1/* 2** 2001 September 15 3** 4** The author disclaims copyright to this source code. In place of 5** a legal notice, here is a blessing: 6** 7** May you do good and not evil. 8** May you find forgiveness for yourself and forgive others. 9** May you share freely, never taking more than you give. 10** 11************************************************************************* 12** This header file defines the interface that the SQLite library 13** presents to client programs. If a C-function, structure, datatype, 14** or constant definition does not appear in this file, then it is 15** not a published API of SQLite, is subject to change without 16** notice, and should not be referenced by programs that use SQLite. 17** 18** Some of the definitions that are in this file are marked as 19** "experimental". Experimental interfaces are normally new 20** features recently added to SQLite. We do not anticipate changes 21** to experimental interfaces but reserve the right to make minor changes 22** if experience from use "in the wild" suggest such changes are prudent. 23** 24** The official C-language API documentation for SQLite is derived 25** from comments in this file. This file is the authoritative source 26** on how SQLite interfaces are supposed to operate. 27** 28** The name of this file under configuration management is "sqlite.h.in". 29** The makefile makes some minor changes to this file (such as inserting 30** the version number) and changes its name to "sqlite3.h" as 31** part of the build process. 32*/ 33#ifndef SQLITE3_H 34#define SQLITE3_H 35#include <stdarg.h> /* Needed for the definition of va_list */ 36 37/* 38** Make sure we can call this stuff from C++. 39*/ 40#ifdef __cplusplus 41extern "C" { 42#endif 43 44 45/* 46** Provide the ability to override linkage features of the interface. 47*/ 48#ifndef SQLITE_EXTERN 49# define SQLITE_EXTERN extern 50#endif 51#ifndef SQLITE_API 52# define SQLITE_API 53#endif 54#ifndef SQLITE_CDECL 55# define SQLITE_CDECL 56#endif 57#ifndef SQLITE_APICALL 58# define SQLITE_APICALL 59#endif 60#ifndef SQLITE_STDCALL 61# define SQLITE_STDCALL SQLITE_APICALL 62#endif 63#ifndef SQLITE_CALLBACK 64# define SQLITE_CALLBACK 65#endif 66#ifndef SQLITE_SYSAPI 67# define SQLITE_SYSAPI 68#endif 69 70 71/* 72** These no-op macros are used in front of interfaces to mark those 73** interfaces as either deprecated or experimental. New applications 74** should not use deprecated interfaces - they are supported for backwards 75** compatibility only. Application writers should be aware that 76** experimental interfaces are subject to change in point releases. 77** 78** These macros used to resolve to various kinds of compiler magic that 79** would generate warning messages when they were used. But that 80** compiler magic ended up generating such a flurry of bug reports 81** that we have taken it all out and gone back to using simple 82** noop macros. 83*/ 84#define SQLITE_DEPRECATED 85#define SQLITE_EXPERIMENTAL 86 87/* 88** Ensure these symbols were not defined by some previous header file. 89*/ 90#ifdef SQLITE_VERSION 91# undef SQLITE_VERSION 92#endif 93#ifdef SQLITE_VERSION_NUMBER 94# undef SQLITE_VERSION_NUMBER 95#endif 96 97/* 98** CAPI3REF: Compile-Time Library Version Numbers 99** 100** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 101** evaluates to a string literal that is the SQLite version in the 102** format "X.Y.Z" where X is the major version number (always 3 for 103** SQLite3) and Y is the minor version number and Z is the release number.)^ 104** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 105** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 106** numbers used in [SQLITE_VERSION].)^ 107** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 108** be larger than the release from which it is derived. Either Y will 109** be held constant and Z will be incremented or else Y will be incremented 110** and Z will be reset to zero. 111** 112** Since version 3.6.18, SQLite source code has been stored in the 113** <a href="http://www.fossil-scm.org/">Fossil configuration management 114** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 115** a string which identifies a particular check-in of SQLite 116** within its configuration management system. ^The SQLITE_SOURCE_ID 117** string contains the date and time of the check-in (UTC) and an SHA1 118** hash of the entire source tree. 119** 120** See also: [sqlite3_libversion()], 121** [sqlite3_libversion_number()], [sqlite3_sourceid()], 122** [sqlite_version()] and [sqlite_source_id()]. 123*/ 124#define SQLITE_VERSION "--VERS--" 125#define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- 126#define SQLITE_SOURCE_ID "--SOURCE-ID--" 127 128/* 129** CAPI3REF: Run-Time Library Version Numbers 130** KEYWORDS: sqlite3_version, sqlite3_sourceid 131** 132** These interfaces provide the same information as the [SQLITE_VERSION], 133** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 134** but are associated with the library instead of the header file. ^(Cautious 135** programmers might include assert() statements in their application to 136** verify that values returned by these interfaces match the macros in 137** the header, and thus ensure that the application is 138** compiled with matching library and header files. 139** 140** <blockquote><pre> 141** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 142** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 143** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 144** </pre></blockquote>)^ 145** 146** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 147** macro. ^The sqlite3_libversion() function returns a pointer to the 148** to the sqlite3_version[] string constant. The sqlite3_libversion() 149** function is provided for use in DLLs since DLL users usually do not have 150** direct access to string constants within the DLL. ^The 151** sqlite3_libversion_number() function returns an integer equal to 152** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 153** a pointer to a string constant whose value is the same as the 154** [SQLITE_SOURCE_ID] C preprocessor macro. 155** 156** See also: [sqlite_version()] and [sqlite_source_id()]. 157*/ 158SQLITE_EXTERN const char sqlite3_version[]; 159const char *sqlite3_libversion(void); 160const char *sqlite3_sourceid(void); 161int sqlite3_libversion_number(void); 162 163/* 164** CAPI3REF: Run-Time Library Compilation Options Diagnostics 165** 166** ^The sqlite3_compileoption_used() function returns 0 or 1 167** indicating whether the specified option was defined at 168** compile time. ^The SQLITE_ prefix may be omitted from the 169** option name passed to sqlite3_compileoption_used(). 170** 171** ^The sqlite3_compileoption_get() function allows iterating 172** over the list of options that were defined at compile time by 173** returning the N-th compile time option string. ^If N is out of range, 174** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 175** prefix is omitted from any strings returned by 176** sqlite3_compileoption_get(). 177** 178** ^Support for the diagnostic functions sqlite3_compileoption_used() 179** and sqlite3_compileoption_get() may be omitted by specifying the 180** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 181** 182** See also: SQL functions [sqlite_compileoption_used()] and 183** [sqlite_compileoption_get()] and the [compile_options pragma]. 184*/ 185#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 186int sqlite3_compileoption_used(const char *zOptName); 187const char *sqlite3_compileoption_get(int N); 188#endif 189 190/* 191** CAPI3REF: Test To See If The Library Is Threadsafe 192** 193** ^The sqlite3_threadsafe() function returns zero if and only if 194** SQLite was compiled with mutexing code omitted due to the 195** [SQLITE_THREADSAFE] compile-time option being set to 0. 196** 197** SQLite can be compiled with or without mutexes. When 198** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 199** are enabled and SQLite is threadsafe. When the 200** [SQLITE_THREADSAFE] macro is 0, 201** the mutexes are omitted. Without the mutexes, it is not safe 202** to use SQLite concurrently from more than one thread. 203** 204** Enabling mutexes incurs a measurable performance penalty. 205** So if speed is of utmost importance, it makes sense to disable 206** the mutexes. But for maximum safety, mutexes should be enabled. 207** ^The default behavior is for mutexes to be enabled. 208** 209** This interface can be used by an application to make sure that the 210** version of SQLite that it is linking against was compiled with 211** the desired setting of the [SQLITE_THREADSAFE] macro. 212** 213** This interface only reports on the compile-time mutex setting 214** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 215** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 216** can be fully or partially disabled using a call to [sqlite3_config()] 217** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 218** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 219** sqlite3_threadsafe() function shows only the compile-time setting of 220** thread safety, not any run-time changes to that setting made by 221** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 222** is unchanged by calls to sqlite3_config().)^ 223** 224** See the [threading mode] documentation for additional information. 225*/ 226int sqlite3_threadsafe(void); 227 228/* 229** CAPI3REF: Database Connection Handle 230** KEYWORDS: {database connection} {database connections} 231** 232** Each open SQLite database is represented by a pointer to an instance of 233** the opaque structure named "sqlite3". It is useful to think of an sqlite3 234** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 235** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 236** and [sqlite3_close_v2()] are its destructors. There are many other 237** interfaces (such as 238** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 239** [sqlite3_busy_timeout()] to name but three) that are methods on an 240** sqlite3 object. 241*/ 242typedef struct sqlite3 sqlite3; 243 244/* 245** CAPI3REF: 64-Bit Integer Types 246** KEYWORDS: sqlite_int64 sqlite_uint64 247** 248** Because there is no cross-platform way to specify 64-bit integer types 249** SQLite includes typedefs for 64-bit signed and unsigned integers. 250** 251** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 252** The sqlite_int64 and sqlite_uint64 types are supported for backwards 253** compatibility only. 254** 255** ^The sqlite3_int64 and sqlite_int64 types can store integer values 256** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 257** sqlite3_uint64 and sqlite_uint64 types can store integer values 258** between 0 and +18446744073709551615 inclusive. 259*/ 260#ifdef SQLITE_INT64_TYPE 261 typedef SQLITE_INT64_TYPE sqlite_int64; 262 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 263#elif defined(_MSC_VER) || defined(__BORLANDC__) 264 typedef __int64 sqlite_int64; 265 typedef unsigned __int64 sqlite_uint64; 266#else 267 typedef long long int sqlite_int64; 268 typedef unsigned long long int sqlite_uint64; 269#endif 270typedef sqlite_int64 sqlite3_int64; 271typedef sqlite_uint64 sqlite3_uint64; 272 273/* 274** If compiling for a processor that lacks floating point support, 275** substitute integer for floating-point. 276*/ 277#ifdef SQLITE_OMIT_FLOATING_POINT 278# define double sqlite3_int64 279#endif 280 281/* 282** CAPI3REF: Closing A Database Connection 283** DESTRUCTOR: sqlite3 284** 285** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 286** for the [sqlite3] object. 287** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 288** the [sqlite3] object is successfully destroyed and all associated 289** resources are deallocated. 290** 291** ^If the database connection is associated with unfinalized prepared 292** statements or unfinished sqlite3_backup objects then sqlite3_close() 293** will leave the database connection open and return [SQLITE_BUSY]. 294** ^If sqlite3_close_v2() is called with unfinalized prepared statements 295** and/or unfinished sqlite3_backups, then the database connection becomes 296** an unusable "zombie" which will automatically be deallocated when the 297** last prepared statement is finalized or the last sqlite3_backup is 298** finished. The sqlite3_close_v2() interface is intended for use with 299** host languages that are garbage collected, and where the order in which 300** destructors are called is arbitrary. 301** 302** Applications should [sqlite3_finalize | finalize] all [prepared statements], 303** [sqlite3_blob_close | close] all [BLOB handles], and 304** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 305** with the [sqlite3] object prior to attempting to close the object. ^If 306** sqlite3_close_v2() is called on a [database connection] that still has 307** outstanding [prepared statements], [BLOB handles], and/or 308** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 309** of resources is deferred until all [prepared statements], [BLOB handles], 310** and [sqlite3_backup] objects are also destroyed. 311** 312** ^If an [sqlite3] object is destroyed while a transaction is open, 313** the transaction is automatically rolled back. 314** 315** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 316** must be either a NULL 317** pointer or an [sqlite3] object pointer obtained 318** from [sqlite3_open()], [sqlite3_open16()], or 319** [sqlite3_open_v2()], and not previously closed. 320** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 321** argument is a harmless no-op. 322*/ 323int sqlite3_close(sqlite3*); 324int sqlite3_close_v2(sqlite3*); 325 326/* 327** The type for a callback function. 328** This is legacy and deprecated. It is included for historical 329** compatibility and is not documented. 330*/ 331typedef int (SQLITE_CALLBACK *sqlite3_callback)(void*,int,char**, char**); 332 333/* 334** CAPI3REF: One-Step Query Execution Interface 335** METHOD: sqlite3 336** 337** The sqlite3_exec() interface is a convenience wrapper around 338** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 339** that allows an application to run multiple statements of SQL 340** without having to use a lot of C code. 341** 342** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 343** semicolon-separate SQL statements passed into its 2nd argument, 344** in the context of the [database connection] passed in as its 1st 345** argument. ^If the callback function of the 3rd argument to 346** sqlite3_exec() is not NULL, then it is invoked for each result row 347** coming out of the evaluated SQL statements. ^The 4th argument to 348** sqlite3_exec() is relayed through to the 1st argument of each 349** callback invocation. ^If the callback pointer to sqlite3_exec() 350** is NULL, then no callback is ever invoked and result rows are 351** ignored. 