1/* 2** 2001 September 15 3** 4** The author disclaims copyright to this source code. In place of 5** a legal notice, here is a blessing: 6** 7** May you do good and not evil. 8** May you find forgiveness for yourself and forgive others. 9** May you share freely, never taking more than you give. 10** 11************************************************************************* 12** This header file defines the interface that the SQLite library 13** presents to client programs. If a C-function, structure, datatype, 14** or constant definition does not appear in this file, then it is 15** not a published API of SQLite, is subject to change without 16** notice, and should not be referenced by programs that use SQLite. 17** 18** Some of the definitions that are in this file are marked as 19** "experimental". Experimental interfaces are normally new 20** features recently added to SQLite. We do not anticipate changes 21** to experimental interfaces but reserve the right to make minor changes 22** if experience from use "in the wild" suggest such changes are prudent. 23** 24** The official C-language API documentation for SQLite is derived 25** from comments in this file. This file is the authoritative source 26** on how SQLite interfaces are supposed to operate. 27** 28** The name of this file under configuration management is "sqlite.h.in". 29** The makefile makes some minor changes to this file (such as inserting 30** the version number) and changes its name to "sqlite3.h" as 31** part of the build process. 32*/ 33#ifndef _SQLITE3_H_ 34#define _SQLITE3_H_ 35#include <stdarg.h> /* Needed for the definition of va_list */ 36 37/* 38** Make sure we can call this stuff from C++. 39*/ 40#ifdef __cplusplus 41extern "C" { 42#endif 43 44 45/* 46** Provide the ability to override linkage features of the interface. 47*/ 48#ifndef SQLITE_EXTERN 49# define SQLITE_EXTERN extern 50#endif 51#ifndef SQLITE_API 52# define SQLITE_API 53#endif 54#ifndef SQLITE_CDECL 55# define SQLITE_CDECL 56#endif 57#ifndef SQLITE_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 "--VERS--" 115#define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- 116#define SQLITE_SOURCE_ID "--SOURCE-ID--" 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_EXTERN const char sqlite3_version[]; 149const char *sqlite3_libversion(void); 150const char *sqlite3_sourceid(void); 151int 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 176int sqlite3_compileoption_used(const char *zOptName); 177const char *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*/ 216int 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*/ 313int sqlite3_close(sqlite3*); 314int 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*/ 385int 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_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 481#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 482#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 483#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 484#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 485#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 486#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 487#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 488#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 489#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 490#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 491#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 492#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 493#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 494#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 495#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 496#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 497#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 498#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 499#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 500#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 501#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 502#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 503#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 504#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 505#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 506#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 507#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 508 509/* 510** CAPI3REF: Flags For File Open Operations 511** 512** These bit values are intended for use in the 513** 3rd parameter to the [sqlite3_open_v2()] interface and 514** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 515*/ 516#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 517#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 518#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 519#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 520#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 521#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 522#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 523#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 524#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 525#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 526#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 527#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 528#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 529#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 530#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 531#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 532#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 533#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 534#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 535#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 536 537/* Reserved: 0x00F00000 */ 538 539/* 540** CAPI3REF: Device Characteristics 541** 542** The xDeviceCharacteristics method of the [sqlite3_io_methods] 543** object returns an integer which is a vector of these 544** bit values expressing I/O characteristics of the mass storage 545** device that holds the file that the [sqlite3_io_methods] 546** refers to. 547** 548** The SQLITE_IOCAP_ATOMIC property means that all writes of 549** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 550** mean that writes of blocks that are nnn bytes in size and 551** are aligned to an address which is an integer multiple of 552** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 553** that when data is appended to a file, the data is appended 554** first then the size of the file is extended, never the other 555** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 556** information is written to disk in the same order as calls 557** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 558** after reboot following a crash or power loss, the only bytes in a 559** file that were written at the application level might have changed 560** and that adjacent bytes, even bytes within the same sector are 561** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 562** flag indicate that a file cannot be deleted when open. The 563** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 564** read-only media and cannot be changed even by processes with 565** elevated privileges. 566*/ 567#define SQLITE_IOCAP_ATOMIC 0x00000001 568#define SQLITE_IOCAP_ATOMIC512 0x00000002 569#define SQLITE_IOCAP_ATOMIC1K 0x00000004 570#define SQLITE_IOCAP_ATOMIC2K 0x00000008 571#define SQLITE_IOCAP_ATOMIC4K 0x00000010 572#define SQLITE_IOCAP_ATOMIC8K 0x00000020 573#define SQLITE_IOCAP_ATOMIC16K 0x00000040 574#define SQLITE_IOCAP_ATOMIC32K 0x00000080 575#define SQLITE_IOCAP_ATOMIC64K 0x00000100 576#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 577#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 578#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 579#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 580#define SQLITE_IOCAP_IMMUTABLE 0x00002000 581 582/* 583** CAPI3REF: File Locking Levels 584** 585** SQLite uses one of these integer values as the second 586** argument to calls it makes to the xLock() and xUnlock() methods 587** of an [sqlite3_io_methods] object. 588*/ 589#define SQLITE_LOCK_NONE 0 590#define SQLITE_LOCK_SHARED 1 591#define SQLITE_LOCK_RESERVED 2 592#define SQLITE_LOCK_PENDING 3 593#define SQLITE_LOCK_EXCLUSIVE 4 594 595/* 596** CAPI3REF: Synchronization Type Flags 597** 598** When SQLite invokes the xSync() method of an 599** [sqlite3_io_methods] object it uses a combination of 600** these integer values as the second argument. 601** 602** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 603** sync operation only needs to flush data to mass storage. Inode 604** information need not be flushed. If the lower four bits of the flag 605** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 606** If the lower four bits equal SQLITE_SYNC_FULL, that means 607** to use Mac OS X style fullsync instead of fsync(). 608** 609** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 610** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 611** settings. The [synchronous pragma] determines when calls to the 612** xSync VFS method occur and applies uniformly across all platforms. 613** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 614** energetic or rigorous or forceful the sync operations are and 615** only make a difference on Mac OSX for the default SQLite code. 616** (Third-party VFS implementations might also make the distinction 617** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 618** operating systems natively supported by SQLite, only Mac OSX 619** cares about the difference.) 620*/ 621#define SQLITE_SYNC_NORMAL 0x00002 622#define SQLITE_SYNC_FULL 0x00003 623#define SQLITE_SYNC_DATAONLY 0x00010 624 625/* 626** CAPI3REF: OS Interface Open File Handle 627** 628** An [sqlite3_file] object represents an open file in the 629** [sqlite3_vfs | OS interface layer]. Individual OS interface 630** implementations will 631** want to subclass this object by appending additional fields 632** for their own use. The pMethods entry is a pointer to an 633** [sqlite3_io_methods] object that defines methods for performing 634** I/O operations on the open file. 635*/ 636typedef struct sqlite3_file sqlite3_file; 637struct sqlite3_file { 638 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 639}; 640 641/* 642** CAPI3REF: OS Interface File Virtual Methods Object 643** 644** Every file opened by the [sqlite3_vfs.xOpen] method populates an 645** [sqlite3_file] object (or, more commonly, a subclass of the 646** [sqlite3_file] object) with a pointer to an instance of this object. 647** This object defines the methods used to perform various operations 648** against the open file represented by the [sqlite3_file] object. 649** 650** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 651** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 652** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 653** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 654** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 655** to NULL. 656** 657** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 658** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 659** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 660** flag may be ORed in to indicate that only the data of the file 661** and not its inode needs to be synced. 662** 663** The integer values to xLock() and xUnlock() are one of 664** <ul> 665** <li> [SQLITE_LOCK_NONE], 666** <li> [SQLITE_LOCK_SHARED], 667** <li> [SQLITE_LOCK_RESERVED], 668** <li> [SQLITE_LOCK_PENDING], or 669** <li> [SQLITE_LOCK_EXCLUSIVE]. 670** </ul> 671** xLock() increases the lock. xUnlock() decreases the lock. 672** The xCheckReservedLock() method checks whether any database connection, 673** either in this process or in some other process, is holding a RESERVED, 674** PENDING, or EXCLUSIVE lock on the file. It returns true 675** if such a lock exists and false otherwise. 676** 677** The xFileControl() method is a generic interface that allows custom 678** VFS implementations to directly control an open file using the 679** [sqlite3_file_control()] interface. The second "op" argument is an 680** integer opcode. The third argument is a generic pointer intended to 681** point to a structure that may contain arguments or space in which to 682** write return values. Potential uses for xFileControl() might be 683** functions to enable blocking locks with timeouts, to change the 684** locking strategy (for example to use dot-file locks), to inquire 685** about the status of a lock, or to break stale locks. The SQLite 686** core reserves all opcodes less than 100 for its own use. 687** A [file control opcodes | list of opcodes] less than 100 is available. 688** Applications that define a custom xFileControl method should use opcodes 689** greater than 100 to avoid conflicts. VFS implementations should 690** return [SQLITE_NOTFOUND] for file control opcodes that they do not 691** recognize. 692** 693** The xSectorSize() method returns the sector size of the 694** device that underlies the file. The sector size is the 695** minimum write that can be performed without disturbing 696** other bytes in the file. The xDeviceCharacteristics() 697** method returns a bit vector describing behaviors of the 698** underlying device: 699** 700** <ul> 701** <li> [SQLITE_IOCAP_ATOMIC] 702** <li> [SQLITE_IOCAP_ATOMIC512] 703** <li> [SQLITE_IOCAP_ATOMIC1K] 704** <li> [SQLITE_IOCAP_ATOMIC2K] 705** <li> [SQLITE_IOCAP_ATOMIC4K] 706** <li> [SQLITE_IOCAP_ATOMIC8K] 707** <li> [SQLITE_IOCAP_ATOMIC16K] 708** <li> [SQLITE_IOCAP_ATOMIC32K] 709** <li> [SQLITE_IOCAP_ATOMIC64K] 710** <li> [SQLITE_IOCAP_SAFE_APPEND] 711** <li> [SQLITE_IOCAP_SEQUENTIAL] 712** </ul> 713** 714** The SQLITE_IOCAP_ATOMIC property means that all writes of 715** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 716** mean that writes of blocks that are nnn bytes in size and 717** are aligned to an address which is an integer multiple of 718** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 719** that when data is appended to a file, the data is appended 720** first then the size of the file is extended, never the other 721** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 722** information is written to disk in the same order as calls 723** to xWrite(). 724** 725** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 726** in the unread portions of the buffer with zeros. A VFS that 727** fails to zero-fill short reads might seem to work. However, 728** failure to zero-fill short reads will eventually lead to 729** database corruption. 730*/ 731typedef struct sqlite3_io_methods sqlite3_io_methods; 732struct sqlite3_io_methods { 733 int iVersion; 734 int (*xClose)(sqlite3_file*); 735 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 736 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 737 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 738 int (*xSync)(sqlite3_file*, int flags); 739 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 740 int (*xLock)(sqlite3_file*, int); 741 int (*xUnlock)(sqlite3_file*, int); 742 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 743 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 744 int (*xSectorSize)(sqlite3_file*); 745 int (*xDeviceCharacteristics)(sqlite3_file*); 746 /* Methods above are valid for version 1 */ 747 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 748 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 749 void (*xShmBarrier)(sqlite3_file*); 750 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 751 /* Methods above are valid for version 2 */ 752 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 753 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 754 /* Methods above are valid for version 3 */ 755 /* Additional methods may be added in future releases */ 756}; 757 758/* 759** CAPI3REF: Standard File Control Opcodes 760** KEYWORDS: {file control opcodes} {file control opcode} 761** 762** These integer constants are opcodes for the xFileControl method 763** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 764** interface. 765** 766** <ul> 767** <li>[[SQLITE_FCNTL_LOCKSTATE]] 768** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 769** opcode causes the xFileControl method to write the current state of 770** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 771** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 772** into an integer that the pArg argument points to. This capability 773** is used during testing and is only available when the SQLITE_TEST 774** compile-time option is used. 775** 776** <li>[[SQLITE_FCNTL_SIZE_HINT]] 777** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 778** layer a hint of how large the database file will grow to be during the 779** current transaction. This hint is not guaranteed to be accurate but it 780** is often close. The underlying VFS might choose to preallocate database 781** file space based on this hint in order to help writes to the database 782** file run faster. 783** 784** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 785** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 786** extends and truncates the database file in chunks of a size specified 787** by the user. The fourth argument to [sqlite3_file_control()] should 788** point to an integer (type int) containing the new chunk-size to use 789** for the nominated database. Allocating database file space in large 790** chunks (say 1MB at a time), may reduce file-system fragmentation and 791** improve performance on some systems. 792** 793** <li>[[SQLITE_FCNTL_FILE_POINTER]] 794** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 795** to the [sqlite3_file] object associated with a particular database 796** connection. See the [sqlite3_file_control()] documentation for 797** additional information. 798** 799** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 800** No longer in use. 801** 802** <li>[[SQLITE_FCNTL_SYNC]] 803** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 804** sent to the VFS immediately before the xSync method is invoked on a 805** database file descriptor. Or, if the xSync method is not invoked 806** because the user has configured SQLite with 807** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 808** of the xSync method. In most cases, the pointer argument passed with 809** this file-control is NULL. However, if the database file is being synced 810** as part of a multi-database commit, the argument points to a nul-terminated 811** string containing the transactions master-journal file name. VFSes that 812** do not need this signal should silently ignore this opcode. Applications 813** should not call [sqlite3_file_control()] with this opcode as doing so may 814** disrupt the operation of the specialized VFSes that do require it. 815** 816** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 817** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 818** and sent to the VFS after a transaction has been committed immediately 819** but before the database is unlocked. VFSes that do not need this signal 820** should silently ignore this opcode. Applications should not call 821** [sqlite3_file_control()] with this opcode as doing so may disrupt the 822** operation of the specialized VFSes that do require it. 823** 824** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 825** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 826** retry counts and intervals for certain disk I/O operations for the 827** windows [VFS] in order to provide robustness in the presence of 828** anti-virus programs. By default, the windows VFS will retry file read, 829** file write, and file delete operations up to 10 times, with a delay 830** of 25 milliseconds before the first retry and with the delay increasing 831** by an additional 25 milliseconds with each subsequent retry. This 832** opcode allows these two values (10 retries and 25 milliseconds of delay) 833** to be adjusted. The values are changed for all database connections 834** within the same process. The argument is a pointer to an array of two 835** integers where the first integer i the new retry count and the second 836** integer is the delay. If either integer is negative, then the setting 837** is not changed but instead the prior value of that setting is written 838** into the array entry, allowing the current retry settings to be 839** interrogated. The zDbName parameter is ignored. 840** 841** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 842** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 843** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 844** write ahead log and shared memory files used for transaction control 845** are automatically deleted when the latest connection to the database 846** closes. Setting persistent WAL mode causes those files to persist after 847** close. Persisting the files is useful when other processes that do not 848** have write permission on the directory containing the database file want 849** to read the database file, as the WAL and shared memory files must exist 850** in order for the database to be readable. The fourth parameter to 851** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 852** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 853** WAL mode. If the integer is -1, then it is overwritten with the current 854** WAL persistence setting. 855** 856** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 857** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 858** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 859** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 860** xDeviceCharacteristics methods. The fourth parameter to 861** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 862** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 863** mode. If the integer is -1, then it is overwritten with the current 864** zero-damage mode setting. 865** 866** <li>[[SQLITE_FCNTL_OVERWRITE]] 867** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 868** a write transaction to indicate that, unless it is rolled back for some 869** reason, the entire database file will be overwritten by the current 870** transaction. This is used by VACUUM operations. 871** 872** <li>[[SQLITE_FCNTL_VFSNAME]] 873** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 874** all [VFSes] in the VFS stack. The names are of all VFS shims and the 875** final bottom-level VFS are written into memory obtained from 876** [sqlite3_malloc()] and the result is stored in the char* variable 877** that the fourth parameter of [sqlite3_file_control()] points to. 878** The caller is responsible for freeing the memory when done. As with 879** all file-control actions, there is no guarantee that this will actually 880** do anything. Callers should initialize the char* variable to a NULL 881** pointer in case this file-control is not implemented. This file-control 882** is intended for diagnostic use only. 883** 884** <li>[[SQLITE_FCNTL_PRAGMA]] 885** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 886** file control is sent to the open [sqlite3_file] object corresponding 887** to the database file to which the pragma statement refers. ^The argument 888** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 889** pointers to strings (char**) in which the second element of the array 890** is the name of the pragma and the third element is the argument to the 891** pragma or NULL if the pragma has no argument. ^The handler for an 892** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 893** of the char** argument point to a string obtained from [sqlite3_mprintf()] 894** or the equivalent and that string will become the result of the pragma or 895** the error message if the pragma fails. ^If the 896** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 897** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 898** file control returns [SQLITE_OK], then the parser assumes that the 899** VFS has handled the PRAGMA itself and the parser generates a no-op 900** prepared statement if result string is NULL, or that returns a copy 901** of the result string if the string is non-NULL. 902** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 903** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 904** that the VFS encountered an error while handling the [PRAGMA] and the 905** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 906** file control occurs at the beginning of pragma statement analysis and so 907** it is able to override built-in [PRAGMA] statements. 908** 909** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 910** ^The [SQLITE_FCNTL_BUSYHANDLER] 911** file-control may be invoked by SQLite on the database file handle 912** shortly after it is opened in order to provide a custom VFS with access 913** to the connections busy-handler callback. The argument is of type (void **) 914** - an array of two (void *) values. The first (void *) actually points 915** to a function of type (int (*)(void *)). In order to invoke the connections 916** busy-handler, this function should be invoked with the second (void *) in 917** the array as the only argument. If it returns non-zero, then the operation 918** should be retried. If it returns zero, the custom VFS should abandon the 919** current operation. 920** 921** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 922** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 923** to have SQLite generate a 924** temporary filename using the same algorithm that is followed to generate 925** temporary filenames for TEMP tables and other internal uses. The 926** argument should be a char** which will be filled with the filename 927** written into memory obtained from [sqlite3_malloc()]. The caller should 928** invoke [sqlite3_free()] on the result to avoid a memory leak. 929** 930** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 931** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 932** maximum number of bytes that will be used for memory-mapped I/O. 933** The argument is a pointer to a value of type sqlite3_int64 that 934** is an advisory maximum number of bytes in the file to memory map. The 935** pointer is overwritten with the old value. The limit is not changed if 936** the value originally pointed to is negative, and so the current limit 937** can be queried by passing in a pointer to a negative number. This 938** file-control is used internally to implement [PRAGMA mmap_size]. 939** 940** <li>[[SQLITE_FCNTL_TRACE]] 941** The [SQLITE_FCNTL_TRACE] file control provides advisory information 942** to the VFS about what the higher layers of the SQLite stack are doing. 943** This file control is used by some VFS activity tracing [shims]. 944** The argument is a zero-terminated string. Higher layers in the 945** SQLite stack may generate instances of this file control if 946** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 947** 948** <li>[[SQLITE_FCNTL_HAS_MOVED]] 949** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 950** pointer to an integer and it writes a boolean into that integer depending 951** on whether or not the file has been renamed, moved, or deleted since it 952** was first opened. 953** 954** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 955** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 956** opcode causes the xFileControl method to swap the file handle with the one 957** pointed to by the pArg argument. This capability is used during testing 958** and only needs to be supported when SQLITE_TEST is defined. 959** 960** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 961** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 962** be advantageous to block on the next WAL lock if the lock is not immediately 963** available. The WAL subsystem issues this signal during rare 964** circumstances in order to fix a problem with priority inversion. 965** Applications should <em>not</em> use this file-control. 966** 967** <li>[[SQLITE_FCNTL_ZIPVFS]] 968** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 969** VFS should return SQLITE_NOTFOUND for this opcode. 970** 971** <li>[[SQLITE_FCNTL_RBU]] 972** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 973** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 974** this opcode. 975** </ul> 976*/ 977#define SQLITE_FCNTL_LOCKSTATE 1 978#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 979#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 980#define SQLITE_FCNTL_LAST_ERRNO 4 981#define SQLITE_FCNTL_SIZE_HINT 5 982#define SQLITE_FCNTL_CHUNK_SIZE 6 983#define SQLITE_FCNTL_FILE_POINTER 7 984#define SQLITE_FCNTL_SYNC_OMITTED 8 985#define SQLITE_FCNTL_WIN32_AV_RETRY 9 986#define SQLITE_FCNTL_PERSIST_WAL 10 987#define SQLITE_FCNTL_OVERWRITE 11 988#define SQLITE_FCNTL_VFSNAME 12 989#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 990#define SQLITE_FCNTL_PRAGMA 14 991#define SQLITE_FCNTL_BUSYHANDLER 15 992#define SQLITE_FCNTL_TEMPFILENAME 16 993#define SQLITE_FCNTL_MMAP_SIZE 18 994#define SQLITE_FCNTL_TRACE 19 995#define SQLITE_FCNTL_HAS_MOVED 20 996#define SQLITE_FCNTL_SYNC 21 997#define SQLITE_FCNTL_COMMIT_PHASETWO 22 998#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 999#define SQLITE_FCNTL_WAL_BLOCK 24 1000#define SQLITE_FCNTL_ZIPVFS 25 1001#define SQLITE_FCNTL_RBU 26 1002 1003/* deprecated names */ 1004#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1005#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1006#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1007 1008 1009/* 1010** CAPI3REF: Mutex Handle 1011** 1012** The mutex module within SQLite defines [sqlite3_mutex] to be an 1013** abstract type for a mutex object. The SQLite core never looks 1014** at the internal representation of an [sqlite3_mutex]. It only 1015** deals with pointers to the [sqlite3_mutex] object. 1016** 1017** Mutexes are created using [sqlite3_mutex_alloc()]. 1018*/ 1019typedef struct sqlite3_mutex sqlite3_mutex; 1020 1021/* 1022** CAPI3REF: OS Interface Object 1023** 1024** An instance of the sqlite3_vfs object defines the interface between 1025** the SQLite core and the underlying operating system. The "vfs" 1026** in the name of the object stands for "virtual file system". See 1027** the [VFS | VFS documentation] for further information. 1028** 1029** The value of the iVersion field is initially 1 but may be larger in 1030** future versions of SQLite. Additional fields may be appended to this 1031** object when the iVersion value is increased. Note that the structure 1032** of the sqlite3_vfs object changes in the transaction between 1033** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 1034** modified. 1035** 1036** The szOsFile field is the size of the subclassed [sqlite3_file] 1037** structure used by this VFS. mxPathname is the maximum length of 1038** a pathname in this VFS. 1039** 1040** Registered sqlite3_vfs objects are kept on a linked list formed by 1041** the pNext pointer. The [sqlite3_vfs_register()] 1042** and [sqlite3_vfs_unregister()] interfaces manage this list 1043** in a thread-safe way. The [sqlite3_vfs_find()] interface 1044** searches the list. Neither the application code nor the VFS 1045** implementation should use the pNext pointer. 1046** 1047** The pNext field is the only field in the sqlite3_vfs 1048** structure that SQLite will ever modify. SQLite will only access 1049** or modify this field while holding a particular static mutex. 1050** The application should never modify anything within the sqlite3_vfs 1051** object once the object has been registered. 1052** 1053** The zName field holds the name of the VFS module. The name must 1054** be unique across all VFS modules. 1055** 1056** [[sqlite3_vfs.xOpen]] 1057** ^SQLite guarantees that the zFilename parameter to xOpen 1058** is either a NULL pointer or string obtained 1059** from xFullPathname() with an optional suffix added. 1060** ^If a suffix is added to the zFilename parameter, it will 1061** consist of a single "-" character followed by no more than 1062** 11 alphanumeric and/or "-" characters. 1063** ^SQLite further guarantees that 1064** the string will be valid and unchanged until xClose() is 1065** called. Because of the previous sentence, 1066** the [sqlite3_file] can safely store a pointer to the 1067** filename if it needs to remember the filename for some reason. 1068** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1069** must invent its own temporary name for the file. ^Whenever the 1070** xFilename parameter is NULL it will also be the case that the 1071** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1072** 1073** The flags argument to xOpen() includes all bits set in 1074** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1075** or [sqlite3_open16()] is used, then flags includes at least 1076** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1077** If xOpen() opens a file read-only then it sets *pOutFlags to 1078** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1079** 1080** ^(SQLite will also add one of the following flags to the xOpen() 1081** call, depending on the object being opened: 1082** 1083** <ul> 1084** <li> [SQLITE_OPEN_MAIN_DB] 1085** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1086** <li> [SQLITE_OPEN_TEMP_DB] 1087** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1088** <li> [SQLITE_OPEN_TRANSIENT_DB] 1089** <li> [SQLITE_OPEN_SUBJOURNAL] 1090** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1091** <li> [SQLITE_OPEN_WAL] 1092** </ul>)^ 1093** 1094** The file I/O implementation can use the object type flags to 1095** change the way it deals with files. For example, an application 1096** that does not care about crash recovery or rollback might make 1097** the open of a journal file a no-op. Writes to this journal would 1098** also be no-ops, and any attempt to read the journal would return 1099** SQLITE_IOERR. Or the implementation might recognize that a database 1100** file will be doing page-aligned sector reads and writes in a random 1101** order and set up its I/O subsystem accordingly. 1102** 1103** SQLite might also add one of the following flags to the xOpen method: 1104** 1105** <ul> 1106** <li> [SQLITE_OPEN_DELETEONCLOSE] 1107** <li> [SQLITE_OPEN_EXCLUSIVE] 1108** </ul> 1109** 1110** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1111** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1112** will be set for TEMP databases and their journals, transient 1113** databases, and subjournals. 1114** 1115** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1116** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1117** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1118** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1119** SQLITE_OPEN_CREATE, is used to indicate that file should always 1120** be created, and that it is an error if it already exists. 1121** It is <i>not</i> used to indicate the file should be opened 1122** for exclusive access. 1123** 1124** ^At least szOsFile bytes of memory are allocated by SQLite 1125** to hold the [sqlite3_file] structure passed as the third 1126** argument to xOpen. The xOpen method does not have to 1127** allocate the structure; it should just fill it in. Note that 1128** the xOpen method must set the sqlite3_file.pMethods to either 1129** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1130** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1131** element will be valid after xOpen returns regardless of the success 1132** or failure of the xOpen call. 1133** 1134** [[sqlite3_vfs.xAccess]] 1135** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1136** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1137** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1138** to test whether a file is at least readable. The file can be a 1139** directory. 1140** 1141** ^SQLite will always allocate at least mxPathname+1 bytes for the 1142** output buffer xFullPathname. The exact size of the output buffer 1143** is also passed as a parameter to both methods. If the output buffer 1144** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1145** handled as a fatal error by SQLite, vfs implementations should endeavor 1146** to prevent this by setting mxPathname to a sufficiently large value. 1147** 1148** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1149** interfaces are not strictly a part of the filesystem, but they are 1150** included in the VFS structure for completeness. 1151** The xRandomness() function attempts to return nBytes bytes 1152** of good-quality randomness into zOut. The return value is 1153** the actual number of bytes of randomness obtained. 1154** The xSleep() method causes the calling thread to sleep for at 1155** least the number of microseconds given. ^The xCurrentTime() 1156** method returns a Julian Day Number for the current date and time as 1157** a floating point value. 1158** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1159** Day Number multiplied by 86400000 (the number of milliseconds in 1160** a 24-hour day). 1161** ^SQLite will use the xCurrentTimeInt64() method to get the current 1162** date and time if that method is available (if iVersion is 2 or 1163** greater and the function pointer is not NULL) and will fall back 1164** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1165** 1166** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1167** are not used by the SQLite core. These optional interfaces are provided 1168** by some VFSes to facilitate testing of the VFS code. By overriding 1169** system calls with functions under its control, a test program can 1170** simulate faults and error conditions that would otherwise be difficult 1171** or impossible to induce. The set of system calls that can be overridden 1172** varies from one VFS to another, and from one version of the same VFS to the 1173** next. Applications that use these interfaces must be prepared for any 1174** or all of these interfaces to be NULL or for their behavior to change 1175** from one release to the next. Applications must not attempt to access 1176** any of these methods if the iVersion of the VFS is less than 3. 1177*/ 1178typedef struct sqlite3_vfs sqlite3_vfs; 1179typedef void (*sqlite3_syscall_ptr)(void); 1180struct sqlite3_vfs { 1181 int iVersion; /* Structure version number (currently 3) */ 1182 int szOsFile; /* Size of subclassed sqlite3_file */ 1183 int mxPathname; /* Maximum file pathname length */ 1184 sqlite3_vfs *pNext; /* Next registered VFS */ 1185 const char *zName; /* Name of this virtual file system */ 1186 void *pAppData; /* Pointer to application-specific data */ 1187 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1188 int flags, int *pOutFlags); 1189 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1190 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1191 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1192 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1193 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1194 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1195 void (*xDlClose)(sqlite3_vfs*, void*); 1196 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1197 int (*xSleep)(sqlite3_vfs*, int microseconds); 1198 int (*xCurrentTime)(sqlite3_vfs*, double*); 1199 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1200 /* 1201 ** The methods above are in version 1 of the sqlite_vfs object 1202 ** definition. Those that follow are added in version 2 or later 1203 */ 1204 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1205 /* 1206 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1207 ** Those below are for version 3 and greater. 1208 */ 1209 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1210 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1211 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1212 /* 1213 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1214 ** New fields may be appended in figure versions. The iVersion 1215 ** value will increment whenever this happens. 1216 */ 1217}; 1218 1219/* 1220** CAPI3REF: Flags for the xAccess VFS method 1221** 1222** These integer constants can be used as the third parameter to 1223** the xAccess method of an [sqlite3_vfs] object. They determine 1224** what kind of permissions the xAccess method is looking for. 1225** With SQLITE_ACCESS_EXISTS, the xAccess method 1226** simply checks whether the file exists. 1227** With SQLITE_ACCESS_READWRITE, the xAccess method 1228** checks whether the named directory is both readable and writable 1229** (in other words, if files can be added, removed, and renamed within 1230** the directory). 1231** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1232** [temp_store_directory pragma], though this could change in a future 1233** release of SQLite. 1234** With SQLITE_ACCESS_READ, the xAccess method 1235** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1236** currently unused, though it might be used in a future release of 1237** SQLite. 1238*/ 1239#define SQLITE_ACCESS_EXISTS 0 1240#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1241#define SQLITE_ACCESS_READ 2 /* Unused */ 1242 1243/* 1244** CAPI3REF: Flags for the xShmLock VFS method 1245** 1246** These integer constants define the various locking operations 1247** allowed by the xShmLock method of [sqlite3_io_methods]. The 1248** following are the only legal combinations of flags to the 1249** xShmLock method: 1250** 1251** <ul> 1252** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1253** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1254** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1255** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1256** </ul> 1257** 1258** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1259** was given on the corresponding lock. 1260** 1261** The xShmLock method can transition between unlocked and SHARED or 1262** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1263** and EXCLUSIVE. 1264*/ 1265#define SQLITE_SHM_UNLOCK 1 1266#define SQLITE_SHM_LOCK 2 1267#define SQLITE_SHM_SHARED 4 1268#define SQLITE_SHM_EXCLUSIVE 8 1269 1270/* 1271** CAPI3REF: Maximum xShmLock index 1272** 1273** The xShmLock method on [sqlite3_io_methods] may use values 1274** between 0 and this upper bound as its "offset" argument. 1275** The SQLite core will never attempt to acquire or release a 1276** lock outside of this range 1277*/ 1278#define SQLITE_SHM_NLOCK 8 1279 1280 1281/* 1282** CAPI3REF: Initialize The SQLite Library 1283** 1284** ^The sqlite3_initialize() routine initializes the 1285** SQLite library. ^The sqlite3_shutdown() routine 1286** deallocates any resources that were allocated by sqlite3_initialize(). 1287** These routines are designed to aid in process initialization and 1288** shutdown on embedded systems. Workstation applications using 1289** SQLite normally do not need to invoke either of these routines. 1290** 1291** A call to sqlite3_initialize() is an "effective" call if it is 1292** the first time sqlite3_initialize() is invoked during the lifetime of 1293** the process, or if it is the first time sqlite3_initialize() is invoked 1294** following a call to sqlite3_shutdown(). ^(Only an effective call 1295** of sqlite3_initialize() does any initialization. All other calls 1296** are harmless no-ops.)^ 1297** 1298** A call to sqlite3_shutdown() is an "effective" call if it is the first 1299** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1300** an effective call to sqlite3_shutdown() does any deinitialization. 1301** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1302** 1303** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1304** is not. The sqlite3_shutdown() interface must only be called from a 1305** single thread. All open [database connections] must be closed and all 1306** other SQLite resources must be deallocated prior to invoking 1307** sqlite3_shutdown(). 1308** 1309** Among other things, ^sqlite3_initialize() will invoke 1310** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1311** will invoke sqlite3_os_end(). 