 7382** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 7383** 7384** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 7385** [write-ahead log] for database X on [database connection] D to be 7386** transferred into the database file and for the write-ahead log to 7387** be reset. See the [checkpointing] documentation for addition 7388** information. 7389** 7390** This interface used to be the only way to cause a checkpoint to 7391** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 7392** interface was added. This interface is retained for backwards 7393** compatibility and as a convenience for applications that need to manually 7394** start a callback but which do not need the full power (and corresponding 7395** complication) of [sqlite3_wal_checkpoint_v2()]. 7396*/ 7397SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 7398 7399/* 7400** CAPI3REF: Checkpoint a database 7401** METHOD: sqlite3 7402** 7403** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 7404** operation on database X of [database connection] D in mode M. Status 7405** information is written back into integers pointed to by L and C.)^ 7406** ^(The M parameter must be a valid [checkpoint mode]:)^ 7407** 7408** <dl> 7409** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 7410** ^Checkpoint as many frames as possible without waiting for any database 7411** readers or writers to finish, then sync the database file if all frames 7412** in the log were checkpointed. ^The [busy-handler callback] 7413** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 7414** ^On the other hand, passive mode might leave the checkpoint unfinished 7415** if there are concurrent readers or writers. 7416** 7417** <dt>SQLITE_CHECKPOINT_FULL<dd> 7418** ^This mode blocks (it invokes the 7419** [sqlite3_busy_handler|busy-handler callback]) until there is no 7420** database writer and all readers are reading from the most recent database 7421** snapshot. ^It then checkpoints all frames in the log file and syncs the 7422** database file. ^This mode blocks new database writers while it is pending, 7423** but new database readers are allowed to continue unimpeded. 7424** 7425** <dt>SQLITE_CHECKPOINT_RESTART<dd> 7426** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 7427** that after checkpointing the log file it blocks (calls the 7428** [busy-handler callback]) 7429** until all readers are reading from the database file only. ^This ensures 7430** that the next writer will restart the log file from the beginning. 7431** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 7432** database writer attempts while it is pending, but does not impede readers. 7433** 7434** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 7435** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 7436** addition that it also truncates the log file to zero bytes just prior 7437** to a successful return. 7438** </dl> 7439** 7440** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 7441** the log file or to -1 if the checkpoint could not run because 7442** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 7443** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 7444** log file (including any that were already checkpointed before the function 7445** was called) or to -1 if the checkpoint could not run due to an error or 7446** because the database is not in WAL mode. ^Note that upon successful 7447** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 7448** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 7449** 7450** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 7451** any other process is running a checkpoint operation at the same time, the 7452** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 7453** busy-handler configured, it will not be invoked in this case. 7454** 7455** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 7456** exclusive "writer" lock on the database file. ^If the writer lock cannot be 7457** obtained immediately, and a busy-handler is configured, it is invoked and 7458** the writer lock retried until either the busy-handler returns 0 or the lock 7459** is successfully obtained. ^The busy-handler is also invoked while waiting for 7460** database readers as described above. ^If the busy-handler returns 0 before 7461** the writer lock is obtained or while waiting for database readers, the 7462** checkpoint operation proceeds from that point in the same way as 7463** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 7464** without blocking any further. ^SQLITE_BUSY is returned in this case. 7465** 7466** ^If parameter zDb is NULL or points to a zero length string, then the 7467** specified operation is attempted on all WAL databases [attached] to 7468** [database connection] db. In this case the 7469** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 7470** an SQLITE_BUSY error is encountered when processing one or more of the 7471** attached WAL databases, the operation is still attempted on any remaining 7472** attached databases and SQLITE_BUSY is returned at the end. ^If any other 7473** error occurs while processing an attached database, processing is abandoned 7474** and the error code is returned to the caller immediately. ^If no error 7475** (SQLITE_BUSY or otherwise) is encountered while processing the attached 7476** databases, SQLITE_OK is returned. 