352** 353** ^If an error occurs while evaluating the SQL statements passed into 354** sqlite3_exec(), then execution of the current statement stops and 355** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 356** is not NULL then any error message is written into memory obtained 357** from [sqlite3_malloc()] and passed back through the 5th parameter. 358** To avoid memory leaks, the application should invoke [sqlite3_free()] 359** on error message strings returned through the 5th parameter of 360** sqlite3_exec() after the error message string is no longer needed. 361** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 362** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 363** NULL before returning. 364** 365** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 366** routine returns SQLITE_ABORT without invoking the callback again and 367** without running any subsequent SQL statements. 368** 369** ^The 2nd argument to the sqlite3_exec() callback function is the 370** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 371** callback is an array of pointers to strings obtained as if from 372** [sqlite3_column_text()], one for each column. ^If an element of a 373** result row is NULL then the corresponding string pointer for the 374** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 375** sqlite3_exec() callback is an array of pointers to strings where each 376** entry represents the name of corresponding result column as obtained 377** from [sqlite3_column_name()]. 378** 379** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 380** to an empty string, or a pointer that contains only whitespace and/or 381** SQL comments, then no SQL statements are evaluated and the database 382** is not changed. 383** 384** Restrictions: 385** 386** <ul> 387** <li> The application must ensure that the 1st parameter to sqlite3_exec() 388** is a valid and open [database connection]. 389** <li> The application must not close the [database connection] specified by 390** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 391** <li> The application must not modify the SQL statement text passed into 392** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 393** </ul> 394*/ 395int sqlite3_exec( 396 sqlite3*, /* An open database */ 397 const char *sql, /* SQL to be evaluated */ 398 int (SQLITE_CALLBACK *callback)(void*,int,char**,char**), /* Callback func */ 399 void *, /* 1st argument to callback */ 400 char **errmsg /* Error msg written here */ 401); 402 403/* 404** CAPI3REF: Result Codes 405** KEYWORDS: {result code definitions} 406** 407** Many SQLite functions return an integer result code from the set shown 408** here in order to indicate success or failure. 409** 410** New error codes may be added in future versions of SQLite. 411** 412** See also: [extended result code definitions] 413*/ 414#define SQLITE_OK 0 /* Successful result */ 415/* beginning-of-error-codes */ 416#define SQLITE_ERROR 1 /* SQL error or missing database */ 417#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 418#define SQLITE_PERM 3 /* Access permission denied */ 419#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 420#define SQLITE_BUSY 5 /* The database file is locked */ 421#define SQLITE_LOCKED 6 /* A table in the database is locked */ 422#define SQLITE_NOMEM 7 /* A malloc() failed */ 423#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 424#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 425#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 426#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 427#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 428#define SQLITE_FULL 13 /* Insertion failed because database is full */ 429#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 430#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 431#define SQLITE_EMPTY 16 /* Database is empty */ 432#define SQLITE_SCHEMA 17 /* The database schema changed */ 433#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 434#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 435#define SQLITE_MISMATCH 20 /* Data type mismatch */ 436#define SQLITE_MISUSE 21 /* Library used incorrectly */ 437#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 438#define SQLITE_AUTH 23 /* Authorization denied */ 439#define SQLITE_FORMAT 24 /* Auxiliary database format error */ 440#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 441#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 442#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 443#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 444#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 445#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 446/* end-of-error-codes */ 447 448/* 449** CAPI3REF: Extended Result Codes 450** KEYWORDS: {extended result code definitions} 451** 452** In its default configuration, SQLite API routines return one of 30 integer 453** [result codes]. However, experience has shown that many of 454** these result codes are too coarse-grained. They do not provide as 455** much information about problems as programmers might like. In an effort to 456** address this, newer versions of SQLite (version 3.3.8 and later) include 457** support for additional result codes that provide more detailed information 458** about errors. These [extended result codes] are enabled or disabled 459** on a per database connection basis using the 460** [sqlite3_extended_result_codes()] API. Or, the extended code for 461** the most recent error can be obtained using 462** [sqlite3_extended_errcode()]. 463*/ 464#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 465#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 466#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 467#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 468#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 469#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 470#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 471#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 472#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 473#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 474#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 475#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 476#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 477#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 478#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 479#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 480#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 481#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 482#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 483#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 484#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 485#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 486#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 487#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 488#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 489#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 490#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 491#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 492#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 493#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 494#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 495#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 496#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 497#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 498#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 499#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 500#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 501#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 502#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 503#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 504#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 505#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 506#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 507#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 508#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 509#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 510#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 511#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 512#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 513#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 514#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 515#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 516#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 517#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 518#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 519#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 520 521/* 522** CAPI3REF: Flags For File Open Operations 523** 524** These bit values are intended for use in the 525** 3rd parameter to the [sqlite3_open_v2()] interface and 526** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 527*/ 528#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 529#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 530#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 531#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 532#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 533#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 534#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 535#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 536#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 537#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 538#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 539#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 540#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 541#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 542#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 543#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 544#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 545#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 546#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 547#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 548 549/* Reserved: 0x00F00000 */ 550 551/* 552** CAPI3REF: Device Characteristics 553** 554** The xDeviceCharacteristics method of the [sqlite3_io_methods] 555** object returns an integer which is a vector of these 556** bit values expressing I/O characteristics of the mass storage 557** device that holds the file that the [sqlite3_io_methods] 558** refers to. 559** 560** The SQLITE_IOCAP_ATOMIC property means that all writes of 561** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 562** mean that writes of blocks that are nnn bytes in size and 563** are aligned to an address which is an integer multiple of 564** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 565** that when data is appended to a file, the data is appended 566** first then the size of the file is extended, never the other 567** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 568** information is written to disk in the same order as calls 569** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 570** after reboot following a crash or power loss, the only bytes in a 571** file that were written at the application level might have changed 572** and that adjacent bytes, even bytes within the same sector are 573** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 574** flag indicate that a file cannot be deleted when open. The 575** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 576** read-only media and cannot be changed even by processes with 577** elevated privileges. 578*/ 579#define SQLITE_IOCAP_ATOMIC 0x00000001 580#define SQLITE_IOCAP_ATOMIC512 0x00000002 581#define SQLITE_IOCAP_ATOMIC1K 0x00000004 582#define SQLITE_IOCAP_ATOMIC2K 0x00000008 583#define SQLITE_IOCAP_ATOMIC4K 0x00000010 584#define SQLITE_IOCAP_ATOMIC8K 0x00000020 585#define SQLITE_IOCAP_ATOMIC16K 0x00000040 586#define SQLITE_IOCAP_ATOMIC32K 0x00000080 587#define SQLITE_IOCAP_ATOMIC64K 0x00000100 588#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 589#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 590#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 591#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 592#define SQLITE_IOCAP_IMMUTABLE 0x00002000 593 594/* 595** CAPI3REF: File Locking Levels 596** 597** SQLite uses one of these integer values as the second 598** argument to calls it makes to the xLock() and xUnlock() methods 599** of an [sqlite3_io_methods] object. 600*/ 601#define SQLITE_LOCK_NONE 0 602#define SQLITE_LOCK_SHARED 1 603#define SQLITE_LOCK_RESERVED 2 604#define SQLITE_LOCK_PENDING 3 605#define SQLITE_LOCK_EXCLUSIVE 4 606 607/* 608** CAPI3REF: Synchronization Type Flags 609** 610** When SQLite invokes the xSync() method of an 611** [sqlite3_io_methods] object it uses a combination of 612** these integer values as the second argument. 613** 614** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 615** sync operation only needs to flush data to mass storage. Inode 616** information need not be flushed. If the lower four bits of the flag 617** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 618** If the lower four bits equal SQLITE_SYNC_FULL, that means 619** to use Mac OS X style fullsync instead of fsync(). 620** 621** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 622** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 623** settings. The [synchronous pragma] determines when calls to the 624** xSync VFS method occur and applies uniformly across all platforms. 625** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 626** energetic or rigorous or forceful the sync operations are and 627** only make a difference on Mac OSX for the default SQLite code. 628** (Third-party VFS implementations might also make the distinction 629** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 630** operating systems natively supported by SQLite, only Mac OSX 631** cares about the difference.) 632*/ 633#define SQLITE_SYNC_NORMAL 0x00002 634#define SQLITE_SYNC_FULL 0x00003 635#define SQLITE_SYNC_DATAONLY 0x00010 636 637/* 638** CAPI3REF: OS Interface Open File Handle 639** 640** An [sqlite3_file] object represents an open file in the 641** [sqlite3_vfs | OS interface layer]. Individual OS interface 642** implementations will 643** want to subclass this object by appending additional fields 644** for their own use. The pMethods entry is a pointer to an 645** [sqlite3_io_methods] object that defines methods for performing 646** I/O operations on the open file. 647*/ 648typedef struct sqlite3_file sqlite3_file; 649struct sqlite3_file { 650 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 651}; 652 653/* 654** CAPI3REF: OS Interface File Virtual Methods Object 655** 656** Every file opened by the [sqlite3_vfs.xOpen] method populates an 657** [sqlite3_file] object (or, more commonly, a subclass of the 658** [sqlite3_file] object) with a pointer to an instance of this object. 