1312** 1313** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1314** ^If for some reason, sqlite3_initialize() is unable to initialize 1315** the library (perhaps it is unable to allocate a needed resource such 1316** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1317** 1318** ^The sqlite3_initialize() routine is called internally by many other 1319** SQLite interfaces so that an application usually does not need to 1320** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1321** calls sqlite3_initialize() so the SQLite library will be automatically 1322** initialized when [sqlite3_open()] is called if it has not be initialized 1323** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1324** compile-time option, then the automatic calls to sqlite3_initialize() 1325** are omitted and the application must call sqlite3_initialize() directly 1326** prior to using any other SQLite interface. For maximum portability, 1327** it is recommended that applications always invoke sqlite3_initialize() 1328** directly prior to using any other SQLite interface. Future releases 1329** of SQLite may require this. In other words, the behavior exhibited 1330** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1331** default behavior in some future release of SQLite. 1332** 1333** The sqlite3_os_init() routine does operating-system specific 1334** initialization of the SQLite library. The sqlite3_os_end() 1335** routine undoes the effect of sqlite3_os_init(). Typical tasks 1336** performed by these routines include allocation or deallocation 1337** of static resources, initialization of global variables, 1338** setting up a default [sqlite3_vfs] module, or setting up 1339** a default configuration using [sqlite3_config()]. 1340** 1341** The application should never invoke either sqlite3_os_init() 1342** or sqlite3_os_end() directly. The application should only invoke 1343** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1344** interface is called automatically by sqlite3_initialize() and 1345** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1346** implementations for sqlite3_os_init() and sqlite3_os_end() 1347** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1348** When [custom builds | built for other platforms] 1349** (using the [SQLITE_OS_OTHER=1] compile-time 1350** option) the application must supply a suitable implementation for 1351** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1352** implementation of sqlite3_os_init() or sqlite3_os_end() 1353** must return [SQLITE_OK] on success and some other [error code] upon 1354** failure. 1355*/ 1356int sqlite3_initialize(void); 1357int sqlite3_shutdown(void); 1358int sqlite3_os_init(void); 1359int sqlite3_os_end(void); 1360 1361/* 1362** CAPI3REF: Configuring The SQLite Library 1363** 1364** The sqlite3_config() interface is used to make global configuration 1365** changes to SQLite in order to tune SQLite to the specific needs of 1366** the application. The default configuration is recommended for most 1367** applications and so this routine is usually not necessary. It is 1368** provided to support rare applications with unusual needs. 1369** 1370** The sqlite3_config() interface is not threadsafe. The application 1371** must insure that no other SQLite interfaces are invoked by other 1372** threads while sqlite3_config() is running. Furthermore, sqlite3_config() 1373** may only be invoked prior to library initialization using 1374** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1375** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1376** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1377** Note, however, that ^sqlite3_config() can be called as part of the 1378** implementation of an application-defined [sqlite3_os_init()]. 1379** 1380** The first argument to sqlite3_config() is an integer 1381** [configuration option] that determines 1382** what property of SQLite is to be configured. Subsequent arguments 1383** vary depending on the [configuration option] 1384** in the first argument. 1385** 1386** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1387** ^If the option is unknown or SQLite is unable to set the option 1388** then this routine returns a non-zero [error code]. 1389*/ 1390int sqlite3_config(int, ...); 1391 1392/* 1393** CAPI3REF: Configure database connections 1394** METHOD: sqlite3 1395** 1396** The sqlite3_db_config() interface is used to make configuration 1397** changes to a [database connection]. The interface is similar to 1398** [sqlite3_config()] except that the changes apply to a single 1399** [database connection] (specified in the first argument). 1400** 1401** The second argument to sqlite3_db_config(D,V,...) is the 1402** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1403** that indicates what aspect of the [database connection] is being configured. 1404** Subsequent arguments vary depending on the configuration verb. 1405** 1406** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1407** the call is considered successful. 1408*/ 1409int sqlite3_db_config(sqlite3*, int op, ...); 1410 1411/* 1412** CAPI3REF: Memory Allocation Routines 1413** 1414** An instance of this object defines the interface between SQLite 1415** and low-level memory allocation routines. 1416** 1417** This object is used in only one place in the SQLite interface. 1418** A pointer to an instance of this object is the argument to 1419** [sqlite3_config()] when the configuration option is 1420** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1421** By creating an instance of this object 1422** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1423** during configuration, an application can specify an alternative 1424** memory allocation subsystem for SQLite to use for all of its 1425** dynamic memory needs. 1426** 1427** Note that SQLite comes with several [built-in memory allocators] 1428** that are perfectly adequate for the overwhelming majority of applications 1429** and that this object is only useful to a tiny minority of applications 1430** with specialized memory allocation requirements. This object is 1431** also used during testing of SQLite in order to specify an alternative 1432** memory allocator that simulates memory out-of-memory conditions in 1433** order to verify that SQLite recovers gracefully from such 1434** conditions. 1435** 1436** The xMalloc, xRealloc, and xFree methods must work like the 1437** malloc(), realloc() and free() functions from the standard C library. 1438** ^SQLite guarantees that the second argument to 1439** xRealloc is always a value returned by a prior call to xRoundup. 1440** 1441** xSize should return the allocated size of a memory allocation 1442** previously obtained from xMalloc or xRealloc. The allocated size 1443** is always at least as big as the requested size but may be larger. 1444** 1445** The xRoundup method returns what would be the allocated size of 1446** a memory allocation given a particular requested size. Most memory 1447** allocators round up memory allocations at least to the next multiple 1448** of 8. Some allocators round up to a larger multiple or to a power of 2. 1449** Every memory allocation request coming in through [sqlite3_malloc()] 1450** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1451** that causes the corresponding memory allocation to fail. 1452** 1453** The xInit method initializes the memory allocator. For example, 1454** it might allocate any require mutexes or initialize internal data 1455** structures. The xShutdown method is invoked (indirectly) by 1456** [sqlite3_shutdown()] and should deallocate any resources acquired 1457** by xInit. The pAppData pointer is used as the only parameter to 1458** xInit and xShutdown. 1459** 1460** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1461** the xInit method, so the xInit method need not be threadsafe. The 1462** xShutdown method is only called from [sqlite3_shutdown()] so it does 1463** not need to be threadsafe either. For all other methods, SQLite 1464** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1465** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1466** it is by default) and so the methods are automatically serialized. 1467** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1468** methods must be threadsafe or else make their own arrangements for 1469** serialization. 1470** 1471** SQLite will never invoke xInit() more than once without an intervening 1472** call to xShutdown(). 1473*/ 1474typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1475struct sqlite3_mem_methods { 1476 void *(*xMalloc)(int); /* Memory allocation function */ 1477 void (*xFree)(void*); /* Free a prior allocation */ 1478 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1479 int (*xSize)(void*); /* Return the size of an allocation */ 1480 int (*xRoundup)(int); /* Round up request size to allocation size */ 1481 int (*xInit)(void*); /* Initialize the memory allocator */ 1482 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1483 void *pAppData; /* Argument to xInit() and xShutdown() */ 1484}; 1485 1486/* 1487** CAPI3REF: Configuration Options 1488** KEYWORDS: {configuration option} 1489** 1490** These constants are the available integer configuration options that 1491** can be passed as the first argument to the [sqlite3_config()] interface. 1492** 1493** New configuration options may be added in future releases of SQLite. 1494** Existing configuration options might be discontinued. Applications 1495** should check the return code from [sqlite3_config()] to make sure that 1496** the call worked. The [sqlite3_config()] interface will return a 1497** non-zero [error code] if a discontinued or unsupported configuration option 1498** is invoked. 1499** 1500** <dl> 1501** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1502** <dd>There are no arguments to this option. ^This option sets the 1503** [threading mode] to Single-thread. In other words, it disables 1504** all mutexing and puts SQLite into a mode where it can only be used 1505** by a single thread. ^If SQLite is compiled with 1506** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1507** it is not possible to change the [threading mode] from its default 1508** value of Single-thread and so [sqlite3_config()] will return 1509** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1510** configuration option.</dd> 1511** 1512** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1513** <dd>There are no arguments to this option. ^This option sets the 1514** [threading mode] to Multi-thread. In other words, it disables 1515** mutexing on [database connection] and [prepared statement] objects. 1516** The application is responsible for serializing access to 1517** [database connections] and [prepared statements]. But other mutexes 1518** are enabled so that SQLite will be safe to use in a multi-threaded 1519** environment as long as no two threads attempt to use the same 1520** [database connection] at the same time. ^If SQLite is compiled with 1521** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1522** it is not possible to set the Multi-thread [threading mode] and 1523** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1524** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1525** 1526** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1527** <dd>There are no arguments to this option. ^This option sets the 1528** [threading mode] to Serialized. In other words, this option enables 1529** all mutexes including the recursive 1530** mutexes on [database connection] and [prepared statement] objects. 1531** In this mode (which is the default when SQLite is compiled with 1532** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1533** to [database connections] and [prepared statements] so that the 1534** application is free to use the same [database connection] or the 1535** same [prepared statement] in different threads at the same time. 1536** ^If SQLite is compiled with 1537** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1538** it is not possible to set the Serialized [threading mode] and 1539** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1540** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1541** 1542** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1543** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1544** a pointer to an instance of the [sqlite3_mem_methods] structure. 1545** The argument specifies 1546** alternative low-level memory allocation routines to be used in place of 1547** the memory allocation routines built into SQLite.)^ ^SQLite makes 1548** its own private copy of the content of the [sqlite3_mem_methods] structure 1549** before the [sqlite3_config()] call returns.</dd> 1550** 1551** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1552** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1553** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1554** The [sqlite3_mem_methods] 1555** structure is filled with the currently defined memory allocation routines.)^ 1556** This option can be used to overload the default memory allocation 1557** routines with a wrapper that simulations memory allocation failure or 1558** tracks memory usage, for example. </dd> 1559** 1560** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1561** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1562** interpreted as a boolean, which enables or disables the collection of 1563** memory allocation statistics. ^(When memory allocation statistics are 1564** disabled, the following SQLite interfaces become non-operational: 1565** <ul> 1566** <li> [sqlite3_memory_used()] 1567** <li> [sqlite3_memory_highwater()] 1568** <li> [sqlite3_soft_heap_limit64()] 1569** <li> [sqlite3_status64()] 1570** </ul>)^ 1571** ^Memory allocation statistics are enabled by default unless SQLite is 1572** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1573** allocation statistics are disabled by default. 1574** </dd> 1575** 1576** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1577** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer 1578** that SQLite can use for scratch memory. ^(There are three arguments 1579** to SQLITE_CONFIG_SCRATCH: A pointer an 8-byte 1580** aligned memory buffer from which the scratch allocations will be 1581** drawn, the size of each scratch allocation (sz), 1582** and the maximum number of scratch allocations (N).)^ 1583** The first argument must be a pointer to an 8-byte aligned buffer 1584** of at least sz*N bytes of memory. 1585** ^SQLite will not use more than one scratch buffers per thread. 1586** ^SQLite will never request a scratch buffer that is more than 6 1587** times the database page size. 1588** ^If SQLite needs needs additional 1589** scratch memory beyond what is provided by this configuration option, then 1590** [sqlite3_malloc()] will be used to obtain the memory needed.<p> 1591** ^When the application provides any amount of scratch memory using 1592** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large 1593** [sqlite3_malloc|heap allocations]. 1594** This can help [Robson proof|prevent memory allocation failures] due to heap 1595** fragmentation in low-memory embedded systems. 1596** </dd> 1597** 1598** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1599** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a static memory buffer 1600** that SQLite can use for the database page cache with the default page 1601** cache implementation. 1602** This configuration should not be used if an application-define page 1603** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2] 1604** configuration option. 1605** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1606** 8-byte aligned 1607** memory, the size of each page buffer (sz), and the number of pages (N). 1608** The sz argument should be the size of the largest database page 1609** (a power of two between 512 and 65536) plus some extra bytes for each 1610** page header. ^The number of extra bytes needed by the page header 1611** can be determined using the [SQLITE_CONFIG_PCACHE_HDRSZ] option 1612** to [sqlite3_config()]. 1613** ^It is harmless, apart from the wasted memory, 1614** for the sz parameter to be larger than necessary. The first 1615** argument should pointer to an 8-byte aligned block of memory that 1616** is at least sz*N bytes of memory, otherwise subsequent behavior is 1617** undefined. 1618** ^SQLite will use the memory provided by the first argument to satisfy its 1619** memory needs for the first N pages that it adds to cache. ^If additional 1620** page cache memory is needed beyond what is provided by this option, then 1621** SQLite goes to [sqlite3_malloc()] for the additional storage space.</dd> 1622** 1623** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1624** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1625** that SQLite will use for all of its dynamic memory allocation needs 1626** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and 1627** [SQLITE_CONFIG_PAGECACHE]. 1628** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1629** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1630** [SQLITE_ERROR] if invoked otherwise. 1631** ^There are three arguments to SQLITE_CONFIG_HEAP: 1632** An 8-byte aligned pointer to the memory, 1633** the number of bytes in the memory buffer, and the minimum allocation size. 1634** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1635** to using its default memory allocator (the system malloc() implementation), 1636** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1637** memory pointer is not NULL then the alternative memory 1638** allocator is engaged to handle all of SQLites memory allocation needs. 1639** The first pointer (the memory pointer) must be aligned to an 8-byte 1640** boundary or subsequent behavior of SQLite will be undefined. 1641** The minimum allocation size is capped at 2**12. Reasonable values 1642** for the minimum allocation size are 2**5 through 2**8.</dd> 1643** 1644** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1645** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1646** pointer to an instance of the [sqlite3_mutex_methods] structure. 1647** The argument specifies alternative low-level mutex routines to be used 1648** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1649** the content of the [sqlite3_mutex_methods] structure before the call to 1650** [sqlite3_config()] returns. ^If SQLite is compiled with 1651** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1652** the entire mutexing subsystem is omitted from the build and hence calls to 1653** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1654** return [SQLITE_ERROR].</dd> 1655** 1656** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1657** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1658** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1659** [sqlite3_mutex_methods] 1660** structure is filled with the currently defined mutex routines.)^ 1661** This option can be used to overload the default mutex allocation 1662** routines with a wrapper used to track mutex usage for performance 1663** profiling or testing, for example. ^If SQLite is compiled with 1664** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1665** the entire mutexing subsystem is omitted from the build and hence calls to 1666** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1667** return [SQLITE_ERROR].</dd> 1668** 1669** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1670** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1671** the default size of lookaside memory on each [database connection]. 1672** The first argument is the 1673** size of each lookaside buffer slot and the second is the number of 1674** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1675** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1676** option to [sqlite3_db_config()] can be used to change the lookaside 1677** configuration on individual connections.)^ </dd> 1678** 1679** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1680** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1681** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1682** the interface to a custom page cache implementation.)^ 1683** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1684** 1685** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1686** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1687** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1688** the current page cache implementation into that object.)^ </dd> 1689** 1690** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1691** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1692** global [error log]. 1693** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1694** function with a call signature of void(*)(void*,int,const char*), 1695** and a pointer to void. ^If the function pointer is not NULL, it is 1696** invoked by [sqlite3_log()] to process each logging event. ^If the 1697** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1698** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1699** passed through as the first parameter to the application-defined logger 1700** function whenever that function is invoked. ^The second parameter to 1701** the logger function is a copy of the first parameter to the corresponding 1702** [sqlite3_log()] call and is intended to be a [result code] or an 1703** [extended result code]. ^The third parameter passed to the logger is 1704** log message after formatting via [sqlite3_snprintf()]. 1705** The SQLite logging interface is not reentrant; the logger function 1706** supplied by the application must not invoke any SQLite interface. 1707** In a multi-threaded application, the application-defined logger 1708** function must be threadsafe. </dd> 1709** 1710** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1711** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1712** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1713** then URI handling is globally disabled.)^ ^If URI handling is globally 1714** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1715** [sqlite3_open16()] or 1716** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1717** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1718** connection is opened. ^If it is globally disabled, filenames are 1719** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1720** database connection is opened. ^(By default, URI handling is globally 1721** disabled. The default value may be changed by compiling with the 1722** [SQLITE_USE_URI] symbol defined.)^ 1723** 1724** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1725** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1726** argument which is interpreted as a boolean in order to enable or disable 1727** the use of covering indices for full table scans in the query optimizer. 1728** ^The default setting is determined 1729** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1730** if that compile-time option is omitted. 1731** The ability to disable the use of covering indices for full table scans 1732** is because some incorrectly coded legacy applications might malfunction 1733** when the optimization is enabled. Providing the ability to 1734** disable the optimization allows the older, buggy application code to work 1735** without change even with newer versions of SQLite. 1736** 1737** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1738** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1739** <dd> These options are obsolete and should not be used by new code. 1740** They are retained for backwards compatibility but are now no-ops. 1741** </dd> 1742** 1743** [[SQLITE_CONFIG_SQLLOG]] 1744** <dt>SQLITE_CONFIG_SQLLOG 1745** <dd>This option is only available if sqlite is compiled with the 1746** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1747** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1748** The second should be of type (void*). The callback is invoked by the library 1749** in three separate circumstances, identified by the value passed as the 1750** fourth parameter. If the fourth parameter is 0, then the database connection 1751** passed as the second argument has just been opened. The third argument 1752** points to a buffer containing the name of the main database file. If the 1753** fourth parameter is 1, then the SQL statement that the third parameter 1754** points to has just been executed. Or, if the fourth parameter is 2, then 1755** the connection being passed as the second parameter is being closed. The 1756** third parameter is passed NULL In this case. An example of using this 1757** configuration option can be seen in the "test_sqllog.c" source file in 1758** the canonical SQLite source tree.</dd> 1759** 1760** [[SQLITE_CONFIG_MMAP_SIZE]] 1761** <dt>SQLITE_CONFIG_MMAP_SIZE 1762** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1763** that are the default mmap size limit (the default setting for 1764** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1765** ^The default setting can be overridden by each database connection using 1766** either the [PRAGMA mmap_size] command, or by using the 1767** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1768** will be silently truncated if necessary so that it does not exceed the 1769** compile-time maximum mmap size set by the 1770** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1771** ^If either argument to this option is negative, then that argument is 1772** changed to its compile-time default. 1773** 1774** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1775** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1776** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1777** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1778** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1779** that specifies the maximum size of the created heap. 1780** 1781** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1782** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1783** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1784** is a pointer to an integer and writes into that integer the number of extra 1785** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1786** The amount of extra space required can change depending on the compiler, 1787** target platform, and SQLite version. 1788** 1789** [[SQLITE_CONFIG_PMASZ]] 1790** <dt>SQLITE_CONFIG_PMASZ 1791** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1792** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1793** sorter to that integer. The default minimum PMA Size is set by the 1794** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1795** to help with sort operations when multithreaded sorting 1796** is enabled (using the [PRAGMA threads] command) and the amount of content 1797** to be sorted exceeds the page size times the minimum of the 1798** [PRAGMA cache_size] setting and this value. 1799** </dl> 1800*/ 1801#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1802#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1803#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1804#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1805#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1806#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1807#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1808#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1809#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1810#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1811#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1812/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1813#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1814#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1815#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1816#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1817#define SQLITE_CONFIG_URI 17 /* int */ 1818#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1819#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1820#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1821#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1822#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1823#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1824#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 1825#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 1826 1827/* 1828** CAPI3REF: Database Connection Configuration Options 1829** 1830** These constants are the available integer configuration options that 1831** can be passed as the second argument to the [sqlite3_db_config()] interface. 1832** 1833** New configuration options may be added in future releases of SQLite. 1834** Existing configuration options might be discontinued. Applications 1835** should check the return code from [sqlite3_db_config()] to make sure that 1836** the call worked. ^The [sqlite3_db_config()] interface will return a 1837** non-zero [error code] if a discontinued or unsupported configuration option 1838** is invoked. 1839** 1840** <dl> 1841** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1842** <dd> ^This option takes three additional arguments that determine the 1843** [lookaside memory allocator] configuration for the [database connection]. 1844** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1845** pointer to a memory buffer to use for lookaside memory. 1846** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1847** may be NULL in which case SQLite will allocate the 1848** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1849** size of each lookaside buffer slot. ^The third argument is the number of 1850** slots. The size of the buffer in the first argument must be greater than 1851** or equal to the product of the second and third arguments. The buffer 1852** must be aligned to an 8-byte boundary. ^If the second argument to 1853** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1854** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1855** configuration for a database connection can only be changed when that 1856** connection is not currently using lookaside memory, or in other words 1857** when the "current value" returned by 1858** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1859** Any attempt to change the lookaside memory configuration when lookaside 1860** memory is in use leaves the configuration unchanged and returns 1861** [SQLITE_BUSY].)^</dd> 1862** 1863** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1864** <dd> ^This option is used to enable or disable the enforcement of 1865** [foreign key constraints]. There should be two additional arguments. 1866** The first argument is an integer which is 0 to disable FK enforcement, 1867** positive to enable FK enforcement or negative to leave FK enforcement 1868** unchanged. The second parameter is a pointer to an integer into which 1869** is written 0 or 1 to indicate whether FK enforcement is off or on 1870** following this call. The second parameter may be a NULL pointer, in 1871** which case the FK enforcement setting is not reported back. </dd> 1872** 1873** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1874** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1875** There should be two additional arguments. 1876** The first argument is an integer which is 0 to disable triggers, 1877** positive to enable triggers or negative to leave the setting unchanged. 1878** The second parameter is a pointer to an integer into which 1879** is written 0 or 1 to indicate whether triggers are disabled or enabled 1880** following this call. The second parameter may be a NULL pointer, in 1881** which case the trigger setting is not reported back. </dd> 1882** 1883** </dl> 1884*/ 1885#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1886#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1887#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1888 1889 1890/* 1891** CAPI3REF: Enable Or Disable Extended Result Codes 1892** METHOD: sqlite3 1893** 1894** ^The sqlite3_extended_result_codes() routine enables or disables the 1895** [extended result codes] feature of SQLite. ^The extended result 1896** codes are disabled by default for historical compatibility. 1897*/ 1898int sqlite3_extended_result_codes(sqlite3*, int onoff); 1899 1900/* 1901** CAPI3REF: Last Insert Rowid 1902** METHOD: sqlite3 1903** 1904** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 1905** has a unique 64-bit signed 1906** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1907** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1908** names are not also used by explicitly declared columns. ^If 1909** the table has a column of type [INTEGER PRIMARY KEY] then that column 1910** is another alias for the rowid. 1911** 1912** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the 1913** most recent successful [INSERT] into a rowid table or [virtual table] 1914** on database connection D. 1915** ^Inserts into [WITHOUT ROWID] tables are not recorded. 1916** ^If no successful [INSERT]s into rowid tables 1917** have ever occurred on the database connection D, 1918** then sqlite3_last_insert_rowid(D) returns zero. 1919** 1920** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 1921** method, then this routine will return the [rowid] of the inserted 1922** row as long as the trigger or virtual table method is running. 1923** But once the trigger or virtual table method ends, the value returned 1924** by this routine reverts to what it was before the trigger or virtual 1925** table method began.)^ 1926** 1927** ^An [INSERT] that fails due to a constraint violation is not a 1928** successful [INSERT] and does not change the value returned by this 1929** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1930** and INSERT OR ABORT make no changes to the return value of this 1931** routine when their insertion fails. ^(When INSERT OR REPLACE 1932** encounters a constraint violation, it does not fail. The 1933** INSERT continues to completion after deleting rows that caused 1934** the constraint problem so INSERT OR REPLACE will always change 1935** the return value of this interface.)^ 1936** 1937** ^For the purposes of this routine, an [INSERT] is considered to 1938** be successful even if it is subsequently rolled back. 1939** 1940** This function is accessible to SQL statements via the 1941** [last_insert_rowid() SQL function]. 1942** 1943** If a separate thread performs a new [INSERT] on the same 1944** database connection while the [sqlite3_last_insert_rowid()] 1945** function is running and thus changes the last insert [rowid], 1946** then the value returned by [sqlite3_last_insert_rowid()] is 1947** unpredictable and might not equal either the old or the new 1948** last insert [rowid]. 1949*/ 1950sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 1951 1952/* 1953** CAPI3REF: Count The Number Of Rows Modified 1954** METHOD: sqlite3 1955** 1956** ^This function returns the number of rows modified, inserted or 1957** deleted by the most recently completed INSERT, UPDATE or DELETE 1958** statement on the database connection specified by the only parameter. 1959** ^Executing any other type of SQL statement does not modify the value 1960** returned by this function. 1961** 1962** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 1963** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 1964** [foreign key actions] or [REPLACE] constraint resolution are not counted. 1965** 1966** Changes to a view that are intercepted by 1967** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 1968** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 1969** DELETE statement run on a view is always zero. Only changes made to real 1970** tables are counted. 1971** 1972** Things are more complicated if the sqlite3_changes() function is 1973** executed while a trigger program is running. This may happen if the 1974** program uses the [changes() SQL function], or if some other callback 1975** function invokes sqlite3_changes() directly. Essentially: 1976** 1977** <ul> 1978** <li> ^(Before entering a trigger program the value returned by 1979** sqlite3_changes() function is saved. After the trigger program 1980** has finished, the original value is restored.)^ 1981** 1982** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 1983** statement sets the value returned by sqlite3_changes() 1984** upon completion as normal. Of course, this value will not include 1985** any changes performed by sub-triggers, as the sqlite3_changes() 1986** value will be saved and restored after each sub-trigger has run.)^ 1987** </ul> 1988** 1989** ^This means that if the changes() SQL function (or similar) is used 1990** by the first INSERT, UPDATE or DELETE statement within a trigger, it 1991** returns the value as set when the calling statement began executing. 1992** ^If it is used by the second or subsequent such statement within a trigger 1993** program, the value returned reflects the number of rows modified by the 1994** previous INSERT, UPDATE or DELETE statement within the same trigger. 1995** 1996** See also the [sqlite3_total_changes()] interface, the 1997** [count_changes pragma], and the [changes() SQL function]. 1998** 1999** If a separate thread makes changes on the same database connection 2000** while [sqlite3_changes()] is running then the value returned 2001** is unpredictable and not meaningful. 2002*/ 2003int sqlite3_changes(sqlite3*); 2004 2005/* 2006** CAPI3REF: Total Number Of Rows Modified 2007** METHOD: sqlite3 2008** 2009** ^This function returns the total number of rows inserted, modified or 2010** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2011** since the database connection was opened, including those executed as 2012** part of trigger programs. ^Executing any other type of SQL statement 2013** does not affect the value returned by sqlite3_total_changes(). 2014** 2015** ^Changes made as part of [foreign key actions] are included in the 2016** count, but those made as part of REPLACE constraint resolution are 2017** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2018** are not counted. 2019** 2020** See also the [sqlite3_changes()] interface, the 2021** [count_changes pragma], and the [total_changes() SQL function]. 2022** 2023** If a separate thread makes changes on the same database connection 2024** while [sqlite3_total_changes()] is running then the value 2025** returned is unpredictable and not meaningful. 2026*/ 2027int sqlite3_total_changes(sqlite3*); 2028 2029/* 2030** CAPI3REF: Interrupt A Long-Running Query 2031** METHOD: sqlite3 2032** 2033** ^This function causes any pending database operation to abort and 2034** return at its earliest opportunity. This routine is typically 2035** called in response to a user action such as pressing "Cancel" 2036** or Ctrl-C where the user wants a long query operation to halt 2037** immediately. 2038** 2039** ^It is safe to call this routine from a thread different from the 2040** thread that is currently running the database operation. But it 2041** is not safe to call this routine with a [database connection] that 2042** is closed or might close before sqlite3_interrupt() returns. 2043** 2044** ^If an SQL operation is very nearly finished at the time when 2045** sqlite3_interrupt() is called, then it might not have an opportunity 2046** to be interrupted and might continue to completion. 2047** 2048** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2049** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2050** that is inside an explicit transaction, then the entire transaction 2051** will be rolled back automatically. 2052** 2053** ^The sqlite3_interrupt(D) call is in effect until all currently running 2054** SQL statements on [database connection] D complete. ^Any new SQL statements 2055** that are started after the sqlite3_interrupt() call and before the 2056** running statements reaches zero are interrupted as if they had been 2057** running prior to the sqlite3_interrupt() call. ^New SQL statements 2058** that are started after the running statement count reaches zero are 2059** not effected by the sqlite3_interrupt(). 2060** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2061** SQL statements is a no-op and has no effect on SQL statements 2062** that are started after the sqlite3_interrupt() call returns. 2063** 2064** If the database connection closes while [sqlite3_interrupt()] 2065** is running then bad things will likely happen. 2066*/ 2067void sqlite3_interrupt(sqlite3*); 2068 2069/* 2070** CAPI3REF: Determine If An SQL Statement Is Complete 2071** 2072** These routines are useful during command-line input to determine if the 2073** currently entered text seems to form a complete SQL statement or 2074** if additional input is needed before sending the text into 2075** SQLite for parsing. ^These routines return 1 if the input string 2076** appears to be a complete SQL statement. ^A statement is judged to be 2077** complete if it ends with a semicolon token and is not a prefix of a 2078** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2079** string literals or quoted identifier names or comments are not 2080** independent tokens (they are part of the token in which they are 2081** embedded) and thus do not count as a statement terminator. ^Whitespace 2082** and comments that follow the final semicolon are ignored. 2083** 2084** ^These routines return 0 if the statement is incomplete. ^If a 2085** memory allocation fails, then SQLITE_NOMEM is returned. 2086** 2087** ^These routines do not parse the SQL statements thus 2088** will not detect syntactically incorrect SQL. 2089** 2090** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2091** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2092** automatically by sqlite3_complete16(). If that initialization fails, 2093** then the return value from sqlite3_complete16() will be non-zero 2094** regardless of whether or not the input SQL is complete.)^ 2095** 2096** The input to [sqlite3_complete()] must be a zero-terminated 2097** UTF-8 string. 2098** 2099** The input to [sqlite3_complete16()] must be a zero-terminated 2100** UTF-16 string in native byte order. 2101*/ 2102int sqlite3_complete(const char *sql); 2103int sqlite3_complete16(const void *sql); 2104 2105/* 2106** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2107** KEYWORDS: {busy-handler callback} {busy handler} 2108** METHOD: sqlite3 2109** 2110** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2111** that might be invoked with argument P whenever 2112** an attempt is made to access a database table associated with 2113** [database connection] D when another thread 2114** or process has the table locked. 2115** The sqlite3_busy_handler() interface is used to implement 2116** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2117** 2118** ^If the busy callback is NULL, then [SQLITE_BUSY] 2119** is returned immediately upon encountering the lock. ^If the busy callback 2120** is not NULL, then the callback might be invoked with two arguments. 2121** 2122** ^The first argument to the busy handler is a copy of the void* pointer which 2123** is the third argument to sqlite3_busy_handler(). ^The second argument to 2124** the busy handler callback is the number of times that the busy handler has 2125** been invoked previously for the same locking event. ^If the 2126** busy callback returns 0, then no additional attempts are made to 2127** access the database and [SQLITE_BUSY] is returned 2128** to the application. 2129** ^If the callback returns non-zero, then another attempt 2130** is made to access the database and the cycle repeats. 2131** 2132** The presence of a busy handler does not guarantee that it will be invoked 2133** when there is lock contention. ^If SQLite determines that invoking the busy 2134** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2135** to the application instead of invoking the 2136** busy handler. 2137** Consider a scenario where one process is holding a read lock that 2138** it is trying to promote to a reserved lock and 2139** a second process is holding a reserved lock that it is trying 2140** to promote to an exclusive lock. The first process cannot proceed 2141** because it is blocked by the second and the second process cannot 2142** proceed because it is blocked by the first. If both processes 2143** invoke the busy handlers, neither will make any progress. Therefore, 2144** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2145** will induce the first process to release its read lock and allow 2146** the second process to proceed. 2147** 2148** ^The default busy callback is NULL. 2149** 2150** ^(There can only be a single busy handler defined for each 2151** [database connection]. Setting a new busy handler clears any 2152** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2153** or evaluating [PRAGMA busy_timeout=N] will change the 2154** busy handler and thus clear any previously set busy handler. 2155** 2156** The busy callback should not take any actions which modify the 2157** database connection that invoked the busy handler. In other words, 2158** the busy handler is not reentrant. Any such actions 2159** result in undefined behavior. 