7477** 7478** ^If database zDb is the name of an attached database that is not in WAL 7479** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 7480** zDb is not NULL (or a zero length string) and is not the name of any 7481** attached database, SQLITE_ERROR is returned to the caller. 7482** 7483** ^Unless it returns SQLITE_MISUSE, 7484** the sqlite3_wal_checkpoint_v2() interface 7485** sets the error information that is queried by 7486** [sqlite3_errcode()] and [sqlite3_errmsg()]. 7487** 7488** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 7489** from SQL. 7490*/ 7491SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint_v2( 7492 sqlite3 *db, /* Database handle */ 7493 const char *zDb, /* Name of attached database (or NULL) */ 7494 int eMode, /* SQLITE_CHECKPOINT_* value */ 7495 int *pnLog, /* OUT: Size of WAL log in frames */ 7496 int *pnCkpt /* OUT: Total number of frames checkpointed */ 7497); 7498 7499/* 7500** CAPI3REF: Checkpoint Mode Values 7501** KEYWORDS: {checkpoint mode} 7502** 7503** These constants define all valid values for the "checkpoint mode" passed 7504** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 7505** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 7506** meaning of each of these checkpoint modes. 7507*/ 7508#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 7509#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 7510#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 7511#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 7512 7513/* 7514** CAPI3REF: Virtual Table Interface Configuration 7515** 7516** This function may be called by either the [xConnect] or [xCreate] method 7517** of a [virtual table] implementation to configure 7518** various facets of the virtual table interface. 7519** 7520** If this interface is invoked outside the context of an xConnect or 7521** xCreate virtual table method then the behavior is undefined. 7522** 7523** At present, there is only one option that may be configured using 7524** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 7525** may be added in the future. 7526*/ 7527SQLITE_API int SQLITE_CDECL sqlite3_vtab_config(sqlite3*, int op, ...); 7528 7529/* 7530** CAPI3REF: Virtual Table Configuration Options 7531** 7532** These macros define the various options to the 7533** [sqlite3_vtab_config()] interface that [virtual table] implementations 7534** can use to customize and optimize their behavior. 7535** 7536** <dl> 7537** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 7538** <dd>Calls of the form 7539** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 7540** where X is an integer. If X is zero, then the [virtual table] whose 7541** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 7542** support constraints. In this configuration (which is the default) if 7543** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 7544** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 7545** specified as part of the users SQL statement, regardless of the actual 7546** ON CONFLICT mode specified. 7547** 7548** If X is non-zero, then the virtual table implementation guarantees 7549** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 7550** any modifications to internal or persistent data structures have been made. 7551** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 7552** is able to roll back a statement or database transaction, and abandon 7553** or continue processing the current SQL statement as appropriate. 7554** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 7555** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 7556** had been ABORT. 7557** 7558** Virtual table implementations that are required to handle OR REPLACE 7559** must do so within the [xUpdate] method. If a call to the 7560** [sqlite3_vtab_on_conflict()] function indicates that the current ON 7561** CONFLICT policy is REPLACE, the virtual table implementation should 7562** silently replace the appropriate rows within the xUpdate callback and 7563** return SQLITE_OK. Or, if this is not possible, it may return 7564** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 7565** constraint handling. 7566** </dl> 7567*/ 7568#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 7569 7570/* 7571** CAPI3REF: Determine The Virtual Table Conflict Policy 7572** 7573** This function may only be called from within a call to the [xUpdate] method 7574** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 7575** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 7576** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 7577** of the SQL statement that triggered the call to the [xUpdate] method of the 7578** [virtual table]. 