659** This object defines the methods used to perform various operations 660** against the open file represented by the [sqlite3_file] object. 661** 662** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 663** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 664** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 665** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 666** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 667** to NULL. 668** 669** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 670** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 671** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 672** flag may be ORed in to indicate that only the data of the file 673** and not its inode needs to be synced. 674** 675** The integer values to xLock() and xUnlock() are one of 676** <ul> 677** <li> [SQLITE_LOCK_NONE], 678** <li> [SQLITE_LOCK_SHARED], 679** <li> [SQLITE_LOCK_RESERVED], 680** <li> [SQLITE_LOCK_PENDING], or 681** <li> [SQLITE_LOCK_EXCLUSIVE]. 682** </ul> 683** xLock() increases the lock. xUnlock() decreases the lock. 684** The xCheckReservedLock() method checks whether any database connection, 685** either in this process or in some other process, is holding a RESERVED, 686** PENDING, or EXCLUSIVE lock on the file. It returns true 687** if such a lock exists and false otherwise. 688** 689** The xFileControl() method is a generic interface that allows custom 690** VFS implementations to directly control an open file using the 691** [sqlite3_file_control()] interface. The second "op" argument is an 692** integer opcode. The third argument is a generic pointer intended to 693** point to a structure that may contain arguments or space in which to 694** write return values. Potential uses for xFileControl() might be 695** functions to enable blocking locks with timeouts, to change the 696** locking strategy (for example to use dot-file locks), to inquire 697** about the status of a lock, or to break stale locks. The SQLite 698** core reserves all opcodes less than 100 for its own use. 699** A [file control opcodes | list of opcodes] less than 100 is available. 700** Applications that define a custom xFileControl method should use opcodes 701** greater than 100 to avoid conflicts. VFS implementations should 702** return [SQLITE_NOTFOUND] for file control opcodes that they do not 703** recognize. 704** 705** The xSectorSize() method returns the sector size of the 706** device that underlies the file. The sector size is the 707** minimum write that can be performed without disturbing 708** other bytes in the file. The xDeviceCharacteristics() 709** method returns a bit vector describing behaviors of the 710** underlying device: 711** 712** <ul> 713** <li> [SQLITE_IOCAP_ATOMIC] 714** <li> [SQLITE_IOCAP_ATOMIC512] 715** <li> [SQLITE_IOCAP_ATOMIC1K] 716** <li> [SQLITE_IOCAP_ATOMIC2K] 717** <li> [SQLITE_IOCAP_ATOMIC4K] 718** <li> [SQLITE_IOCAP_ATOMIC8K] 719** <li> [SQLITE_IOCAP_ATOMIC16K] 720** <li> [SQLITE_IOCAP_ATOMIC32K] 721** <li> [SQLITE_IOCAP_ATOMIC64K] 722** <li> [SQLITE_IOCAP_SAFE_APPEND] 723** <li> [SQLITE_IOCAP_SEQUENTIAL] 724** </ul> 725** 726** The SQLITE_IOCAP_ATOMIC property means that all writes of 727** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 728** mean that writes of blocks that are nnn bytes in size and 729** are aligned to an address which is an integer multiple of 730** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 731** that when data is appended to a file, the data is appended 732** first then the size of the file is extended, never the other 733** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 734** information is written to disk in the same order as calls 735** to xWrite(). 736** 737** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 738** in the unread portions of the buffer with zeros. A VFS that 739** fails to zero-fill short reads might seem to work. However, 740** failure to zero-fill short reads will eventually lead to 741** database corruption. 742*/ 743typedef struct sqlite3_io_methods sqlite3_io_methods; 744struct sqlite3_io_methods { 745 int iVersion; 746 int (SQLITE_CALLBACK *xClose)(sqlite3_file*); 747 int (SQLITE_CALLBACK *xRead)(sqlite3_file*, void*, int iAmt, 748 sqlite3_int64 iOfst); 749 int (SQLITE_CALLBACK *xWrite)(sqlite3_file*, const void*, int iAmt, 750 sqlite3_int64 iOfst); 751 int (SQLITE_CALLBACK *xTruncate)(sqlite3_file*, sqlite3_int64 size); 752 int (SQLITE_CALLBACK *xSync)(sqlite3_file*, int flags); 753 int (SQLITE_CALLBACK *xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 754 int (SQLITE_CALLBACK *xLock)(sqlite3_file*, int); 755 int (SQLITE_CALLBACK *xUnlock)(sqlite3_file*, int); 756 int (SQLITE_CALLBACK *xCheckReservedLock)(sqlite3_file*, int *pResOut); 757 int (SQLITE_CALLBACK *xFileControl)(sqlite3_file*, int op, void *pArg); 758 int (SQLITE_CALLBACK *xSectorSize)(sqlite3_file*); 759 int (SQLITE_CALLBACK *xDeviceCharacteristics)(sqlite3_file*); 760 /* Methods above are valid for version 1 */ 761 int (SQLITE_CALLBACK *xShmMap)(sqlite3_file*, int iPg, int pgsz, int, 762 void volatile**); 763 int (SQLITE_CALLBACK *xShmLock)(sqlite3_file*, int offset, int n, int flags); 764 void (SQLITE_CALLBACK *xShmBarrier)(sqlite3_file*); 765 int (SQLITE_CALLBACK *xShmUnmap)(sqlite3_file*, int deleteFlag); 766 /* Methods above are valid for version 2 */ 767 int (SQLITE_CALLBACK *xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, 768 void **pp); 769 int (SQLITE_CALLBACK *xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 770 /* Methods above are valid for version 3 */ 771 /* Additional methods may be added in future releases */ 772}; 773 774/* 775** CAPI3REF: Standard File Control Opcodes 776** KEYWORDS: {file control opcodes} {file control opcode} 777** 778** These integer constants are opcodes for the xFileControl method 779** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 780** interface. 781** 782** <ul> 783** <li>[[SQLITE_FCNTL_LOCKSTATE]] 784** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 785** opcode causes the xFileControl method to write the current state of 786** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 787** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 788** into an integer that the pArg argument points to. This capability 789** is used during testing and is only available when the SQLITE_TEST 790** compile-time option is used. 791** 792** <li>[[SQLITE_FCNTL_SIZE_HINT]] 793** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 794** layer a hint of how large the database file will grow to be during the 795** current transaction. This hint is not guaranteed to be accurate but it 796** is often close. The underlying VFS might choose to preallocate database 797** file space based on this hint in order to help writes to the database 798** file run faster. 799** 800** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 801** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 802** extends and truncates the database file in chunks of a size specified 803** by the user. The fourth argument to [sqlite3_file_control()] should 804** point to an integer (type int) containing the new chunk-size to use 805** for the nominated database. Allocating database file space in large 806** chunks (say 1MB at a time), may reduce file-system fragmentation and 807** improve performance on some systems. 808** 809** <li>[[SQLITE_FCNTL_FILE_POINTER]] 810** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 811** to the [sqlite3_file] object associated with a particular database 812** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 813** 814** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 815** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 816** to the [sqlite3_file] object associated with the journal file (either 817** the [rollback journal] or the [write-ahead log]) for a particular database 818** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 819** 820** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 821** No longer in use. 822** 823** <li>[[SQLITE_FCNTL_SYNC]] 824** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 825** sent to the VFS immediately before the xSync method is invoked on a 826** database file descriptor. Or, if the xSync method is not invoked 827** because the user has configured SQLite with 828** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 829** of the xSync method. In most cases, the pointer argument passed with 830** this file-control is NULL. However, if the database file is being synced 831** as part of a multi-database commit, the argument points to a nul-terminated 832** string containing the transactions master-journal file name. VFSes that 833** do not need this signal should silently ignore this opcode. Applications 834** should not call [sqlite3_file_control()] with this opcode as doing so may 835** disrupt the operation of the specialized VFSes that do require it. 836** 837** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 838** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 839** and sent to the VFS after a transaction has been committed immediately 840** but before the database is unlocked. VFSes that do not need this signal 841** should silently ignore this opcode. Applications should not call 842** [sqlite3_file_control()] with this opcode as doing so may disrupt the 843** operation of the specialized VFSes that do require it. 844** 845** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 846** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 847** retry counts and intervals for certain disk I/O operations for the 848** windows [VFS] in order to provide robustness in the presence of 849** anti-virus programs. By default, the windows VFS will retry file read, 850** file write, and file delete operations up to 10 times, with a delay 851** of 25 milliseconds before the first retry and with the delay increasing 852** by an additional 25 milliseconds with each subsequent retry. This 853** opcode allows these two values (10 retries and 25 milliseconds of delay) 854** to be adjusted. The values are changed for all database connections 855** within the same process. The argument is a pointer to an array of two 856** integers where the first integer i the new retry count and the second 857** integer is the delay. If either integer is negative, then the setting 858** is not changed but instead the prior value of that setting is written 859** into the array entry, allowing the current retry settings to be 860** interrogated. The zDbName parameter is ignored. 861** 862** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 863** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 864** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 865** write ahead log and shared memory files used for transaction control 866** are automatically deleted when the latest connection to the database 867** closes. Setting persistent WAL mode causes those files to persist after 868** close. Persisting the files is useful when other processes that do not 869** have write permission on the directory containing the database file want 870** to read the database file, as the WAL and shared memory files must exist 871** in order for the database to be readable. The fourth parameter to 872** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 873** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 874** WAL mode. If the integer is -1, then it is overwritten with the current 875** WAL persistence setting. 876** 877** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 878** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 879** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 880** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 881** xDeviceCharacteristics methods. The fourth parameter to 882** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 883** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 884** mode. If the integer is -1, then it is overwritten with the current 885** zero-damage mode setting. 886** 887** <li>[[SQLITE_FCNTL_OVERWRITE]] 888** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 889** a write transaction to indicate that, unless it is rolled back for some 890** reason, the entire database file will be overwritten by the current 891** transaction. This is used by VACUUM operations. 892** 893** <li>[[SQLITE_FCNTL_VFSNAME]] 894** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 895** all [VFSes] in the VFS stack. The names are of all VFS shims and the 896** final bottom-level VFS are written into memory obtained from 897** [sqlite3_malloc()] and the result is stored in the char* variable 898** that the fourth parameter of [sqlite3_file_control()] points to. 899** The caller is responsible for freeing the memory when done. As with 900** all file-control actions, there is no guarantee that this will actually 901** do anything. Callers should initialize the char* variable to a NULL 902** pointer in case this file-control is not implemented. This file-control 903** is intended for diagnostic use only. 904** 905** <li>[[SQLITE_FCNTL_VFS_POINTER]] 906** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 907** [VFSes] currently in use. ^(The argument X in 908** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 909** of type "[sqlite3_vfs] **". This opcodes will set *X 910** to a pointer to the top-level VFS.)^ 911** ^When there are multiple VFS shims in the stack, this opcode finds the 912** upper-most shim only. 913** 914** <li>[[SQLITE_FCNTL_PRAGMA]] 915** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 916** file control is sent to the open [sqlite3_file] object corresponding 917** to the database file to which the pragma statement refers. ^The argument 918** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 919** pointers to strings (char**) in which the second element of the array 920** is the name of the pragma and the third element is the argument to the 921** pragma or NULL if the pragma has no argument. ^The handler for an 922** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 923** of the char** argument point to a string obtained from [sqlite3_mprintf()] 924** or the equivalent and that string will become the result of the pragma or 925** the error message if the pragma fails. ^If the 926** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 927** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 928** file control returns [SQLITE_OK], then the parser assumes that the 929** VFS has handled the PRAGMA itself and the parser generates a no-op 930** prepared statement if result string is NULL, or that returns a copy 931** of the result string if the string is non-NULL. 932** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 933** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 934** that the VFS encountered an error while handling the [PRAGMA] and the 935** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 936** file control occurs at the beginning of pragma statement analysis and so 937** it is able to override built-in [PRAGMA] statements. 