2160** 2161** A busy handler must not close the database connection 2162** or [prepared statement] that invoked the busy handler. 2163*/ 2164int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 2165 2166/* 2167** CAPI3REF: Set A Busy Timeout 2168** METHOD: sqlite3 2169** 2170** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2171** for a specified amount of time when a table is locked. ^The handler 2172** will sleep multiple times until at least "ms" milliseconds of sleeping 2173** have accumulated. ^After at least "ms" milliseconds of sleeping, 2174** the handler returns 0 which causes [sqlite3_step()] to return 2175** [SQLITE_BUSY]. 2176** 2177** ^Calling this routine with an argument less than or equal to zero 2178** turns off all busy handlers. 2179** 2180** ^(There can only be a single busy handler for a particular 2181** [database connection] at any given moment. If another busy handler 2182** was defined (using [sqlite3_busy_handler()]) prior to calling 2183** this routine, that other busy handler is cleared.)^ 2184** 2185** See also: [PRAGMA busy_timeout] 2186*/ 2187int sqlite3_busy_timeout(sqlite3*, int ms); 2188 2189/* 2190** CAPI3REF: Convenience Routines For Running Queries 2191** METHOD: sqlite3 2192** 2193** This is a legacy interface that is preserved for backwards compatibility. 2194** Use of this interface is not recommended. 2195** 2196** Definition: A <b>result table</b> is memory data structure created by the 2197** [sqlite3_get_table()] interface. A result table records the 2198** complete query results from one or more queries. 2199** 2200** The table conceptually has a number of rows and columns. But 2201** these numbers are not part of the result table itself. These 2202** numbers are obtained separately. Let N be the number of rows 2203** and M be the number of columns. 2204** 2205** A result table is an array of pointers to zero-terminated UTF-8 strings. 2206** There are (N+1)*M elements in the array. The first M pointers point 2207** to zero-terminated strings that contain the names of the columns. 2208** The remaining entries all point to query results. NULL values result 2209** in NULL pointers. All other values are in their UTF-8 zero-terminated 2210** string representation as returned by [sqlite3_column_text()]. 2211** 2212** A result table might consist of one or more memory allocations. 2213** It is not safe to pass a result table directly to [sqlite3_free()]. 2214** A result table should be deallocated using [sqlite3_free_table()]. 2215** 2216** ^(As an example of the result table format, suppose a query result 2217** is as follows: 2218** 2219** <blockquote><pre> 2220** Name | Age 2221** ----------------------- 2222** Alice | 43 2223** Bob | 28 2224** Cindy | 21 2225** </pre></blockquote> 2226** 2227** There are two column (M==2) and three rows (N==3). Thus the 2228** result table has 8 entries. Suppose the result table is stored 2229** in an array names azResult. Then azResult holds this content: 2230** 2231** <blockquote><pre> 2232** azResult[0] = "Name"; 2233** azResult[1] = "Age"; 2234** azResult[2] = "Alice"; 2235** azResult[3] = "43"; 2236** azResult[4] = "Bob"; 2237** azResult[5] = "28"; 2238** azResult[6] = "Cindy"; 2239** azResult[7] = "21"; 2240** </pre></blockquote>)^ 2241** 2242** ^The sqlite3_get_table() function evaluates one or more 2243** semicolon-separated SQL statements in the zero-terminated UTF-8 2244** string of its 2nd parameter and returns a result table to the 2245** pointer given in its 3rd parameter. 2246** 2247** After the application has finished with the result from sqlite3_get_table(), 2248** it must pass the result table pointer to sqlite3_free_table() in order to 2249** release the memory that was malloced. Because of the way the 2250** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2251** function must not try to call [sqlite3_free()] directly. Only 2252** [sqlite3_free_table()] is able to release the memory properly and safely. 2253** 2254** The sqlite3_get_table() interface is implemented as a wrapper around 2255** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2256** to any internal data structures of SQLite. It uses only the public 2257** interface defined here. As a consequence, errors that occur in the 2258** wrapper layer outside of the internal [sqlite3_exec()] call are not 2259** reflected in subsequent calls to [sqlite3_errcode()] or 2260** [sqlite3_errmsg()]. 2261*/ 2262int sqlite3_get_table( 2263 sqlite3 *db, /* An open database */ 2264 const char *zSql, /* SQL to be evaluated */ 2265 char ***pazResult, /* Results of the query */ 2266 int *pnRow, /* Number of result rows written here */ 2267 int *pnColumn, /* Number of result columns written here */ 2268 char **pzErrmsg /* Error msg written here */ 2269); 2270void sqlite3_free_table(char **result); 2271 2272/* 2273** CAPI3REF: Formatted String Printing Functions 2274** 2275** These routines are work-alikes of the "printf()" family of functions 2276** from the standard C library. 2277** These routines understand most of the common K&R formatting options, 2278** plus some additional non-standard formats, detailed below. 2279** Note that some of the more obscure formatting options from recent 2280** C-library standards are omitted from this implementation. 2281** 2282** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2283** results into memory obtained from [sqlite3_malloc()]. 2284** The strings returned by these two routines should be 2285** released by [sqlite3_free()]. ^Both routines return a 2286** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2287** memory to hold the resulting string. 2288** 2289** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2290** the standard C library. The result is written into the 2291** buffer supplied as the second parameter whose size is given by 2292** the first parameter. Note that the order of the 2293** first two parameters is reversed from snprintf().)^ This is an 2294** historical accident that cannot be fixed without breaking 2295** backwards compatibility. ^(Note also that sqlite3_snprintf() 2296** returns a pointer to its buffer instead of the number of 2297** characters actually written into the buffer.)^ We admit that 2298** the number of characters written would be a more useful return 2299** value but we cannot change the implementation of sqlite3_snprintf() 2300** now without breaking compatibility. 2301** 2302** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2303** guarantees that the buffer is always zero-terminated. ^The first 2304** parameter "n" is the total size of the buffer, including space for 2305** the zero terminator. So the longest string that can be completely 2306** written will be n-1 characters. 2307** 2308** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2309** 2310** These routines all implement some additional formatting 2311** options that are useful for constructing SQL statements. 2312** All of the usual printf() formatting options apply. In addition, there 2313** is are "%q", "%Q", "%w" and "%z" options. 2314** 2315** ^(The %q option works like %s in that it substitutes a nul-terminated 2316** string from the argument list. But %q also doubles every '\'' character. 2317** %q is designed for use inside a string literal.)^ By doubling each '\'' 2318** character it escapes that character and allows it to be inserted into 2319** the string. 2320** 2321** For example, assume the string variable zText contains text as follows: 2322** 2323** <blockquote><pre> 2324** char *zText = "It's a happy day!"; 2325** </pre></blockquote> 2326** 2327** One can use this text in an SQL statement as follows: 2328** 2329** <blockquote><pre> 2330** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2331** sqlite3_exec(db, zSQL, 0, 0, 0); 2332** sqlite3_free(zSQL); 2333** </pre></blockquote> 2334** 2335** Because the %q format string is used, the '\'' character in zText 2336** is escaped and the SQL generated is as follows: 2337** 2338** <blockquote><pre> 2339** INSERT INTO table1 VALUES('It''s a happy day!') 2340** </pre></blockquote> 2341** 2342** This is correct. Had we used %s instead of %q, the generated SQL 2343** would have looked like this: 2344** 2345** <blockquote><pre> 2346** INSERT INTO table1 VALUES('It's a happy day!'); 2347** </pre></blockquote> 2348** 2349** This second example is an SQL syntax error. As a general rule you should 2350** always use %q instead of %s when inserting text into a string literal. 2351** 2352** ^(The %Q option works like %q except it also adds single quotes around 2353** the outside of the total string. Additionally, if the parameter in the 2354** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2355** single quotes).)^ So, for example, one could say: 2356** 2357** <blockquote><pre> 2358** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2359** sqlite3_exec(db, zSQL, 0, 0, 0); 2360** sqlite3_free(zSQL); 2361** </pre></blockquote> 2362** 2363** The code above will render a correct SQL statement in the zSQL 2364** variable even if the zText variable is a NULL pointer. 2365** 2366** ^(The "%w" formatting option is like "%q" except that it expects to 2367** be contained within double-quotes instead of single quotes, and it 2368** escapes the double-quote character instead of the single-quote 2369** character.)^ The "%w" formatting option is intended for safely inserting 2370** table and column names into a constructed SQL statement. 2371** 2372** ^(The "%z" formatting option works like "%s" but with the 2373** addition that after the string has been read and copied into 2374** the result, [sqlite3_free()] is called on the input string.)^ 2375*/ 2376char *sqlite3_mprintf(const char*,...); 2377char *sqlite3_vmprintf(const char*, va_list); 2378char *sqlite3_snprintf(int,char*,const char*, ...); 2379char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2380 2381/* 2382** CAPI3REF: Memory Allocation Subsystem 2383** 2384** The SQLite core uses these three routines for all of its own 2385** internal memory allocation needs. "Core" in the previous sentence 2386** does not include operating-system specific VFS implementation. The 2387** Windows VFS uses native malloc() and free() for some operations. 2388** 2389** ^The sqlite3_malloc() routine returns a pointer to a block 2390** of memory at least N bytes in length, where N is the parameter. 2391** ^If sqlite3_malloc() is unable to obtain sufficient free 2392** memory, it returns a NULL pointer. ^If the parameter N to 2393** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2394** a NULL pointer. 2395** 2396** ^The sqlite3_malloc64(N) routine works just like 2397** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2398** of a signed 32-bit integer. 2399** 2400** ^Calling sqlite3_free() with a pointer previously returned 2401** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2402** that it might be reused. ^The sqlite3_free() routine is 2403** a no-op if is called with a NULL pointer. Passing a NULL pointer 2404** to sqlite3_free() is harmless. After being freed, memory 2405** should neither be read nor written. Even reading previously freed 2406** memory might result in a segmentation fault or other severe error. 2407** Memory corruption, a segmentation fault, or other severe error 2408** might result if sqlite3_free() is called with a non-NULL pointer that 2409** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2410** 2411** ^The sqlite3_realloc(X,N) interface attempts to resize a 2412** prior memory allocation X to be at least N bytes. 2413** ^If the X parameter to sqlite3_realloc(X,N) 2414** is a NULL pointer then its behavior is identical to calling 2415** sqlite3_malloc(N). 2416** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2417** negative then the behavior is exactly the same as calling 2418** sqlite3_free(X). 2419** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2420** of at least N bytes in size or NULL if insufficient memory is available. 2421** ^If M is the size of the prior allocation, then min(N,M) bytes 2422** of the prior allocation are copied into the beginning of buffer returned 2423** by sqlite3_realloc(X,N) and the prior allocation is freed. 2424** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2425** prior allocation is not freed. 2426** 2427** ^The sqlite3_realloc64(X,N) interfaces works the same as 2428** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2429** of a 32-bit signed integer. 2430** 2431** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2432** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2433** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2434** ^The value returned by sqlite3_msize(X) might be larger than the number 2435** of bytes requested when X was allocated. ^If X is a NULL pointer then 2436** sqlite3_msize(X) returns zero. If X points to something that is not 2437** the beginning of memory allocation, or if it points to a formerly 2438** valid memory allocation that has now been freed, then the behavior 2439** of sqlite3_msize(X) is undefined and possibly harmful. 2440** 2441** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2442** sqlite3_malloc64(), and sqlite3_realloc64() 2443** is always aligned to at least an 8 byte boundary, or to a 2444** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2445** option is used. 2446** 2447** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2448** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2449** implementation of these routines to be omitted. That capability 2450** is no longer provided. Only built-in memory allocators can be used. 2451** 2452** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2453** the system malloc() and free() directly when converting 2454** filenames between the UTF-8 encoding used by SQLite 2455** and whatever filename encoding is used by the particular Windows 2456** installation. Memory allocation errors were detected, but 2457** they were reported back as [SQLITE_CANTOPEN] or 2458** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2459** 2460** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2461** must be either NULL or else pointers obtained from a prior 2462** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2463** not yet been released. 2464** 2465** The application must not read or write any part of 2466** a block of memory after it has been released using 2467** [sqlite3_free()] or [sqlite3_realloc()]. 2468*/ 2469void *sqlite3_malloc(int); 2470void *sqlite3_malloc64(sqlite3_uint64); 2471void *sqlite3_realloc(void*, int); 2472void *sqlite3_realloc64(void*, sqlite3_uint64); 2473void sqlite3_free(void*); 2474sqlite3_uint64 sqlite3_msize(void*); 2475 2476/* 2477** CAPI3REF: Memory Allocator Statistics 2478** 2479** SQLite provides these two interfaces for reporting on the status 2480** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2481** routines, which form the built-in memory allocation subsystem. 2482** 2483** ^The [sqlite3_memory_used()] routine returns the number of bytes 2484** of memory currently outstanding (malloced but not freed). 2485** ^The [sqlite3_memory_highwater()] routine returns the maximum 2486** value of [sqlite3_memory_used()] since the high-water mark 2487** was last reset. ^The values returned by [sqlite3_memory_used()] and 2488** [sqlite3_memory_highwater()] include any overhead 2489** added by SQLite in its implementation of [sqlite3_malloc()], 2490** but not overhead added by the any underlying system library 2491** routines that [sqlite3_malloc()] may call. 2492** 2493** ^The memory high-water mark is reset to the current value of 2494** [sqlite3_memory_used()] if and only if the parameter to 2495** [sqlite3_memory_highwater()] is true. ^The value returned 2496** by [sqlite3_memory_highwater(1)] is the high-water mark 2497** prior to the reset. 2498*/ 2499sqlite3_int64 sqlite3_memory_used(void); 2500sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2501 2502/* 2503** CAPI3REF: Pseudo-Random Number Generator 2504** 2505** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2506** select random [ROWID | ROWIDs] when inserting new records into a table that 2507** already uses the largest possible [ROWID]. The PRNG is also used for 2508** the build-in random() and randomblob() SQL functions. This interface allows 2509** applications to access the same PRNG for other purposes. 2510** 2511** ^A call to this routine stores N bytes of randomness into buffer P. 2512** ^The P parameter can be a NULL pointer. 2513** 2514** ^If this routine has not been previously called or if the previous 2515** call had N less than one or a NULL pointer for P, then the PRNG is 2516** seeded using randomness obtained from the xRandomness method of 2517** the default [sqlite3_vfs] object. 2518** ^If the previous call to this routine had an N of 1 or more and a 2519** non-NULL P then the pseudo-randomness is generated 2520** internally and without recourse to the [sqlite3_vfs] xRandomness 2521** method. 2522*/ 2523void sqlite3_randomness(int N, void *P); 2524 2525/* 2526** CAPI3REF: Compile-Time Authorization Callbacks 2527** METHOD: sqlite3 2528** 2529** ^This routine registers an authorizer callback with a particular 2530** [database connection], supplied in the first argument. 2531** ^The authorizer callback is invoked as SQL statements are being compiled 2532** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2533** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2534** points during the compilation process, as logic is being created 2535** to perform various actions, the authorizer callback is invoked to 2536** see if those actions are allowed. ^The authorizer callback should 2537** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2538** specific action but allow the SQL statement to continue to be 2539** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2540** rejected with an error. ^If the authorizer callback returns 2541** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2542** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2543** the authorizer will fail with an error message. 2544** 2545** When the callback returns [SQLITE_OK], that means the operation 2546** requested is ok. ^When the callback returns [SQLITE_DENY], the 2547** [sqlite3_prepare_v2()] or equivalent call that triggered the 2548** authorizer will fail with an error message explaining that 2549** access is denied. 2550** 2551** ^The first parameter to the authorizer callback is a copy of the third 2552** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2553** to the callback is an integer [SQLITE_COPY | action code] that specifies 2554** the particular action to be authorized. ^The third through sixth parameters 2555** to the callback are zero-terminated strings that contain additional 2556** details about the action to be authorized. 2557** 2558** ^If the action code is [SQLITE_READ] 2559** and the callback returns [SQLITE_IGNORE] then the 2560** [prepared statement] statement is constructed to substitute 2561** a NULL value in place of the table column that would have 2562** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2563** return can be used to deny an untrusted user access to individual 2564** columns of a table. 2565** ^If the action code is [SQLITE_DELETE] and the callback returns 2566** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2567** [truncate optimization] is disabled and all rows are deleted individually. 2568** 2569** An authorizer is used when [sqlite3_prepare | preparing] 2570** SQL statements from an untrusted source, to ensure that the SQL statements 2571** do not try to access data they are not allowed to see, or that they do not 2572** try to execute malicious statements that damage the database. For 2573** example, an application may allow a user to enter arbitrary 2574** SQL queries for evaluation by a database. But the application does 2575** not want the user to be able to make arbitrary changes to the 2576** database. An authorizer could then be put in place while the 2577** user-entered SQL is being [sqlite3_prepare | prepared] that 2578** disallows everything except [SELECT] statements. 2579** 2580** Applications that need to process SQL from untrusted sources 2581** might also consider lowering resource limits using [sqlite3_limit()] 2582** and limiting database size using the [max_page_count] [PRAGMA] 2583** in addition to using an authorizer. 2584** 2585** ^(Only a single authorizer can be in place on a database connection 2586** at a time. Each call to sqlite3_set_authorizer overrides the 2587** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2588** The authorizer is disabled by default. 2589** 2590** The authorizer callback must not do anything that will modify 2591** the database connection that invoked the authorizer callback. 2592** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2593** database connections for the meaning of "modify" in this paragraph. 2594** 2595** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2596** statement might be re-prepared during [sqlite3_step()] due to a 2597** schema change. Hence, the application should ensure that the 2598** correct authorizer callback remains in place during the [sqlite3_step()]. 2599** 2600** ^Note that the authorizer callback is invoked only during 2601** [sqlite3_prepare()] or its variants. Authorization is not 2602** performed during statement evaluation in [sqlite3_step()], unless 2603** as stated in the previous paragraph, sqlite3_step() invokes 2604** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2605*/ 2606int sqlite3_set_authorizer( 2607 sqlite3*, 2608 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2609 void *pUserData 2610); 2611 2612/* 2613** CAPI3REF: Authorizer Return Codes 2614** 2615** The [sqlite3_set_authorizer | authorizer callback function] must 2616** return either [SQLITE_OK] or one of these two constants in order 2617** to signal SQLite whether or not the action is permitted. See the 2618** [sqlite3_set_authorizer | authorizer documentation] for additional 2619** information. 2620** 2621** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2622** returned from the [sqlite3_vtab_on_conflict()] interface. 2623*/ 2624#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2625#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2626 2627/* 2628** CAPI3REF: Authorizer Action Codes 2629** 2630** The [sqlite3_set_authorizer()] interface registers a callback function 2631** that is invoked to authorize certain SQL statement actions. The 2632** second parameter to the callback is an integer code that specifies 2633** what action is being authorized. These are the integer action codes that 2634** the authorizer callback may be passed. 2635** 2636** These action code values signify what kind of operation is to be 2637** authorized. The 3rd and 4th parameters to the authorization 2638** callback function will be parameters or NULL depending on which of these 2639** codes is used as the second parameter. ^(The 5th parameter to the 2640** authorizer callback is the name of the database ("main", "temp", 2641** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2642** is the name of the inner-most trigger or view that is responsible for 2643** the access attempt or NULL if this access attempt is directly from 2644** top-level SQL code. 2645*/ 2646/******************************************* 3rd ************ 4th ***********/ 2647#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2648#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2649#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2650#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2651#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2652#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2653#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2654#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2655#define SQLITE_DELETE 9 /* Table Name NULL */ 2656#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2657#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2658#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2659#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2660#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2661#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2662#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2663#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2664#define SQLITE_INSERT 18 /* Table Name NULL */ 2665#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2666#define SQLITE_READ 20 /* Table Name Column Name */ 2667#define SQLITE_SELECT 21 /* NULL NULL */ 2668#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2669#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2670#define SQLITE_ATTACH 24 /* Filename NULL */ 2671#define SQLITE_DETACH 25 /* Database Name NULL */ 2672#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2673#define SQLITE_REINDEX 27 /* Index Name NULL */ 2674#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2675#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2676#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2677#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2678#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2679#define SQLITE_COPY 0 /* No longer used */ 2680#define SQLITE_RECURSIVE 33 /* NULL NULL */ 2681 2682/* 2683** CAPI3REF: Tracing And Profiling Functions 2684** METHOD: sqlite3 2685** 2686** These routines register callback functions that can be used for 2687** tracing and profiling the execution of SQL statements. 2688** 2689** ^The callback function registered by sqlite3_trace() is invoked at 2690** various times when an SQL statement is being run by [sqlite3_step()]. 2691** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2692** SQL statement text as the statement first begins executing. 2693** ^(Additional sqlite3_trace() callbacks might occur 2694** as each triggered subprogram is entered. The callbacks for triggers 2695** contain a UTF-8 SQL comment that identifies the trigger.)^ 2696** 2697** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2698** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2699** 2700** ^The callback function registered by sqlite3_profile() is invoked 2701** as each SQL statement finishes. ^The profile callback contains 2702** the original statement text and an estimate of wall-clock time 2703** of how long that statement took to run. ^The profile callback 2704** time is in units of nanoseconds, however the current implementation 2705** is only capable of millisecond resolution so the six least significant 2706** digits in the time are meaningless. Future versions of SQLite 2707** might provide greater resolution on the profiler callback. The 2708** sqlite3_profile() function is considered experimental and is 2709** subject to change in future versions of SQLite. 2710*/ 2711void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 2712SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, 2713 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2714 2715/* 2716** CAPI3REF: Query Progress Callbacks 2717** METHOD: sqlite3 2718** 2719** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2720** function X to be invoked periodically during long running calls to 2721** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2722** database connection D. An example use for this 2723** interface is to keep a GUI updated during a large query. 2724** 2725** ^The parameter P is passed through as the only parameter to the 2726** callback function X. ^The parameter N is the approximate number of 2727** [virtual machine instructions] that are evaluated between successive 2728** invocations of the callback X. ^If N is less than one then the progress 2729** handler is disabled. 2730** 2731** ^Only a single progress handler may be defined at one time per 2732** [database connection]; setting a new progress handler cancels the 2733** old one. ^Setting parameter X to NULL disables the progress handler. 2734** ^The progress handler is also disabled by setting N to a value less 2735** than 1. 2736** 2737** ^If the progress callback returns non-zero, the operation is 2738** interrupted. This feature can be used to implement a 2739** "Cancel" button on a GUI progress dialog box. 2740** 2741** The progress handler callback must not do anything that will modify 2742** the database connection that invoked the progress handler. 2743** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2744** database connections for the meaning of "modify" in this paragraph. 2745** 2746*/ 2747void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2748 2749/* 2750** CAPI3REF: Opening A New Database Connection 2751** CONSTRUCTOR: sqlite3 2752** 2753** ^These routines open an SQLite database file as specified by the 2754** filename argument. ^The filename argument is interpreted as UTF-8 for 2755** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2756** order for sqlite3_open16(). ^(A [database connection] handle is usually 2757** returned in *ppDb, even if an error occurs. The only exception is that 2758** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2759** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2760** object.)^ ^(If the database is opened (and/or created) successfully, then 2761** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2762** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2763** an English language description of the error following a failure of any 2764** of the sqlite3_open() routines. 2765** 2766** ^The default encoding will be UTF-8 for databases created using 2767** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 2768** created using sqlite3_open16() will be UTF-16 in the native byte order. 2769** 2770** Whether or not an error occurs when it is opened, resources 2771** associated with the [database connection] handle should be released by 2772** passing it to [sqlite3_close()] when it is no longer required. 2773** 2774** The sqlite3_open_v2() interface works like sqlite3_open() 2775** except that it accepts two additional parameters for additional control 2776** over the new database connection. ^(The flags parameter to 2777** sqlite3_open_v2() can take one of 2778** the following three values, optionally combined with the 2779** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2780** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 2781** 2782** <dl> 2783** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2784** <dd>The database is opened in read-only mode. If the database does not 2785** already exist, an error is returned.</dd>)^ 2786** 2787** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2788** <dd>The database is opened for reading and writing if possible, or reading 2789** only if the file is write protected by the operating system. In either 2790** case the database must already exist, otherwise an error is returned.</dd>)^ 2791** 2792** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2793** <dd>The database is opened for reading and writing, and is created if 2794** it does not already exist. This is the behavior that is always used for 2795** sqlite3_open() and sqlite3_open16().</dd>)^ 2796** </dl> 2797** 2798** If the 3rd parameter to sqlite3_open_v2() is not one of the 2799** combinations shown above optionally combined with other 2800** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 2801** then the behavior is undefined. 2802** 2803** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2804** opens in the multi-thread [threading mode] as long as the single-thread 2805** mode has not been set at compile-time or start-time. ^If the 2806** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2807** in the serialized [threading mode] unless single-thread was 2808** previously selected at compile-time or start-time. 2809** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 2810** eligible to use [shared cache mode], regardless of whether or not shared 2811** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 2812** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 2813** participate in [shared cache mode] even if it is enabled. 2814** 2815** ^The fourth parameter to sqlite3_open_v2() is the name of the 2816** [sqlite3_vfs] object that defines the operating system interface that 2817** the new database connection should use. ^If the fourth parameter is 2818** a NULL pointer then the default [sqlite3_vfs] object is used. 2819** 2820** ^If the filename is ":memory:", then a private, temporary in-memory database 2821** is created for the connection. ^This in-memory database will vanish when 2822** the database connection is closed. Future versions of SQLite might 2823** make use of additional special filenames that begin with the ":" character. 2824** It is recommended that when a database filename actually does begin with 2825** a ":" character you should prefix the filename with a pathname such as 2826** "./" to avoid ambiguity. 2827** 2828** ^If the filename is an empty string, then a private, temporary 2829** on-disk database will be created. ^This private database will be 2830** automatically deleted as soon as the database connection is closed. 2831** 2832** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 2833** 2834** ^If [URI filename] interpretation is enabled, and the filename argument 2835** begins with "file:", then the filename is interpreted as a URI. ^URI 2836** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 2837** set in the fourth argument to sqlite3_open_v2(), or if it has 2838** been enabled globally using the [SQLITE_CONFIG_URI] option with the 2839** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 2840** As of SQLite version 3.7.7, URI filename interpretation is turned off 2841** by default, but future releases of SQLite might enable URI filename 2842** interpretation by default. See "[URI filenames]" for additional 2843** information. 2844** 2845** URI filenames are parsed according to RFC 3986. ^If the URI contains an 2846** authority, then it must be either an empty string or the string 2847** "localhost". ^If the authority is not an empty string or "localhost", an 2848** error is returned to the caller. ^The fragment component of a URI, if 2849** present, is ignored. 2850** 2851** ^SQLite uses the path component of the URI as the name of the disk file 2852** which contains the database. ^If the path begins with a '/' character, 2853** then it is interpreted as an absolute path. ^If the path does not begin 2854** with a '/' (meaning that the authority section is omitted from the URI) 2855** then the path is interpreted as a relative path. 2856** ^(On windows, the first component of an absolute path 2857** is a drive specification (e.g. "C:").)^ 2858** 2859** [[core URI query parameters]] 2860** The query component of a URI may contain parameters that are interpreted 2861** either by SQLite itself, or by a [VFS | custom VFS implementation]. 2862** SQLite and its built-in [VFSes] interpret the 2863** following query parameters: 2864** 2865** <ul> 2866** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 2867** a VFS object that provides the operating system interface that should 2868** be used to access the database file on disk. ^If this option is set to 2869** an empty string the default VFS object is used. ^Specifying an unknown 2870** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 2871** present, then the VFS specified by the option takes precedence over 2872** the value passed as the fourth parameter to sqlite3_open_v2(). 2873** 2874** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 2875** "rwc", or "memory". Attempting to set it to any other value is 2876** an error)^. 2877** ^If "ro" is specified, then the database is opened for read-only 2878** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 2879** third argument to sqlite3_open_v2(). ^If the mode option is set to 2880** "rw", then the database is opened for read-write (but not create) 2881** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 2882** been set. ^Value "rwc" is equivalent to setting both 2883** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 2884** set to "memory" then a pure [in-memory database] that never reads 2885** or writes from disk is used. ^It is an error to specify a value for 2886** the mode parameter that is less restrictive than that specified by 2887** the flags passed in the third parameter to sqlite3_open_v2(). 2888** 2889** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 2890** "private". ^Setting it to "shared" is equivalent to setting the 2891** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 2892** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 2893** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 2894** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 2895** a URI filename, its value overrides any behavior requested by setting 2896** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 2897** 2898** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 2899** [powersafe overwrite] property does or does not apply to the 2900** storage media on which the database file resides. 2901** 2902** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 2903** which if set disables file locking in rollback journal modes. This 2904** is useful for accessing a database on a filesystem that does not 2905** support locking. Caution: Database corruption might result if two 2906** or more processes write to the same database and any one of those 2907** processes uses nolock=1. 2908** 2909** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 2910** parameter that indicates that the database file is stored on 2911** read-only media. ^When immutable is set, SQLite assumes that the 2912** database file cannot be changed, even by a process with higher 2913** privilege, and so the database is opened read-only and all locking 2914** and change detection is disabled. Caution: Setting the immutable 2915** property on a database file that does in fact change can result 2916** in incorrect query results and/or [SQLITE_CORRUPT] errors. 2917** See also: [SQLITE_IOCAP_IMMUTABLE]. 2918** 2919** </ul> 2920** 2921** ^Specifying an unknown parameter in the query component of a URI is not an 2922** error. Future versions of SQLite might understand additional query 2923** parameters. See "[query parameters with special meaning to SQLite]" for 2924** additional information. 2925** 2926** [[URI filename examples]] <h3>URI filename examples</h3> 2927** 2928** <table border="1" align=center cellpadding=5> 2929** <tr><th> URI filenames <th> Results 2930** <tr><td> file:data.db <td> 2931** Open the file "data.db" in the current directory. 2932** <tr><td> file:/home/fred/data.db<br> 2933** file:///home/fred/data.db <br> 2934** file://localhost/home/fred/data.db <br> <td> 2935** Open the database file "/home/fred/data.db". 2936** <tr><td> file://darkstar/home/fred/data.db <td> 2937** An error. "darkstar" is not a recognized authority. 2938** <tr><td style="white-space:nowrap"> 2939** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 2940** <td> Windows only: Open the file "data.db" on fred's desktop on drive 2941** C:. Note that the %20 escaping in this example is not strictly 2942** necessary - space characters can be used literally 2943** in URI filenames. 2944** <tr><td> file:data.db?mode=ro&cache=private <td> 2945** Open file "data.db" in the current directory for read-only access. 2946** Regardless of whether or not shared-cache mode is enabled by 2947** default, use a private cache. 2948** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 2949** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 2950** that uses dot-files in place of posix advisory locking. 2951** <tr><td> file:data.db?mode=readonly <td> 2952** An error. "readonly" is not a valid option for the "mode" parameter. 2953** </table> 2954** 2955** ^URI hexadecimal escape sequences (%HH) are supported within the path and 2956** query components of a URI. A hexadecimal escape sequence consists of a 2957** percent sign - "%" - followed by exactly two hexadecimal digits 2958** specifying an octet value. ^Before the path or query components of a 2959** URI filename are interpreted, they are encoded using UTF-8 and all 2960** hexadecimal escape sequences replaced by a single byte containing the 2961** corresponding octet. If this process generates an invalid UTF-8 encoding, 2962** the results are undefined. 2963** 2964** <b>Note to Windows users:</b> The encoding used for the filename argument 2965** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 2966** codepage is currently defined. Filenames containing international 2967** characters must be converted to UTF-8 prior to passing them into 2968** sqlite3_open() or sqlite3_open_v2(). 2969** 2970** <b>Note to Windows Runtime users:</b> The temporary directory must be set 2971** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 2972** features that require the use of temporary files may fail. 2973** 2974** See also: [sqlite3_temp_directory] 2975*/ 2976int sqlite3_open( 2977 const char *filename, /* Database filename (UTF-8) */ 2978 sqlite3 **ppDb /* OUT: SQLite db handle */ 2979); 2980int sqlite3_open16( 2981 const void *filename, /* Database filename (UTF-16) */ 2982 sqlite3 **ppDb /* OUT: SQLite db handle */ 2983); 2984int sqlite3_open_v2( 2985 const char *filename, /* Database filename (UTF-8) */ 2986 sqlite3 **ppDb, /* OUT: SQLite db handle */ 2987 int flags, /* Flags */ 2988 const char *zVfs /* Name of VFS module to use */ 2989); 2990 2991/* 2992** CAPI3REF: Obtain Values For URI Parameters 2993** 2994** These are utility routines, useful to VFS implementations, that check 2995** to see if a database file was a URI that contained a specific query 2996** parameter, and if so obtains the value of that query parameter. 2997** 2998** If F is the database filename pointer passed into the xOpen() method of 2999** a VFS implementation when the flags parameter to xOpen() has one or 3000** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3001** P is the name of the query parameter, then 3002** sqlite3_uri_parameter(F,P) returns the value of the P 3003** parameter if it exists or a NULL pointer if P does not appear as a 3004** query parameter on F. If P is a query parameter of F 3005** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3006** a pointer to an empty string. 3007** 3008** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3009** parameter and returns true (1) or false (0) according to the value 3010** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3011** value of query parameter P is one of "yes", "true", or "on" in any 3012** case or if the value begins with a non-zero number. The 3013** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3014** query parameter P is one of "no", "false", or "off" in any case or 3015** if the value begins with a numeric zero. If P is not a query 3016** parameter on F or if the value of P is does not match any of the 3017** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3018** 3019** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3020** 64-bit signed integer and returns that integer, or D if P does not 3021** exist. If the value of P is something other than an integer, then 3022** zero is returned. 3023** 3024** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3025** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3026** is not a database file pathname pointer that SQLite passed into the xOpen 3027** VFS method, then the behavior of this routine is undefined and probably 3028** undesirable. 3029*/ 3030const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3031int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3032sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3033 3034 3035/* 3036** CAPI3REF: Error Codes And Messages 3037** METHOD: sqlite3 3038** 3039** ^If the most recent sqlite3_* API call associated with 3040** [database connection] D failed, then the sqlite3_errcode(D) interface 3041** returns the numeric [result code] or [extended result code] for that 3042** API call. 3043** If the most recent API call was successful, 3044** then the return value from sqlite3_errcode() is undefined. 3045** ^The sqlite3_extended_errcode() 3046** interface is the same except that it always returns the 3047** [extended result code] even when extended result codes are 3048** disabled. 3049** 3050** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3051** text that describes the error, as either UTF-8 or UTF-16 respectively. 3052** ^(Memory to hold the error message string is managed internally. 3053** The application does not need to worry about freeing the result. 