7579*/ 7580SQLITE_API int SQLITE_STDCALL sqlite3_vtab_on_conflict(sqlite3 *); 7581 7582/* 7583** CAPI3REF: Conflict resolution modes 7584** KEYWORDS: {conflict resolution mode} 7585** 7586** These constants are returned by [sqlite3_vtab_on_conflict()] to 7587** inform a [virtual table] implementation what the [ON CONFLICT] mode 7588** is for the SQL statement being evaluated. 7589** 7590** Note that the [SQLITE_IGNORE] constant is also used as a potential 7591** return value from the [sqlite3_set_authorizer()] callback and that 7592** [SQLITE_ABORT] is also a [result code]. 7593*/ 7594#define SQLITE_ROLLBACK 1 7595/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 7596#define SQLITE_FAIL 3 7597/* #define SQLITE_ABORT 4 // Also an error code */ 7598#define SQLITE_REPLACE 5 7599 7600/* 7601** CAPI3REF: Prepared Statement Scan Status Opcodes 7602** KEYWORDS: {scanstatus options} 7603** 7604** The following constants can be used for the T parameter to the 7605** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 7606** different metric for sqlite3_stmt_scanstatus() to return. 7607** 7608** When the value returned to V is a string, space to hold that string is 7609** managed by the prepared statement S and will be automatically freed when 7610** S is finalized. 7611** 7612** <dl> 7613** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 7614** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 7615** set to the total number of times that the X-th loop has run.</dd> 7616** 7617** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 7618** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 7619** to the total number of rows examined by all iterations of the X-th loop.</dd> 7620** 7621** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 7622** <dd>^The "double" variable pointed to by the T parameter will be set to the 7623** query planner's estimate for the average number of rows output from each 7624** iteration of the X-th loop. If the query planner's estimates was accurate, 7625** then this value will approximate the quotient NVISIT/NLOOP and the 7626** product of this value for all prior loops with the same SELECTID will 7627** be the NLOOP value for the current loop. 7628** 7629** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 7630** <dd>^The "const char *" variable pointed to by the T parameter will be set 7631** to a zero-terminated UTF-8 string containing the name of the index or table 7632** used for the X-th loop. 7633** 7634** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 7635** <dd>^The "const char *" variable pointed to by the T parameter will be set 7636** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 7637** description for the X-th loop. 7638** 7639** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 7640** <dd>^The "int" variable pointed to by the T parameter will be set to the 7641** "select-id" for the X-th loop. The select-id identifies which query or 7642** subquery the loop is part of. The main query has a select-id of zero. 7643** The select-id is the same value as is output in the first column 7644** of an [EXPLAIN QUERY PLAN] query. 7645** </dl> 7646*/ 7647#define SQLITE_SCANSTAT_NLOOP 0 7648#define SQLITE_SCANSTAT_NVISIT 1 7649#define SQLITE_SCANSTAT_EST 2 7650#define SQLITE_SCANSTAT_NAME 3 7651#define SQLITE_SCANSTAT_EXPLAIN 4 7652#define SQLITE_SCANSTAT_SELECTID 5 7653 7654/* 7655** CAPI3REF: Prepared Statement Scan Status 7656** METHOD: sqlite3_stmt 7657** 7658** This interface returns information about the predicted and measured 7659** performance for pStmt. Advanced applications can use this 7660** interface to compare the predicted and the measured performance and 7661** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 7662** 7663** Since this interface is expected to be rarely used, it is only 7664** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 7665** compile-time option. 7666** 7667** The "iScanStatusOp" parameter determines which status information to return. 7668** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 7669** of this interface is undefined. 7670** ^The requested measurement is written into a variable pointed to by 7671** the "pOut" parameter. 7672** Parameter "idx" identifies the specific loop to retrieve statistics for. 7673** Loops are numbered starting from zero. ^If idx is out of range - less than 7674** zero or greater than or equal to the total number of loops used to implement 7675** the statement - a non-zero value is returned and the variable that pOut 7676** points to is unchanged. 7677** 7678** ^Statistics might not be available for all loops in all statements. ^In cases 7679** where there exist loops with no available statistics, this function behaves 7680** as if the loop did not exist - it returns non-zero and leave the variable 7681** that pOut points to unchanged. 