938** 939** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 940** ^The [SQLITE_FCNTL_BUSYHANDLER] 941** file-control may be invoked by SQLite on the database file handle 942** shortly after it is opened in order to provide a custom VFS with access 943** to the connections busy-handler callback. The argument is of type (void **) 944** - an array of two (void *) values. The first (void *) actually points 945** to a function of type (int (*)(void *)). In order to invoke the connections 946** busy-handler, this function should be invoked with the second (void *) in 947** the array as the only argument. If it returns non-zero, then the operation 948** should be retried. If it returns zero, the custom VFS should abandon the 949** current operation. 950** 951** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 952** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 953** to have SQLite generate a 954** temporary filename using the same algorithm that is followed to generate 955** temporary filenames for TEMP tables and other internal uses. The 956** argument should be a char** which will be filled with the filename 957** written into memory obtained from [sqlite3_malloc()]. The caller should 958** invoke [sqlite3_free()] on the result to avoid a memory leak. 959** 960** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 961** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 962** maximum number of bytes that will be used for memory-mapped I/O. 963** The argument is a pointer to a value of type sqlite3_int64 that 964** is an advisory maximum number of bytes in the file to memory map. The 965** pointer is overwritten with the old value. The limit is not changed if 966** the value originally pointed to is negative, and so the current limit 967** can be queried by passing in a pointer to a negative number. This 968** file-control is used internally to implement [PRAGMA mmap_size]. 969** 970** <li>[[SQLITE_FCNTL_TRACE]] 971** The [SQLITE_FCNTL_TRACE] file control provides advisory information 972** to the VFS about what the higher layers of the SQLite stack are doing. 973** This file control is used by some VFS activity tracing [shims]. 974** The argument is a zero-terminated string. Higher layers in the 975** SQLite stack may generate instances of this file control if 976** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 977** 978** <li>[[SQLITE_FCNTL_HAS_MOVED]] 979** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 980** pointer to an integer and it writes a boolean into that integer depending 981** on whether or not the file has been renamed, moved, or deleted since it 982** was first opened. 983** 984** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 985** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 986** opcode causes the xFileControl method to swap the file handle with the one 987** pointed to by the pArg argument. This capability is used during testing 988** and only needs to be supported when SQLITE_TEST is defined. 989** 990** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 991** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 992** be advantageous to block on the next WAL lock if the lock is not immediately 993** available. The WAL subsystem issues this signal during rare 994** circumstances in order to fix a problem with priority inversion. 995** Applications should <em>not</em> use this file-control. 996** 997** <li>[[SQLITE_FCNTL_ZIPVFS]] 998** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 999** VFS should return SQLITE_NOTFOUND for this opcode. 1000** 1001** <li>[[SQLITE_FCNTL_RBU]] 1002** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1003** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1004** this opcode. 1005** </ul> 1006*/ 1007#define SQLITE_FCNTL_LOCKSTATE 1 1008#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1009#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1010#define SQLITE_FCNTL_LAST_ERRNO 4 1011#define SQLITE_FCNTL_SIZE_HINT 5 1012#define SQLITE_FCNTL_CHUNK_SIZE 6 1013#define SQLITE_FCNTL_FILE_POINTER 7 1014#define SQLITE_FCNTL_SYNC_OMITTED 8 1015#define SQLITE_FCNTL_WIN32_AV_RETRY 9 1016#define SQLITE_FCNTL_PERSIST_WAL 10 1017#define SQLITE_FCNTL_OVERWRITE 11 1018#define SQLITE_FCNTL_VFSNAME 12 1019#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1020#define SQLITE_FCNTL_PRAGMA 14 1021#define SQLITE_FCNTL_BUSYHANDLER 15 1022#define SQLITE_FCNTL_TEMPFILENAME 16 1023#define SQLITE_FCNTL_MMAP_SIZE 18 1024#define SQLITE_FCNTL_TRACE 19 1025#define SQLITE_FCNTL_HAS_MOVED 20 1026#define SQLITE_FCNTL_SYNC 21 1027#define SQLITE_FCNTL_COMMIT_PHASETWO 22 1028#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1029#define SQLITE_FCNTL_WAL_BLOCK 24 1030#define SQLITE_FCNTL_ZIPVFS 25 1031#define SQLITE_FCNTL_RBU 26 1032#define SQLITE_FCNTL_VFS_POINTER 27 1033#define SQLITE_FCNTL_JOURNAL_POINTER 28 1034 1035/* deprecated names */ 1036#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1037#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1038#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1039 1040 1041/* 1042** CAPI3REF: Mutex Handle 1043** 1044** The mutex module within SQLite defines [sqlite3_mutex] to be an 1045** abstract type for a mutex object. The SQLite core never looks 1046** at the internal representation of an [sqlite3_mutex]. It only 1047** deals with pointers to the [sqlite3_mutex] object. 1048** 1049** Mutexes are created using [sqlite3_mutex_alloc()]. 1050*/ 1051typedef struct sqlite3_mutex sqlite3_mutex; 1052 1053/* 1054** CAPI3REF: OS Interface Object 1055** 1056** An instance of the sqlite3_vfs object defines the interface between 1057** the SQLite core and the underlying operating system. The "vfs" 1058** in the name of the object stands for "virtual file system". See 1059** the [VFS | VFS documentation] for further information. 1060** 1061** The value of the iVersion field is initially 1 but may be larger in 1062** future versions of SQLite. Additional fields may be appended to this 1063** object when the iVersion value is increased. Note that the structure 1064** of the sqlite3_vfs object changes in the transaction between 1065** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 1066** modified. 1067** 1068** The szOsFile field is the size of the subclassed [sqlite3_file] 1069** structure used by this VFS. mxPathname is the maximum length of 1070** a pathname in this VFS. 1071** 1072** Registered sqlite3_vfs objects are kept on a linked list formed by 1073** the pNext pointer. The [sqlite3_vfs_register()] 1074** and [sqlite3_vfs_unregister()] interfaces manage this list 1075** in a thread-safe way. The [sqlite3_vfs_find()] interface 1076** searches the list. Neither the application code nor the VFS 1077** implementation should use the pNext pointer. 1078** 1079** The pNext field is the only field in the sqlite3_vfs 1080** structure that SQLite will ever modify. SQLite will only access 1081** or modify this field while holding a particular static mutex. 1082** The application should never modify anything within the sqlite3_vfs 1083** object once the object has been registered. 1084** 1085** The zName field holds the name of the VFS module. The name must 1086** be unique across all VFS modules. 1087** 1088** [[sqlite3_vfs.xOpen]] 1089** ^SQLite guarantees that the zFilename parameter to xOpen 1090** is either a NULL pointer or string obtained 1091** from xFullPathname() with an optional suffix added. 1092** ^If a suffix is added to the zFilename parameter, it will 1093** consist of a single "-" character followed by no more than 1094** 11 alphanumeric and/or "-" characters. 1095** ^SQLite further guarantees that 1096** the string will be valid and unchanged until xClose() is 1097** called. Because of the previous sentence, 1098** the [sqlite3_file] can safely store a pointer to the 1099** filename if it needs to remember the filename for some reason. 1100** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1101** must invent its own temporary name for the file. ^Whenever the 1102** xFilename parameter is NULL it will also be the case that the 1103** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1104** 1105** The flags argument to xOpen() includes all bits set in 1106** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1107** or [sqlite3_open16()] is used, then flags includes at least 1108** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1109** If xOpen() opens a file read-only then it sets *pOutFlags to 1110** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1111** 1112** ^(SQLite will also add one of the following flags to the xOpen() 1113** call, depending on the object being opened: 1114** 1115** <ul> 1116** <li> [SQLITE_OPEN_MAIN_DB] 1117** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1118** <li> [SQLITE_OPEN_TEMP_DB] 1119** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1120** <li> [SQLITE_OPEN_TRANSIENT_DB] 1121** <li> [SQLITE_OPEN_SUBJOURNAL] 1122** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1123** <li> [SQLITE_OPEN_WAL] 1124** </ul>)^ 1125** 1126** The file I/O implementation can use the object type flags to 1127** change the way it deals with files. For example, an application 1128** that does not care about crash recovery or rollback might make 1129** the open of a journal file a no-op. Writes to this journal would 1130** also be no-ops, and any attempt to read the journal would return 1131** SQLITE_IOERR. Or the implementation might recognize that a database 1132** file will be doing page-aligned sector reads and writes in a random 1133** order and set up its I/O subsystem accordingly. 1134** 1135** SQLite might also add one of the following flags to the xOpen method: 1136** 1137** <ul> 1138** <li> [SQLITE_OPEN_DELETEONCLOSE] 1139** <li> [SQLITE_OPEN_EXCLUSIVE] 1140** </ul> 1141** 1142** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1143** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1144** will be set for TEMP databases and their journals, transient 1145** databases, and subjournals. 1146** 1147** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1148** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1149** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1150** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1151** SQLITE_OPEN_CREATE, is used to indicate that file should always 1152** be created, and that it is an error if it already exists. 1153** It is <i>not</i> used to indicate the file should be opened 1154** for exclusive access. 1155** 1156** ^At least szOsFile bytes of memory are allocated by SQLite 1157** to hold the [sqlite3_file] structure passed as the third 1158** argument to xOpen. The xOpen method does not have to 1159** allocate the structure; it should just fill it in. Note that 1160** the xOpen method must set the sqlite3_file.pMethods to either 1161** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1162** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1163** element will be valid after xOpen returns regardless of the success 1164** or failure of the xOpen call. 1165** 1166** [[sqlite3_vfs.xAccess]] 1167** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1168** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1169** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1170** to test whether a file is at least readable. The file can be a 1171** directory. 1172** 1173** ^SQLite will always allocate at least mxPathname+1 bytes for the 1174** output buffer xFullPathname. The exact size of the output buffer 1175** is also passed as a parameter to both methods. If the output buffer 1176** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1177** handled as a fatal error by SQLite, vfs implementations should endeavor 1178** to prevent this by setting mxPathname to a sufficiently large value. 1179** 1180** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1181** interfaces are not strictly a part of the filesystem, but they are 1182** included in the VFS structure for completeness. 1183** The xRandomness() function attempts to return nBytes bytes 1184** of good-quality randomness into zOut. The return value is 1185** the actual number of bytes of randomness obtained. 1186** The xSleep() method causes the calling thread to sleep for at 1187** least the number of microseconds given. ^The xCurrentTime() 1188** method returns a Julian Day Number for the current date and time as 1189** a floating point value. 1190** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1191** Day Number multiplied by 86400000 (the number of milliseconds in 1192** a 24-hour day). 1193** ^SQLite will use the xCurrentTimeInt64() method to get the current 1194** date and time if that method is available (if iVersion is 2 or 1195** greater and the function pointer is not NULL) and will fall back 1196** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1197** 1198** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1199** are not used by the SQLite core. These optional interfaces are provided 1200** by some VFSes to facilitate testing of the VFS code. By overriding 1201** system calls with functions under its control, a test program can 1202** simulate faults and error conditions that would otherwise be difficult 1203** or impossible to induce. The set of system calls that can be overridden 1204** varies from one VFS to another, and from one version of the same VFS to the 1205** next. Applications that use these interfaces must be prepared for any 1206** or all of these interfaces to be NULL or for their behavior to change 1207** from one release to the next. Applications must not attempt to access 1208** any of these methods if the iVersion of the VFS is less than 3. 1209*/ 1210typedef struct sqlite3_vfs sqlite3_vfs; 1211typedef void (SQLITE_SYSAPI *sqlite3_syscall_ptr)(void); 1212struct sqlite3_vfs { 1213 int iVersion; /* Structure version number (currently 3) */ 1214 int szOsFile; /* Size of subclassed sqlite3_file */ 1215 int mxPathname; /* Maximum file pathname length */ 1216 sqlite3_vfs *pNext; /* Next registered VFS */ 1217 const char *zName; /* Name of this virtual file system */ 1218 void *pAppData; /* Pointer to application-specific data */ 1219 int (SQLITE_CALLBACK *xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1220 int flags, int *pOutFlags); 1221 int (SQLITE_CALLBACK *xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1222 int (SQLITE_CALLBACK *xAccess)(sqlite3_vfs*, const char *zName, int flags, 1223 int *pResOut); 1224 int (SQLITE_CALLBACK *xFullPathname)(sqlite3_vfs*, const char *zName, 1225 int nOut, char *zOut); 1226 void *(SQLITE_CALLBACK *xDlOpen)(sqlite3_vfs*, const char *zFilename); 1227 void (SQLITE_CALLBACK *xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1228 void (*(SQLITE_CALLBACK *xDlSym)(sqlite3_vfs*,void*, 1229 const char *zSymbol))(void); 1230 void (SQLITE_CALLBACK *xDlClose)(sqlite3_vfs*, void*); 1231 int (SQLITE_CALLBACK *xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1232 int (SQLITE_CALLBACK *xSleep)(sqlite3_vfs*, int microseconds); 1233 int (SQLITE_CALLBACK *xCurrentTime)(sqlite3_vfs*, double*); 1234 int (SQLITE_CALLBACK *xGetLastError)(sqlite3_vfs*, int, char *); 1235 /* 1236 ** The methods above are in version 1 of the sqlite_vfs object 1237 ** definition. Those that follow are added in version 2 or later 1238 */ 1239 int (SQLITE_CALLBACK *xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1240 /* 1241 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1242 ** Those below are for version 3 and greater. 