3054** However, the error string might be overwritten or deallocated by 3055** subsequent calls to other SQLite interface functions.)^ 3056** 3057** ^The sqlite3_errstr() interface returns the English-language text 3058** that describes the [result code], as UTF-8. 3059** ^(Memory to hold the error message string is managed internally 3060** and must not be freed by the application)^. 3061** 3062** When the serialized [threading mode] is in use, it might be the 3063** case that a second error occurs on a separate thread in between 3064** the time of the first error and the call to these interfaces. 3065** When that happens, the second error will be reported since these 3066** interfaces always report the most recent result. To avoid 3067** this, each thread can obtain exclusive use of the [database connection] D 3068** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3069** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3070** all calls to the interfaces listed here are completed. 3071** 3072** If an interface fails with SQLITE_MISUSE, that means the interface 3073** was invoked incorrectly by the application. In that case, the 3074** error code and message may or may not be set. 3075*/ 3076int sqlite3_errcode(sqlite3 *db); 3077int sqlite3_extended_errcode(sqlite3 *db); 3078const char *sqlite3_errmsg(sqlite3*); 3079const void *sqlite3_errmsg16(sqlite3*); 3080const char *sqlite3_errstr(int); 3081 3082/* 3083** CAPI3REF: Prepared Statement Object 3084** KEYWORDS: {prepared statement} {prepared statements} 3085** 3086** An instance of this object represents a single SQL statement that 3087** has been compiled into binary form and is ready to be evaluated. 3088** 3089** Think of each SQL statement as a separate computer program. The 3090** original SQL text is source code. A prepared statement object 3091** is the compiled object code. All SQL must be converted into a 3092** prepared statement before it can be run. 3093** 3094** The life-cycle of a prepared statement object usually goes like this: 3095** 3096** <ol> 3097** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3098** <li> Bind values to [parameters] using the sqlite3_bind_*() 3099** interfaces. 3100** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3101** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3102** to step 2. Do this zero or more times. 3103** <li> Destroy the object using [sqlite3_finalize()]. 3104** </ol> 3105*/ 3106typedef struct sqlite3_stmt sqlite3_stmt; 3107 3108/* 3109** CAPI3REF: Run-time Limits 3110** METHOD: sqlite3 3111** 3112** ^(This interface allows the size of various constructs to be limited 3113** on a connection by connection basis. The first parameter is the 3114** [database connection] whose limit is to be set or queried. The 3115** second parameter is one of the [limit categories] that define a 3116** class of constructs to be size limited. The third parameter is the 3117** new limit for that construct.)^ 3118** 3119** ^If the new limit is a negative number, the limit is unchanged. 3120** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3121** [limits | hard upper bound] 3122** set at compile-time by a C preprocessor macro called 3123** [limits | SQLITE_MAX_<i>NAME</i>]. 3124** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3125** ^Attempts to increase a limit above its hard upper bound are 3126** silently truncated to the hard upper bound. 3127** 3128** ^Regardless of whether or not the limit was changed, the 3129** [sqlite3_limit()] interface returns the prior value of the limit. 3130** ^Hence, to find the current value of a limit without changing it, 3131** simply invoke this interface with the third parameter set to -1. 3132** 3133** Run-time limits are intended for use in applications that manage 3134** both their own internal database and also databases that are controlled 3135** by untrusted external sources. An example application might be a 3136** web browser that has its own databases for storing history and 3137** separate databases controlled by JavaScript applications downloaded 3138** off the Internet. The internal databases can be given the 3139** large, default limits. Databases managed by external sources can 3140** be given much smaller limits designed to prevent a denial of service 3141** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3142** interface to further control untrusted SQL. The size of the database 3143** created by an untrusted script can be contained using the 3144** [max_page_count] [PRAGMA]. 3145** 3146** New run-time limit categories may be added in future releases. 3147*/ 3148int sqlite3_limit(sqlite3*, int id, int newVal); 3149 3150/* 3151** CAPI3REF: Run-Time Limit Categories 3152** KEYWORDS: {limit category} {*limit categories} 3153** 3154** These constants define various performance limits 3155** that can be lowered at run-time using [sqlite3_limit()]. 3156** The synopsis of the meanings of the various limits is shown below. 3157** Additional information is available at [limits | Limits in SQLite]. 3158** 3159** <dl> 3160** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3161** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3162** 3163** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3164** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3165** 3166** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3167** <dd>The maximum number of columns in a table definition or in the 3168** result set of a [SELECT] or the maximum number of columns in an index 3169** or in an ORDER BY or GROUP BY clause.</dd>)^ 3170** 3171** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3172** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3173** 3174** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3175** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3176** 3177** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3178** <dd>The maximum number of instructions in a virtual machine program 3179** used to implement an SQL statement. This limit is not currently 3180** enforced, though that might be added in some future release of 3181** SQLite.</dd>)^ 3182** 3183** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3184** <dd>The maximum number of arguments on a function.</dd>)^ 3185** 3186** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3187** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3188** 3189** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3190** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3191** <dd>The maximum length of the pattern argument to the [LIKE] or 3192** [GLOB] operators.</dd>)^ 3193** 3194** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3195** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3196** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3197** 3198** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3199** <dd>The maximum depth of recursion for triggers.</dd>)^ 3200** 3201** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3202** <dd>The maximum number of auxiliary worker threads that a single 3203** [prepared statement] may start.</dd>)^ 3204** </dl> 3205*/ 3206#define SQLITE_LIMIT_LENGTH 0 3207#define SQLITE_LIMIT_SQL_LENGTH 1 3208#define SQLITE_LIMIT_COLUMN 2 3209#define SQLITE_LIMIT_EXPR_DEPTH 3 3210#define SQLITE_LIMIT_COMPOUND_SELECT 4 3211#define SQLITE_LIMIT_VDBE_OP 5 3212#define SQLITE_LIMIT_FUNCTION_ARG 6 3213#define SQLITE_LIMIT_ATTACHED 7 3214#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3215#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3216#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3217#define SQLITE_LIMIT_WORKER_THREADS 11 3218 3219/* 3220** CAPI3REF: Compiling An SQL Statement 3221** KEYWORDS: {SQL statement compiler} 3222** METHOD: sqlite3 3223** CONSTRUCTOR: sqlite3_stmt 3224** 3225** To execute an SQL query, it must first be compiled into a byte-code 3226** program using one of these routines. 3227** 3228** The first argument, "db", is a [database connection] obtained from a 3229** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3230** [sqlite3_open16()]. The database connection must not have been closed. 3231** 3232** The second argument, "zSql", is the statement to be compiled, encoded 3233** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 3234** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 3235** use UTF-16. 3236** 3237** ^If the nByte argument is negative, then zSql is read up to the 3238** first zero terminator. ^If nByte is positive, then it is the 3239** number of bytes read from zSql. ^If nByte is zero, then no prepared 3240** statement is generated. 3241** If the caller knows that the supplied string is nul-terminated, then 3242** there is a small performance advantage to passing an nByte parameter that 3243** is the number of bytes in the input string <i>including</i> 3244** the nul-terminator. 3245** 3246** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3247** past the end of the first SQL statement in zSql. These routines only 3248** compile the first statement in zSql, so *pzTail is left pointing to 3249** what remains uncompiled. 3250** 3251** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3252** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3253** to NULL. ^If the input text contains no SQL (if the input is an empty 3254** string or a comment) then *ppStmt is set to NULL. 3255** The calling procedure is responsible for deleting the compiled 3256** SQL statement using [sqlite3_finalize()] after it has finished with it. 3257** ppStmt may not be NULL. 3258** 3259** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3260** otherwise an [error code] is returned. 3261** 3262** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 3263** recommended for all new programs. The two older interfaces are retained 3264** for backwards compatibility, but their use is discouraged. 3265** ^In the "v2" interfaces, the prepared statement 3266** that is returned (the [sqlite3_stmt] object) contains a copy of the 3267** original SQL text. This causes the [sqlite3_step()] interface to 3268** behave differently in three ways: 3269** 3270** <ol> 3271** <li> 3272** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3273** always used to do, [sqlite3_step()] will automatically recompile the SQL 3274** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3275** retries will occur before sqlite3_step() gives up and returns an error. 3276** </li> 3277** 3278** <li> 3279** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3280** [error codes] or [extended error codes]. ^The legacy behavior was that 3281** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3282** and the application would have to make a second call to [sqlite3_reset()] 3283** in order to find the underlying cause of the problem. With the "v2" prepare 3284** interfaces, the underlying reason for the error is returned immediately. 3285** </li> 3286** 3287** <li> 3288** ^If the specific value bound to [parameter | host parameter] in the 3289** WHERE clause might influence the choice of query plan for a statement, 3290** then the statement will be automatically recompiled, as if there had been 3291** a schema change, on the first [sqlite3_step()] call following any change 3292** to the [sqlite3_bind_text | bindings] of that [parameter]. 3293** ^The specific value of WHERE-clause [parameter] might influence the 3294** choice of query plan if the parameter is the left-hand side of a [LIKE] 3295** or [GLOB] operator or if the parameter is compared to an indexed column 3296** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3297** </li> 3298** </ol> 3299*/ 3300int sqlite3_prepare( 3301 sqlite3 *db, /* Database handle */ 3302 const char *zSql, /* SQL statement, UTF-8 encoded */ 3303 int nByte, /* Maximum length of zSql in bytes. */ 3304 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3305 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3306); 3307int sqlite3_prepare_v2( 3308 sqlite3 *db, /* Database handle */ 3309 const char *zSql, /* SQL statement, UTF-8 encoded */ 3310 int nByte, /* Maximum length of zSql in bytes. */ 3311 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3312 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3313); 3314int sqlite3_prepare16( 3315 sqlite3 *db, /* Database handle */ 3316 const void *zSql, /* SQL statement, UTF-16 encoded */ 3317 int nByte, /* Maximum length of zSql in bytes. */ 3318 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3319 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3320); 3321int sqlite3_prepare16_v2( 3322 sqlite3 *db, /* Database handle */ 3323 const void *zSql, /* SQL statement, UTF-16 encoded */ 3324 int nByte, /* Maximum length of zSql in bytes. */ 3325 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3326 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3327); 3328 3329/* 3330** CAPI3REF: Retrieving Statement SQL 3331** METHOD: sqlite3_stmt 3332** 3333** ^This interface can be used to retrieve a saved copy of the original 3334** SQL text used to create a [prepared statement] if that statement was 3335** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3336*/ 3337const char *sqlite3_sql(sqlite3_stmt *pStmt); 3338 3339/* 3340** CAPI3REF: Determine If An SQL Statement Writes The Database 3341** METHOD: sqlite3_stmt 3342** 3343** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3344** and only if the [prepared statement] X makes no direct changes to 3345** the content of the database file. 3346** 3347** Note that [application-defined SQL functions] or 3348** [virtual tables] might change the database indirectly as a side effect. 3349** ^(For example, if an application defines a function "eval()" that 3350** calls [sqlite3_exec()], then the following SQL statement would 3351** change the database file through side-effects: 3352** 3353** <blockquote><pre> 3354** SELECT eval('DELETE FROM t1') FROM t2; 3355** </pre></blockquote> 3356** 3357** But because the [SELECT] statement does not change the database file 3358** directly, sqlite3_stmt_readonly() would still return true.)^ 3359** 3360** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3361** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3362** since the statements themselves do not actually modify the database but 3363** rather they control the timing of when other statements modify the 3364** database. ^The [ATTACH] and [DETACH] statements also cause 3365** sqlite3_stmt_readonly() to return true since, while those statements 3366** change the configuration of a database connection, they do not make 3367** changes to the content of the database files on disk. 3368*/ 3369int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3370 3371/* 3372** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3373** METHOD: sqlite3_stmt 3374** 3375** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3376** [prepared statement] S has been stepped at least once using 3377** [sqlite3_step(S)] but has neither run to completion (returned 3378** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3379** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3380** interface returns false if S is a NULL pointer. If S is not a 3381** NULL pointer and is not a pointer to a valid [prepared statement] 3382** object, then the behavior is undefined and probably undesirable. 3383** 3384** This interface can be used in combination [sqlite3_next_stmt()] 3385** to locate all prepared statements associated with a database 3386** connection that are in need of being reset. This can be used, 3387** for example, in diagnostic routines to search for prepared 3388** statements that are holding a transaction open. 3389*/ 3390int sqlite3_stmt_busy(sqlite3_stmt*); 3391 3392/* 3393** CAPI3REF: Dynamically Typed Value Object 3394** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3395** 3396** SQLite uses the sqlite3_value object to represent all values 3397** that can be stored in a database table. SQLite uses dynamic typing 3398** for the values it stores. ^Values stored in sqlite3_value objects 3399** can be integers, floating point values, strings, BLOBs, or NULL. 3400** 3401** An sqlite3_value object may be either "protected" or "unprotected". 3402** Some interfaces require a protected sqlite3_value. Other interfaces 3403** will accept either a protected or an unprotected sqlite3_value. 3404** Every interface that accepts sqlite3_value arguments specifies 3405** whether or not it requires a protected sqlite3_value. The 3406** [sqlite3_value_dup()] interface can be used to construct a new 3407** protected sqlite3_value from an unprotected sqlite3_value. 3408** 3409** The terms "protected" and "unprotected" refer to whether or not 3410** a mutex is held. An internal mutex is held for a protected 3411** sqlite3_value object but no mutex is held for an unprotected 3412** sqlite3_value object. If SQLite is compiled to be single-threaded 3413** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3414** or if SQLite is run in one of reduced mutex modes 3415** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3416** then there is no distinction between protected and unprotected 3417** sqlite3_value objects and they can be used interchangeably. However, 3418** for maximum code portability it is recommended that applications 3419** still make the distinction between protected and unprotected 3420** sqlite3_value objects even when not strictly required. 3421** 3422** ^The sqlite3_value objects that are passed as parameters into the 3423** implementation of [application-defined SQL functions] are protected. 3424** ^The sqlite3_value object returned by 3425** [sqlite3_column_value()] is unprotected. 3426** Unprotected sqlite3_value objects may only be used with 3427** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3428** The [sqlite3_value_blob | sqlite3_value_type()] family of 3429** interfaces require protected sqlite3_value objects. 3430*/ 3431typedef struct Mem sqlite3_value; 3432 3433/* 3434** CAPI3REF: SQL Function Context Object 3435** 3436** The context in which an SQL function executes is stored in an 3437** sqlite3_context object. ^A pointer to an sqlite3_context object 3438** is always first parameter to [application-defined SQL functions]. 3439** The application-defined SQL function implementation will pass this 3440** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3441** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3442** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3443** and/or [sqlite3_set_auxdata()]. 3444*/ 3445typedef struct sqlite3_context sqlite3_context; 3446 3447/* 3448** CAPI3REF: Binding Values To Prepared Statements 3449** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3450** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3451** METHOD: sqlite3_stmt 3452** 3453** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3454** literals may be replaced by a [parameter] that matches one of following 3455** templates: 3456** 3457** <ul> 3458** <li> ? 3459** <li> ?NNN 3460** <li> :VVV 3461** <li> @VVV 3462** <li> $VVV 3463** </ul> 3464** 3465** In the templates above, NNN represents an integer literal, 3466** and VVV represents an alphanumeric identifier.)^ ^The values of these 3467** parameters (also called "host parameter names" or "SQL parameters") 3468** can be set using the sqlite3_bind_*() routines defined here. 3469** 3470** ^The first argument to the sqlite3_bind_*() routines is always 3471** a pointer to the [sqlite3_stmt] object returned from 3472** [sqlite3_prepare_v2()] or its variants. 3473** 3474** ^The second argument is the index of the SQL parameter to be set. 3475** ^The leftmost SQL parameter has an index of 1. ^When the same named 3476** SQL parameter is used more than once, second and subsequent 3477** occurrences have the same index as the first occurrence. 3478** ^The index for named parameters can be looked up using the 3479** [sqlite3_bind_parameter_index()] API if desired. ^The index 3480** for "?NNN" parameters is the value of NNN. 3481** ^The NNN value must be between 1 and the [sqlite3_limit()] 3482** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3483** 3484** ^The third argument is the value to bind to the parameter. 3485** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3486** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3487** is ignored and the end result is the same as sqlite3_bind_null(). 3488** 3489** ^(In those routines that have a fourth argument, its value is the 3490** number of bytes in the parameter. To be clear: the value is the 3491** number of <u>bytes</u> in the value, not the number of characters.)^ 3492** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3493** is negative, then the length of the string is 3494** the number of bytes up to the first zero terminator. 3495** If the fourth parameter to sqlite3_bind_blob() is negative, then 3496** the behavior is undefined. 3497** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3498** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3499** that parameter must be the byte offset 3500** where the NUL terminator would occur assuming the string were NUL 3501** terminated. If any NUL characters occur at byte offsets less than 3502** the value of the fourth parameter then the resulting string value will 3503** contain embedded NULs. The result of expressions involving strings 3504** with embedded NULs is undefined. 3505** 3506** ^The fifth argument to the BLOB and string binding interfaces 3507** is a destructor used to dispose of the BLOB or 3508** string after SQLite has finished with it. ^The destructor is called 3509** to dispose of the BLOB or string even if the call to bind API fails. 3510** ^If the fifth argument is 3511** the special value [SQLITE_STATIC], then SQLite assumes that the 3512** information is in static, unmanaged space and does not need to be freed. 3513** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3514** SQLite makes its own private copy of the data immediately, before 3515** the sqlite3_bind_*() routine returns. 3516** 3517** ^The sixth argument to sqlite3_bind_text64() must be one of 3518** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 3519** to specify the encoding of the text in the third parameter. If 3520** the sixth argument to sqlite3_bind_text64() is not one of the 3521** allowed values shown above, or if the text encoding is different 3522** from the encoding specified by the sixth parameter, then the behavior 3523** is undefined. 3524** 3525** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3526** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3527** (just an integer to hold its size) while it is being processed. 3528** Zeroblobs are intended to serve as placeholders for BLOBs whose 3529** content is later written using 3530** [sqlite3_blob_open | incremental BLOB I/O] routines. 3531** ^A negative value for the zeroblob results in a zero-length BLOB. 3532** 3533** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3534** for the [prepared statement] or with a prepared statement for which 3535** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3536** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3537** routine is passed a [prepared statement] that has been finalized, the 3538** result is undefined and probably harmful. 3539** 3540** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3541** ^Unbound parameters are interpreted as NULL. 3542** 3543** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3544** [error code] if anything goes wrong. 3545** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 3546** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 3547** [SQLITE_MAX_LENGTH]. 3548** ^[SQLITE_RANGE] is returned if the parameter 3549** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3550** 3551** See also: [sqlite3_bind_parameter_count()], 3552** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3553*/ 3554int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3555int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 3556 void(*)(void*)); 3557int sqlite3_bind_double(sqlite3_stmt*, int, double); 3558int sqlite3_bind_int(sqlite3_stmt*, int, int); 3559int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3560int sqlite3_bind_null(sqlite3_stmt*, int); 3561int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 3562int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3563int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 3564 void(*)(void*), unsigned char encoding); 3565int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3566int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3567int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 3568 3569/* 3570** CAPI3REF: Number Of SQL Parameters 3571** METHOD: sqlite3_stmt 3572** 3573** ^This routine can be used to find the number of [SQL parameters] 3574** in a [prepared statement]. SQL parameters are tokens of the 3575** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3576** placeholders for values that are [sqlite3_bind_blob | bound] 3577** to the parameters at a later time. 3578** 3579** ^(This routine actually returns the index of the largest (rightmost) 3580** parameter. For all forms except ?NNN, this will correspond to the 3581** number of unique parameters. If parameters of the ?NNN form are used, 3582** there may be gaps in the list.)^ 3583** 3584** See also: [sqlite3_bind_blob|sqlite3_bind()], 3585** [sqlite3_bind_parameter_name()], and 3586** [sqlite3_bind_parameter_index()]. 3587*/ 3588int sqlite3_bind_parameter_count(sqlite3_stmt*); 3589 3590/* 3591** CAPI3REF: Name Of A Host Parameter 3592** METHOD: sqlite3_stmt 3593** 3594** ^The sqlite3_bind_parameter_name(P,N) interface returns 3595** the name of the N-th [SQL parameter] in the [prepared statement] P. 3596** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3597** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3598** respectively. 3599** In other words, the initial ":" or "$" or "@" or "?" 3600** is included as part of the name.)^ 3601** ^Parameters of the form "?" without a following integer have no name 3602** and are referred to as "nameless" or "anonymous parameters". 3603** 3604** ^The first host parameter has an index of 1, not 0. 3605** 3606** ^If the value N is out of range or if the N-th parameter is 3607** nameless, then NULL is returned. ^The returned string is 3608** always in UTF-8 encoding even if the named parameter was 3609** originally specified as UTF-16 in [sqlite3_prepare16()] or 3610** [sqlite3_prepare16_v2()]. 3611** 3612** See also: [sqlite3_bind_blob|sqlite3_bind()], 3613** [sqlite3_bind_parameter_count()], and 3614** [sqlite3_bind_parameter_index()]. 3615*/ 3616const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3617 3618/* 3619** CAPI3REF: Index Of A Parameter With A Given Name 3620** METHOD: sqlite3_stmt 3621** 3622** ^Return the index of an SQL parameter given its name. ^The 3623** index value returned is suitable for use as the second 3624** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3625** is returned if no matching parameter is found. ^The parameter 3626** name must be given in UTF-8 even if the original statement 3627** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3628** 3629** See also: [sqlite3_bind_blob|sqlite3_bind()], 3630** [sqlite3_bind_parameter_count()], and 3631** [sqlite3_bind_parameter_index()]. 3632*/ 3633int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3634 3635/* 3636** CAPI3REF: Reset All Bindings On A Prepared Statement 3637** METHOD: sqlite3_stmt 3638** 3639** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3640** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3641** ^Use this routine to reset all host parameters to NULL. 3642*/ 3643int sqlite3_clear_bindings(sqlite3_stmt*); 3644 3645/* 3646** CAPI3REF: Number Of Columns In A Result Set 3647** METHOD: sqlite3_stmt 3648** 3649** ^Return the number of columns in the result set returned by the 3650** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 3651** statement that does not return data (for example an [UPDATE]). 3652** 3653** See also: [sqlite3_data_count()] 3654*/ 3655int sqlite3_column_count(sqlite3_stmt *pStmt); 3656 3657/* 3658** CAPI3REF: Column Names In A Result Set 3659** METHOD: sqlite3_stmt 3660** 3661** ^These routines return the name assigned to a particular column 3662** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3663** interface returns a pointer to a zero-terminated UTF-8 string 3664** and sqlite3_column_name16() returns a pointer to a zero-terminated 3665** UTF-16 string. ^The first parameter is the [prepared statement] 3666** that implements the [SELECT] statement. ^The second parameter is the 3667** column number. ^The leftmost column is number 0. 3668** 3669** ^The returned string pointer is valid until either the [prepared statement] 3670** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3671** reprepared by the first call to [sqlite3_step()] for a particular run 3672** or until the next call to 3673** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3674** 3675** ^If sqlite3_malloc() fails during the processing of either routine 3676** (for example during a conversion from UTF-8 to UTF-16) then a 3677** NULL pointer is returned. 3678** 3679** ^The name of a result column is the value of the "AS" clause for 3680** that column, if there is an AS clause. If there is no AS clause 3681** then the name of the column is unspecified and may change from 3682** one release of SQLite to the next. 3683*/ 3684const char *sqlite3_column_name(sqlite3_stmt*, int N); 3685const void *sqlite3_column_name16(sqlite3_stmt*, int N); 3686 3687/* 3688** CAPI3REF: Source Of Data In A Query Result 3689** METHOD: sqlite3_stmt 3690** 3691** ^These routines provide a means to determine the database, table, and 3692** table column that is the origin of a particular result column in 3693** [SELECT] statement. 3694** ^The name of the database or table or column can be returned as 3695** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3696** the database name, the _table_ routines return the table name, and 3697** the origin_ routines return the column name. 3698** ^The returned string is valid until the [prepared statement] is destroyed 3699** using [sqlite3_finalize()] or until the statement is automatically 3700** reprepared by the first call to [sqlite3_step()] for a particular run 3701** or until the same information is requested 3702** again in a different encoding. 3703** 3704** ^The names returned are the original un-aliased names of the 3705** database, table, and column. 3706** 3707** ^The first argument to these interfaces is a [prepared statement]. 3708** ^These functions return information about the Nth result column returned by 3709** the statement, where N is the second function argument. 3710** ^The left-most column is column 0 for these routines. 3711** 3712** ^If the Nth column returned by the statement is an expression or 3713** subquery and is not a column value, then all of these functions return 3714** NULL. ^These routine might also return NULL if a memory allocation error 3715** occurs. ^Otherwise, they return the name of the attached database, table, 3716** or column that query result column was extracted from. 3717** 3718** ^As with all other SQLite APIs, those whose names end with "16" return 3719** UTF-16 encoded strings and the other functions return UTF-8. 3720** 3721** ^These APIs are only available if the library was compiled with the 3722** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3723** 3724** If two or more threads call one or more of these routines against the same 3725** prepared statement and column at the same time then the results are 3726** undefined. 3727** 3728** If two or more threads call one or more 3729** [sqlite3_column_database_name | column metadata interfaces] 3730** for the same [prepared statement] and result column 3731** at the same time then the results are undefined. 3732*/ 3733const char *sqlite3_column_database_name(sqlite3_stmt*,int); 3734const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 3735const char *sqlite3_column_table_name(sqlite3_stmt*,int); 3736const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 3737const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 3738const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 3739 3740/* 3741** CAPI3REF: Declared Datatype Of A Query Result 3742** METHOD: sqlite3_stmt 3743** 3744** ^(The first parameter is a [prepared statement]. 3745** If this statement is a [SELECT] statement and the Nth column of the 3746** returned result set of that [SELECT] is a table column (not an 3747** expression or subquery) then the declared type of the table 3748** column is returned.)^ ^If the Nth column of the result set is an 3749** expression or subquery, then a NULL pointer is returned. 3750** ^The returned string is always UTF-8 encoded. 3751** 3752** ^(For example, given the database schema: 3753** 3754** CREATE TABLE t1(c1 VARIANT); 3755** 3756** and the following statement to be compiled: 3757** 3758** SELECT c1 + 1, c1 FROM t1; 3759** 3760** this routine would return the string "VARIANT" for the second result 3761** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3762** 3763** ^SQLite uses dynamic run-time typing. ^So just because a column 3764** is declared to contain a particular type does not mean that the 3765** data stored in that column is of the declared type. SQLite is 3766** strongly typed, but the typing is dynamic not static. ^Type 3767** is associated with individual values, not with the containers 3768** used to hold those values. 3769*/ 3770const char *sqlite3_column_decltype(sqlite3_stmt*,int); 3771const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 3772 3773/* 3774** CAPI3REF: Evaluate An SQL Statement 3775** METHOD: sqlite3_stmt 3776** 3777** After a [prepared statement] has been prepared using either 3778** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3779** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3780** must be called one or more times to evaluate the statement. 3781** 3782** The details of the behavior of the sqlite3_step() interface depend 3783** on whether the statement was prepared using the newer "v2" interface 3784** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3785** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3786** new "v2" interface is recommended for new applications but the legacy 3787** interface will continue to be supported. 3788** 3789** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 3790** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 3791** ^With the "v2" interface, any of the other [result codes] or 3792** [extended result codes] might be returned as well. 3793** 3794** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 3795** database locks it needs to do its job. ^If the statement is a [COMMIT] 3796** or occurs outside of an explicit transaction, then you can retry the 3797** statement. If the statement is not a [COMMIT] and occurs within an 3798** explicit transaction then you should rollback the transaction before 3799** continuing. 3800** 3801** ^[SQLITE_DONE] means that the statement has finished executing 3802** successfully. sqlite3_step() should not be called again on this virtual 3803** machine without first calling [sqlite3_reset()] to reset the virtual 3804** machine back to its initial state. 3805** 3806** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 3807** is returned each time a new row of data is ready for processing by the 3808** caller. The values may be accessed using the [column access functions]. 3809** sqlite3_step() is called again to retrieve the next row of data. 3810** 3811** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 3812** violation) has occurred. sqlite3_step() should not be called again on 3813** the VM. More information may be found by calling [sqlite3_errmsg()]. 3814** ^With the legacy interface, a more specific error code (for example, 3815** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 3816** can be obtained by calling [sqlite3_reset()] on the 3817** [prepared statement]. ^In the "v2" interface, 3818** the more specific error code is returned directly by sqlite3_step(). 3819** 3820** [SQLITE_MISUSE] means that the this routine was called inappropriately. 3821** Perhaps it was called on a [prepared statement] that has 3822** already been [sqlite3_finalize | finalized] or on one that had 3823** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 3824** be the case that the same database connection is being used by two or 3825** more threads at the same moment in time. 3826** 3827** For all versions of SQLite up to and including 3.6.23.1, a call to 3828** [sqlite3_reset()] was required after sqlite3_step() returned anything 3829** other than [SQLITE_ROW] before any subsequent invocation of 3830** sqlite3_step(). Failure to reset the prepared statement using 3831** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 3832** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 3833** calling [sqlite3_reset()] automatically in this circumstance rather 3834** than returning [SQLITE_MISUSE]. This is not considered a compatibility 3835** break because any application that ever receives an SQLITE_MISUSE error 3836** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 3837** can be used to restore the legacy behavior. 3838** 3839** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 3840** API always returns a generic error code, [SQLITE_ERROR], following any 3841** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 3842** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 3843** specific [error codes] that better describes the error. 3844** We admit that this is a goofy design. The problem has been fixed 3845** with the "v2" interface. If you prepare all of your SQL statements 3846** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 3847** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 3848** then the more specific [error codes] are returned directly 3849** by sqlite3_step(). The use of the "v2" interface is recommended. 3850*/ 3851int sqlite3_step(sqlite3_stmt*); 3852 3853/* 3854** CAPI3REF: Number of columns in a result set 3855** METHOD: sqlite3_stmt 3856** 3857** ^The sqlite3_data_count(P) interface returns the number of columns in the 3858** current row of the result set of [prepared statement] P. 3859** ^If prepared statement P does not have results ready to return 3860** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 3861** interfaces) then sqlite3_data_count(P) returns 0. 3862** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 3863** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 3864** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 3865** will return non-zero if previous call to [sqlite3_step](P) returned 3866** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 3867** where it always returns zero since each step of that multi-step 3868** pragma returns 0 columns of data. 3869** 3870** See also: [sqlite3_column_count()] 3871*/ 3872int sqlite3_data_count(sqlite3_stmt *pStmt); 3873 3874/* 3875** CAPI3REF: Fundamental Datatypes 3876** KEYWORDS: SQLITE_TEXT 3877** 3878** ^(Every value in SQLite has one of five fundamental datatypes: 3879** 3880** <ul> 3881** <li> 64-bit signed integer 3882** <li> 64-bit IEEE floating point number 3883** <li> string 3884** <li> BLOB 3885** <li> NULL 3886** </ul>)^ 3887** 3888** These constants are codes for each of those types. 3889** 3890** Note that the SQLITE_TEXT constant was also used in SQLite version 2 3891** for a completely different meaning. Software that links against both 3892** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 3893** SQLITE_TEXT. 3894*/ 3895#define SQLITE_INTEGER 1 3896#define SQLITE_FLOAT 2 3897#define SQLITE_BLOB 4 3898#define SQLITE_NULL 5 3899#ifdef SQLITE_TEXT 3900# undef SQLITE_TEXT 3901#else 3902# define SQLITE_TEXT 3 3903#endif 3904#define SQLITE3_TEXT 3 3905 3906/* 3907** CAPI3REF: Result Values From A Query 3908** KEYWORDS: {column access functions} 3909** METHOD: sqlite3_stmt 3910** 3911** ^These routines return information about a single column of the current 3912** result row of a query. ^In every case the first argument is a pointer 3913** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 3914** that was returned from [sqlite3_prepare_v2()] or one of its variants) 3915** and the second argument is the index of the column for which information 3916** should be returned. ^The leftmost column of the result set has the index 0. 3917** ^The number of columns in the result can be determined using 3918** [sqlite3_column_count()]. 3919** 3920** If the SQL statement does not currently point to a valid row, or if the 3921** column index is out of range, the result is undefined. 3922** These routines may only be called when the most recent call to 3923** [sqlite3_step()] has returned [SQLITE_ROW] and neither 3924** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 3925** If any of these routines are called after [sqlite3_reset()] or 3926** [sqlite3_finalize()] or after [sqlite3_step()] has returned 3927** something other than [SQLITE_ROW], the results are undefined. 3928** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 3929** are called from a different thread while any of these routines 3930** are pending, then the results are undefined. 3931** 3932** ^The sqlite3_column_type() routine returns the 3933** [SQLITE_INTEGER | datatype code] for the initial data type 3934** of the result column. ^The returned value is one of [SQLITE_INTEGER], 3935** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 3936** returned by sqlite3_column_type() is only meaningful if no type 3937** conversions have occurred as described below. After a type conversion, 3938** the value returned by sqlite3_column_type() is undefined. Future 3939** versions of SQLite may change the behavior of sqlite3_column_type() 3940** following a type conversion. 3941** 3942** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 3943** routine returns the number of bytes in that BLOB or string. 3944** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 3945** the string to UTF-8 and then returns the number of bytes. 3946** ^If the result is a numeric value then sqlite3_column_bytes() uses 3947** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 3948** the number of bytes in that string. 3949** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 3950** 3951** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 3952** routine returns the number of bytes in that BLOB or string. 3953** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 3954** the string to UTF-16 and then returns the number of bytes. 3955** ^If the result is a numeric value then sqlite3_column_bytes16() uses 3956** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 3957** the number of bytes in that string. 3958** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 3959** 3960** ^The values returned by [sqlite3_column_bytes()] and 3961** [sqlite3_column_bytes16()] do not include the zero terminators at the end 3962** of the string. ^For clarity: the values returned by 3963** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 3964** bytes in the string, not the number of characters. 3965** 3966** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 3967** even empty strings, are always zero-terminated. ^The return 3968** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 3969** 3970** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 3971** [unprotected sqlite3_value] object. In a multithreaded environment, 3972** an unprotected sqlite3_value object may only be used safely with 3973** [sqlite3_bind_value()] and [sqlite3_result_value()]. 3974** If the [unprotected sqlite3_value] object returned by 3975** [sqlite3_column_value()] is used in any other way, including calls 3976** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 3977** or [sqlite3_value_bytes()], the behavior is not threadsafe. 