7682** 7683** See also: [sqlite3_stmt_scanstatus_reset()] 7684*/ 7685SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_stmt_scanstatus( 7686 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 7687 int idx, /* Index of loop to report on */ 7688 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 7689 void *pOut /* Result written here */ 7690); 7691 7692/* 7693** CAPI3REF: Zero Scan-Status Counters 7694** METHOD: sqlite3_stmt 7695** 7696** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 7697** 7698** This API is only available if the library is built with pre-processor 7699** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 7700*/ 7701SQLITE_API SQLITE_EXPERIMENTAL void SQLITE_STDCALL sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 7702 7703 7704/* 7705** Undo the hack that converts floating point types to integer for 7706** builds on processors without floating point support. 7707*/ 7708#ifdef SQLITE_OMIT_FLOATING_POINT 7709# undef double 7710#endif 7711 7712#ifdef __cplusplus 7713} /* End of the 'extern "C"' block */ 7714#endif 7715#endif /* _SQLITE3_H_ */ 7716 7717/* 7718** 2010 August 30 7719** 7720** The author disclaims copyright to this source code. In place of 7721** a legal notice, here is a blessing: 7722** 7723** May you do good and not evil. 7724** May you find forgiveness for yourself and forgive others. 7725** May you share freely, never taking more than you give. 7726** 7727************************************************************************* 7728*/ 7729 7730#ifndef _SQLITE3RTREE_H_ 7731#define _SQLITE3RTREE_H_ 7732 7733 7734#ifdef __cplusplus 7735extern "C" { 7736#endif 7737 7738typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 7739typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 7740 7741/* The double-precision datatype used by RTree depends on the 7742** SQLITE_RTREE_INT_ONLY compile-time option. 7743*/ 7744#ifdef SQLITE_RTREE_INT_ONLY 7745 typedef sqlite3_int64 sqlite3_rtree_dbl; 7746#else 7747 typedef double sqlite3_rtree_dbl; 7748#endif 7749 7750/* 7751** Register a geometry callback named zGeom that can be used as part of an 7752** R-Tree geometry query as follows: 7753** 7754** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 7755*/ 7756SQLITE_API int SQLITE_STDCALL sqlite3_rtree_geometry_callback( 7757 sqlite3 *db, 7758 const char *zGeom, 7759 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 7760 void *pContext 7761); 7762 7763 7764/* 7765** A pointer to a structure of the following type is passed as the first 7766** argument to callbacks registered using rtree_geometry_callback(). 7767*/ 7768struct sqlite3_rtree_geometry { 7769 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 7770 int nParam; /* Size of array aParam[] */ 7771 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 7772 void *pUser; /* Callback implementation user data */ 7773 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 7774}; 7775 7776/* 7777** Register a 2nd-generation geometry callback named zScore that can be 7778** used as part of an R-Tree geometry query as follows: 7779** 7780** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 7781*/ 7782SQLITE_API int SQLITE_STDCALL sqlite3_rtree_query_callback( 7783 sqlite3 *db, 7784 const char *zQueryFunc, 7785 int (*xQueryFunc)(sqlite3_rtree_query_info*), 7786 void *pContext, 7787 void (*xDestructor)(void*) 7788); 7789 7790 7791/* 7792** A pointer to a structure of the following type is passed as the 7793** argument to scored geometry callback registered using 7794** sqlite3_rtree_query_callback(). 7795** 7796** Note that the first 5 fields of this structure are identical to 7797** sqlite3_rtree_geometry. This structure is a subclass of 7798** sqlite3_rtree_geometry. 7799*/ 7800struct sqlite3_rtree_query_info { 7801 void *pContext; /* pContext from when function registered */ 7802 int nParam; /* Number of function parameters */ 7803 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 7804 void *pUser; /* callback can use this, if desired */ 7805 void (*xDelUser)(void*); /* function to free pUser */ 7806 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 7807 unsigned int *anQueue; /* Number of pending entries in the queue */ 7808 int nCoord; /* Number of coordinates */ 7809 int iLevel; /* Level of current node or entry */ 7810 int mxLevel; /* The largest iLevel value in the tree */ 7811 sqlite3_int64 iRowid; /* Rowid for current entry */ 7812 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 7813 int eParentWithin; /* Visibility of parent node */ 7814 int eWithin; /* OUT: Visiblity */ 7815 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 7816}; 7817 7818/* 7819** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 7820*/ 7821#define NOT_WITHIN 0 /* Object completely outside of query region */ 7822#define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 7823#define FULLY_WITHIN 2 /* Object fully contained within query region */ 7824 7825 7826#ifdef __cplusplus 7827} /* end of the 'extern "C"' block */ 7828#endif 7829 7830#endif /* ifndef _SQLITE3RTREE_H_ */ 7831 7832