1243 */ 1244 int (SQLITE_CALLBACK *xSetSystemCall)(sqlite3_vfs*, const char *zName, 1245 sqlite3_syscall_ptr); 1246 sqlite3_syscall_ptr (SQLITE_CALLBACK *xGetSystemCall)(sqlite3_vfs*, 1247 const char *zName); 1248 const char *(SQLITE_CALLBACK *xNextSystemCall)(sqlite3_vfs*, 1249 const char *zName); 1250 /* 1251 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1252 ** New fields may be appended in future versions. The iVersion 1253 ** value will increment whenever this happens. 1254 */ 1255}; 1256 1257/* 1258** CAPI3REF: Flags for the xAccess VFS method 1259** 1260** These integer constants can be used as the third parameter to 1261** the xAccess method of an [sqlite3_vfs] object. They determine 1262** what kind of permissions the xAccess method is looking for. 1263** With SQLITE_ACCESS_EXISTS, the xAccess method 1264** simply checks whether the file exists. 1265** With SQLITE_ACCESS_READWRITE, the xAccess method 1266** checks whether the named directory is both readable and writable 1267** (in other words, if files can be added, removed, and renamed within 1268** the directory). 1269** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1270** [temp_store_directory pragma], though this could change in a future 1271** release of SQLite. 1272** With SQLITE_ACCESS_READ, the xAccess method 1273** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1274** currently unused, though it might be used in a future release of 1275** SQLite. 1276*/ 1277#define SQLITE_ACCESS_EXISTS 0 1278#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1279#define SQLITE_ACCESS_READ 2 /* Unused */ 1280 1281/* 1282** CAPI3REF: Flags for the xShmLock VFS method 1283** 1284** These integer constants define the various locking operations 1285** allowed by the xShmLock method of [sqlite3_io_methods]. The 1286** following are the only legal combinations of flags to the 1287** xShmLock method: 1288** 1289** <ul> 1290** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1291** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1292** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1293** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1294** </ul> 1295** 1296** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1297** was given on the corresponding lock. 1298** 1299** The xShmLock method can transition between unlocked and SHARED or 1300** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1301** and EXCLUSIVE. 1302*/ 1303#define SQLITE_SHM_UNLOCK 1 1304#define SQLITE_SHM_LOCK 2 1305#define SQLITE_SHM_SHARED 4 1306#define SQLITE_SHM_EXCLUSIVE 8 1307 1308/* 1309** CAPI3REF: Maximum xShmLock index 1310** 1311** The xShmLock method on [sqlite3_io_methods] may use values 1312** between 0 and this upper bound as its "offset" argument. 1313** The SQLite core will never attempt to acquire or release a 1314** lock outside of this range 1315*/ 1316#define SQLITE_SHM_NLOCK 8 1317 1318 1319/* 1320** CAPI3REF: Initialize The SQLite Library 1321** 1322** ^The sqlite3_initialize() routine initializes the 1323** SQLite library. ^The sqlite3_shutdown() routine 1324** deallocates any resources that were allocated by sqlite3_initialize(). 1325** These routines are designed to aid in process initialization and 1326** shutdown on embedded systems. Workstation applications using 1327** SQLite normally do not need to invoke either of these routines. 1328** 1329** A call to sqlite3_initialize() is an "effective" call if it is 1330** the first time sqlite3_initialize() is invoked during the lifetime of 1331** the process, or if it is the first time sqlite3_initialize() is invoked 1332** following a call to sqlite3_shutdown(). ^(Only an effective call 1333** of sqlite3_initialize() does any initialization. All other calls 1334** are harmless no-ops.)^ 1335** 1336** A call to sqlite3_shutdown() is an "effective" call if it is the first 1337** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1338** an effective call to sqlite3_shutdown() does any deinitialization. 1339** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1340** 1341** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1342** is not. The sqlite3_shutdown() interface must only be called from a 1343** single thread. All open [database connections] must be closed and all 1344** other SQLite resources must be deallocated prior to invoking 1345** sqlite3_shutdown(). 1346** 1347** Among other things, ^sqlite3_initialize() will invoke 1348** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1349** will invoke sqlite3_os_end(). 1350** 1351** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1352** ^If for some reason, sqlite3_initialize() is unable to initialize 1353** the library (perhaps it is unable to allocate a needed resource such 1354** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1355** 1356** ^The sqlite3_initialize() routine is called internally by many other 1357** SQLite interfaces so that an application usually does not need to 1358** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1359** calls sqlite3_initialize() so the SQLite library will be automatically 1360** initialized when [sqlite3_open()] is called if it has not be initialized 1361** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1362** compile-time option, then the automatic calls to sqlite3_initialize() 1363** are omitted and the application must call sqlite3_initialize() directly 1364** prior to using any other SQLite interface. For maximum portability, 1365** it is recommended that applications always invoke sqlite3_initialize() 1366** directly prior to using any other SQLite interface. Future releases 1367** of SQLite may require this. In other words, the behavior exhibited 1368** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1369** default behavior in some future release of SQLite. 1370** 1371** The sqlite3_os_init() routine does operating-system specific 1372** initialization of the SQLite library. The sqlite3_os_end() 1373** routine undoes the effect of sqlite3_os_init(). Typical tasks 1374** performed by these routines include allocation or deallocation 1375** of static resources, initialization of global variables, 1376** setting up a default [sqlite3_vfs] module, or setting up 1377** a default configuration using [sqlite3_config()]. 1378** 1379** The application should never invoke either sqlite3_os_init() 1380** or sqlite3_os_end() directly. The application should only invoke 1381** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1382** interface is called automatically by sqlite3_initialize() and 1383** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1384** implementations for sqlite3_os_init() and sqlite3_os_end() 1385** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1386** When [custom builds | built for other platforms] 1387** (using the [SQLITE_OS_OTHER=1] compile-time 1388** option) the application must supply a suitable implementation for 1389** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1390** implementation of sqlite3_os_init() or sqlite3_os_end() 1391** must return [SQLITE_OK] on success and some other [error code] upon 1392** failure. 1393*/ 1394int sqlite3_initialize(void); 1395int sqlite3_shutdown(void); 1396int sqlite3_os_init(void); 1397int sqlite3_os_end(void); 1398 1399/* 1400** CAPI3REF: Configuring The SQLite Library 1401** 1402** The sqlite3_config() interface is used to make global configuration 1403** changes to SQLite in order to tune SQLite to the specific needs of 1404** the application. The default configuration is recommended for most 1405** applications and so this routine is usually not necessary. It is 1406** provided to support rare applications with unusual needs. 1407** 1408** <b>The sqlite3_config() interface is not threadsafe. The application 1409** must ensure that no other SQLite interfaces are invoked by other 1410** threads while sqlite3_config() is running.</b> 1411** 1412** The sqlite3_config() interface 1413** may only be invoked prior to library initialization using 1414** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1415** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1416** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1417** Note, however, that ^sqlite3_config() can be called as part of the 1418** implementation of an application-defined [sqlite3_os_init()]. 1419** 1420** The first argument to sqlite3_config() is an integer 1421** [configuration option] that determines 1422** what property of SQLite is to be configured. Subsequent arguments 1423** vary depending on the [configuration option] 1424** in the first argument. 1425** 1426** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1427** ^If the option is unknown or SQLite is unable to set the option 1428** then this routine returns a non-zero [error code]. 1429*/ 1430int sqlite3_config(int, ...); 1431 1432/* 1433** CAPI3REF: Configure database connections 1434** METHOD: sqlite3 1435** 1436** The sqlite3_db_config() interface is used to make configuration 1437** changes to a [database connection]. The interface is similar to 1438** [sqlite3_config()] except that the changes apply to a single 1439** [database connection] (specified in the first argument). 1440** 1441** The second argument to sqlite3_db_config(D,V,...) is the 1442** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1443** that indicates what aspect of the [database connection] is being configured. 1444** Subsequent arguments vary depending on the configuration verb. 1445** 1446** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1447** the call is considered successful. 1448*/ 1449int sqlite3_db_config(sqlite3*, int op, ...); 1450 1451/* 1452** CAPI3REF: Memory Allocation Routines 1453** 1454** An instance of this object defines the interface between SQLite 1455** and low-level memory allocation routines. 1456** 1457** This object is used in only one place in the SQLite interface. 1458** A pointer to an instance of this object is the argument to 1459** [sqlite3_config()] when the configuration option is 1460** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1461** By creating an instance of this object 1462** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1463** during configuration, an application can specify an alternative 1464** memory allocation subsystem for SQLite to use for all of its 1465** dynamic memory needs. 1466** 1467** Note that SQLite comes with several [built-in memory allocators] 1468** that are perfectly adequate for the overwhelming majority of applications 1469** and that this object is only useful to a tiny minority of applications 1470** with specialized memory allocation requirements. This object is 1471** also used during testing of SQLite in order to specify an alternative 1472** memory allocator that simulates memory out-of-memory conditions in 1473** order to verify that SQLite recovers gracefully from such 1474** conditions. 1475** 1476** The xMalloc, xRealloc, and xFree methods must work like the 1477** malloc(), realloc() and free() functions from the standard C library. 1478** ^SQLite guarantees that the second argument to 1479** xRealloc is always a value returned by a prior call to xRoundup. 1480** 1481** xSize should return the allocated size of a memory allocation 1482** previously obtained from xMalloc or xRealloc. The allocated size 1483** is always at least as big as the requested size but may be larger. 1484** 1485** The xRoundup method returns what would be the allocated size of 1486** a memory allocation given a particular requested size. Most memory 1487** allocators round up memory allocations at least to the next multiple 1488** of 8. Some allocators round up to a larger multiple or to a power of 2. 1489** Every memory allocation request coming in through [sqlite3_malloc()] 1490** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1491** that causes the corresponding memory allocation to fail. 1492** 1493** The xInit method initializes the memory allocator. For example, 1494** it might allocate any require mutexes or initialize internal data 1495** structures. The xShutdown method is invoked (indirectly) by 1496** [sqlite3_shutdown()] and should deallocate any resources acquired 1497** by xInit. The pAppData pointer is used as the only parameter to 1498** xInit and xShutdown. 1499** 1500** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1501** the xInit method, so the xInit method need not be threadsafe. The 1502** xShutdown method is only called from [sqlite3_shutdown()] so it does 1503** not need to be threadsafe either. For all other methods, SQLite 1504** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1505** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1506** it is by default) and so the methods are automatically serialized. 1507** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1508** methods must be threadsafe or else make their own arrangements for 1509** serialization. 1510** 1511** SQLite will never invoke xInit() more than once without an intervening 1512** call to xShutdown(). 1513*/ 1514typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1515struct sqlite3_mem_methods { 1516 void *(SQLITE_CALLBACK *xMalloc)(int); /* Memory allocation function */ 1517 void (SQLITE_CALLBACK *xFree)(void*); /* Free a prior allocation */ 1518 void *(SQLITE_CALLBACK *xRealloc)(void*,int); /* Resize an allocation */ 1519 int (SQLITE_CALLBACK *xSize)(void*); /* Return the size of an allocation */ 1520 int (SQLITE_CALLBACK *xRoundup)(int); /* Round up size to allocation size */ 1521 int (SQLITE_CALLBACK *xInit)(void*); /* Initialize the memory allocator */ 1522 void (SQLITE_CALLBACK *xShutdown)(void*); /* Deinitialize memory allocator */ 1523 void *pAppData; /* Argument to xInit() and xShutdown() */ 1524}; 1525 1526/* 1527** CAPI3REF: Configuration Options 1528** KEYWORDS: {configuration option} 1529** 1530** These constants are the available integer configuration options that 1531** can be passed as the first argument to the [sqlite3_config()] interface. 1532** 1533** New configuration options may be added in future releases of SQLite. 