3978** 3979** These routines attempt to convert the value where appropriate. ^For 3980** example, if the internal representation is FLOAT and a text result 3981** is requested, [sqlite3_snprintf()] is used internally to perform the 3982** conversion automatically. ^(The following table details the conversions 3983** that are applied: 3984** 3985** <blockquote> 3986** <table border="1"> 3987** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 3988** 3989** <tr><td> NULL <td> INTEGER <td> Result is 0 3990** <tr><td> NULL <td> FLOAT <td> Result is 0.0 3991** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 3992** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 3993** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 3994** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 3995** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 3996** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 3997** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 3998** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 3999** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4000** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4001** <tr><td> TEXT <td> BLOB <td> No change 4002** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4003** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4004** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4005** </table> 4006** </blockquote>)^ 4007** 4008** Note that when type conversions occur, pointers returned by prior 4009** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4010** sqlite3_column_text16() may be invalidated. 4011** Type conversions and pointer invalidations might occur 4012** in the following cases: 4013** 4014** <ul> 4015** <li> The initial content is a BLOB and sqlite3_column_text() or 4016** sqlite3_column_text16() is called. A zero-terminator might 4017** need to be added to the string.</li> 4018** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4019** sqlite3_column_text16() is called. The content must be converted 4020** to UTF-16.</li> 4021** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4022** sqlite3_column_text() is called. The content must be converted 4023** to UTF-8.</li> 4024** </ul> 4025** 4026** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4027** not invalidate a prior pointer, though of course the content of the buffer 4028** that the prior pointer references will have been modified. Other kinds 4029** of conversion are done in place when it is possible, but sometimes they 4030** are not possible and in those cases prior pointers are invalidated. 4031** 4032** The safest policy is to invoke these routines 4033** in one of the following ways: 4034** 4035** <ul> 4036** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4037** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4038** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4039** </ul> 4040** 4041** In other words, you should call sqlite3_column_text(), 4042** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4043** into the desired format, then invoke sqlite3_column_bytes() or 4044** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4045** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4046** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4047** with calls to sqlite3_column_bytes(). 4048** 4049** ^The pointers returned are valid until a type conversion occurs as 4050** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4051** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4052** and BLOBs is freed automatically. Do <em>not</em> pass the pointers returned 4053** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4054** [sqlite3_free()]. 4055** 4056** ^(If a memory allocation error occurs during the evaluation of any 4057** of these routines, a default value is returned. The default value 4058** is either the integer 0, the floating point number 0.0, or a NULL 4059** pointer. Subsequent calls to [sqlite3_errcode()] will return 4060** [SQLITE_NOMEM].)^ 4061*/ 4062const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4063int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4064int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4065double sqlite3_column_double(sqlite3_stmt*, int iCol); 4066int sqlite3_column_int(sqlite3_stmt*, int iCol); 4067sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4068const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4069const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4070int sqlite3_column_type(sqlite3_stmt*, int iCol); 4071sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4072 4073/* 4074** CAPI3REF: Destroy A Prepared Statement Object 4075** DESTRUCTOR: sqlite3_stmt 4076** 4077** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4078** ^If the most recent evaluation of the statement encountered no errors 4079** or if the statement is never been evaluated, then sqlite3_finalize() returns 4080** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4081** sqlite3_finalize(S) returns the appropriate [error code] or 4082** [extended error code]. 4083** 4084** ^The sqlite3_finalize(S) routine can be called at any point during 4085** the life cycle of [prepared statement] S: 4086** before statement S is ever evaluated, after 4087** one or more calls to [sqlite3_reset()], or after any call 4088** to [sqlite3_step()] regardless of whether or not the statement has 4089** completed execution. 4090** 4091** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4092** 4093** The application must finalize every [prepared statement] in order to avoid 4094** resource leaks. It is a grievous error for the application to try to use 4095** a prepared statement after it has been finalized. Any use of a prepared 4096** statement after it has been finalized can result in undefined and 4097** undesirable behavior such as segfaults and heap corruption. 4098*/ 4099int sqlite3_finalize(sqlite3_stmt *pStmt); 4100 4101/* 4102** CAPI3REF: Reset A Prepared Statement Object 4103** METHOD: sqlite3_stmt 4104** 4105** The sqlite3_reset() function is called to reset a [prepared statement] 4106** object back to its initial state, ready to be re-executed. 4107** ^Any SQL statement variables that had values bound to them using 4108** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4109** Use [sqlite3_clear_bindings()] to reset the bindings. 4110** 4111** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4112** back to the beginning of its program. 4113** 4114** ^If the most recent call to [sqlite3_step(S)] for the 4115** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4116** or if [sqlite3_step(S)] has never before been called on S, 4117** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4118** 4119** ^If the most recent call to [sqlite3_step(S)] for the 4120** [prepared statement] S indicated an error, then 4121** [sqlite3_reset(S)] returns an appropriate [error code]. 4122** 4123** ^The [sqlite3_reset(S)] interface does not change the values 4124** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4125*/ 4126int sqlite3_reset(sqlite3_stmt *pStmt); 4127 4128/* 4129** CAPI3REF: Create Or Redefine SQL Functions 4130** KEYWORDS: {function creation routines} 4131** KEYWORDS: {application-defined SQL function} 4132** KEYWORDS: {application-defined SQL functions} 4133** METHOD: sqlite3 4134** 4135** ^These functions (collectively known as "function creation routines") 4136** are used to add SQL functions or aggregates or to redefine the behavior 4137** of existing SQL functions or aggregates. The only differences between 4138** these routines are the text encoding expected for 4139** the second parameter (the name of the function being created) 4140** and the presence or absence of a destructor callback for 4141** the application data pointer. 4142** 4143** ^The first parameter is the [database connection] to which the SQL 4144** function is to be added. ^If an application uses more than one database 4145** connection then application-defined SQL functions must be added 4146** to each database connection separately. 4147** 4148** ^The second parameter is the name of the SQL function to be created or 4149** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4150** representation, exclusive of the zero-terminator. ^Note that the name 4151** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4152** ^Any attempt to create a function with a longer name 4153** will result in [SQLITE_MISUSE] being returned. 4154** 4155** ^The third parameter (nArg) 4156** is the number of arguments that the SQL function or 4157** aggregate takes. ^If this parameter is -1, then the SQL function or 4158** aggregate may take any number of arguments between 0 and the limit 4159** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4160** parameter is less than -1 or greater than 127 then the behavior is 4161** undefined. 4162** 4163** ^The fourth parameter, eTextRep, specifies what 4164** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4165** its parameters. The application should set this parameter to 4166** [SQLITE_UTF16LE] if the function implementation invokes 4167** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4168** implementation invokes [sqlite3_value_text16be()] on an input, or 4169** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4170** otherwise. ^The same SQL function may be registered multiple times using 4171** different preferred text encodings, with different implementations for 4172** each encoding. 4173** ^When multiple implementations of the same function are available, SQLite 4174** will pick the one that involves the least amount of data conversion. 4175** 4176** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4177** to signal that the function will always return the same result given 4178** the same inputs within a single SQL statement. Most SQL functions are 4179** deterministic. The built-in [random()] SQL function is an example of a 4180** function that is not deterministic. The SQLite query planner is able to 4181** perform additional optimizations on deterministic functions, so use 4182** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4183** 4184** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4185** function can gain access to this pointer using [sqlite3_user_data()].)^ 4186** 4187** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4188** pointers to C-language functions that implement the SQL function or 4189** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4190** callback only; NULL pointers must be passed as the xStep and xFinal 4191** parameters. ^An aggregate SQL function requires an implementation of xStep 4192** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4193** SQL function or aggregate, pass NULL pointers for all three function 4194** callbacks. 4195** 4196** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4197** then it is destructor for the application data pointer. 4198** The destructor is invoked when the function is deleted, either by being 4199** overloaded or when the database connection closes.)^ 4200** ^The destructor is also invoked if the call to 4201** sqlite3_create_function_v2() fails. 4202** ^When the destructor callback of the tenth parameter is invoked, it 4203** is passed a single argument which is a copy of the application data 4204** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4205** 4206** ^It is permitted to register multiple implementations of the same 4207** functions with the same name but with either differing numbers of 4208** arguments or differing preferred text encodings. ^SQLite will use 4209** the implementation that most closely matches the way in which the 4210** SQL function is used. ^A function implementation with a non-negative 4211** nArg parameter is a better match than a function implementation with 4212** a negative nArg. ^A function where the preferred text encoding 4213** matches the database encoding is a better 4214** match than a function where the encoding is different. 4215** ^A function where the encoding difference is between UTF16le and UTF16be 4216** is a closer match than a function where the encoding difference is 4217** between UTF8 and UTF16. 4218** 4219** ^Built-in functions may be overloaded by new application-defined functions. 4220** 4221** ^An application-defined function is permitted to call other 4222** SQLite interfaces. However, such calls must not 4223** close the database connection nor finalize or reset the prepared 4224** statement in which the function is running. 4225*/ 4226int sqlite3_create_function( 4227 sqlite3 *db, 4228 const char *zFunctionName, 4229 int nArg, 4230 int eTextRep, 4231 void *pApp, 4232 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4233 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4234 void (*xFinal)(sqlite3_context*) 4235); 4236int sqlite3_create_function16( 4237 sqlite3 *db, 4238 const void *zFunctionName, 4239 int nArg, 4240 int eTextRep, 4241 void *pApp, 4242 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4243 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4244 void (*xFinal)(sqlite3_context*) 4245); 4246int sqlite3_create_function_v2( 4247 sqlite3 *db, 4248 const char *zFunctionName, 4249 int nArg, 4250 int eTextRep, 4251 void *pApp, 4252 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4253 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4254 void (*xFinal)(sqlite3_context*), 4255 void(*xDestroy)(void*) 4256); 4257 4258/* 4259** CAPI3REF: Text Encodings 4260** 4261** These constant define integer codes that represent the various 4262** text encodings supported by SQLite. 4263*/ 4264#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4265#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4266#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4267#define SQLITE_UTF16 4 /* Use native byte order */ 4268#define SQLITE_ANY 5 /* Deprecated */ 4269#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4270 4271/* 4272** CAPI3REF: Function Flags 4273** 4274** These constants may be ORed together with the 4275** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4276** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4277** [sqlite3_create_function_v2()]. 4278*/ 4279#define SQLITE_DETERMINISTIC 0x800 4280 4281/* 4282** CAPI3REF: Deprecated Functions 4283** DEPRECATED 4284** 4285** These functions are [deprecated]. In order to maintain 4286** backwards compatibility with older code, these functions continue 4287** to be supported. However, new applications should avoid 4288** the use of these functions. To encourage programmers to avoid 4289** these functions, we will not explain what they do. 4290*/ 4291#ifndef SQLITE_OMIT_DEPRECATED 4292SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4293SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4294SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4295SQLITE_DEPRECATED int sqlite3_global_recover(void); 4296SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4297SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4298 void*,sqlite3_int64); 4299#endif 4300 4301/* 4302** CAPI3REF: Obtaining SQL Values 4303** METHOD: sqlite3_value 4304** 4305** The C-language implementation of SQL functions and aggregates uses 4306** this set of interface routines to access the parameter values on 4307** the function or aggregate. 4308** 4309** The xFunc (for scalar functions) or xStep (for aggregates) parameters 4310** to [sqlite3_create_function()] and [sqlite3_create_function16()] 4311** define callbacks that implement the SQL functions and aggregates. 4312** The 3rd parameter to these callbacks is an array of pointers to 4313** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 4314** each parameter to the SQL function. These routines are used to 4315** extract values from the [sqlite3_value] objects. 4316** 4317** These routines work only with [protected sqlite3_value] objects. 4318** Any attempt to use these routines on an [unprotected sqlite3_value] 4319** object results in undefined behavior. 4320** 4321** ^These routines work just like the corresponding [column access functions] 4322** except that these routines take a single [protected sqlite3_value] object 4323** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4324** 4325** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4326** in the native byte-order of the host machine. ^The 4327** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4328** extract UTF-16 strings as big-endian and little-endian respectively. 4329** 4330** ^(The sqlite3_value_numeric_type() interface attempts to apply 4331** numeric affinity to the value. This means that an attempt is 4332** made to convert the value to an integer or floating point. If 4333** such a conversion is possible without loss of information (in other 4334** words, if the value is a string that looks like a number) 4335** then the conversion is performed. Otherwise no conversion occurs. 4336** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4337** 4338** Please pay particular attention to the fact that the pointer returned 4339** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4340** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4341** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4342** or [sqlite3_value_text16()]. 4343** 4344** These routines must be called from the same thread as 4345** the SQL function that supplied the [sqlite3_value*] parameters. 4346*/ 4347const void *sqlite3_value_blob(sqlite3_value*); 4348int sqlite3_value_bytes(sqlite3_value*); 4349int sqlite3_value_bytes16(sqlite3_value*); 4350double sqlite3_value_double(sqlite3_value*); 4351int sqlite3_value_int(sqlite3_value*); 4352sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4353const unsigned char *sqlite3_value_text(sqlite3_value*); 4354const void *sqlite3_value_text16(sqlite3_value*); 4355const void *sqlite3_value_text16le(sqlite3_value*); 4356const void *sqlite3_value_text16be(sqlite3_value*); 4357int sqlite3_value_type(sqlite3_value*); 4358int sqlite3_value_numeric_type(sqlite3_value*); 4359 4360/* 4361** CAPI3REF: Copy And Free SQL Values 4362** METHOD: sqlite3_value 4363** 4364** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 4365** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 4366** is a [protected sqlite3_value] object even if the input is not. 4367** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 4368** memory allocation fails. 4369** 4370** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 4371** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 4372** then sqlite3_value_free(V) is a harmless no-op. 4373*/ 4374SQLITE_EXPERIMENTAL sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 4375SQLITE_EXPERIMENTAL void sqlite3_value_free(sqlite3_value*); 4376 4377/* 4378** CAPI3REF: Obtain Aggregate Function Context 4379** METHOD: sqlite3_context 4380** 4381** Implementations of aggregate SQL functions use this 4382** routine to allocate memory for storing their state. 4383** 4384** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4385** for a particular aggregate function, SQLite 4386** allocates N of memory, zeroes out that memory, and returns a pointer 4387** to the new memory. ^On second and subsequent calls to 4388** sqlite3_aggregate_context() for the same aggregate function instance, 4389** the same buffer is returned. Sqlite3_aggregate_context() is normally 4390** called once for each invocation of the xStep callback and then one 4391** last time when the xFinal callback is invoked. ^(When no rows match 4392** an aggregate query, the xStep() callback of the aggregate function 4393** implementation is never called and xFinal() is called exactly once. 4394** In those cases, sqlite3_aggregate_context() might be called for the 4395** first time from within xFinal().)^ 4396** 4397** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4398** when first called if N is less than or equal to zero or if a memory 4399** allocate error occurs. 4400** 4401** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4402** determined by the N parameter on first successful call. Changing the 4403** value of N in subsequent call to sqlite3_aggregate_context() within 4404** the same aggregate function instance will not resize the memory 4405** allocation.)^ Within the xFinal callback, it is customary to set 4406** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4407** pointless memory allocations occur. 4408** 4409** ^SQLite automatically frees the memory allocated by 4410** sqlite3_aggregate_context() when the aggregate query concludes. 4411** 4412** The first parameter must be a copy of the 4413** [sqlite3_context | SQL function context] that is the first parameter 4414** to the xStep or xFinal callback routine that implements the aggregate 4415** function. 4416** 4417** This routine must be called from the same thread in which 4418** the aggregate SQL function is running. 4419*/ 4420void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4421 4422/* 4423** CAPI3REF: User Data For Functions 4424** METHOD: sqlite3_context 4425** 4426** ^The sqlite3_user_data() interface returns a copy of 4427** the pointer that was the pUserData parameter (the 5th parameter) 4428** of the [sqlite3_create_function()] 4429** and [sqlite3_create_function16()] routines that originally 4430** registered the application defined function. 4431** 4432** This routine must be called from the same thread in which 4433** the application-defined function is running. 4434*/ 4435void *sqlite3_user_data(sqlite3_context*); 4436 4437/* 4438** CAPI3REF: Database Connection For Functions 4439** METHOD: sqlite3_context 4440** 4441** ^The sqlite3_context_db_handle() interface returns a copy of 4442** the pointer to the [database connection] (the 1st parameter) 4443** of the [sqlite3_create_function()] 4444** and [sqlite3_create_function16()] routines that originally 4445** registered the application defined function. 4446*/ 4447sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 4448 4449/* 4450** CAPI3REF: Function Auxiliary Data 4451** METHOD: sqlite3_context 4452** 4453** These functions may be used by (non-aggregate) SQL functions to 4454** associate metadata with argument values. If the same value is passed to 4455** multiple invocations of the same SQL function during query execution, under 4456** some circumstances the associated metadata may be preserved. An example 4457** of where this might be useful is in a regular-expression matching 4458** function. The compiled version of the regular expression can be stored as 4459** metadata associated with the pattern string. 4460** Then as long as the pattern string remains the same, 4461** the compiled regular expression can be reused on multiple 4462** invocations of the same function. 4463** 4464** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4465** associated by the sqlite3_set_auxdata() function with the Nth argument 4466** value to the application-defined function. ^If there is no metadata 4467** associated with the function argument, this sqlite3_get_auxdata() interface 4468** returns a NULL pointer. 4469** 4470** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 4471** argument of the application-defined function. ^Subsequent 4472** calls to sqlite3_get_auxdata(C,N) return P from the most recent 4473** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 4474** NULL if the metadata has been discarded. 4475** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 4476** SQLite will invoke the destructor function X with parameter P exactly 4477** once, when the metadata is discarded. 4478** SQLite is free to discard the metadata at any time, including: <ul> 4479** <li> when the corresponding function parameter changes, or 4480** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 4481** SQL statement, or 4482** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or 4483** <li> during the original sqlite3_set_auxdata() call when a memory 4484** allocation error occurs. </ul>)^ 4485** 4486** Note the last bullet in particular. The destructor X in 4487** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 4488** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 4489** should be called near the end of the function implementation and the 4490** function implementation should not make any use of P after 4491** sqlite3_set_auxdata() has been called. 4492** 4493** ^(In practice, metadata is preserved between function calls for 4494** function parameters that are compile-time constants, including literal 4495** values and [parameters] and expressions composed from the same.)^ 4496** 4497** These routines must be called from the same thread in which 4498** the SQL function is running. 4499*/ 4500void *sqlite3_get_auxdata(sqlite3_context*, int N); 4501void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4502 4503 4504/* 4505** CAPI3REF: Constants Defining Special Destructor Behavior 4506** 4507** These are special values for the destructor that is passed in as the 4508** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4509** argument is SQLITE_STATIC, it means that the content pointer is constant 4510** and will never change. It does not need to be destroyed. ^The 4511** SQLITE_TRANSIENT value means that the content will likely change in 4512** the near future and that SQLite should make its own private copy of 4513** the content before returning. 4514** 4515** The typedef is necessary to work around problems in certain 4516** C++ compilers. 4517*/ 4518typedef void (*sqlite3_destructor_type)(void*); 4519#define SQLITE_STATIC ((sqlite3_destructor_type)0) 4520#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4521 4522/* 4523** CAPI3REF: Setting The Result Of An SQL Function 4524** METHOD: sqlite3_context 4525** 4526** These routines are used by the xFunc or xFinal callbacks that 4527** implement SQL functions and aggregates. See 4528** [sqlite3_create_function()] and [sqlite3_create_function16()] 4529** for additional information. 4530** 4531** These functions work very much like the [parameter binding] family of 4532** functions used to bind values to host parameters in prepared statements. 4533** Refer to the [SQL parameter] documentation for additional information. 4534** 4535** ^The sqlite3_result_blob() interface sets the result from 4536** an application-defined function to be the BLOB whose content is pointed 4537** to by the second parameter and which is N bytes long where N is the 4538** third parameter. 4539** 4540** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 4541** interfaces set the result of the application-defined function to be 4542** a BLOB containing all zero bytes and N bytes in size. 4543** 4544** ^The sqlite3_result_double() interface sets the result from 4545** an application-defined function to be a floating point value specified 4546** by its 2nd argument. 4547** 4548** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4549** cause the implemented SQL function to throw an exception. 4550** ^SQLite uses the string pointed to by the 4551** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4552** as the text of an error message. ^SQLite interprets the error 4553** message string from sqlite3_result_error() as UTF-8. ^SQLite 4554** interprets the string from sqlite3_result_error16() as UTF-16 in native 4555** byte order. ^If the third parameter to sqlite3_result_error() 4556** or sqlite3_result_error16() is negative then SQLite takes as the error 4557** message all text up through the first zero character. 4558** ^If the third parameter to sqlite3_result_error() or 4559** sqlite3_result_error16() is non-negative then SQLite takes that many 4560** bytes (not characters) from the 2nd parameter as the error message. 4561** ^The sqlite3_result_error() and sqlite3_result_error16() 4562** routines make a private copy of the error message text before 4563** they return. Hence, the calling function can deallocate or 4564** modify the text after they return without harm. 4565** ^The sqlite3_result_error_code() function changes the error code 4566** returned by SQLite as a result of an error in a function. ^By default, 4567** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4568** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4569** 4570** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4571** error indicating that a string or BLOB is too long to represent. 4572** 4573** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4574** error indicating that a memory allocation failed. 4575** 4576** ^The sqlite3_result_int() interface sets the return value 4577** of the application-defined function to be the 32-bit signed integer 4578** value given in the 2nd argument. 4579** ^The sqlite3_result_int64() interface sets the return value 4580** of the application-defined function to be the 64-bit signed integer 4581** value given in the 2nd argument. 4582** 4583** ^The sqlite3_result_null() interface sets the return value 4584** of the application-defined function to be NULL. 4585** 4586** ^The sqlite3_result_text(), sqlite3_result_text16(), 4587** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4588** set the return value of the application-defined function to be 4589** a text string which is represented as UTF-8, UTF-16 native byte order, 4590** UTF-16 little endian, or UTF-16 big endian, respectively. 4591** ^The sqlite3_result_text64() interface sets the return value of an 4592** application-defined function to be a text string in an encoding 4593** specified by the fifth (and last) parameter, which must be one 4594** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 4595** ^SQLite takes the text result from the application from 4596** the 2nd parameter of the sqlite3_result_text* interfaces. 4597** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4598** is negative, then SQLite takes result text from the 2nd parameter 4599** through the first zero character. 4600** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4601** is non-negative, then as many bytes (not characters) of the text 4602** pointed to by the 2nd parameter are taken as the application-defined 4603** function result. If the 3rd parameter is non-negative, then it 4604** must be the byte offset into the string where the NUL terminator would 4605** appear if the string where NUL terminated. If any NUL characters occur 4606** in the string at a byte offset that is less than the value of the 3rd 4607** parameter, then the resulting string will contain embedded NULs and the 4608** result of expressions operating on strings with embedded NULs is undefined. 4609** ^If the 4th parameter to the sqlite3_result_text* interfaces 4610** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4611** function as the destructor on the text or BLOB result when it has 4612** finished using that result. 4613** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4614** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4615** assumes that the text or BLOB result is in constant space and does not 4616** copy the content of the parameter nor call a destructor on the content 4617** when it has finished using that result. 4618** ^If the 4th parameter to the sqlite3_result_text* interfaces 4619** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4620** then SQLite makes a copy of the result into space obtained from 4621** from [sqlite3_malloc()] before it returns. 4622** 4623** ^The sqlite3_result_value() interface sets the result of 4624** the application-defined function to be a copy of the 4625** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4626** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4627** so that the [sqlite3_value] specified in the parameter may change or 4628** be deallocated after sqlite3_result_value() returns without harm. 4629** ^A [protected sqlite3_value] object may always be used where an 4630** [unprotected sqlite3_value] object is required, so either 4631** kind of [sqlite3_value] object can be used with this interface. 4632** 4633** If these routines are called from within the different thread 4634** than the one containing the application-defined function that received 4635** the [sqlite3_context] pointer, the results are undefined. 4636*/ 4637void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4638void sqlite3_result_blob64(sqlite3_context*,const void*, 4639 sqlite3_uint64,void(*)(void*)); 4640void sqlite3_result_double(sqlite3_context*, double); 4641void sqlite3_result_error(sqlite3_context*, const char*, int); 4642void sqlite3_result_error16(sqlite3_context*, const void*, int); 4643void sqlite3_result_error_toobig(sqlite3_context*); 4644void sqlite3_result_error_nomem(sqlite3_context*); 4645void sqlite3_result_error_code(sqlite3_context*, int); 4646void sqlite3_result_int(sqlite3_context*, int); 4647void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4648void sqlite3_result_null(sqlite3_context*); 4649void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4650void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 4651 void(*)(void*), unsigned char encoding); 4652void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4653void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4654void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4655void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4656void sqlite3_result_zeroblob(sqlite3_context*, int n); 4657int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 4658 4659/* 4660** CAPI3REF: Define New Collating Sequences 4661** METHOD: sqlite3 4662** 4663** ^These functions add, remove, or modify a [collation] associated 4664** with the [database connection] specified as the first argument. 4665** 4666** ^The name of the collation is a UTF-8 string 4667** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4668** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4669** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4670** considered to be the same name. 4671** 4672** ^(The third argument (eTextRep) must be one of the constants: 4673** <ul> 4674** <li> [SQLITE_UTF8], 4675** <li> [SQLITE_UTF16LE], 4676** <li> [SQLITE_UTF16BE], 4677** <li> [SQLITE_UTF16], or 4678** <li> [SQLITE_UTF16_ALIGNED]. 4679** </ul>)^ 4680** ^The eTextRep argument determines the encoding of strings passed 4681** to the collating function callback, xCallback. 4682** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4683** force strings to be UTF16 with native byte order. 4684** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4685** on an even byte address. 4686** 4687** ^The fourth argument, pArg, is an application data pointer that is passed 4688** through as the first argument to the collating function callback. 4689** 4690** ^The fifth argument, xCallback, is a pointer to the collating function. 4691** ^Multiple collating functions can be registered using the same name but 4692** with different eTextRep parameters and SQLite will use whichever 4693** function requires the least amount of data transformation. 4694** ^If the xCallback argument is NULL then the collating function is 4695** deleted. ^When all collating functions having the same name are deleted, 4696** that collation is no longer usable. 4697** 4698** ^The collating function callback is invoked with a copy of the pArg 4699** application data pointer and with two strings in the encoding specified 4700** by the eTextRep argument. The collating function must return an 4701** integer that is negative, zero, or positive 4702** if the first string is less than, equal to, or greater than the second, 4703** respectively. A collating function must always return the same answer 4704** given the same inputs. If two or more collating functions are registered 4705** to the same collation name (using different eTextRep values) then all 4706** must give an equivalent answer when invoked with equivalent strings. 4707** The collating function must obey the following properties for all 4708** strings A, B, and C: 4709** 4710** <ol> 4711** <li> If A==B then B==A. 4712** <li> If A==B and B==C then A==C. 4713** <li> If A<B THEN B>A. 4714** <li> If A<B and B<C then A<C. 4715** </ol> 4716** 4717** If a collating function fails any of the above constraints and that 4718** collating function is registered and used, then the behavior of SQLite 4719** is undefined. 4720** 4721** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4722** with the addition that the xDestroy callback is invoked on pArg when 4723** the collating function is deleted. 4724** ^Collating functions are deleted when they are overridden by later 4725** calls to the collation creation functions or when the 4726** [database connection] is closed using [sqlite3_close()]. 4727** 4728** ^The xDestroy callback is <u>not</u> called if the 4729** sqlite3_create_collation_v2() function fails. Applications that invoke 4730** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 4731** check the return code and dispose of the application data pointer 4732** themselves rather than expecting SQLite to deal with it for them. 4733** This is different from every other SQLite interface. The inconsistency 4734** is unfortunate but cannot be changed without breaking backwards 4735** compatibility. 4736** 4737** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 4738*/ 4739int sqlite3_create_collation( 4740 sqlite3*, 4741 const char *zName, 4742 int eTextRep, 4743 void *pArg, 4744 int(*xCompare)(void*,int,const void*,int,const void*) 4745); 4746int sqlite3_create_collation_v2( 4747 sqlite3*, 4748 const char *zName, 4749 int eTextRep, 4750 void *pArg, 4751 int(*xCompare)(void*,int,const void*,int,const void*), 4752 void(*xDestroy)(void*) 4753); 4754int sqlite3_create_collation16( 4755 sqlite3*, 4756 const void *zName, 4757 int eTextRep, 4758 void *pArg, 4759 int(*xCompare)(void*,int,const void*,int,const void*) 4760); 4761 4762/* 4763** CAPI3REF: Collation Needed Callbacks 4764** METHOD: sqlite3 4765** 4766** ^To avoid having to register all collation sequences before a database 4767** can be used, a single callback function may be registered with the 4768** [database connection] to be invoked whenever an undefined collation 4769** sequence is required. 4770** 4771** ^If the function is registered using the sqlite3_collation_needed() API, 4772** then it is passed the names of undefined collation sequences as strings 4773** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 4774** the names are passed as UTF-16 in machine native byte order. 4775** ^A call to either function replaces the existing collation-needed callback. 4776** 4777** ^(When the callback is invoked, the first argument passed is a copy 4778** of the second argument to sqlite3_collation_needed() or 4779** sqlite3_collation_needed16(). The second argument is the database 4780** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 4781** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 4782** sequence function required. The fourth parameter is the name of the 4783** required collation sequence.)^ 4784** 4785** The callback function should register the desired collation using 4786** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 4787** [sqlite3_create_collation_v2()]. 4788*/ 4789int sqlite3_collation_needed( 4790 sqlite3*, 4791 void*, 4792 void(*)(void*,sqlite3*,int eTextRep,const char*) 4793); 4794int sqlite3_collation_needed16( 4795 sqlite3*, 4796 void*, 4797 void(*)(void*,sqlite3*,int eTextRep,const void*) 4798); 4799 4800#ifdef SQLITE_HAS_CODEC 4801/* 4802** Specify the key for an encrypted database. This routine should be 4803** called right after sqlite3_open(). 4804** 4805** The code to implement this API is not available in the public release 4806** of SQLite. 4807*/ 4808int sqlite3_key( 4809 sqlite3 *db, /* Database to be rekeyed */ 4810 const void *pKey, int nKey /* The key */ 4811); 4812int sqlite3_key_v2( 4813 sqlite3 *db, /* Database to be rekeyed */ 4814 const char *zDbName, /* Name of the database */ 4815 const void *pKey, int nKey /* The key */ 4816); 4817 4818/* 4819** Change the key on an open database. If the current database is not 4820** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 4821** database is decrypted. 4822** 4823** The code to implement this API is not available in the public release 4824** of SQLite. 4825*/ 4826int sqlite3_rekey( 4827 sqlite3 *db, /* Database to be rekeyed */ 4828 const void *pKey, int nKey /* The new key */ 4829); 4830int sqlite3_rekey_v2( 4831 sqlite3 *db, /* Database to be rekeyed */ 4832 const char *zDbName, /* Name of the database */ 4833 const void *pKey, int nKey /* The new key */ 4834); 4835 4836/* 4837** Specify the activation key for a SEE database. Unless 4838** activated, none of the SEE routines will work. 4839*/ 4840void sqlite3_activate_see( 4841 const char *zPassPhrase /* Activation phrase */ 4842); 4843#endif 4844 4845#ifdef SQLITE_ENABLE_CEROD 4846/* 4847** Specify the activation key for a CEROD database. Unless 4848** activated, none of the CEROD routines will work. 4849*/ 4850void sqlite3_activate_cerod( 4851 const char *zPassPhrase /* Activation phrase */ 4852); 4853#endif 4854 4855/* 4856** CAPI3REF: Suspend Execution For A Short Time 4857** 4858** The sqlite3_sleep() function causes the current thread to suspend execution 4859** for at least a number of milliseconds specified in its parameter. 4860** 4861** If the operating system does not support sleep requests with 4862** millisecond time resolution, then the time will be rounded up to 4863** the nearest second. The number of milliseconds of sleep actually 4864** requested from the operating system is returned. 4865** 4866** ^SQLite implements this interface by calling the xSleep() 4867** method of the default [sqlite3_vfs] object. If the xSleep() method 4868** of the default VFS is not implemented correctly, or not implemented at 4869** all, then the behavior of sqlite3_sleep() may deviate from the description 4870** in the previous paragraphs. 4871*/ 4872int sqlite3_sleep(int); 4873 4874/* 4875** CAPI3REF: Name Of The Folder Holding Temporary Files 4876** 4877** ^(If this global variable is made to point to a string which is 4878** the name of a folder (a.k.a. directory), then all temporary files 4879** created by SQLite when using a built-in [sqlite3_vfs | VFS] 4880** will be placed in that directory.)^ ^If this variable 4881** is a NULL pointer, then SQLite performs a search for an appropriate 4882** temporary file directory. 4883** 4884** Applications are strongly discouraged from using this global variable. 4885** It is required to set a temporary folder on Windows Runtime (WinRT). 4886** But for all other platforms, it is highly recommended that applications 4887** neither read nor write this variable. This global variable is a relic 4888** that exists for backwards compatibility of legacy applications and should 4889** be avoided in new projects. 4890** 4891** It is not safe to read or modify this variable in more than one 4892** thread at a time. It is not safe to read or modify this variable 4893** if a [database connection] is being used at the same time in a separate 4894** thread. 4895** It is intended that this variable be set once 4896** as part of process initialization and before any SQLite interface 4897** routines have been called and that this variable remain unchanged 4898** thereafter. 4899** 4900** ^The [temp_store_directory pragma] may modify this variable and cause 4901** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4902** the [temp_store_directory pragma] always assumes that any string 4903** that this variable points to is held in memory obtained from 4904** [sqlite3_malloc] and the pragma may attempt to free that memory 4905** using [sqlite3_free]. 4906** Hence, if this variable is modified directly, either it should be 4907** made NULL or made to point to memory obtained from [sqlite3_malloc] 4908** or else the use of the [temp_store_directory pragma] should be avoided. 4909** Except when requested by the [temp_store_directory pragma], SQLite 4910** does not free the memory that sqlite3_temp_directory points to. If 4911** the application wants that memory to be freed, it must do 4912** so itself, taking care to only do so after all [database connection] 4913** objects have been destroyed. 4914** 4915** <b>Note to Windows Runtime users:</b> The temporary directory must be set 4916** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 4917** features that require the use of temporary files may fail. Here is an 4918** example of how to do this using C++ with the Windows Runtime: 4919** 4920** <blockquote><pre> 4921** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 4922** TemporaryFolder->Path->Data(); 4923** char zPathBuf[MAX_PATH + 1]; 4924** memset(zPathBuf, 0, sizeof(zPathBuf)); 4925** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 4926** NULL, NULL); 4927** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 4928** </pre></blockquote> 4929*/ 4930SQLITE_EXTERN char *sqlite3_temp_directory; 4931 4932/* 4933** CAPI3REF: Name Of The Folder Holding Database Files 4934** 4935** ^(If this global variable is made to point to a string which is 4936** the name of a folder (a.k.a. directory), then all database files 4937** specified with a relative pathname and created or accessed by 4938** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 4939** to be relative to that directory.)