1534** Existing configuration options might be discontinued. Applications 1535** should check the return code from [sqlite3_config()] to make sure that 1536** the call worked. The [sqlite3_config()] interface will return a 1537** non-zero [error code] if a discontinued or unsupported configuration option 1538** is invoked. 1539** 1540** <dl> 1541** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1542** <dd>There are no arguments to this option. ^This option sets the 1543** [threading mode] to Single-thread. In other words, it disables 1544** all mutexing and puts SQLite into a mode where it can only be used 1545** by a single thread. ^If SQLite is compiled with 1546** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1547** it is not possible to change the [threading mode] from its default 1548** value of Single-thread and so [sqlite3_config()] will return 1549** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1550** configuration option.</dd> 1551** 1552** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1553** <dd>There are no arguments to this option. ^This option sets the 1554** [threading mode] to Multi-thread. In other words, it disables 1555** mutexing on [database connection] and [prepared statement] objects. 1556** The application is responsible for serializing access to 1557** [database connections] and [prepared statements]. But other mutexes 1558** are enabled so that SQLite will be safe to use in a multi-threaded 1559** environment as long as no two threads attempt to use the same 1560** [database connection] at the same time. ^If SQLite is compiled with 1561** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1562** it is not possible to set the Multi-thread [threading mode] and 1563** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1564** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1565** 1566** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1567** <dd>There are no arguments to this option. ^This option sets the 1568** [threading mode] to Serialized. In other words, this option enables 1569** all mutexes including the recursive 1570** mutexes on [database connection] and [prepared statement] objects. 1571** In this mode (which is the default when SQLite is compiled with 1572** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1573** to [database connections] and [prepared statements] so that the 1574** application is free to use the same [database connection] or the 1575** same [prepared statement] in different threads at the same time. 1576** ^If SQLite is compiled with 1577** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1578** it is not possible to set the Serialized [threading mode] and 1579** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1580** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1581** 1582** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1583** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1584** a pointer to an instance of the [sqlite3_mem_methods] structure. 1585** The argument specifies 1586** alternative low-level memory allocation routines to be used in place of 1587** the memory allocation routines built into SQLite.)^ ^SQLite makes 1588** its own private copy of the content of the [sqlite3_mem_methods] structure 1589** before the [sqlite3_config()] call returns.</dd> 1590** 1591** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1592** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1593** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1594** The [sqlite3_mem_methods] 1595** structure is filled with the currently defined memory allocation routines.)^ 1596** This option can be used to overload the default memory allocation 1597** routines with a wrapper that simulations memory allocation failure or 1598** tracks memory usage, for example. </dd> 1599** 1600** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1601** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1602** interpreted as a boolean, which enables or disables the collection of 1603** memory allocation statistics. ^(When memory allocation statistics are 1604** disabled, the following SQLite interfaces become non-operational: 1605** <ul> 1606** <li> [sqlite3_memory_used()] 1607** <li> [sqlite3_memory_highwater()] 1608** <li> [sqlite3_soft_heap_limit64()] 1609** <li> [sqlite3_status64()] 1610** </ul>)^ 1611** ^Memory allocation statistics are enabled by default unless SQLite is 1612** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1613** allocation statistics are disabled by default. 1614** </dd> 1615** 1616** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1617** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer 1618** that SQLite can use for scratch memory. ^(There are three arguments 1619** to SQLITE_CONFIG_SCRATCH: A pointer an 8-byte 1620** aligned memory buffer from which the scratch allocations will be 1621** drawn, the size of each scratch allocation (sz), 1622** and the maximum number of scratch allocations (N).)^ 1623** The first argument must be a pointer to an 8-byte aligned buffer 1624** of at least sz*N bytes of memory. 1625** ^SQLite will not use more than one scratch buffers per thread. 1626** ^SQLite will never request a scratch buffer that is more than 6 1627** times the database page size. 1628** ^If SQLite needs needs additional 1629** scratch memory beyond what is provided by this configuration option, then 1630** [sqlite3_malloc()] will be used to obtain the memory needed.<p> 1631** ^When the application provides any amount of scratch memory using 1632** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large 1633** [sqlite3_malloc|heap allocations]. 1634** This can help [Robson proof|prevent memory allocation failures] due to heap 1635** fragmentation in low-memory embedded systems. 1636** </dd> 1637** 1638** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1639** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1640** that SQLite can use for the database page cache with the default page 1641** cache implementation. 1642** This configuration option is a no-op if an application-define page 1643** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1644** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1645** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1646** and the number of cache lines (N). 1647** The sz argument should be the size of the largest database page 1648** (a power of two between 512 and 65536) plus some extra bytes for each 1649** page header. ^The number of extra bytes needed by the page header 1650** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1651** ^It is harmless, apart from the wasted memory, 1652** for the sz parameter to be larger than necessary. The pMem 1653** argument must be either a NULL pointer or a pointer to an 8-byte 1654** aligned block of memory of at least sz*N bytes, otherwise 1655** subsequent behavior is undefined. 1656** ^When pMem is not NULL, SQLite will strive to use the memory provided 1657** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1658** a page cache line is larger than sz bytes or if all of the pMem buffer 1659** is exhausted. 1660** ^If pMem is NULL and N is non-zero, then each database connection 1661** does an initial bulk allocation for page cache memory 1662** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1663** of -1024*N bytes if N is negative, . ^If additional 1664** page cache memory is needed beyond what is provided by the initial 1665** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1666** additional cache line. </dd> 1667** 1668** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1669** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1670** that SQLite will use for all of its dynamic memory allocation needs 1671** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and 1672** [SQLITE_CONFIG_PAGECACHE]. 1673** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1674** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1675** [SQLITE_ERROR] if invoked otherwise. 1676** ^There are three arguments to SQLITE_CONFIG_HEAP: 1677** An 8-byte aligned pointer to the memory, 1678** the number of bytes in the memory buffer, and the minimum allocation size. 1679** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1680** to using its default memory allocator (the system malloc() implementation), 1681** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1682** memory pointer is not NULL then the alternative memory 1683** allocator is engaged to handle all of SQLites memory allocation needs. 1684** The first pointer (the memory pointer) must be aligned to an 8-byte 1685** boundary or subsequent behavior of SQLite will be undefined. 1686** The minimum allocation size is capped at 2**12. Reasonable values 1687** for the minimum allocation size are 2**5 through 2**8.</dd> 1688** 1689** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1690** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1691** pointer to an instance of the [sqlite3_mutex_methods] structure. 1692** The argument specifies alternative low-level mutex routines to be used 1693** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1694** the content of the [sqlite3_mutex_methods] structure before the call to 1695** [sqlite3_config()] returns. ^If SQLite is compiled with 1696** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1697** the entire mutexing subsystem is omitted from the build and hence calls to 1698** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1699** return [SQLITE_ERROR].</dd> 1700** 1701** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1702** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1703** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1704** [sqlite3_mutex_methods] 1705** structure is filled with the currently defined mutex routines.)^ 1706** This option can be used to overload the default mutex allocation 1707** routines with a wrapper used to track mutex usage for performance 1708** profiling or testing, for example. ^If SQLite is compiled with 1709** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1710** the entire mutexing subsystem is omitted from the build and hence calls to 1711** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1712** return [SQLITE_ERROR].</dd> 1713** 1714** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1715** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1716** the default size of lookaside memory on each [database connection]. 1717** The first argument is the 1718** size of each lookaside buffer slot and the second is the number of 1719** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1720** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1721** option to [sqlite3_db_config()] can be used to change the lookaside 1722** configuration on individual connections.)^ </dd> 1723** 1724** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1725** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1726** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1727** the interface to a custom page cache implementation.)^ 1728** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1729** 1730** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1731** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1732** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1733** the current page cache implementation into that object.)^ </dd> 1734** 1735** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1736** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1737** global [error log]. 1738** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1739** function with a call signature of void(*)(void*,int,const char*), 1740** and a pointer to void. ^If the function pointer is not NULL, it is 1741** invoked by [sqlite3_log()] to process each logging event. ^If the 1742** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1743** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1744** passed through as the first parameter to the application-defined logger 1745** function whenever that function is invoked. ^The second parameter to 1746** the logger function is a copy of the first parameter to the corresponding 1747** [sqlite3_log()] call and is intended to be a [result code] or an 1748** [extended result code]. ^The third parameter passed to the logger is 1749** log message after formatting via [sqlite3_snprintf()]. 1750** The SQLite logging interface is not reentrant; the logger function 1751** supplied by the application must not invoke any SQLite interface. 1752** In a multi-threaded application, the application-defined logger 1753** function must be threadsafe. </dd> 1754** 1755** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1756** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1757** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1758** then URI handling is globally disabled.)^ ^If URI handling is globally 1759** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1760** [sqlite3_open16()] or 1761** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1762** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1763** connection is opened. ^If it is globally disabled, filenames are 1764** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1765** database connection is opened. ^(By default, URI handling is globally 1766** disabled. The default value may be changed by compiling with the 1767** [SQLITE_USE_URI] symbol defined.)^ 1768** 1769** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1770** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1771** argument which is interpreted as a boolean in order to enable or disable 1772** the use of covering indices for full table scans in the query optimizer. 1773** ^The default setting is determined 1774** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1775** if that compile-time option is omitted. 1776** The ability to disable the use of covering indices for full table scans 1777** is because some incorrectly coded legacy applications might malfunction 1778** when the optimization is enabled. Providing the ability to 1779** disable the optimization allows the older, buggy application code to work 1780** without change even with newer versions of SQLite. 1781** 1782** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1783** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1784** <dd> These options are obsolete and should not be used by new code. 1785** They are retained for backwards compatibility but are now no-ops. 1786** </dd> 1787** 1788** [[SQLITE_CONFIG_SQLLOG]] 1789** <dt>SQLITE_CONFIG_SQLLOG 1790** <dd>This option is only available if sqlite is compiled with the 1791** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1792** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1793** The second should be of type (void*). The callback is invoked by the library 1794** in three separate circumstances, identified by the value passed as the 1795** fourth parameter. If the fourth parameter is 0, then the database connection 1796** passed as the second argument has just been opened. The third argument 1797** points to a buffer containing the name of the main database file. If the 1798** fourth parameter is 1, then the SQL statement that the third parameter 1799** points to has just been executed. Or, if the fourth parameter is 2, then 1800** the connection being passed as the second parameter is being closed. The 1801** third parameter is passed NULL In this case. An example of using this 1802** configuration option can be seen in the "test_sqllog.c" source file in 1803** the canonical SQLite source tree.</dd> 1804** 1805** [[SQLITE_CONFIG_MMAP_SIZE]] 1806** <dt>SQLITE_CONFIG_MMAP_SIZE 1807** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1808** that are the default mmap size limit (the default setting for 1809** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1810** ^The default setting can be overridden by each database connection using 1811** either the [PRAGMA mmap_size] command, or by using the 1812** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1813** will be silently truncated if necessary so that it does not exceed the 1814** compile-time maximum mmap size set by the 1815** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1816** ^If either argument to this option is negative, then that argument is 1817** changed to its compile-time default. 1818** 1819** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1820** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1821** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1822** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1823** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1824** that specifies the maximum size of the created heap. 1825** 1826** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1827** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1828** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1829** is a pointer to an integer and writes into that integer the number of extra 1830** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1831** The amount of extra space required can change depending on the compiler, 1832** target platform, and SQLite version. 1833** 1834** [[SQLITE_CONFIG_PMASZ]] 1835** <dt>SQLITE_CONFIG_PMASZ 1836** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1837** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1838** sorter to that integer. The default minimum PMA Size is set by the 1839** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1840** to help with sort operations when multithreaded sorting 1841** is enabled (using the [PRAGMA threads] command) and the amount of content 1842** to be sorted exceeds the page size times the minimum of the 1843** [PRAGMA cache_size] setting and this value. 1844** 1845** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1846** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1847** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1848** becomes the [statement journal] spill-to-disk threshold. 1849** [Statement journals] are held in memory until their size (in bytes) 1850** exceeds this threshold, at which point they are written to disk. 1851** Or if the threshold is -1, statement journals are always held 1852** exclusively in memory. 1853** Since many statement journals never become large, setting the spill 1854** threshold to a value such as 64KiB can greatly reduce the amount of 1855** I/O required to support statement rollback. 1856** The default value for this setting is controlled by the 1857** [SQLITE_STMTJRNL_SPILL] compile-time option. 1858** </dl> 1859*/ 1860#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1861#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1862#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1863#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1864#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1865#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1866#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1867#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1868#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1869#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1870#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1871/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1872#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1873#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1874#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1875#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1876#define SQLITE_CONFIG_URI 17 /* int */ 1877#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1878#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1879#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1880#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1881#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1882#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1883#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 1884#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 1885#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 1886 1887/* 1888** CAPI3REF: Database Connection Configuration Options 1889** 1890** These constants are the available integer configuration options that 1891** can be passed as the second argument to the [sqlite3_db_config()] interface. 1892** 1893** New configuration options may be added in future releases of SQLite. 1894** Existing configuration options might be discontinued. Applications 1895** should check the return code from [sqlite3_db_config()] to make sure that 1896** the call worked. ^The [sqlite3_db_config()] interface will return a 1897** non-zero [error code] if a discontinued or unsupported configuration option 1898** is invoked. 1899** 1900** <dl> 1901** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1902** <dd> ^This option takes three additional arguments that determine the 1903** [lookaside memory allocator] configuration for the [database connection]. 1904** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1905** pointer to a memory buffer to use for lookaside memory. 1906** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1907** may be NULL in which case SQLite will allocate the 1908** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1909** size of each lookaside buffer slot. ^The third argument is the number of 1910** slots. The size of the buffer in the first argument must be greater than 1911** or equal to the product of the second and third arguments. The buffer 1912** must be aligned to an 8-byte boundary. ^If the second argument to 1913** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1914** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1915** configuration for a database connection can only be changed when that 1916** connection is not currently using lookaside memory, or in other words 1917** when the "current value" returned by 1918** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1919** Any attempt to change the lookaside memory configuration when lookaside 1920** memory is in use leaves the configuration unchanged and returns 1921** [SQLITE_BUSY].)^</dd> 1922** 1923** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1924** <dd> ^This option is used to enable or disable the enforcement of 1925** [foreign key constraints]. There should be two additional arguments. 1926** The first argument is an integer which is 0 to disable FK enforcement, 1927** positive to enable FK enforcement or negative to leave FK enforcement 1928** unchanged. The second parameter is a pointer to an integer into which 1929** is written 0 or 1 to indicate whether FK enforcement is off or on 1930** following this call. The second parameter may be a NULL pointer, in 1931** which case the FK enforcement setting is not reported back. </dd> 1932** 1933** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1934** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1935** There should be two additional arguments. 1936** The first argument is an integer which is 0 to disable triggers, 1937** positive to enable triggers or negative to leave the setting unchanged. 1938** The second parameter is a pointer to an integer into which 1939** is written 0 or 1 to indicate whether triggers are disabled or enabled 1940** following this call. The second parameter may be a NULL pointer, in 1941** which case the trigger setting is not reported back. </dd> 1942** 1943** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 1944** <dd> ^This option is used to enable or disable the two-argument 1945** version of the [fts3_tokenizer()] function which is part of the 1946** [FTS3] full-text search engine extension. 1947** There should be two additional arguments. 1948** The first argument is an integer which is 0 to disable fts3_tokenizer() or 1949** positive to enable fts3_tokenizer() or negative to leave the setting 1950** unchanged. 1951** The second parameter is a pointer to an integer into which 1952** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 1953** following this call. The second parameter may be a NULL pointer, in 1954** which case the new setting is not reported back. </dd> 1955** 1956** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 1957** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 1958** interface independently of the [load_extension()] SQL function. 1959** The [sqlite3_enable_load_extension()] API enables or disables both the 1960** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 1961** There should be two additional arguments. 1962** When the first argument to this interface is 1, then only the C-API is 1963** enabled and the SQL function remains disabled. If the first argment to 1964** this interface is 0, then both the C-API and the SQL function are disabled. 1965** If the first argument is -1, then no changes are made to state of either the 1966** C-API or the SQL function. 1967** The second parameter is a pointer to an integer into which 1968** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 1969** is disabled or enabled following this call. The second parameter may 1970** be a NULL pointer, in which case the new setting is not reported back. 1971** </dd> 1972** 1973** </dl> 1974*/ 1975#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1976#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1977#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1978#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 1979#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 1980 1981 1982/* 1983** CAPI3REF: Enable Or Disable Extended Result Codes 1984** METHOD: sqlite3 1985** 1986** ^The sqlite3_extended_result_codes() routine enables or disables the 1987** [extended result codes] feature of SQLite. ^The extended result 1988** codes are disabled by default for historical compatibility. 1989*/ 1990int sqlite3_extended_result_codes(sqlite3*, int onoff); 1991 1992/* 1993** CAPI3REF: Last Insert Rowid 1994** METHOD: sqlite3 1995** 1996** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 1997** has a unique 64-bit signed 1998** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1999** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2000** names are not also used by explicitly declared columns. ^If 2001** the table has a column of type [INTEGER PRIMARY KEY] then that column 2002** is another alias for the rowid. 2003** 2004** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the 2005** most recent successful [INSERT] into a rowid table or [virtual table] 2006** on database connection D. 2007** ^Inserts into [WITHOUT ROWID] tables are not recorded. 2008** ^If no successful [INSERT]s into rowid tables 2009** have ever occurred on the database connection D, 2010** then sqlite3_last_insert_rowid(D) returns zero. 2011** 2012** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 2013** method, then this routine will return the [rowid] of the inserted 2014** row as long as the trigger or virtual table method is running. 2015** But once the trigger or virtual table method ends, the value returned 2016** by this routine reverts to what it was before the trigger or virtual 2017** table method began.)^ 2018** 2019** ^An [INSERT] that fails due to a constraint violation is not a 2020** successful [INSERT] and does not change the value returned by this 2021** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2022** and INSERT OR ABORT make no changes to the return value of this 2023** routine when their insertion fails. ^(When INSERT OR REPLACE 2024** encounters a constraint violation, it does not fail. The 2025** INSERT continues to completion after deleting rows that caused 2026** the constraint problem so INSERT OR REPLACE will always change 2027** the return value of this interface.)^ 2028** 2029** ^For the purposes of this routine, an [INSERT] is considered to 2030** be successful even if it is subsequently rolled back. 2031** 2032** This function is accessible to SQL statements via the 2033** [last_insert_rowid() SQL function]. 2034** 2035** If a separate thread performs a new [INSERT] on the same 2036** database connection while the [sqlite3_last_insert_rowid()] 2037** function is running and thus changes the last insert [rowid], 2038** then the value returned by [sqlite3_last_insert_rowid()] is 2039** unpredictable and might not equal either the old or the new 2040** last insert [rowid]. 2041*/ 2042sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2043 2044/* 2045** CAPI3REF: Count The Number Of Rows Modified 2046** METHOD: sqlite3 2047** 2048** ^This function returns the number of rows modified, inserted or 2049** deleted by the most recently completed INSERT, UPDATE or DELETE 2050** statement on the database connection specified by the only parameter. 2051** ^Executing any other type of SQL statement does not modify the value 2052** returned by this function. 2053** 2054** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2055** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2056** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2057** 2058** Changes to a view that are intercepted by 2059** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2060** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2061** DELETE statement run on a view is always zero. Only changes made to real 2062** tables are counted. 2063** 2064** Things are more complicated if the sqlite3_changes() function is 2065** executed while a trigger program is running. This may happen if the 2066** program uses the [changes() SQL function], or if some other callback 2067** function invokes sqlite3_changes() directly. Essentially: 2068** 2069** <ul> 2070** <li> ^(Before entering a trigger program the value returned by 2071** sqlite3_changes() function is saved. After the trigger program 2072** has finished, the original value is restored.)