^ ^If this variable is a NULL 4940** pointer, then SQLite assumes that all database files specified 4941** with a relative pathname are relative to the current directory 4942** for the process. Only the windows VFS makes use of this global 4943** variable; it is ignored by the unix VFS. 4944** 4945** Changing the value of this variable while a database connection is 4946** open can result in a corrupt database. 4947** 4948** It is not safe to read or modify this variable in more than one 4949** thread at a time. It is not safe to read or modify this variable 4950** if a [database connection] is being used at the same time in a separate 4951** thread. 4952** It is intended that this variable be set once 4953** as part of process initialization and before any SQLite interface 4954** routines have been called and that this variable remain unchanged 4955** thereafter. 4956** 4957** ^The [data_store_directory pragma] may modify this variable and cause 4958** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4959** the [data_store_directory pragma] always assumes that any string 4960** that this variable points to is held in memory obtained from 4961** [sqlite3_malloc] and the pragma may attempt to free that memory 4962** using [sqlite3_free]. 4963** Hence, if this variable is modified directly, either it should be 4964** made NULL or made to point to memory obtained from [sqlite3_malloc] 4965** or else the use of the [data_store_directory pragma] should be avoided. 4966*/ 4967SQLITE_EXTERN char *sqlite3_data_directory; 4968 4969/* 4970** CAPI3REF: Test For Auto-Commit Mode 4971** KEYWORDS: {autocommit mode} 4972** METHOD: sqlite3 4973** 4974** ^The sqlite3_get_autocommit() interface returns non-zero or 4975** zero if the given database connection is or is not in autocommit mode, 4976** respectively. ^Autocommit mode is on by default. 4977** ^Autocommit mode is disabled by a [BEGIN] statement. 4978** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 4979** 4980** If certain kinds of errors occur on a statement within a multi-statement 4981** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 4982** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 4983** transaction might be rolled back automatically. The only way to 4984** find out whether SQLite automatically rolled back the transaction after 4985** an error is to use this function. 4986** 4987** If another thread changes the autocommit status of the database 4988** connection while this routine is running, then the return value 4989** is undefined. 4990*/ 4991int sqlite3_get_autocommit(sqlite3*); 4992 4993/* 4994** CAPI3REF: Find The Database Handle Of A Prepared Statement 4995** METHOD: sqlite3_stmt 4996** 4997** ^The sqlite3_db_handle interface returns the [database connection] handle 4998** to which a [prepared statement] belongs. ^The [database connection] 4999** returned by sqlite3_db_handle is the same [database connection] 5000** that was the first argument 5001** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5002** create the statement in the first place. 5003*/ 5004sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 5005 5006/* 5007** CAPI3REF: Return The Filename For A Database Connection 5008** METHOD: sqlite3 5009** 5010** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5011** associated with database N of connection D. ^The main database file 5012** has the name "main". If there is no attached database N on the database 5013** connection D, or if database N is a temporary or in-memory database, then 5014** a NULL pointer is returned. 5015** 5016** ^The filename returned by this function is the output of the 5017** xFullPathname method of the [VFS]. ^In other words, the filename 5018** will be an absolute pathname, even if the filename used 5019** to open the database originally was a URI or relative pathname. 5020*/ 5021const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5022 5023/* 5024** CAPI3REF: Determine if a database is read-only 5025** METHOD: sqlite3 5026** 5027** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5028** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5029** the name of a database on connection D. 5030*/ 5031int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5032 5033/* 5034** CAPI3REF: Find the next prepared statement 5035** METHOD: sqlite3 5036** 5037** ^This interface returns a pointer to the next [prepared statement] after 5038** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5039** then this interface returns a pointer to the first prepared statement 5040** associated with the database connection pDb. ^If no prepared statement 5041** satisfies the conditions of this routine, it returns NULL. 5042** 5043** The [database connection] pointer D in a call to 5044** [sqlite3_next_stmt(D,S)] must refer to an open database 5045** connection and in particular must not be a NULL pointer. 5046*/ 5047sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5048 5049/* 5050** CAPI3REF: Commit And Rollback Notification Callbacks 5051** METHOD: sqlite3 5052** 5053** ^The sqlite3_commit_hook() interface registers a callback 5054** function to be invoked whenever a transaction is [COMMIT | committed]. 5055** ^Any callback set by a previous call to sqlite3_commit_hook() 5056** for the same database connection is overridden. 5057** ^The sqlite3_rollback_hook() interface registers a callback 5058** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5059** ^Any callback set by a previous call to sqlite3_rollback_hook() 5060** for the same database connection is overridden. 5061** ^The pArg argument is passed through to the callback. 5062** ^If the callback on a commit hook function returns non-zero, 5063** then the commit is converted into a rollback. 5064** 5065** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5066** return the P argument from the previous call of the same function 5067** on the same [database connection] D, or NULL for 5068** the first call for each function on D. 5069** 5070** The commit and rollback hook callbacks are not reentrant. 5071** The callback implementation must not do anything that will modify 5072** the database connection that invoked the callback. Any actions 5073** to modify the database connection must be deferred until after the 5074** completion of the [sqlite3_step()] call that triggered the commit 5075** or rollback hook in the first place. 5076** Note that running any other SQL statements, including SELECT statements, 5077** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5078** the database connections for the meaning of "modify" in this paragraph. 5079** 5080** ^Registering a NULL function disables the callback. 5081** 5082** ^When the commit hook callback routine returns zero, the [COMMIT] 5083** operation is allowed to continue normally. ^If the commit hook 5084** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5085** ^The rollback hook is invoked on a rollback that results from a commit 5086** hook returning non-zero, just as it would be with any other rollback. 5087** 5088** ^For the purposes of this API, a transaction is said to have been 5089** rolled back if an explicit "ROLLBACK" statement is executed, or 5090** an error or constraint causes an implicit rollback to occur. 5091** ^The rollback callback is not invoked if a transaction is 5092** automatically rolled back because the database connection is closed. 5093** 5094** See also the [sqlite3_update_hook()] interface. 5095*/ 5096void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5097void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5098 5099/* 5100** CAPI3REF: Data Change Notification Callbacks 5101** METHOD: sqlite3 5102** 5103** ^The sqlite3_update_hook() interface registers a callback function 5104** with the [database connection] identified by the first argument 5105** to be invoked whenever a row is updated, inserted or deleted in 5106** a rowid table. 5107** ^Any callback set by a previous call to this function 5108** for the same database connection is overridden. 5109** 5110** ^The second argument is a pointer to the function to invoke when a 5111** row is updated, inserted or deleted in a rowid table. 5112** ^The first argument to the callback is a copy of the third argument 5113** to sqlite3_update_hook(). 5114** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5115** or [SQLITE_UPDATE], depending on the operation that caused the callback 5116** to be invoked. 5117** ^The third and fourth arguments to the callback contain pointers to the 5118** database and table name containing the affected row. 5119** ^The final callback parameter is the [rowid] of the row. 5120** ^In the case of an update, this is the [rowid] after the update takes place. 5121** 5122** ^(The update hook is not invoked when internal system tables are 5123** modified (i.e. sqlite_master and sqlite_sequence).)^ 5124** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5125** 5126** ^In the current implementation, the update hook 5127** is not invoked when duplication rows are deleted because of an 5128** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5129** invoked when rows are deleted using the [truncate optimization]. 5130** The exceptions defined in this paragraph might change in a future 5131** release of SQLite. 5132** 5133** The update hook implementation must not do anything that will modify 5134** the database connection that invoked the update hook. Any actions 5135** to modify the database connection must be deferred until after the 5136** completion of the [sqlite3_step()] call that triggered the update hook. 5137** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5138** database connections for the meaning of "modify" in this paragraph. 5139** 5140** ^The sqlite3_update_hook(D,C,P) function 5141** returns the P argument from the previous call 5142** on the same [database connection] D, or NULL for 5143** the first call on D. 5144** 5145** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] 5146** interfaces. 5147*/ 5148void *sqlite3_update_hook( 5149 sqlite3*, 5150 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5151 void* 5152); 5153 5154/* 5155** CAPI3REF: Enable Or Disable Shared Pager Cache 5156** 5157** ^(This routine enables or disables the sharing of the database cache 5158** and schema data structures between [database connection | connections] 5159** to the same database. Sharing is enabled if the argument is true 5160** and disabled if the argument is false.)^ 5161** 5162** ^Cache sharing is enabled and disabled for an entire process. 5163** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 5164** sharing was enabled or disabled for each thread separately. 5165** 5166** ^(The cache sharing mode set by this interface effects all subsequent 5167** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5168** Existing database connections continue use the sharing mode 5169** that was in effect at the time they were opened.)^ 5170** 5171** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5172** successfully. An [error code] is returned otherwise.)^ 5173** 5174** ^Shared cache is disabled by default. But this might change in 5175** future releases of SQLite. Applications that care about shared 5176** cache setting should set it explicitly. 5177** 5178** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5179** and will always return SQLITE_MISUSE. On those systems, 5180** shared cache mode should be enabled per-database connection via 5181** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5182** 5183** This interface is threadsafe on processors where writing a 5184** 32-bit integer is atomic. 5185** 5186** See Also: [SQLite Shared-Cache Mode] 5187*/ 5188int sqlite3_enable_shared_cache(int); 5189 5190/* 5191** CAPI3REF: Attempt To Free Heap Memory 5192** 5193** ^The sqlite3_release_memory() interface attempts to free N bytes 5194** of heap memory by deallocating non-essential memory allocations 5195** held by the database library. Memory used to cache database 5196** pages to improve performance is an example of non-essential memory. 5197** ^sqlite3_release_memory() returns the number of bytes actually freed, 5198** which might be more or less than the amount requested. 5199** ^The sqlite3_release_memory() routine is a no-op returning zero 5200** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5201** 5202** See also: [sqlite3_db_release_memory()] 5203*/ 5204int sqlite3_release_memory(int); 5205 5206/* 5207** CAPI3REF: Free Memory Used By A Database Connection 5208** METHOD: sqlite3 5209** 5210** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5211** memory as possible from database connection D. Unlike the 5212** [sqlite3_release_memory()] interface, this interface is in effect even 5213** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5214** omitted. 5215** 5216** See also: [sqlite3_release_memory()] 5217*/ 5218int sqlite3_db_release_memory(sqlite3*); 5219 5220/* 5221** CAPI3REF: Impose A Limit On Heap Size 5222** 5223** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5224** soft limit on the amount of heap memory that may be allocated by SQLite. 5225** ^SQLite strives to keep heap memory utilization below the soft heap 5226** limit by reducing the number of pages held in the page cache 5227** as heap memory usages approaches the limit. 5228** ^The soft heap limit is "soft" because even though SQLite strives to stay 5229** below the limit, it will exceed the limit rather than generate 5230** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5231** is advisory only. 5232** 5233** ^The return value from sqlite3_soft_heap_limit64() is the size of 5234** the soft heap limit prior to the call, or negative in the case of an 5235** error. ^If the argument N is negative 5236** then no change is made to the soft heap limit. Hence, the current 5237** size of the soft heap limit can be determined by invoking 5238** sqlite3_soft_heap_limit64() with a negative argument. 5239** 5240** ^If the argument N is zero then the soft heap limit is disabled. 5241** 5242** ^(The soft heap limit is not enforced in the current implementation 5243** if one or more of following conditions are true: 5244** 5245** <ul> 5246** <li> The soft heap limit is set to zero. 5247** <li> Memory accounting is disabled using a combination of the 5248** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5249** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5250** <li> An alternative page cache implementation is specified using 5251** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5252** <li> The page cache allocates from its own memory pool supplied 5253** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5254** from the heap. 5255** </ul>)^ 5256** 5257** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 5258** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5259** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5260** the soft heap limit is enforced on every memory allocation. Without 5261** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5262** when memory is allocated by the page cache. Testing suggests that because 5263** the page cache is the predominate memory user in SQLite, most 5264** applications will achieve adequate soft heap limit enforcement without 5265** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5266** 5267** The circumstances under which SQLite will enforce the soft heap limit may 5268** changes in future releases of SQLite. 5269*/ 5270sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 5271 5272/* 5273** CAPI3REF: Deprecated Soft Heap Limit Interface 5274** DEPRECATED 5275** 5276** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5277** interface. This routine is provided for historical compatibility 5278** only. All new applications should use the 5279** [sqlite3_soft_heap_limit64()] interface rather than this one. 5280*/ 5281SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 5282 5283 5284/* 5285** CAPI3REF: Extract Metadata About A Column Of A Table 5286** METHOD: sqlite3 5287** 5288** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 5289** information about column C of table T in database D 5290** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 5291** interface returns SQLITE_OK and fills in the non-NULL pointers in 5292** the final five arguments with appropriate values if the specified 5293** column exists. ^The sqlite3_table_column_metadata() interface returns 5294** SQLITE_ERROR and if the specified column does not exist. 5295** ^If the column-name parameter to sqlite3_table_column_metadata() is a 5296** NULL pointer, then this routine simply checks for the existance of the 5297** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 5298** does not. 5299** 5300** ^The column is identified by the second, third and fourth parameters to 5301** this function. ^(The second parameter is either the name of the database 5302** (i.e. "main", "temp", or an attached database) containing the specified 5303** table or NULL.)^ ^If it is NULL, then all attached databases are searched 5304** for the table using the same algorithm used by the database engine to 5305** resolve unqualified table references. 5306** 5307** ^The third and fourth parameters to this function are the table and column 5308** name of the desired column, respectively. 5309** 5310** ^Metadata is returned by writing to the memory locations passed as the 5th 5311** and subsequent parameters to this function. ^Any of these arguments may be 5312** NULL, in which case the corresponding element of metadata is omitted. 5313** 5314** ^(<blockquote> 5315** <table border="1"> 5316** <tr><th> Parameter <th> Output<br>Type <th> Description 5317** 5318** <tr><td> 5th <td> const char* <td> Data type 5319** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5320** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5321** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5322** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5323** </table> 5324** </blockquote>)^ 5325** 5326** ^The memory pointed to by the character pointers returned for the 5327** declaration type and collation sequence is valid until the next 5328** call to any SQLite API function. 5329** 5330** ^If the specified table is actually a view, an [error code] is returned. 5331** 5332** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 5333** is not a [WITHOUT ROWID] table and an 5334** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5335** parameters are set for the explicitly declared column. ^(If there is no 5336** [INTEGER PRIMARY KEY] column, then the outputs 5337** for the [rowid] are set as follows: 5338** 5339** <pre> 5340** data type: "INTEGER" 5341** collation sequence: "BINARY" 5342** not null: 0 5343** primary key: 1 5344** auto increment: 0 5345** </pre>)^ 5346** 5347** ^This function causes all database schemas to be read from disk and 5348** parsed, if that has not already been done, and returns an error if 5349** any errors are encountered while loading the schema. 5350*/ 5351int sqlite3_table_column_metadata( 5352 sqlite3 *db, /* Connection handle */ 5353 const char *zDbName, /* Database name or NULL */ 5354 const char *zTableName, /* Table name */ 5355 const char *zColumnName, /* Column name */ 5356 char const **pzDataType, /* OUTPUT: Declared data type */ 5357 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5358 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5359 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5360 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5361); 5362 5363/* 5364** CAPI3REF: Load An Extension 5365** METHOD: sqlite3 5366** 5367** ^This interface loads an SQLite extension library from the named file. 5368** 5369** ^The sqlite3_load_extension() interface attempts to load an 5370** [SQLite extension] library contained in the file zFile. If 5371** the file cannot be loaded directly, attempts are made to load 5372** with various operating-system specific extensions added. 5373** So for example, if "samplelib" cannot be loaded, then names like 5374** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5375** be tried also. 5376** 5377** ^The entry point is zProc. 5378** ^(zProc may be 0, in which case SQLite will try to come up with an 5379** entry point name on its own. It first tries "sqlite3_extension_init". 5380** If that does not work, it constructs a name "sqlite3_X_init" where the 5381** X is consists of the lower-case equivalent of all ASCII alphabetic 5382** characters in the filename from the last "/" to the first following 5383** "." and omitting any initial "lib".)^ 5384** ^The sqlite3_load_extension() interface returns 5385** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5386** ^If an error occurs and pzErrMsg is not 0, then the 5387** [sqlite3_load_extension()] interface shall attempt to 5388** fill *pzErrMsg with error message text stored in memory 5389** obtained from [sqlite3_malloc()]. The calling function 5390** should free this memory by calling [sqlite3_free()]. 5391** 5392** ^Extension loading must be enabled using 5393** [sqlite3_enable_load_extension()] prior to calling this API, 5394** otherwise an error will be returned. 5395** 5396** See also the [load_extension() SQL function]. 5397*/ 5398int sqlite3_load_extension( 5399 sqlite3 *db, /* Load the extension into this database connection */ 5400 const char *zFile, /* Name of the shared library containing extension */ 5401 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5402 char **pzErrMsg /* Put error message here if not 0 */ 5403); 5404 5405/* 5406** CAPI3REF: Enable Or Disable Extension Loading 5407** METHOD: sqlite3 5408** 5409** ^So as not to open security holes in older applications that are 5410** unprepared to deal with [extension loading], and as a means of disabling 5411** [extension loading] while evaluating user-entered SQL, the following API 5412** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5413** 5414** ^Extension loading is off by default. 5415** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5416** to turn extension loading on and call it with onoff==0 to turn 5417** it back off again. 5418*/ 5419int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5420 5421/* 5422** CAPI3REF: Automatically Load Statically Linked Extensions 5423** 5424** ^This interface causes the xEntryPoint() function to be invoked for 5425** each new [database connection] that is created. The idea here is that 5426** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5427** that is to be automatically loaded into all new database connections. 5428** 5429** ^(Even though the function prototype shows that xEntryPoint() takes 5430** no arguments and returns void, SQLite invokes xEntryPoint() with three 5431** arguments and expects and integer result as if the signature of the 5432** entry point where as follows: 5433** 5434** <blockquote><pre> 5435** int xEntryPoint( 5436** sqlite3 *db, 5437** const char **pzErrMsg, 5438** const struct sqlite3_api_routines *pThunk 5439** ); 5440** </pre></blockquote>)^ 5441** 5442** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5443** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5444** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5445** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5446** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5447** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5448** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5449** 5450** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5451** on the list of automatic extensions is a harmless no-op. ^No entry point 5452** will be called more than once for each database connection that is opened. 5453** 5454** See also: [sqlite3_reset_auto_extension()] 5455** and [sqlite3_cancel_auto_extension()] 5456*/ 5457int sqlite3_auto_extension(void (*xEntryPoint)(void)); 5458 5459/* 5460** CAPI3REF: Cancel Automatic Extension Loading 5461** 5462** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 5463** initialization routine X that was registered using a prior call to 5464** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 5465** routine returns 1 if initialization routine X was successfully 5466** unregistered and it returns 0 if X was not on the list of initialization 5467** routines. 5468*/ 5469int sqlite3_cancel_auto_extension(void (*xEntryPoint)(void)); 5470 5471/* 5472** CAPI3REF: Reset Automatic Extension Loading 5473** 5474** ^This interface disables all automatic extensions previously 5475** registered using [sqlite3_auto_extension()]. 5476*/ 5477void sqlite3_reset_auto_extension(void); 5478 5479/* 5480** The interface to the virtual-table mechanism is currently considered 5481** to be experimental. The interface might change in incompatible ways. 5482** If this is a problem for you, do not use the interface at this time. 5483** 5484** When the virtual-table mechanism stabilizes, we will declare the 5485** interface fixed, support it indefinitely, and remove this comment. 5486*/ 5487 5488/* 5489** Structures used by the virtual table interface 5490*/ 5491typedef struct sqlite3_vtab sqlite3_vtab; 5492typedef struct sqlite3_index_info sqlite3_index_info; 5493typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5494typedef struct sqlite3_module sqlite3_module; 5495 5496/* 5497** CAPI3REF: Virtual Table Object 5498** KEYWORDS: sqlite3_module {virtual table module} 5499** 5500** This structure, sometimes called a "virtual table module", 5501** defines the implementation of a [virtual tables]. 5502** This structure consists mostly of methods for the module. 5503** 5504** ^A virtual table module is created by filling in a persistent 5505** instance of this structure and passing a pointer to that instance 5506** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5507** ^The registration remains valid until it is replaced by a different 5508** module or until the [database connection] closes. The content 5509** of this structure must not change while it is registered with 5510** any database connection. 5511*/ 5512struct sqlite3_module { 5513 int iVersion; 5514 int (*xCreate)(sqlite3*, void *pAux, 5515 int argc, const char *const*argv, 5516 sqlite3_vtab **ppVTab, char**); 5517 int (*xConnect)(sqlite3*, void *pAux, 5518 int argc, const char *const*argv, 5519 sqlite3_vtab **ppVTab, char**); 5520 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5521 int (*xDisconnect)(sqlite3_vtab *pVTab); 5522 int (*xDestroy)(sqlite3_vtab *pVTab); 5523 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5524 int (*xClose)(sqlite3_vtab_cursor*); 5525 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5526 int argc, sqlite3_value **argv); 5527 int (*xNext)(sqlite3_vtab_cursor*); 5528 int (*xEof)(sqlite3_vtab_cursor*); 5529 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5530 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5531 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5532 int (*xBegin)(sqlite3_vtab *pVTab); 5533 int (*xSync)(sqlite3_vtab *pVTab); 5534 int (*xCommit)(sqlite3_vtab *pVTab); 5535 int (*xRollback)(sqlite3_vtab *pVTab); 5536 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5537 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5538 void **ppArg); 5539 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5540 /* The methods above are in version 1 of the sqlite_module object. Those 5541 ** below are for version 2 and greater. */ 5542 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5543 int (*xRelease)(sqlite3_vtab *pVTab, int); 5544 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5545}; 5546 5547/* 5548** CAPI3REF: Virtual Table Indexing Information 5549** KEYWORDS: sqlite3_index_info 5550** 5551** The sqlite3_index_info structure and its substructures is used as part 5552** of the [virtual table] interface to 5553** pass information into and receive the reply from the [xBestIndex] 5554** method of a [virtual table module]. The fields under **Inputs** are the 5555** inputs to xBestIndex and are read-only. xBestIndex inserts its 5556** results into the **Outputs** fields. 5557** 5558** ^(The aConstraint[] array records WHERE clause constraints of the form: 5559** 5560** <blockquote>column OP expr</blockquote> 5561** 5562** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5563** stored in aConstraint[].op using one of the 5564** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5565** ^(The index of the column is stored in 5566** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5567** expr on the right-hand side can be evaluated (and thus the constraint 5568** is usable) and false if it cannot.)^ 5569** 5570** ^The optimizer automatically inverts terms of the form "expr OP column" 5571** and makes other simplifications to the WHERE clause in an attempt to 5572** get as many WHERE clause terms into the form shown above as possible. 5573** ^The aConstraint[] array only reports WHERE clause terms that are 5574** relevant to the particular virtual table being queried. 5575** 5576** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5577** ^Each term of aOrderBy records a column of the ORDER BY clause. 5578** 5579** The [xBestIndex] method must fill aConstraintUsage[] with information 5580** about what parameters to pass to xFilter. ^If argvIndex>0 then 5581** the right-hand side of the corresponding aConstraint[] is evaluated 5582** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5583** is true, then the constraint is assumed to be fully handled by the 5584** virtual table and is not checked again by SQLite.)^ 5585** 5586** ^The idxNum and idxPtr values are recorded and passed into the 5587** [xFilter] method. 5588** ^[sqlite3_free()] is used to free idxPtr if and only if 5589** needToFreeIdxPtr is true. 5590** 5591** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5592** the correct order to satisfy the ORDER BY clause so that no separate 5593** sorting step is required. 5594** 5595** ^The estimatedCost value is an estimate of the cost of a particular 5596** strategy. A cost of N indicates that the cost of the strategy is similar 5597** to a linear scan of an SQLite table with N rows. A cost of log(N) 5598** indicates that the expense of the operation is similar to that of a 5599** binary search on a unique indexed field of an SQLite table with N rows. 5600** 5601** ^The estimatedRows value is an estimate of the number of rows that 5602** will be returned by the strategy. 5603** 5604** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 5605** structure for SQLite version 3.8.2. If a virtual table extension is 5606** used with an SQLite version earlier than 3.8.2, the results of attempting 5607** to read or write the estimatedRows field are undefined (but are likely 5608** to included crashing the application). The estimatedRows field should 5609** therefore only be used if [sqlite3_libversion_number()] returns a 5610** value greater than or equal to 3008002. 5611*/ 5612struct sqlite3_index_info { 5613 /* Inputs */ 5614 int nConstraint; /* Number of entries in aConstraint */ 5615 struct sqlite3_index_constraint { 5616 int iColumn; /* Column on left-hand side of constraint */ 5617 unsigned char op; /* Constraint operator */ 5618 unsigned char usable; /* True if this constraint is usable */ 5619 int iTermOffset; /* Used internally - xBestIndex should ignore */ 5620 } *aConstraint; /* Table of WHERE clause constraints */ 5621 int nOrderBy; /* Number of terms in the ORDER BY clause */ 5622 struct sqlite3_index_orderby { 5623 int iColumn; /* Column number */ 5624 unsigned char desc; /* True for DESC. False for ASC. */ 5625 } *aOrderBy; /* The ORDER BY clause */ 5626 /* Outputs */ 5627 struct sqlite3_index_constraint_usage { 5628 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5629 unsigned char omit; /* Do not code a test for this constraint */ 5630 } *aConstraintUsage; 5631 int idxNum; /* Number used to identify the index */ 5632 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5633 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5634 int orderByConsumed; /* True if output is already ordered */ 5635 double estimatedCost; /* Estimated cost of using this index */ 5636 /* Fields below are only available in SQLite 3.8.2 and later */ 5637 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 5638}; 5639 5640/* 5641** CAPI3REF: Virtual Table Constraint Operator Codes 5642** 5643** These macros defined the allowed values for the 5644** [sqlite3_index_info].aConstraint[].op field. Each value represents 5645** an operator that is part of a constraint term in the wHERE clause of 5646** a query that uses a [virtual table]. 5647*/ 5648#define SQLITE_INDEX_CONSTRAINT_EQ 2 5649#define SQLITE_INDEX_CONSTRAINT_GT 4 5650#define SQLITE_INDEX_CONSTRAINT_LE 8 5651#define SQLITE_INDEX_CONSTRAINT_LT 16 5652#define SQLITE_INDEX_CONSTRAINT_GE 32 5653#define SQLITE_INDEX_CONSTRAINT_MATCH 64 5654 5655/* 5656** CAPI3REF: Register A Virtual Table Implementation 5657** METHOD: sqlite3 5658** 5659** ^These routines are used to register a new [virtual table module] name. 5660** ^Module names must be registered before 5661** creating a new [virtual table] using the module and before using a 5662** preexisting [virtual table] for the module. 5663** 5664** ^The module name is registered on the [database connection] specified 5665** by the first parameter. ^The name of the module is given by the 5666** second parameter. ^The third parameter is a pointer to 5667** the implementation of the [virtual table module]. ^The fourth 5668** parameter is an arbitrary client data pointer that is passed through 5669** into the [xCreate] and [xConnect] methods of the virtual table module 5670** when a new virtual table is be being created or reinitialized. 5671** 5672** ^The sqlite3_create_module_v2() interface has a fifth parameter which 5673** is a pointer to a destructor for the pClientData. ^SQLite will 5674** invoke the destructor function (if it is not NULL) when SQLite 5675** no longer needs the pClientData pointer. ^The destructor will also 5676** be invoked if the call to sqlite3_create_module_v2() fails. 5677** ^The sqlite3_create_module() 5678** interface is equivalent to sqlite3_create_module_v2() with a NULL 5679** destructor. 5680*/ 5681int sqlite3_create_module( 5682 sqlite3 *db, /* SQLite connection to register module with */ 5683 const char *zName, /* Name of the module */ 5684 const sqlite3_module *p, /* Methods for the module */ 5685 void *pClientData /* Client data for xCreate/xConnect */ 5686); 5687int sqlite3_create_module_v2( 5688 sqlite3 *db, /* SQLite connection to register module with */ 5689 const char *zName, /* Name of the module */ 5690 const sqlite3_module *p, /* Methods for the module */ 5691 void *pClientData, /* Client data for xCreate/xConnect */ 5692 void(*xDestroy)(void*) /* Module destructor function */ 5693); 5694 5695/* 5696** CAPI3REF: Virtual Table Instance Object 5697** KEYWORDS: sqlite3_vtab 5698** 5699** Every [virtual table module] implementation uses a subclass 5700** of this object to describe a particular instance 5701** of the [virtual table]. Each subclass will 5702** be tailored to the specific needs of the module implementation. 5703** The purpose of this superclass is to define certain fields that are 5704** common to all module implementations. 5705** 5706** ^Virtual tables methods can set an error message by assigning a 5707** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 5708** take care that any prior string is freed by a call to [sqlite3_free()] 5709** prior to assigning a new string to zErrMsg. ^After the error message 5710** is delivered up to the client application, the string will be automatically 5711** freed by sqlite3_free() and the zErrMsg field will be zeroed. 5712*/ 5713struct sqlite3_vtab { 5714 const sqlite3_module *pModule; /* The module for this virtual table */ 5715 int nRef; /* Number of open cursors */ 5716 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 5717 /* Virtual table implementations will typically add additional fields */ 5718}; 5719 5720/* 5721** CAPI3REF: Virtual Table Cursor Object 5722** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 5723** 5724** Every [virtual table module] implementation uses a subclass of the 5725** following structure to describe cursors that point into the 5726** [virtual table] and are used 5727** to loop through the virtual table. Cursors are created using the 5728** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 5729** by the [sqlite3_module.xClose | xClose] method. Cursors are used 5730** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 5731** of the module. Each module implementation will define 5732** the content of a cursor structure to suit its own needs. 5733** 5734** This superclass exists in order to define fields of the cursor that 5735** are common to all implementations. 5736*/ 5737struct sqlite3_vtab_cursor { 5738 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 5739 /* Virtual table implementations will typically add additional fields */ 5740}; 5741 5742/* 5743** CAPI3REF: Declare The Schema Of A Virtual Table 5744** 5745** ^The [xCreate] and [xConnect] methods of a 5746** [virtual table module] call this interface 5747** to declare the format (the names and datatypes of the columns) of 5748** the virtual tables they implement. 5749*/ 5750int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 5751 5752/* 5753** CAPI3REF: Overload A Function For A Virtual Table 5754** METHOD: sqlite3 5755** 5756** ^(Virtual tables can provide alternative implementations of functions 5757** using the [xFindFunction] method of the [virtual table module]. 5758** But global versions of those functions 5759** must exist in order to be overloaded.)^ 5760** 5761** ^(This API makes sure a global version of a function with a particular 5762** name and number of parameters exists. If no such function exists 5763** before this API is called, a new function is created.)^ ^The implementation 5764** of the new function always causes an exception to be thrown. So 5765** the new function is not good for anything by itself. Its only 5766** purpose is to be a placeholder function that can be overloaded 5767** by a [virtual table]. 5768*/ 5769int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 5770 5771/* 5772** The interface to the virtual-table mechanism defined above (back up 5773** to a comment remarkably similar to this one) is currently considered 5774** to be experimental. The interface might change in incompatible ways. 5775** If this is a problem for you, do not use the interface at this time. 5776** 5777** When the virtual-table mechanism stabilizes, we will declare the 5778** interface fixed, support it indefinitely, and remove this comment. 5779*/ 5780 5781/* 5782** CAPI3REF: A Handle To An Open BLOB 5783** KEYWORDS: {BLOB handle} {BLOB handles} 5784** 5785** An instance of this object represents an open BLOB on which 5786** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 5787** ^Objects of this type are created by [sqlite3_blob_open()] 5788** and destroyed by [sqlite3_blob_close()]. 5789** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 5790** can be used to read or write small subsections of the BLOB. 5791** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 5792*/ 5793typedef struct sqlite3_blob sqlite3_blob; 5794 5795/* 5796** CAPI3REF: Open A BLOB For Incremental I/O 5797** METHOD: sqlite3 5798** CONSTRUCTOR: sqlite3_blob 5799** 5800** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 5801** in row iRow, column zColumn, table zTable in database zDb; 5802** in other words, the same BLOB that would be selected by: 5803** 5804** <pre> 5805** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 5806** </pre>)^ 5807** 5808** ^(Parameter zDb is not the filename that contains the database, but 5809** rather the symbolic name of the database. For attached databases, this is 5810** the name that appears after the AS keyword in the [ATTACH] statement. 5811** For the main database file, the database name is "main". For TEMP 5812** tables, the database name is "temp".)^ 5813** 5814** ^If the flags parameter is non-zero, then the BLOB is opened for read 5815** and write access. ^If the flags parameter is zero, the BLOB is opened for 5816** read-only access. 5817** 5818** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 5819** in *ppBlob. Otherwise an [error code] is returned and, unless the error 5820** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 5821** the API is not misused, it is always safe to call [sqlite3_blob_close()] 5822** on *ppBlob after this function it returns. 5823** 5824** This function fails with SQLITE_ERROR if any of the following are true: 5825** <ul> 5826** <li> ^(Database zDb does not exist)^, 5827** <li> ^(Table zTable does not exist within database zDb)^, 5828** <li> ^(Table zTable is a WITHOUT ROWID table)^, 5829** <li> ^(Column zColumn does not exist)^, 5830** <li> ^(Row iRow is not present in the table)^, 5831** <li> ^(The specified column of row iRow contains a value that is not 5832** a TEXT or BLOB value)^, 5833** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 5834** constraint and the blob is being opened for read/write access)^, 5835** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 5836** column zColumn is part of a [child key] definition and the blob is 5837** being opened for read/write access)^. 5838** </ul> 5839** 5840** ^Unless it returns SQLITE_MISUSE, this function sets the 5841** [database connection] error code and message accessible via 5842** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 5843** 5844** 5845** ^(If the row that a BLOB handle points to is modified by an 5846** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 5847** then the BLOB handle is marked as "expired". 5848** This is true if any column of the row is changed, even a column 5849** other than the one the BLOB handle is open on.)^ 5850** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 5851** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 5852** ^(Changes written into a BLOB prior to the BLOB expiring are not 5853** rolled back by the expiration of the BLOB. Such changes will eventually 5854** commit if the transaction continues to completion.)^ 5855** 5856** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 5857** the opened blob. ^The size of a blob may not be changed by this 5858** interface. Use the [UPDATE] SQL command to change the size of a 5859** blob. 5860** 5861** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 5862** and the built-in [zeroblob] SQL function may be used to create a 5863** zero-filled blob to read or write using the incremental-blob interface. 5864** 5865** To avoid a resource leak, every open [BLOB handle] should eventually 5866** be released by a call to [sqlite3_blob_close()]. 5867*/ 5868int sqlite3_blob_open( 5869 sqlite3*, 5870 const char *zDb, 5871 const char *zTable, 5872 const char *zColumn, 5873 sqlite3_int64 iRow, 5874 int flags, 5875 sqlite3_blob **ppBlob 5876); 5877 5878/* 5879** CAPI3REF: Move a BLOB Handle to a New Row 5880** METHOD: sqlite3_blob 5881** 5882** ^This function is used to move an existing blob handle so that it points 5883** to a different row of the same database table. ^The new row is identified 5884** by the rowid value passed as the second argument. Only the row can be 5885** changed. ^The database, table and column on which the blob handle is open 5886** remain the same. Moving an existing blob handle to a new row can be 5887** faster than closing the existing handle and opening a new one. 5888** 5889** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 5890** it must exist and there must be either a blob or text value stored in 5891** the nominated column.)^ ^If the new row is not present in the table, or if 5892** it does not contain a blob or text value, or if another error occurs, an 5893** SQLite error code is returned and the blob handle is considered aborted. 5894** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 5895** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 5896** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 5897** always returns zero. 5898** 5899** ^This function sets the database handle error code and message. 5900*/ 5901int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 5902 5903/* 5904** CAPI3REF: Close A BLOB Handle 5905** DESTRUCTOR: sqlite3_blob 5906** 5907** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 5908** unconditionally. Even if this routine returns an error code, the 5909** handle is still closed.)^ 5910** 5911** ^If the blob handle being closed was opened for read-write access, and if 5912** the database is in auto-commit mode and there are no other open read-write 5913** blob handles or active write statements, the current transaction is 5914** committed. ^If an error occurs while committing the transaction, an error 5915** code is returned and the transaction rolled back. 5916** 5917** Calling this function with an argument that is not a NULL pointer or an 5918** open blob handle results in undefined behaviour. ^Calling this routine 5919** with a null pointer (such as would be returned by a failed call to 5920** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 5921** is passed a valid open blob handle, the values returned by the 5922** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 5923*/ 5924int sqlite3_blob_close(sqlite3_blob *); 5925 5926/* 5927** CAPI3REF: Return The Size Of An Open BLOB 5928** METHOD: sqlite3_blob 5929** 5930** ^Returns the size in bytes of the BLOB accessible via the 5931** successfully opened [BLOB handle] in its only argument. ^The 5932** incremental blob I/O routines can only read or overwriting existing 5933** blob content; they cannot change the size of a blob. 5934** 5935** This routine only works on a [BLOB handle] which has been created 5936** by a prior successful call to [sqlite3_blob_open()] and which has not 5937** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5938** to this routine results in undefined and probably undesirable behavior. 5939*/ 5940int sqlite3_blob_bytes(sqlite3_blob *); 5941 5942/* 5943** CAPI3REF: Read Data From A BLOB Incrementally 5944** METHOD: sqlite3_blob 5945** 5946** ^(This function is used to read data from an open [BLOB handle] into a 5947** caller-supplied buffer. N bytes of data are copied into buffer Z 5948** from the open BLOB, starting at offset iOffset.)^ 5949** 5950** ^If offset iOffset is less than N bytes from the end of the BLOB, 5951** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 5952** less than zero, [SQLITE_ERROR] is returned and no data is read. 5953** ^The size of the blob (and hence the maximum value of N+iOffset) 5954** can be determined using the [sqlite3_blob_bytes()] interface. 5955** 5956** ^An attempt to read from an expired [BLOB handle] fails with an 5957** error code of [SQLITE_ABORT]. 5958** 5959** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 5960** Otherwise, an [error code] or an [extended error code] is returned.)^ 5961** 5962** This routine only works on a [BLOB handle] which has been created 5963** by a prior successful call to [sqlite3_blob_open()] and which has not 5964** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5965** to this routine results in undefined and probably undesirable behavior. 5966** 5967** See also: [sqlite3_blob_write()]. 5968*/ 5969int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 5970 5971/* 5972** CAPI3REF: Write Data Into A BLOB Incrementally 5973** METHOD: sqlite3_blob 5974** 5975** ^(This function is used to write data into an open [BLOB handle] from a 5976** caller-supplied buffer. N bytes of data are copied from the buffer Z 5977** into the open BLOB, starting at offset iOffset.)^ 5978** 5979** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 5980** Otherwise, an [error code] or an [extended error code] is returned.)^ 5981** ^Unless SQLITE_MISUSE is returned, this function sets the 5982** [database connection] error code and message accessible via 5983** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 5984** 5985** ^If the [BLOB handle] passed as the first argument was not opened for 5986** writing (the flags parameter to [sqlite3_blob_open()] was zero), 5987** this function returns [SQLITE_READONLY]. 5988** 5989** This function may only modify the contents of the BLOB; it is 5990** not possible to increase the size of a BLOB using this API. 5991** ^If offset iOffset is less than N bytes from the end of the BLOB, 5992** [SQLITE_ERROR] is returned and no data is written. The size of the 5993** BLOB (and hence the maximum value of N+iOffset) can be determined 5994** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 5995** than zero [SQLITE_ERROR] is returned and no data is written. 5996** 5997** ^An attempt to write to an expired [BLOB handle] fails with an 5998** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 5999** before the [BLOB handle] expired are not rolled back by the 6000** expiration of the handle, though of course those changes might 6001** have been overwritten by the statement that expired the BLOB handle 6002** or by other independent statements. 6003** 6004** This routine only works on a [BLOB handle] which has been created 6005** by a prior successful call to [sqlite3_blob_open()] and which has not 6006** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6007** to this routine results in undefined and probably undesirable behavior. 6008** 6009** See also: [sqlite3_blob_read()]. 6010*/ 6011int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 6012 6013/* 6014** CAPI3REF: Virtual File System Objects 6015** 6016** A virtual filesystem (VFS) is an [sqlite3_vfs] object 6017** that SQLite uses to interact 6018** with the underlying operating system. Most SQLite builds come with a 6019** single default VFS that is appropriate for the host computer. 6020** New VFSes can be registered and existing VFSes can be unregistered. 6021** The following interfaces are provided. 6022** 6023** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 6024** ^Names are case sensitive. 6025** ^Names are zero-terminated UTF-8 strings. 6026** ^If there is no match, a NULL pointer is returned. 6027** ^If zVfsName is NULL then the default VFS is returned. 6028** 6029** ^New VFSes are registered with sqlite3_vfs_register(). 6030** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6031** ^The same VFS can be registered multiple times without injury. 6032** ^To make an existing VFS into the default VFS, register it again 6033** with the makeDflt flag set. If two different VFSes with the 6034** same name are registered, the behavior is undefined. If a 6035** VFS is registered with a name that is NULL or an empty string, 6036** then the behavior is undefined. 6037** 6038** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6039** ^(If the default VFS is unregistered, another VFS is chosen as 6040** the default. The choice for the new VFS is arbitrary.)^ 6041*/ 6042sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 6043int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6044int sqlite3_vfs_unregister(sqlite3_vfs*); 6045 6046/* 6047** CAPI3REF: Mutexes 6048** 6049** The SQLite core uses these routines for thread 6050** synchronization. Though they are intended for internal 6051** use by SQLite, code that links against SQLite is 6052** permitted to use any of these routines. 6053** 6054** The SQLite source code contains multiple implementations 6055** of these mutex routines. An appropriate implementation 6056** is selected automatically at compile-time. The following 6057** implementations are available in the SQLite core: 6058** 6059** <ul> 6060** <li> SQLITE_MUTEX_PTHREADS 6061** <li> SQLITE_MUTEX_W32 6062** <li> SQLITE_MUTEX_NOOP 6063** </ul> 6064** 6065** The SQLITE_MUTEX_NOOP implementation is a set of routines 6066** that does no real locking and is appropriate for use in 6067** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6068** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6069** and Windows. 6070** 6071** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6072** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6073** implementation is included with the library. In this case the 6074** application must supply a custom mutex implementation using the 6075** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6076** before calling sqlite3_initialize() or any other public sqlite3_ 6077** function that calls sqlite3_initialize(). 6078** 6079** ^The sqlite3_mutex_alloc() routine allocates a new 6080** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6081** routine returns NULL if it is unable to allocate the requested 6082** mutex. The argument to sqlite3_mutex_alloc() must one of these 6083** integer constants: 6084** 6085** <ul> 6086** <li> SQLITE_MUTEX_FAST 6087** <li> SQLITE_MUTEX_RECURSIVE 6088** <li> SQLITE_MUTEX_STATIC_MASTER 6089** <li> SQLITE_MUTEX_STATIC_MEM 6090** <li> SQLITE_MUTEX_STATIC_OPEN 6091** <li> SQLITE_MUTEX_STATIC_PRNG 6092** <li> SQLITE_MUTEX_STATIC_LRU 6093** <li> SQLITE_MUTEX_STATIC_PMEM 6094** <li> SQLITE_MUTEX_STATIC_APP1 6095** <li> SQLITE_MUTEX_STATIC_APP2 6096** <li> SQLITE_MUTEX_STATIC_APP3 6097** </ul> 6098** 6099** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6100** cause sqlite3_mutex_alloc() to create 6101** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6102** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6103** The mutex implementation does not need to make a distinction 6104** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6105** not want to. SQLite will only request a recursive mutex in 6106** cases where it really needs one. If a faster non-recursive mutex 6107** implementation is available on the host platform, the mutex subsystem 6108** might return such a mutex in response to SQLITE_MUTEX_FAST. 6109** 6110** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6111** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6112** a pointer to a static preexisting mutex. ^Nine static mutexes are 6113** used by the current version of SQLite. Future versions of SQLite 6114** may add additional static mutexes. Static mutexes are for internal 6115** use by SQLite only. Applications that use SQLite mutexes should 6116** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6117** SQLITE_MUTEX_RECURSIVE. 6118** 6119** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6120** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6121** returns a different mutex on every call. ^For the static 6122** mutex types, the same mutex is returned on every call that has 6123** the same type number. 6124** 6125** ^The sqlite3_mutex_free() routine deallocates a previously 6126** allocated dynamic mutex. Attempting to deallocate a static 6127** mutex results in undefined behavior. 6128** 6129** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6130** to enter a mutex. ^If another thread is already within the mutex, 6131** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6132** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6133** upon successful entry. ^(Mutexes created using 6134** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6135** In such cases, the 6136** mutex must be exited an equal number of times before another thread 6137** can enter.)^ If the same thread tries to enter any mutex other 6138** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6139** 6140** ^(Some systems (for example, Windows 95) do not support the operation 6141** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6142** will always return SQLITE_BUSY. The SQLite core only ever uses 6143** sqlite3_mutex_try() as an optimization so this is acceptable 6144** behavior.)^ 6145** 6146** ^The sqlite3_mutex_leave() routine exits a mutex that was 6147** previously entered by the same thread. The behavior 6148** is undefined if the mutex is not currently entered by the 6149** calling thread or is not currently allocated. 6150** 6151** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6152** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6153** behave as no-ops. 6154** 6155** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6156*/ 6157sqlite3_mutex *sqlite3_mutex_alloc(int); 6158void sqlite3_mutex_free(sqlite3_mutex*); 6159void sqlite3_mutex_enter(sqlite3_mutex*); 6160int sqlite3_mutex_try(sqlite3_mutex*); 6161void sqlite3_mutex_leave(sqlite3_mutex*); 6162 6163/* 6164** CAPI3REF: Mutex Methods Object 6165** 6166** An instance of this structure defines the low-level routines 6167** used to allocate and use mutexes. 6168** 6169** Usually, the default mutex implementations provided by SQLite are 6170** sufficient, however the application has the option of substituting a custom 6171** implementation for specialized deployments or systems for which SQLite 6172** does not provide a suitable implementation. In this case, the application 6173** creates and populates an instance of this structure to pass 6174** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6175** Additionally, an instance of this structure can be used as an 6176** output variable when querying the system for the current mutex 6177** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6178** 6179** ^The xMutexInit method defined by this structure is invoked as 6180** part of system initialization by the sqlite3_initialize() function. 6181** ^The xMutexInit routine is called by SQLite exactly once for each 6182** effective call to [sqlite3_initialize()]. 6183** 6184** ^The xMutexEnd method defined by this structure is invoked as 6185** part of system shutdown by the sqlite3_shutdown() function. The 6186** implementation of this method is expected to release all outstanding 6187** resources obtained by the mutex methods implementation, especially 6188** those obtained by the xMutexInit method. ^The xMutexEnd() 6189** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6190** 6191** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6192** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6193** xMutexNotheld) implement the following interfaces (respectively): 6194** 6195** <ul> 6196** <li> [sqlite3_mutex_alloc()] </li> 6197** <li> [sqlite3_mutex_free()] </li> 6198** <li> [sqlite3_mutex_enter()] </li> 6199** <li> [sqlite3_mutex_try()] </li> 6200** <li> [sqlite3_mutex_leave()] </li> 6201** <li> [sqlite3_mutex_held()] </li> 6202** <li> [sqlite3_mutex_notheld()] </li> 6203** </ul>)^ 6204** 6205** The only difference is that the public sqlite3_XXX functions enumerated 6206** above silently ignore any invocations that pass a NULL pointer instead 6207** of a valid mutex handle. The implementations of the methods defined 6208** by this structure are not required to handle this case, the results 6209** of passing a NULL pointer instead of a valid mutex handle are undefined 6210** (i.e. it is acceptable to provide an implementation that segfaults if 6211** it is passed a NULL pointer). 6212** 6213** The xMutexInit() method must be threadsafe. It must be harmless to 6214** invoke xMutexInit() multiple times within the same process and without 6215** intervening calls to xMutexEnd(). Second and subsequent calls to 6216** xMutexInit() must be no-ops. 6217** 6218** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 6219** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 6220** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 6221** memory allocation for a fast or recursive mutex. 6222** 6223** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 6224** called, but only if the prior call to xMutexInit returned SQLITE_OK. 6225** If xMutexInit fails in any way, it is expected to clean up after itself 6226** prior to returning. 6227*/ 6228typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6229struct sqlite3_mutex_methods { 6230 int (*xMutexInit)(void); 6231 int (*xMutexEnd)(void); 6232 sqlite3_mutex *(*xMutexAlloc)(int); 6233 void (*xMutexFree)(sqlite3_mutex *); 6234 void (*xMutexEnter)(sqlite3_mutex *); 6235 int (*xMutexTry)(sqlite3_mutex *); 6236 void (*xMutexLeave)(sqlite3_mutex *); 6237 int (*xMutexHeld)(sqlite3_mutex *); 6238 int (*xMutexNotheld)(sqlite3_mutex *); 6239}; 6240 6241/* 6242** CAPI3REF: Mutex Verification Routines 6243** 6244** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 6245** are intended for use inside assert() statements. The SQLite core 6246** never uses these routines except inside an assert() and applications 6247** are advised to follow the lead of the core. The SQLite core only 6248** provides implementations for these routines when it is compiled 6249** with the SQLITE_DEBUG flag. External mutex implementations 6250** are only required to provide these routines if SQLITE_DEBUG is 6251** defined and if NDEBUG is not defined. 6252** 6253** These routines should return true if the mutex in their argument 6254** is held or not held, respectively, by the calling thread. 6255** 6256** The implementation is not required to provide versions of these 6257** routines that actually work. If the implementation does not provide working 6258** versions of these routines, it should at least provide stubs that always 6259** return true so that one does not get spurious assertion failures. 6260** 6261** If the argument to sqlite3_mutex_held() is a NULL pointer then 6262** the routine should return 1. This seems counter-intuitive since 6263** clearly the mutex cannot be held if it does not exist. But 6264** the reason the mutex does not exist is because the build is not 6265** using mutexes. And we do not want the assert() containing the 6266** call to sqlite3_mutex_held() to fail, so a non-zero return is 6267** the appropriate thing to do. The sqlite3_mutex_notheld() 6268** interface should also return 1 when given a NULL pointer. 6269*/ 6270#ifndef NDEBUG 6271int sqlite3_mutex_held(sqlite3_mutex*); 6272int sqlite3_mutex_notheld(sqlite3_mutex*); 6273#endif 6274 6275/* 6276** CAPI3REF: Mutex Types 6277** 6278** The [sqlite3_mutex_alloc()] interface takes a single argument 6279** which is one of these integer constants. 6280** 6281** The set of static mutexes may change from one SQLite release to the 6282** next. Applications that override the built-in mutex logic must be 6283** prepared to accommodate additional static mutexes. 6284*/ 6285#define SQLITE_MUTEX_FAST 0 6286#define SQLITE_MUTEX_RECURSIVE 1 6287#define SQLITE_MUTEX_STATIC_MASTER 2 6288#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6289#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6290#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6291#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 6292#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6293#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6294#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6295#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 6296#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 6297#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 6298#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 6299#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 6300#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 6301 6302/* 6303** CAPI3REF: Retrieve the mutex for a database connection 6304** METHOD: sqlite3 6305** 6306** ^This interface returns a pointer the [sqlite3_mutex] object that 6307** serializes access to the [database connection] given in the argument 6308** when the [threading mode] is Serialized. 6309** ^If the [threading mode] is Single-thread or Multi-thread then this 6310** routine returns a NULL pointer. 6311*/ 6312sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 6313 6314/* 6315** CAPI3REF: Low-Level Control Of Database Files 6316** METHOD: sqlite3 6317** 6318** ^The [sqlite3_file_control()] interface makes a direct call to the 6319** xFileControl method for the [sqlite3_io_methods] object associated 6320** with a particular database identified by the second argument. ^The 6321** name of the database is "main" for the main database or "temp" for the 6322** TEMP database, or the name that appears after the AS keyword for 6323** databases that are added using the [ATTACH] SQL command. 6324** ^A NULL pointer can be used in place of "main" to refer to the 6325** main database file. 6326** ^The third and fourth parameters to this routine 6327** are passed directly through to the second and third parameters of 6328** the xFileControl method. ^The return value of the xFileControl 6329** method becomes the return value of this routine. 6330** 6331** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 6332** a pointer to the underlying [sqlite3_file] object to be written into 6333** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 6334** case is a short-circuit path which does not actually invoke the 6335** underlying sqlite3_io_methods.xFileControl method. 6336** 6337** ^If the second parameter (zDbName) does not match the name of any 6338** open database file, then SQLITE_ERROR is returned. ^This error 6339** code is not remembered and will not be recalled by [sqlite3_errcode()] 6340** or [sqlite3_errmsg()]. The underlying xFileControl method might 6341** also return SQLITE_ERROR. There is no way to distinguish between 6342** an incorrect zDbName and an SQLITE_ERROR return from the underlying 6343** xFileControl method. 6344** 6345** See also: [SQLITE_FCNTL_LOCKSTATE] 6346*/ 6347int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 6348 6349/* 6350** CAPI3REF: Testing Interface 6351** 6352** ^The sqlite3_test_control() interface is used to read out internal 6353** state of SQLite and to inject faults into SQLite for testing 6354** purposes. ^The first parameter is an operation code that determines 6355** the number, meaning, and operation of all subsequent parameters. 6356** 6357** This interface is not for use by applications. It exists solely 6358** for verifying the correct operation of the SQLite library. Depending 6359** on how the SQLite library is compiled, this interface might not exist. 6360** 6361** The details of the operation codes, their meanings, the parameters 6362** they take, and what they do are all subject to change without notice. 6363** Unlike most of the SQLite API, this function is not guaranteed to 6364** operate consistently from one release to the next. 6365*/ 6366int sqlite3_test_control(int op, ...); 6367 6368/* 6369** CAPI3REF: Testing Interface Operation Codes 6370** 6371** These constants are the valid operation code parameters used 6372** as the first argument to [sqlite3_test_control()]. 6373** 6374** These parameters and their meanings are subject to change 6375** without notice. These values are for testing purposes only. 6376** Applications should not use any of these parameters or the 6377** [sqlite3_test_control()] interface. 6378*/ 6379#define SQLITE_TESTCTRL_FIRST 5 6380#define SQLITE_TESTCTRL_PRNG_SAVE 5 6381#define SQLITE_TESTCTRL_PRNG_RESTORE 6 6382#define SQLITE_TESTCTRL_PRNG_RESET 7 6383#define SQLITE_TESTCTRL_BITVEC_TEST 8 6384#define SQLITE_TESTCTRL_FAULT_INSTALL 9 6385#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 6386#define SQLITE_TESTCTRL_PENDING_BYTE 11 6387#define SQLITE_TESTCTRL_ASSERT 12 6388#define SQLITE_TESTCTRL_ALWAYS 13 6389#define SQLITE_TESTCTRL_RESERVE 14 6390#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 6391#define SQLITE_TESTCTRL_ISKEYWORD 16 6392#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 6393#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 6394#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 6395#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 6396#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 6397#define SQLITE_TESTCTRL_BYTEORDER 22 6398#define SQLITE_TESTCTRL_ISINIT 23 6399#define SQLITE_TESTCTRL_SORTER_MMAP 24 6400#define SQLITE_TESTCTRL_IMPOSTER 25 6401#define SQLITE_TESTCTRL_LAST 25 6402 6403/* 6404** CAPI3REF: SQLite Runtime Status 6405** 6406** ^These interfaces are used to retrieve runtime status information 6407** about the performance of SQLite, and optionally to reset various 6408** highwater marks. ^The first argument is an integer code for 6409** the specific parameter to measure. ^(Recognized integer codes 6410** are of the form [status parameters | SQLITE_STATUS_...].)^ 6411** ^The current value of the parameter is returned into *pCurrent. 6412** ^The highest recorded value is returned in *pHighwater. ^If the 6413** resetFlag is true, then the highest record value is reset after 6414** *pHighwater is written. ^(Some parameters do not record the highest 6415** value. For those parameters 6416** nothing is written into *pHighwater and the resetFlag is ignored.)^ 6417** ^(Other parameters record only the highwater mark and not the current 6418** value. For these latter parameters nothing is written into *pCurrent.)^ 6419** 6420** ^The sqlite3_status() and sqlite3_status64() routines return 6421** SQLITE_OK on success and a non-zero [error code] on failure. 6422** 6423** If either the current value or the highwater mark is too large to 6424** be represented by a 32-bit integer, then the values returned by 6425** sqlite3_status() are undefined. 6426** 6427** See also: [sqlite3_db_status()] 6428*/ 6429int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 6430int sqlite3_status64( 6431 int op, 6432 sqlite3_int64 *pCurrent, 6433 sqlite3_int64 *pHighwater, 6434 int resetFlag 6435); 6436 6437 6438/* 6439** CAPI3REF: Status Parameters 6440** KEYWORDS: {status parameters} 6441** 6442** These integer constants designate various run-time status parameters 6443** that can be returned by [sqlite3_status()]. 6444** 6445** <dl> 6446** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 6447** <dd>This parameter is the current amount of memory checked out 6448** using [sqlite3_malloc()], either directly or indirectly. The 6449** figure includes calls made to [sqlite3_malloc()] by the application 6450** and internal memory usage by the SQLite library. Scratch memory 6451** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 6452** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 6453** this parameter. The amount returned is the sum of the allocation 6454** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 6455** 6456** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 6457** <dd>This parameter records the largest memory allocation request 6458** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 6459** internal equivalents). Only the value returned in the 6460** *pHighwater parameter to [sqlite3_status()] is of interest. 6461** The value written into the *pCurrent parameter is undefined.</dd>)^ 6462** 6463** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 6464** <dd>This parameter records the number of separate memory allocations 6465** currently checked out.</dd>)^ 6466** 6467** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 6468** <dd>This parameter returns the number of pages used out of the 6469** [pagecache memory allocator] that was configured using 6470** [SQLITE_CONFIG_PAGECACHE]. The 6471** value returned is in pages, not in bytes.</dd>)^ 6472** 6473** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 6474** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6475** <dd>This parameter returns the number of bytes of page cache 6476** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 6477** buffer and where forced to overflow to [sqlite3_malloc()]. The 6478** returned value includes allocations that overflowed because they 6479** where too large (they were larger than the "sz" parameter to 6480** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 6481** no space was left in the page cache.</dd>)^ 6482** 6483** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 6484** <dd>This parameter records the largest memory allocation request 6485** handed to [pagecache memory allocator]. Only the value returned in the 6486** *pHighwater parameter to [sqlite3_status()] is of interest. 6487** The value written into the *pCurrent parameter is undefined.</dd>)^ 6488** 6489** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 6490** <dd>This parameter returns the number of allocations used out of the 6491** [scratch memory allocator] configured using 6492** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6493** in bytes. Since a single thread may only have one scratch allocation 6494** outstanding at time, this parameter also reports the number of threads 6495** using scratch memory at the same time.</dd>)^ 6496** 6497** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6498** <dd>This parameter returns the number of bytes of scratch memory 6499** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 6500** buffer and where forced to overflow to [sqlite3_malloc()]. The values 6501** returned include overflows because the requested allocation was too 6502** larger (that is, because the requested allocation was larger than the 6503** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 6504** slots were available. 6505** </dd>)^ 6506** 6507** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6508** <dd>This parameter records the largest memory allocation request 6509** handed to [scratch memory allocator]. Only the value returned in the 6510** *pHighwater parameter to [sqlite3_status()] is of interest. 6511** The value written into the *pCurrent parameter is undefined.</dd>)^ 6512** 6513** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6514** <dd>This parameter records the deepest parser stack. It is only 6515** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6516** </dl> 6517** 6518** New status parameters may be added from time to time. 6519*/ 6520#define SQLITE_STATUS_MEMORY_USED 0 6521#define SQLITE_STATUS_PAGECACHE_USED 1 6522#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6523#define SQLITE_STATUS_SCRATCH_USED 3 6524#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6525#define SQLITE_STATUS_MALLOC_SIZE 5 6526#define SQLITE_STATUS_PARSER_STACK 6 6527#define SQLITE_STATUS_PAGECACHE_SIZE 7 6528#define SQLITE_STATUS_SCRATCH_SIZE 8 6529#define SQLITE_STATUS_MALLOC_COUNT 9 6530 6531/* 6532** CAPI3REF: Database Connection Status 6533** METHOD: sqlite3 6534** 6535** ^This interface is used to retrieve runtime status information 6536** about a single [database connection]. ^The first argument is the 6537** database connection object to be interrogated. ^The second argument 6538** is an integer constant, taken from the set of 6539** [SQLITE_DBSTATUS options], that 6540** determines the parameter to interrogate. The set of 6541** [SQLITE_DBSTATUS options] is likely 6542** to grow in future releases of SQLite. 6543** 6544** ^The current value of the requested parameter is written into *pCur 6545** and the highest instantaneous value is written into *pHiwtr. ^If 6546** the resetFlg is true, then the highest instantaneous value is 6547** reset back down to the current value. 6548** 6549** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 6550** non-zero [error code] on failure. 6551** 6552** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 6553*/ 6554int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 6555 6556/* 6557** CAPI3REF: Status Parameters for database connections 6558** KEYWORDS: {SQLITE_DBSTATUS options} 6559** 6560** These constants are the available integer "verbs" that can be passed as 6561** the second argument to the [sqlite3_db_status()] interface. 6562** 6563** New verbs may be added in future releases of SQLite. Existing verbs 6564** might be discontinued. Applications should check the return code from 6565** [sqlite3_db_status()] to make sure that the call worked. 6566** The [sqlite3_db_status()] interface will return a non-zero error code 6567** if a discontinued or unsupported verb is invoked. 6568** 6569** <dl> 6570** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6571** <dd>This parameter returns the number of lookaside memory slots currently 6572** checked out.</dd>)^ 6573** 6574** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6575** <dd>This parameter returns the number malloc attempts that were 6576** satisfied using lookaside memory. Only the high-water value is meaningful; 6577** the current value is always zero.)^ 6578** 6579** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6580** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6581** <dd>This parameter returns the number malloc attempts that might have 6582** been satisfied using lookaside memory but failed due to the amount of 6583** memory requested being larger than the lookaside slot size. 6584** Only the high-water value is meaningful; 6585** the current value is always zero.)^ 6586** 6587** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6588** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6589** <dd>This parameter returns the number malloc attempts that might have 6590** been satisfied using lookaside memory but failed due to all lookaside 6591** memory already being in use. 6592** Only the high-water value is meaningful; 6593** the current value is always zero.)^ 6594** 6595** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6596** <dd>This parameter returns the approximate number of bytes of heap 6597** memory used by all pager caches associated with the database connection.)^ 6598** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6599** 6600** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 6601** <dd>This parameter returns the approximate number of bytes of heap 6602** memory used to store the schema for all databases associated 6603** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 6604** ^The full amount of memory used by the schemas is reported, even if the 6605** schema memory is shared with other database connections due to 6606** [shared cache mode] being enabled. 6607** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 6608** 6609** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 6610** <dd>This parameter returns the approximate number of bytes of heap 6611** and lookaside memory used by all prepared statements associated with 6612** the database connection.)^ 6613** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 6614** </dd> 6615** 6616** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 6617** <dd>This parameter returns the number of pager cache hits that have 6618** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 6619** is always 0. 6620** </dd> 6621** 6622** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 6623** <dd>This parameter returns the number of pager cache misses that have 6624** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 6625** is always 0. 6626** </dd> 6627** 6628** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 6629** <dd>This parameter returns the number of dirty cache entries that have 6630** been written to disk. Specifically, the number of pages written to the 6631** wal file in wal mode databases, or the number of pages written to the 6632** database file in rollback mode databases. Any pages written as part of 6633** transaction rollback or database recovery operations are not included. 6634** If an IO or other error occurs while writing a page to disk, the effect 6635** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 6636** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 6637** </dd> 6638** 6639** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 6640** <dd>This parameter returns zero for the current value if and only if 6641** all foreign key constraints (deferred or immediate) have been 6642** resolved.)^ ^The highwater mark is always 0. 6643** </dd> 6644** </dl> 6645*/ 6646#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 6647#define SQLITE_DBSTATUS_CACHE_USED 1 6648#define SQLITE_DBSTATUS_SCHEMA_USED 2 6649#define SQLITE_DBSTATUS_STMT_USED 3 6650#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 6651#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 6652#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 6653#define SQLITE_DBSTATUS_CACHE_HIT 7 6654#define SQLITE_DBSTATUS_CACHE_MISS 8 6655#define SQLITE_DBSTATUS_CACHE_WRITE 9 6656#define SQLITE_DBSTATUS_DEFERRED_FKS 10 6657#define SQLITE_DBSTATUS_MAX 10 /* Largest defined DBSTATUS */ 6658 6659 6660/* 6661** CAPI3REF: Prepared Statement Status 6662** METHOD: sqlite3_stmt 6663** 6664** ^(Each prepared statement maintains various 6665** [SQLITE_STMTSTATUS counters] that measure the number 6666** of times it has performed specific operations.)^ These counters can 6667** be used to monitor the performance characteristics of the prepared 6668** statements. For example, if the number of table steps greatly exceeds 6669** the number of table searches or result rows, that would tend to indicate 6670** that the prepared statement is using a full table scan rather than 6671** an index. 6672** 6673** ^(This interface is used to retrieve and reset counter values from 6674** a [prepared statement]. The first argument is the prepared statement 6675** object to be interrogated. The second argument 6676** is an integer code for a specific [SQLITE_STMTSTATUS counter] 6677** to be interrogated.)^ 6678** ^The current value of the requested counter is returned. 6679** ^If the resetFlg is true, then the counter is reset to zero after this 6680** interface call returns. 6681** 6682** See also: [sqlite3_status()] and [sqlite3_db_status()]. 6683*/ 6684int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 6685 6686/* 6687** CAPI3REF: Status Parameters for prepared statements 6688** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 6689** 6690** These preprocessor macros define integer codes that name counter 6691** values associated with the [sqlite3_stmt_status()] interface. 6692** The meanings of the various counters are as follows: 6693** 6694** <dl> 6695** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 6696** <dd>^This is the number of times that SQLite has stepped forward in 6697** a table as part of a full table scan. Large numbers for this counter 6698** may indicate opportunities for performance improvement through 6699** careful use of indices.</dd> 6700** 6701** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 6702** <dd>^This is the number of sort operations that have occurred. 6703** A non-zero value in this counter may indicate an opportunity to 6704** improvement performance through careful use of indices.</dd> 6705** 6706** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 6707** <dd>^This is the number of rows inserted into transient indices that 6708** were created automatically in order to help joins run faster. 6709** A non-zero value in this counter may indicate an opportunity to 6710** improvement performance by adding permanent indices that do not 6711** need to be reinitialized each time the statement is run.</dd> 6712** 6713** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 6714** <dd>^This is the number of virtual machine operations executed 6715** by the prepared statement if that number is less than or equal 6716** to 2147483647. The number of virtual machine operations can be 6717** used as a proxy for the total work done by the prepared statement. 6718** If the number of virtual machine operations exceeds 2147483647 6719** then the value returned by this statement status code is undefined. 6720** </dd> 6721** </dl> 6722*/ 6723#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 6724#define SQLITE_STMTSTATUS_SORT 2 6725#define SQLITE_STMTSTATUS_AUTOINDEX 3 6726#define SQLITE_STMTSTATUS_VM_STEP 4 6727 6728/* 6729** CAPI3REF: Custom Page Cache Object 6730** 6731** The sqlite3_pcache type is opaque. It is implemented by 6732** the pluggable module. The SQLite core has no knowledge of 6733** its size or internal structure and never deals with the 6734** sqlite3_pcache object except by holding and passing pointers 6735** to the object. 6736** 6737** See [sqlite3_pcache_methods2] for additional information. 6738*/ 6739typedef struct sqlite3_pcache sqlite3_pcache; 6740 6741/* 6742** CAPI3REF: Custom Page Cache Object 6743** 6744** The sqlite3_pcache_page object represents a single page in the 6745** page cache. The page cache will allocate instances of this 6746** object. Various methods of the page cache use pointers to instances 6747** of this object as parameters or as their return value. 6748** 6749** See [sqlite3_pcache_methods2] for additional information. 6750*/ 6751typedef struct sqlite3_pcache_page sqlite3_pcache_page; 6752struct sqlite3_pcache_page { 6753 void *pBuf; /* The content of the page */ 6754 void *pExtra; /* Extra information associated with the page */ 6755}; 6756 6757/* 6758** CAPI3REF: Application Defined Page Cache. 6759** KEYWORDS: {page cache} 6760** 6761** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 6762** register an alternative page cache implementation by passing in an 6763** instance of the sqlite3_pcache_methods2 structure.)^ 6764** In many applications, most of the heap memory allocated by 6765** SQLite is used for the page cache. 6766** By implementing a 6767** custom page cache using this API, an application can better control 6768** the amount of memory consumed by SQLite, the way in which 6769** that memory is allocated and released, and the policies used to 6770** determine exactly which parts of a database file are cached and for 6771** how long. 6772** 6773** The alternative page cache mechanism is an 6774** extreme measure that is only needed by the most demanding applications. 6775** The built-in page cache is recommended for most uses. 6776** 6777** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 6778** internal buffer by SQLite within the call to [sqlite3_config]. Hence 6779** the application may discard the parameter after the call to 6780** [sqlite3_config()] returns.)^ 6781** 6782** [[the xInit() page cache method]] 6783** ^(The xInit() method is called once for each effective 6784** call to [sqlite3_initialize()])^ 6785** (usually only once during the lifetime of the process). ^(The xInit() 6786** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 6787** The intent of the xInit() method is to set up global data structures 6788** required by the custom page cache implementation. 6789** ^(If the xInit() method is NULL, then the 6790** built-in default page cache is used instead of the application defined 6791** page cache.)^ 6792** 6793** [[the xShutdown() page cache method]] 6794** ^The xShutdown() method is called by [sqlite3_shutdown()]. 6795** It can be used to clean up 6796** any outstanding resources before process shutdown, if required. 6797** ^The xShutdown() method may be NULL. 6798** 6799** ^SQLite automatically serializes calls to the xInit method, 6800** so the xInit method need not be threadsafe. ^The 6801** xShutdown method is only called from [sqlite3_shutdown()] so it does 6802** not need to be threadsafe either. All other methods must be threadsafe 6803** in multithreaded applications. 6804** 6805** ^SQLite will never invoke xInit() more than once without an intervening 6806** call to xShutdown(). 6807** 6808** [[the xCreate() page cache methods]] 6809** ^SQLite invokes the xCreate() method to construct a new cache instance. 6810** SQLite will typically create one cache instance for each open database file, 6811** though this is not guaranteed. ^The 6812** first parameter, szPage, is the size in bytes of the pages that must 6813** be allocated by the cache. ^szPage will always a power of two. ^The 6814** second parameter szExtra is a number of bytes of extra storage 6815** associated with each page cache entry. ^The szExtra parameter will 6816** a number less than 250. SQLite will use the 6817** extra szExtra bytes on each page to store metadata about the underlying 6818** database page on disk. The value passed into szExtra depends 6819** on the SQLite version, the target platform, and how SQLite was compiled. 6820** ^The third argument to xCreate(), bPurgeable, is true if the cache being 6821** created will be used to cache database pages of a file stored on disk, or 6822** false if it is used for an in-memory database. The cache implementation 6823** does not have to do anything special based with the value of bPurgeable; 6824** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 6825** never invoke xUnpin() except to deliberately delete a page. 6826** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 6827** false will always have the "discard" flag set to true. 6828** ^Hence, a cache created with bPurgeable false will 6829** never contain any unpinned pages. 6830** 6831** [[the xCachesize() page cache method]] 6832** ^(The xCachesize() method may be called at any time by SQLite to set the 6833** suggested maximum cache-size (number of pages stored by) the cache 6834** instance passed as the first argument. This is the value configured using 6835** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 6836** parameter, the implementation is not required to do anything with this 6837** value; it is advisory only. 6838** 6839** [[the xPagecount() page cache methods]] 6840** The xPagecount() method must return the number of pages currently 6841** stored in the cache, both pinned and unpinned. 6842** 6843** [[the xFetch() page cache methods]] 6844** The xFetch() method locates a page in the cache and returns a pointer to 6845** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 6846** The pBuf element of the returned sqlite3_pcache_page object will be a 6847** pointer to a buffer of szPage bytes used to store the content of a 6848** single database page. The pExtra element of sqlite3_pcache_page will be 6849** a pointer to the szExtra bytes of extra storage that SQLite has requested 6850** for each entry in the page cache. 6851** 6852** The page to be fetched is determined by the key. ^The minimum key value 6853** is 1. After it has been retrieved using xFetch, the page is considered 6854** to be "pinned". 6855** 6856** If the requested page is already in the page cache, then the page cache 6857** implementation must return a pointer to the page buffer with its content 6858** intact. If the requested page is not already in the cache, then the 6859** cache implementation should use the value of the createFlag 6860** parameter to help it determined what action to take: 6861** 6862** <table border=1 width=85% align=center> 6863** <tr><th> createFlag <th> Behavior when page is not already in cache 6864** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 6865** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 6866** Otherwise return NULL. 6867** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 6868** NULL if allocating a new page is effectively impossible. 6869** </table> 6870** 6871** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 6872** will only use a createFlag of 2 after a prior call with a createFlag of 1 6873** failed.)^ In between the to xFetch() calls, SQLite may 6874** attempt to unpin one or more cache pages by spilling the content of 6875** pinned pages to disk and synching the operating system disk cache. 6876** 6877** [[the xUnpin() page cache method]] 6878** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 6879** as its second argument. If the third parameter, discard, is non-zero, 6880** then the page must be evicted from the cache. 6881** ^If the discard parameter is 6882** zero, then the page may be discarded or retained at the discretion of 6883** page cache implementation. ^The page cache implementation 6884** may choose to evict unpinned pages at any time. 6885** 6886** The cache must not perform any reference counting. A single 6887** call to xUnpin() unpins the page regardless of the number of prior calls 6888** to xFetch(). 6889** 6890** [[the xRekey() page cache methods]] 6891** The xRekey() method is used to change the key value associated with the 6892** page passed as the second argument. If the cache 6893** previously contains an entry associated with newKey, it must be 6894** discarded. ^Any prior cache entry associated with newKey is guaranteed not 6895** to be pinned. 6896** 6897** When SQLite calls the xTruncate() method, the cache must discard all 6898** existing cache entries with page numbers (keys) greater than or equal 6899** to the value of the iLimit parameter passed to xTruncate(). If any 6900** of these pages are pinned, they are implicitly unpinned, meaning that 6901** they can be safely discarded. 6902** 6903** [[the xDestroy() page cache method]] 6904** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 6905** All resources associated with the specified cache should be freed. ^After 6906** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 6907** handle invalid, and will not use it with any other sqlite3_pcache_methods2 6908** functions. 6909** 6910** [[the xShrink() page cache method]] 6911** ^SQLite invokes the xShrink() method when it wants the page cache to 6912** free up as much of heap memory as possible. The page cache implementation 6913** is not obligated to free any memory, but well-behaved implementations should 6914** do their best. 6915*/ 6916typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 6917struct sqlite3_pcache_methods2 { 6918 int iVersion; 6919 void *pArg; 6920 int (*xInit)(void*); 6921 void (*xShutdown)(void*); 6922 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 6923 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6924 int (*xPagecount)(sqlite3_pcache*); 6925 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6926 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 6927 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 6928 unsigned oldKey, unsigned newKey); 6929 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6930 void (*xDestroy)(sqlite3_pcache*); 6931 void (*xShrink)(sqlite3_pcache*); 6932}; 6933 6934/* 6935** This is the obsolete pcache_methods object that has now been replaced 6936** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 6937** retained in the header file for backwards compatibility only. 6938*/ 6939typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 6940struct sqlite3_pcache_methods { 6941 void *pArg; 6942 int (*xInit)(void*); 6943 void (*xShutdown)(void*); 6944 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 6945 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6946 int (*xPagecount)(sqlite3_pcache*); 6947 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6948 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 6949 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 6950 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6951 void (*xDestroy)(sqlite3_pcache*); 6952}; 6953 6954 6955/* 6956** CAPI3REF: Online Backup Object 6957** 6958** The sqlite3_backup object records state information about an ongoing 6959** online backup operation. ^The sqlite3_backup object is created by 6960** a call to [sqlite3_backup_init()] and is destroyed by a call to 6961** [sqlite3_backup_finish()]. 6962** 6963** See Also: [Using the SQLite Online Backup API] 6964*/ 6965typedef struct sqlite3_backup sqlite3_backup; 6966 6967/* 6968** CAPI3REF: Online Backup API. 6969** 6970** The backup API copies the content of one database into another. 6971** It is useful either for creating backups of databases or 6972** for copying in-memory databases to or from persistent files. 6973** 6974** See Also: [Using the SQLite Online Backup API] 6975** 6976** ^SQLite holds a write transaction open on the destination database file 6977** for the duration of the backup operation. 6978** ^The source database is read-locked only while it is being read; 6979** it is not locked continuously for the entire backup operation. 6980** ^Thus, the backup may be performed on a live source database without 6981** preventing other database connections from 6982** reading or writing to the source database while the backup is underway. 6983** 6984** ^(To perform a backup operation: 6985** <ol> 6986** <li><b>sqlite3_backup_init()</b> is called once to initialize the 6987** backup, 6988** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 6989** the data between the two databases, and finally 6990** <li><b>sqlite3_backup_finish()</b> is called to release all resources 6991** associated with the backup operation. 6992** </ol>)^ 6993** There should be exactly one call to sqlite3_backup_finish() for each 6994** successful call to sqlite3_backup_init(). 6995** 6996** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 6997** 6998** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 6999** [database connection] associated with the destination database 7000** and the database name, respectively. 7001** ^The database name is "main" for the main database, "temp" for the 7002** temporary database, or the name specified after the AS keyword in 7003** an [ATTACH] statement for an attached database. 7004** ^The S and M arguments passed to 7005** sqlite3_backup_init(D,N,S,M) identify the [database connection] 7006** and database name of the source database, respectively. 7007** ^The source and destination [database connections] (parameters S and D) 7008** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 7009** an error. 7010** 7011** ^A call to sqlite3_backup_init() will fail, returning SQLITE_ERROR, if 7012** there is already a read or read-write transaction open on the 7013** destination database. 7014** 7015** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 7016** returned and an error code and error message are stored in the 7017** destination [database connection] D. 7018** ^The error code and message for the failed call to sqlite3_backup_init() 7019** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 7020** [sqlite3_errmsg16()] functions. 7021** ^A successful call to sqlite3_backup_init() returns a pointer to an 7022** [sqlite3_backup] object. 7023** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 7024** sqlite3_backup_finish() functions to perform the specified backup 7025** operation. 7026** 7027** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 7028** 7029** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 7030** the source and destination databases specified by [sqlite3_backup] object B. 7031** ^If N is negative, all remaining source pages are copied. 7032** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 7033** are still more pages to be copied, then the function returns [SQLITE_OK]. 7034** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 7035** from source to destination, then it returns [SQLITE_DONE]. 7036** ^If an error occurs while running sqlite3_backup_step(B,N), 7037** then an [error code] is returned. ^As well as [SQLITE_OK] and 7038** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 7039** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 7040** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 7041** 7042** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 7043** <ol> 7044** <li> the destination database was opened read-only, or 7045** <li> the destination database is using write-ahead-log journaling 7046** and the destination and source page sizes differ, or 7047** <li> the destination database is an in-memory database and the 7048** destination and source page sizes differ. 7049** </ol>)^ 7050** 7051** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 7052** the [sqlite3_busy_handler | busy-handler function] 7053** is invoked (if one is specified). ^If the 7054** busy-handler returns non-zero before the lock is available, then 7055** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 7056** sqlite3_backup_step() can be retried later. ^If the source 7057** [database connection] 7058** is being used to write to the source database when sqlite3_backup_step() 7059** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 7060** case the call to sqlite3_backup_step() can be retried later on. ^(If 7061** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 7062** [SQLITE_READONLY] is returned, then 7063** there is no point in retrying the call to sqlite3_backup_step(). These 7064** errors are considered fatal.)^ The application must accept 7065** that the backup operation has failed and pass the backup operation handle 7066** to the sqlite3_backup_finish() to release associated resources. 7067** 7068** ^The first call to sqlite3_backup_step() obtains an exclusive lock 7069** on the destination file. ^The exclusive lock is not released until either 7070** sqlite3_backup_finish() is called or the backup operation is complete 7071** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 7072** sqlite3_backup_step() obtains a [shared lock] on the source database that 7073** lasts for the duration of the sqlite3_backup_step() call. 7074** ^Because the source database is not locked between calls to 7075** sqlite3_backup_step(), the source database may be modified mid-way 7076** through the backup process. ^If the source database is modified by an 7077** external process or via a database connection other than the one being 7078** used by the backup operation, then the backup will be automatically 7079** restarted by the next call to sqlite3_backup_step(). ^If the source 7080** database is modified by the using the same database connection as is used 7081** by the backup operation, then the backup database is automatically 7082** updated at the same time. 7083** 7084** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 7085** 7086** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 7087** application wishes to abandon the backup operation, the application 7088** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 7089** ^The sqlite3_backup_finish() interfaces releases all 7090** resources associated with the [sqlite3_backup] object. 7091** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 7092** active write-transaction on the destination database is rolled back. 7093** The [sqlite3_backup] object is invalid 7094** and may not be used following a call to sqlite3_backup_finish(). 7095** 7096** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 7097** sqlite3_backup_step() errors occurred, regardless or whether or not 7098** sqlite3_backup_step() completed. 7099** ^If an out-of-memory condition or IO error occurred during any prior 7100** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 7101** sqlite3_backup_finish() returns the corresponding [error code]. 7102** 7103** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 7104** is not a permanent error and does not affect the return value of 7105** sqlite3_backup_finish(). 7106** 7107** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 7108** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 7109** 7110** ^The sqlite3_backup_remaining() routine returns the number of pages still 7111** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 7112** ^The sqlite3_backup_pagecount() routine returns the total number of pages 7113** in the source database at the conclusion of the most recent 7114** sqlite3_backup_step(). 7115** ^(The values returned by these functions are only updated by 7116** sqlite3_backup_step(). If the source database is modified in a way that 7117** changes the size of the source database or the number of pages remaining, 7118** those changes are not reflected in the output of sqlite3_backup_pagecount() 7119** and sqlite3_backup_remaining() until after the next 7120** sqlite3_backup_step().)^ 7121** 7122** <b>Concurrent Usage of Database Handles</b> 7123** 7124** ^The source [database connection] may be used by the application for other 7125** purposes while a backup operation is underway or being initialized. 7126** ^If SQLite is compiled and configured to support threadsafe database 7127** connections, then the source database connection may be used concurrently 7128** from within other threads. 7129** 7130** However, the application must guarantee that the destination 7131** [database connection] is not passed to any other API (by any thread) after 7132** sqlite3_backup_init() is called and before the corresponding call to 7133** sqlite3_backup_finish(). SQLite does not currently check to see 7134** if the application incorrectly accesses the destination [database connection] 7135** and so no error code is reported, but the operations may malfunction 7136** nevertheless. Use of the destination database connection while a 7137** backup is in progress might also also cause a mutex deadlock. 7138** 7139** If running in [shared cache mode], the application must 7140** guarantee that the shared cache used by the destination database 7141** is not accessed while the backup is running. In practice this means 7142** that the application must guarantee that the disk file being 7143** backed up to is not accessed by any connection within the process, 7144** not just the specific connection that was passed to sqlite3_backup_init(). 7145** 7146** The [sqlite3_backup] object itself is partially threadsafe. Multiple 7147** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 7148** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 7149** APIs are not strictly speaking threadsafe. If they are invoked at the 7150** same time as another thread is invoking sqlite3_backup_step() it is 7151** possible that they return invalid values. 7152*/ 7153sqlite3_backup *sqlite3_backup_init( 7154 sqlite3 *pDest, /* Destination database handle */ 7155 const char *zDestName, /* Destination database name */ 7156 sqlite3 *pSource, /* Source database handle */ 7157 const char *zSourceName /* Source database name */ 7158); 7159int sqlite3_backup_step(sqlite3_backup *p, int nPage); 7160int sqlite3_backup_finish(sqlite3_backup *p); 7161int sqlite3_backup_remaining(sqlite3_backup *p); 7162int sqlite3_backup_pagecount(sqlite3_backup *p); 7163 7164/* 7165** CAPI3REF: Unlock Notification 7166** METHOD: sqlite3 7167** 7168** ^When running in shared-cache mode, a database operation may fail with 7169** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 7170** individual tables within the shared-cache cannot be obtained. See 7171** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 7172** ^This API may be used to register a callback that SQLite will invoke 7173** when the connection currently holding the required lock relinquishes it. 7174** ^This API is only available if the library was compiled with the 7175** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 7176** 7177** See Also: [Using the SQLite Unlock Notification Feature]. 7178** 7179** ^Shared-cache locks are released when a database connection concludes 7180** its current transaction, either by committing it or rolling it back. 7181** 7182** ^When a connection (known as the blocked connection) fails to obtain a 7183** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 7184** identity of the database connection (the blocking connection) that 7185** has locked the required resource is stored internally. ^After an 7186** application receives an SQLITE_LOCKED error, it may call the 7187** sqlite3_unlock_notify() method with the blocked connection handle as 7188** the first argument to register for a callback that will be invoked 7189** when the blocking connections current transaction is concluded. ^The 7190** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 7191** call that concludes the blocking connections transaction. 7192** 7193** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 7194** there is a chance that the blocking connection will have already 7195** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 7196** If this happens, then the specified callback is invoked immediately, 7197** from within the call to sqlite3_unlock_notify().)^ 7198** 7199** ^If the blocked connection is attempting to obtain a write-lock on a 7200** shared-cache table, and more than one other connection currently holds 7201** a read-lock on the same table, then SQLite arbitrarily selects one of 7202** the other connections to use as the blocking connection. 7203** 7204** ^(There may be at most one unlock-notify callback registered by a 7205** blocked connection. If sqlite3_unlock_notify() is called when the 7206** blocked connection already has a registered unlock-notify callback, 7207** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 7208** called with a NULL pointer as its second argument, then any existing 7209** unlock-notify callback is canceled. ^The blocked connections 7210** unlock-notify callback may also be canceled by closing the blocked 7211** connection using [sqlite3_close()]. 7212** 7213** The unlock-notify callback is not reentrant. If an application invokes 7214** any sqlite3_xxx API functions from within an unlock-notify callback, a 7215** crash or deadlock may be the result. 7216** 7217** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 7218** returns SQLITE_OK. 7219** 7220** <b>Callback Invocation Details</b> 7221** 7222** When an unlock-notify callback is registered, the application provides a 7223** single void* pointer that is passed to the callback when it is invoked. 7224** However, the signature of the callback function allows SQLite to pass 7225** it an array of void* context pointers. The first argument passed to 7226** an unlock-notify callback is a pointer to an array of void* pointers, 7227** and the second is the number of entries in the array. 7228** 7229** When a blocking connections transaction is concluded, there may be 7230** more than one blocked connection that has registered for an unlock-notify 7231** callback. ^If two or more such blocked connections have specified the 7232** same callback function, then instead of invoking the callback function 7233** multiple times, it is invoked once with the set of void* context pointers 7234** specified by the blocked connections bundled together into an array. 7235** This gives the application an opportunity to prioritize any actions 7236** related to the set of unblocked database connections. 7237** 7238** <b>Deadlock Detection</b> 7239** 7240** Assuming that after registering for an unlock-notify callback a 7241** database waits for the callback to be issued before taking any further 7242** action (a reasonable assumption), then using this API may cause the 7243** application to deadlock. For example, if connection X is waiting for 7244** connection Y's transaction to be concluded, and similarly connection 7245** Y is waiting on connection X's transaction, then neither connection 7246** will proceed and the system may remain deadlocked indefinitely. 7247** 7248** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 7249** detection. ^If a given call to sqlite3_unlock_notify() would put the 7250** system in a deadlocked state, then SQLITE_LOCKED is returned and no 7251** unlock-notify callback is registered. The system is said to be in 7252** a deadlocked state if connection A has registered for an unlock-notify 7253** callback on the conclusion of connection B's transaction, and connection 7254** B has itself registered for an unlock-notify callback when connection 7255** A's transaction is concluded. ^Indirect deadlock is also detected, so 7256** the system is also considered to be deadlocked if connection B has 7257** registered for an unlock-notify callback on the conclusion of connection 7258** C's transaction, where connection C is waiting on connection A. ^Any 7259** number of levels of indirection are allowed. 7260** 7261** <b>The "DROP TABLE" Exception</b> 7262** 7263** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 7264** always appropriate to call sqlite3_unlock_notify(). There is however, 7265** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 7266** SQLite checks if there are any currently executing SELECT statements 7267** that belong to the same connection. If there are, SQLITE_LOCKED is 7268** returned. In this case there is no "blocking connection", so invoking 7269** sqlite3_unlock_notify() results in the unlock-notify callback being 7270** invoked immediately. If the application then re-attempts the "DROP TABLE" 7271** or "DROP INDEX" query, an infinite loop might be the result. 7272** 7273** One way around this problem is to check the extended error code returned 7274** by an sqlite3_step() call. ^(If there is a blocking connection, then the 7275** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 7276** the special "DROP TABLE/INDEX" case, the extended error code is just 7277** SQLITE_LOCKED.)^ 7278*/ 7279int sqlite3_unlock_notify( 7280 sqlite3 *pBlocked, /* Waiting connection */ 7281 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 7282 void *pNotifyArg /* Argument to pass to xNotify */ 7283); 7284 7285 7286/* 7287** CAPI3REF: String Comparison 7288** 7289** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 7290** and extensions to compare the contents of two buffers containing UTF-8 7291** strings in a case-independent fashion, using the same definition of "case 7292** independence" that SQLite uses internally when comparing identifiers. 7293*/ 7294int sqlite3_stricmp(const char *, const char *); 7295int sqlite3_strnicmp(const char *, const char *, int); 7296 7297/* 7298** CAPI3REF: String Globbing 7299* 7300** ^The [sqlite3_strglob(P,X)] interface returns zero if string X matches 7301** the glob pattern P, and it returns non-zero if string X does not match 7302** the glob pattern P. ^The definition of glob pattern matching used in 7303** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 7304** SQL dialect used by SQLite. ^The sqlite3_strglob(P,X) function is case 7305** sensitive. 7306** 7307** Note that this routine returns zero on a match and non-zero if the strings 7308** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7309*/ 7310int sqlite3_strglob(const char *zGlob, const char *zStr); 7311 7312/* 7313** CAPI3REF: Error Logging Interface 7314** 7315** ^The [sqlite3_log()] interface writes a message into the [error log] 7316** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 7317** ^If logging is enabled, the zFormat string and subsequent arguments are 7318** used with [sqlite3_snprintf()] to generate the final output string. 7319** 7320** The sqlite3_log() interface is intended for use by extensions such as 7321** virtual tables, collating functions, and SQL functions. While there is 7322** nothing to prevent an application from calling sqlite3_log(), doing so 7323** is considered bad form. 7324** 7325** The zFormat string must not be NULL. 7326** 7327** To avoid deadlocks and other threading problems, the sqlite3_log() routine 7328** will not use dynamically allocated memory. The log message is stored in 7329** a fixed-length buffer on the stack. If the log message is longer than 7330** a few hundred characters, it will be truncated to the length of the 7331** buffer. 7332*/ 7333void sqlite3_log(int iErrCode, const char *zFormat, ...); 7334 7335/* 7336** CAPI3REF: Write-Ahead Log Commit Hook 7337** METHOD: sqlite3 7338** 7339** ^The [sqlite3_wal_hook()] function is used to register a callback that 7340** is invoked each time data is committed to a database in wal mode. 7341** 7342** ^(The callback is invoked by SQLite after the commit has taken place and 7343** the associated write-lock on the database released)^, so the implementation 7344** may read, write or [checkpoint] the database as required. 7345** 7346** ^The first parameter passed to the callback function when it is invoked 7347** is a copy of the third parameter passed to sqlite3_wal_hook() when 7348** registering the callback. ^The second is a copy of the database handle. 7349** ^The third parameter is the name of the database that was written to - 7350** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 7351** is the number of pages currently in the write-ahead log file, 7352** including those that were just committed. 7353** 7354** The callback function should normally return [SQLITE_OK]. ^If an error 7355** code is returned, that error will propagate back up through the 7356** SQLite code base to cause the statement that provoked the callback 7357** to report an error, though the commit will have still occurred. If the 7358** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 7359** that does not correspond to any valid SQLite error code, the results 7360** are undefined. 7361** 7362** A single database handle may have at most a single write-ahead log callback 7363** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 7364** previously registered write-ahead log callback. ^Note that the 7365** [sqlite3_wal_autocheckpoint()] interface and the 7366** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 7367** those overwrite any prior [sqlite3_wal_hook()] settings. 7368*/ 7369void *sqlite3_wal_hook( 7370 sqlite3*, 7371 int(*)(void *,sqlite3*,const char*,int), 7372 void* 7373); 7374 7375/* 7376** CAPI3REF: Configure an auto-checkpoint 7377** METHOD: sqlite3 7378** 7379** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 7380** [sqlite3_wal_hook()] that causes any database on [database connection] D 7381** to automatically [checkpoint] 7382** after committing a transaction if there are N or 7383** more frames in the [write-ahead log] file. ^Passing zero or 7384** a negative value as the nFrame parameter disables automatic 7385** checkpoints entirely. 7386** 7387** ^The callback registered by this function replaces any existing callback 7388** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 7389** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 7390** configured by this function. 7391** 7392** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 7393** from SQL. 7394** 7395** ^Checkpoints initiated by this mechanism are 7396** [sqlite3_wal_checkpoint_v2|PASSIVE]. 7397** 7398** ^Every new [database connection] defaults to having the auto-checkpoint 7399** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 7400** pages. The use of this interface 7401** is only necessary if the default setting is found to be suboptimal 7402** for a particular application. 7403*/ 7404int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 7405 7406/* 7407** CAPI3REF: Checkpoint a database 7408** METHOD: sqlite3 7409** 7410** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 7411** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 7412** 7413** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 7414** [write-ahead log] for database X on [database connection] D to be 7415** transferred into the database file and for the write-ahead log to 7416** be reset. See the [checkpointing] documentation for addition 7417** information. 7418** 7419** This interface used to be the only way to cause a checkpoint to 7420** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 7421** interface was added. This interface is retained for backwards 7422** compatibility and as a convenience for applications that need to manually 7423** start a callback but which do not need the full power (and corresponding 7424** complication) of [sqlite3_wal_checkpoint_v2()]. 7425*/ 7426int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 7427 7428/* 7429** CAPI3REF: Checkpoint a database 7430** METHOD: sqlite3 7431** 7432** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 7433** operation on database X of [database connection] D in mode M. Status 7434** information is written back into integers pointed to by L and C.)^ 7435** ^(The M parameter must be a valid [checkpoint mode]:)^ 7436** 7437** <dl> 7438** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 7439** ^Checkpoint as many frames as possible without waiting for any database 7440** readers or writers to finish, then sync the database file if all frames 7441** in the log were checkpointed. ^The [busy-handler callback] 7442** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 7443** ^On the other hand, passive mode might leave the checkpoint unfinished 7444** if there are concurrent readers or writers. 7445** 7446** <dt>SQLITE_CHECKPOINT_FULL<dd> 7447** ^This mode blocks (it invokes the 7448** [sqlite3_busy_handler|busy-handler callback]) until there is no 7449** database writer and all readers are reading from the most recent database 7450** snapshot. ^It then checkpoints all frames in the log file and syncs the 7451** database file. ^This mode blocks new database writers while it is pending, 7452** but new database readers are allowed to continue unimpeded. 7453** 7454** <dt>SQLITE_CHECKPOINT_RESTART<dd> 7455** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 7456** that after checkpointing the log file it blocks (calls the 7457** [busy-handler callback]) 7458** until all readers are reading from the database file only. ^This ensures 7459** that the next writer will restart the log file from the beginning. 7460** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 7461** database writer attempts while it is pending, but does not impede readers. 7462** 7463** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 7464** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 7465** addition that it also truncates the log file to zero bytes just prior 7466** to a successful return. 7467** </dl> 7468** 7469** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 7470** the log file or to -1 if the checkpoint could not run because 7471** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 7472** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 7473** log file (including any that were already checkpointed before the function 7474** was called) or to -1 if the checkpoint could not run due to an error or 7475** because the database is not in WAL mode. ^Note that upon successful 7476** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 7477** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 7478** 7479** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 7480** any other process is running a checkpoint operation at the same time, the 7481** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 7482** busy-handler configured, it will not be invoked in this case. 7483** 7484** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 7485** exclusive "writer" lock on the database file. ^If the writer lock cannot be 7486** obtained immediately, and a busy-handler is configured, it is invoked and 7487** the writer lock retried until either the busy-handler returns 0 or the lock 7488** is successfully obtained. ^The busy-handler is also invoked while waiting for 7489** database readers as described above. ^If the busy-handler returns 0 before 7490** the writer lock is obtained or while waiting for database readers, the 7491** checkpoint operation proceeds from that point in the same way as 7492** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 7493** without blocking any further. ^SQLITE_BUSY is returned in this case. 7494** 7495** ^If parameter zDb is NULL or points to a zero length string, then the 7496** specified operation is attempted on all WAL databases [attached] to 7497** [database connection] db. In this case the 7498** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 7499** an SQLITE_BUSY error is encountered when processing one or more of the 7500** attached WAL databases, the operation is still attempted on any remaining 7501** attached databases and SQLITE_BUSY is returned at the end. ^If any other 7502** error occurs while processing an attached database, processing is abandoned 7503** and the error code is returned to the caller immediately. ^If no error 7504** (SQLITE_BUSY or otherwise) is encountered while processing the attached 7505** databases, SQLITE_OK is returned. 7506** 7507** ^If database zDb is the name of an attached database that is not in WAL 7508** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 7509** zDb is not NULL (or a zero length string) and is not the name of any 7510** attached database, SQLITE_ERROR is returned to the caller. 7511** 7512** ^Unless it returns SQLITE_MISUSE, 7513** the sqlite3_wal_checkpoint_v2() interface 7514** sets the error information that is queried by 7515** [sqlite3_errcode()] and [sqlite3_errmsg()]. 7516** 7517** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 7518** from SQL. 7519*/ 7520int sqlite3_wal_checkpoint_v2( 7521 sqlite3 *db, /* Database handle */ 7522 const char *zDb, /* Name of attached database (or NULL) */ 7523 int eMode, /* SQLITE_CHECKPOINT_* value */ 7524 int *pnLog, /* OUT: Size of WAL log in frames */ 7525 int *pnCkpt /* OUT: Total number of frames checkpointed */ 7526); 7527 7528/* 7529** CAPI3REF: Checkpoint Mode Values 7530** KEYWORDS: {checkpoint mode} 7531** 7532** These constants define all valid values for the "checkpoint mode" passed 7533** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 7534** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 7535** meaning of each of these checkpoint modes. 7536*/ 7537#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 7538#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 7539#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 7540#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 7541 7542/* 7543** CAPI3REF: Virtual Table Interface Configuration 7544** 7545** This function may be called by either the [xConnect] or [xCreate] method 7546** of a [virtual table] implementation to configure 7547** various facets of the virtual table interface. 7548** 7549** If this interface is invoked outside the context of an xConnect or 7550** xCreate virtual table method then the behavior is undefined. 7551** 7552** At present, there is only one option that may be configured using 7553** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 7554** may be added in the future. 7555*/ 7556int sqlite3_vtab_config(sqlite3*, int op, ...); 7557 7558/* 7559** CAPI3REF: Virtual Table Configuration Options 7560** 7561** These macros define the various options to the 7562** [sqlite3_vtab_config()] interface that [virtual table] implementations 7563** can use to customize and optimize their behavior. 7564** 7565** <dl> 7566** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 7567** <dd>Calls of the form 7568** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 7569** where X is an integer. If X is zero, then the [virtual table] whose 7570** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 7571** support constraints. In this configuration (which is the default) if 7572** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 7573** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 7574** specified as part of the users SQL statement, regardless of the actual 7575** ON CONFLICT mode specified. 7576** 7577** If X is non-zero, then the virtual table implementation guarantees 7578** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 7579** any modifications to internal or persistent data structures have been made. 7580** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 7581** is able to roll back a statement or database transaction, and abandon 7582** or continue processing the current SQL statement as appropriate. 7583** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 7584** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 7585** had been ABORT. 7586** 7587** Virtual table implementations that are required to handle OR REPLACE 7588** must do so within the [xUpdate] method. If a call to the 7589** [sqlite3_vtab_on_conflict()] function indicates that the current ON 7590** CONFLICT policy is REPLACE, the virtual table implementation should 7591** silently replace the appropriate rows within the xUpdate callback and 7592** return SQLITE_OK. Or, if this is not possible, it may return 7593** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 7594** constraint handling. 7595** </dl> 7596*/ 7597#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 7598 7599/* 7600** CAPI3REF: Determine The Virtual Table Conflict Policy 7601** 7602** This function may only be called from within a call to the [xUpdate] method 7603** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 7604** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 7605** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 7606** of the SQL statement that triggered the call to the [xUpdate] method of the 7607** [virtual table]. 7608*/ 7609int sqlite3_vtab_on_conflict(sqlite3 *); 7610 7611/* 7612** CAPI3REF: Conflict resolution modes 7613** KEYWORDS: {conflict resolution mode} 7614** 7615** These constants are returned by [sqlite3_vtab_on_conflict()] to 7616** inform a [virtual table] implementation what the [ON CONFLICT] mode 7617** is for the SQL statement being evaluated. 7618** 7619** Note that the [SQLITE_IGNORE] constant is also used as a potential 7620** return value from the [sqlite3_set_authorizer()] callback and that 7621** [SQLITE_ABORT] is also a [result code]. 7622*/ 7623#define SQLITE_ROLLBACK 1 7624/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 7625#define SQLITE_FAIL 3 7626/* #define SQLITE_ABORT 4 // Also an error code */ 7627#define SQLITE_REPLACE 5 7628 7629/* 7630** CAPI3REF: Prepared Statement Scan Status Opcodes 7631** KEYWORDS: {scanstatus options} 7632** 7633** The following constants can be used for the T parameter to the 7634** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 7635** different metric for sqlite3_stmt_scanstatus() to return. 7636** 7637** When the value returned to V is a string, space to hold that string is 7638** managed by the prepared statement S and will be automatically freed when 7639** S is finalized. 7640** 7641** <dl> 7642** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 7643** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 7644** set to the total number of times that the X-th loop has run.</dd> 7645** 7646** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 7647** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 7648** to the total number of rows examined by all iterations of the X-th loop.</dd> 7649** 7650** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 7651** <dd>^The "double" variable pointed to by the T parameter will be set to the 7652** query planner's estimate for the average number of rows output from each 7653** iteration of the X-th loop. If the query planner's estimates was accurate, 7654** then this value will approximate the quotient NVISIT/NLOOP and the 7655** product of this value for all prior loops with the same SELECTID will 7656** be the NLOOP value for the current loop. 7657** 7658** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 7659** <dd>^The "const char *" variable pointed to by the T parameter will be set 7660** to a zero-terminated UTF-8 string containing the name of the index or table 7661** used for the X-th loop. 7662** 7663** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 7664** <dd>^The "const char *" variable pointed to by the T parameter will be set 7665** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 7666** description for the X-th loop. 7667** 7668** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 7669** <dd>^The "int" variable pointed to by the T parameter will be set to the 7670** "select-id" for the X-th loop. The select-id identifies which query or 7671** subquery the loop is part of. The main query has a select-id of zero. 7672** The select-id is the same value as is output in the first column 7673** of an [EXPLAIN QUERY PLAN] query. 7674** </dl> 7675*/ 7676#define SQLITE_SCANSTAT_NLOOP 0 7677#define SQLITE_SCANSTAT_NVISIT 1 7678#define SQLITE_SCANSTAT_EST 2 7679#define SQLITE_SCANSTAT_NAME 3 7680#define SQLITE_SCANSTAT_EXPLAIN 4 7681#define SQLITE_SCANSTAT_SELECTID 5 7682 7683/* 7684** CAPI3REF: Prepared Statement Scan Status 7685** METHOD: sqlite3_stmt 7686** 7687** This interface returns information about the predicted and measured 7688** performance for pStmt. Advanced applications can use this 7689** interface to compare the predicted and the measured performance and 7690** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 7691** 7692** Since this interface is expected to be rarely used, it is only 7693** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 7694** compile-time option. 7695** 7696** The "iScanStatusOp" parameter determines which status information to return. 7697** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 7698** of this interface is undefined. 7699** ^The requested measurement is written into a variable pointed to by 7700** the "pOut" parameter. 7701** Parameter "idx" identifies the specific loop to retrieve statistics for. 7702** Loops are numbered starting from zero. ^If idx is out of range - less than 7703** zero or greater than or equal to the total number of loops used to implement 7704** the statement - a non-zero value is returned and the variable that pOut 7705** points to is unchanged. 7706** 7707** ^Statistics might not be available for all loops in all statements. ^In cases 7708** where there exist loops with no available statistics, this function behaves 7709** as if the loop did not exist - it returns non-zero and leave the variable 7710** that pOut points to unchanged. 7711** 7712** See also: [sqlite3_stmt_scanstatus_reset()] 7713*/ 7714int sqlite3_stmt_scanstatus( 7715 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 7716 int idx, /* Index of loop to report on */ 7717 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 7718 void *pOut /* Result written here */ 7719); 7720 7721/* 7722** CAPI3REF: Zero Scan-Status Counters 7723** METHOD: sqlite3_stmt 7724** 7725** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 7726** 7727** This API is only available if the library is built with pre-processor 7728** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 7729*/ 7730void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 7731 7732 7733/* 7734** Undo the hack that converts floating point types to integer for 7735** builds on processors without floating point support. 7736*/ 7737#ifdef SQLITE_OMIT_FLOATING_POINT 7738# undef double 7739#endif 7740 7741#ifdef __cplusplus 7742} /* End of the 'extern "C"' block */ 7743#endif 7744#endif /* _SQLITE3_H_ */ 7745