^ 2073** 2074** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2075** statement sets the value returned by sqlite3_changes() 2076** upon completion as normal. Of course, this value will not include 2077** any changes performed by sub-triggers, as the sqlite3_changes() 2078** value will be saved and restored after each sub-trigger has run.)^ 2079** </ul> 2080** 2081** ^This means that if the changes() SQL function (or similar) is used 2082** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2083** returns the value as set when the calling statement began executing. 2084** ^If it is used by the second or subsequent such statement within a trigger 2085** program, the value returned reflects the number of rows modified by the 2086** previous INSERT, UPDATE or DELETE statement within the same trigger. 2087** 2088** See also the [sqlite3_total_changes()] interface, the 2089** [count_changes pragma], and the [changes() SQL function]. 2090** 2091** If a separate thread makes changes on the same database connection 2092** while [sqlite3_changes()] is running then the value returned 2093** is unpredictable and not meaningful. 2094*/ 2095int sqlite3_changes(sqlite3*); 2096 2097/* 2098** CAPI3REF: Total Number Of Rows Modified 2099** METHOD: sqlite3 2100** 2101** ^This function returns the total number of rows inserted, modified or 2102** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2103** since the database connection was opened, including those executed as 2104** part of trigger programs. ^Executing any other type of SQL statement 2105** does not affect the value returned by sqlite3_total_changes(). 2106** 2107** ^Changes made as part of [foreign key actions] are included in the 2108** count, but those made as part of REPLACE constraint resolution are 2109** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2110** are not counted. 2111** 2112** See also the [sqlite3_changes()] interface, the 2113** [count_changes pragma], and the [total_changes() SQL function]. 2114** 2115** If a separate thread makes changes on the same database connection 2116** while [sqlite3_total_changes()] is running then the value 2117** returned is unpredictable and not meaningful. 2118*/ 2119int sqlite3_total_changes(sqlite3*); 2120 2121/* 2122** CAPI3REF: Interrupt A Long-Running Query 2123** METHOD: sqlite3 2124** 2125** ^This function causes any pending database operation to abort and 2126** return at its earliest opportunity. This routine is typically 2127** called in response to a user action such as pressing "Cancel" 2128** or Ctrl-C where the user wants a long query operation to halt 2129** immediately. 2130** 2131** ^It is safe to call this routine from a thread different from the 2132** thread that is currently running the database operation. But it 2133** is not safe to call this routine with a [database connection] that 2134** is closed or might close before sqlite3_interrupt() returns. 2135** 2136** ^If an SQL operation is very nearly finished at the time when 2137** sqlite3_interrupt() is called, then it might not have an opportunity 2138** to be interrupted and might continue to completion. 2139** 2140** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2141** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2142** that is inside an explicit transaction, then the entire transaction 2143** will be rolled back automatically. 2144** 2145** ^The sqlite3_interrupt(D) call is in effect until all currently running 2146** SQL statements on [database connection] D complete. ^Any new SQL statements 2147** that are started after the sqlite3_interrupt() call and before the 2148** running statements reaches zero are interrupted as if they had been 2149** running prior to the sqlite3_interrupt() call. ^New SQL statements 2150** that are started after the running statement count reaches zero are 2151** not effected by the sqlite3_interrupt(). 2152** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2153** SQL statements is a no-op and has no effect on SQL statements 2154** that are started after the sqlite3_interrupt() call returns. 2155** 2156** If the database connection closes while [sqlite3_interrupt()] 2157** is running then bad things will likely happen. 2158*/ 2159void sqlite3_interrupt(sqlite3*); 2160 2161/* 2162** CAPI3REF: Determine If An SQL Statement Is Complete 2163** 2164** These routines are useful during command-line input to determine if the 2165** currently entered text seems to form a complete SQL statement or 2166** if additional input is needed before sending the text into 2167** SQLite for parsing. ^These routines return 1 if the input string 2168** appears to be a complete SQL statement. ^A statement is judged to be 2169** complete if it ends with a semicolon token and is not a prefix of a 2170** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2171** string literals or quoted identifier names or comments are not 2172** independent tokens (they are part of the token in which they are 2173** embedded) and thus do not count as a statement terminator. ^Whitespace 2174** and comments that follow the final semicolon are ignored. 2175** 2176** ^These routines return 0 if the statement is incomplete. ^If a 2177** memory allocation fails, then SQLITE_NOMEM is returned. 2178** 2179** ^These routines do not parse the SQL statements thus 2180** will not detect syntactically incorrect SQL. 2181** 2182** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2183** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2184** automatically by sqlite3_complete16(). If that initialization fails, 2185** then the return value from sqlite3_complete16() will be non-zero 2186** regardless of whether or not the input SQL is complete.)^ 2187** 2188** The input to [sqlite3_complete()] must be a zero-terminated 2189** UTF-8 string. 2190** 2191** The input to [sqlite3_complete16()] must be a zero-terminated 2192** UTF-16 string in native byte order. 2193*/ 2194int sqlite3_complete(const char *sql); 2195int sqlite3_complete16(const void *sql); 2196 2197/* 2198** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2199** KEYWORDS: {busy-handler callback} {busy handler} 2200** METHOD: sqlite3 2201** 2202** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2203** that might be invoked with argument P whenever 2204** an attempt is made to access a database table associated with 2205** [database connection] D when another thread 2206** or process has the table locked. 2207** The sqlite3_busy_handler() interface is used to implement 2208** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2209** 2210** ^If the busy callback is NULL, then [SQLITE_BUSY] 2211** is returned immediately upon encountering the lock. ^If the busy callback 2212** is not NULL, then the callback might be invoked with two arguments. 2213** 2214** ^The first argument to the busy handler is a copy of the void* pointer which 2215** is the third argument to sqlite3_busy_handler(). ^The second argument to 2216** the busy handler callback is the number of times that the busy handler has 2217** been invoked previously for the same locking event. ^If the 2218** busy callback returns 0, then no additional attempts are made to 2219** access the database and [SQLITE_BUSY] is returned 2220** to the application. 2221** ^If the callback returns non-zero, then another attempt 2222** is made to access the database and the cycle repeats. 2223** 2224** The presence of a busy handler does not guarantee that it will be invoked 2225** when there is lock contention. ^If SQLite determines that invoking the busy 2226** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2227** to the application instead of invoking the 2228** busy handler. 2229** Consider a scenario where one process is holding a read lock that 2230** it is trying to promote to a reserved lock and 2231** a second process is holding a reserved lock that it is trying 2232** to promote to an exclusive lock. The first process cannot proceed 2233** because it is blocked by the second and the second process cannot 2234** proceed because it is blocked by the first. If both processes 2235** invoke the busy handlers, neither will make any progress. Therefore, 2236** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2237** will induce the first process to release its read lock and allow 2238** the second process to proceed. 2239** 2240** ^The default busy callback is NULL. 2241** 2242** ^(There can only be a single busy handler defined for each 2243** [database connection]. Setting a new busy handler clears any 2244** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2245** or evaluating [PRAGMA busy_timeout=N] will change the 2246** busy handler and thus clear any previously set busy handler. 2247** 2248** The busy callback should not take any actions which modify the 2249** database connection that invoked the busy handler. In other words, 2250** the busy handler is not reentrant. Any such actions 2251** result in undefined behavior. 2252** 2253** A busy handler must not close the database connection 2254** or [prepared statement] that invoked the busy handler. 2255*/ 2256int sqlite3_busy_handler(sqlite3*, int(SQLITE_CALLBACK *)(void*,int), void*); 2257 2258/* 2259** CAPI3REF: Set A Busy Timeout 2260** METHOD: sqlite3 2261** 2262** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2263** for a specified amount of time when a table is locked. ^The handler 2264** will sleep multiple times until at least "ms" milliseconds of sleeping 2265** have accumulated. ^After at least "ms" milliseconds of sleeping, 2266** the handler returns 0 which causes [sqlite3_step()] to return 2267** [SQLITE_BUSY]. 2268** 2269** ^Calling this routine with an argument less than or equal to zero 2270** turns off all busy handlers. 2271** 2272** ^(There can only be a single busy handler for a particular 2273** [database connection] at any given moment. If another busy handler 2274** was defined (using [sqlite3_busy_handler()]) prior to calling 2275** this routine, that other busy handler is cleared.)^ 2276** 2277** See also: [PRAGMA busy_timeout] 2278*/ 2279int sqlite3_busy_timeout(sqlite3*, int ms); 2280 2281/* 2282** CAPI3REF: Convenience Routines For Running Queries 2283** METHOD: sqlite3 2284** 2285** This is a legacy interface that is preserved for backwards compatibility. 2286** Use of this interface is not recommended. 2287** 2288** Definition: A <b>result table</b> is memory data structure created by the 2289** [sqlite3_get_table()] interface. A result table records the 2290** complete query results from one or more queries. 2291** 2292** The table conceptually has a number of rows and columns. But 2293** these numbers are not part of the result table itself. These 2294** numbers are obtained separately. Let N be the number of rows 2295** and M be the number of columns. 2296** 2297** A result table is an array of pointers to zero-terminated UTF-8 strings. 2298** There are (N+1)*M elements in the array. The first M pointers point 2299** to zero-terminated strings that contain the names of the columns. 2300** The remaining entries all point to query results. NULL values result 2301** in NULL pointers. All other values are in their UTF-8 zero-terminated 2302** string representation as returned by [sqlite3_column_text()]. 2303** 2304** A result table might consist of one or more memory allocations. 2305** It is not safe to pass a result table directly to [sqlite3_free()]. 2306** A result table should be deallocated using [sqlite3_free_table()]. 2307** 2308** ^(As an example of the result table format, suppose a query result 2309** is as follows: 2310** 2311** <blockquote><pre> 2312** Name | Age 2313** ----------------------- 2314** Alice | 43 2315** Bob | 28 2316** Cindy | 21 2317** </pre></blockquote> 2318** 2319** There are two column (M==2) and three rows (N==3). Thus the 2320** result table has 8 entries. Suppose the result table is stored 2321** in an array names azResult. Then azResult holds this content: 2322** 2323** <blockquote><pre> 2324** azResult[0] = "Name"; 2325** azResult[1] = "Age"; 2326** azResult[2] = "Alice"; 2327** azResult[3] = "43"; 2328** azResult[4] = "Bob"; 2329** azResult[5] = "28"; 2330** azResult[6] = "Cindy"; 2331** azResult[7] = "21"; 2332** </pre></blockquote>)^ 2333** 2334** ^The sqlite3_get_table() function evaluates one or more 2335** semicolon-separated SQL statements in the zero-terminated UTF-8 2336** string of its 2nd parameter and returns a result table to the 2337** pointer given in its 3rd parameter. 2338** 2339** After the application has finished with the result from sqlite3_get_table(), 2340** it must pass the result table pointer to sqlite3_free_table() in order to 2341** release the memory that was malloced. Because of the way the 2342** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2343** function must not try to call [sqlite3_free()] directly. Only 2344** [sqlite3_free_table()] is able to release the memory properly and safely. 2345** 2346** The sqlite3_get_table() interface is implemented as a wrapper around 2347** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2348** to any internal data structures of SQLite. It uses only the public 2349** interface defined here. As a consequence, errors that occur in the 2350** wrapper layer outside of the internal [sqlite3_exec()] call are not 2351** reflected in subsequent calls to [sqlite3_errcode()] or 2352** [sqlite3_errmsg()]. 2353*/ 2354int sqlite3_get_table( 2355 sqlite3 *db, /* An open database */ 2356 const char *zSql, /* SQL to be evaluated */ 2357 char ***pazResult, /* Results of the query */ 2358 int *pnRow, /* Number of result rows written here */ 2359 int *pnColumn, /* Number of result columns written here */ 2360 char **pzErrmsg /* Error msg written here */ 2361); 2362void sqlite3_free_table(char **result); 2363 2364/* 2365** CAPI3REF: Formatted String Printing Functions 2366** 2367** These routines are work-alikes of the "printf()" family of functions 2368** from the standard C library. 2369** These routines understand most of the common K&R formatting options, 2370** plus some additional non-standard formats, detailed below. 2371** Note that some of the more obscure formatting options from recent 2372** C-library standards are omitted from this implementation. 2373** 2374** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2375** results into memory obtained from [sqlite3_malloc()]. 2376** The strings returned by these two routines should be 2377** released by [sqlite3_free()]. ^Both routines return a 2378** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2379** memory to hold the resulting string. 2380** 2381** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2382** the standard C library. The result is written into the 2383** buffer supplied as the second parameter whose size is given by 2384** the first parameter. Note that the order of the 2385** first two parameters is reversed from snprintf().)^ This is an 2386** historical accident that cannot be fixed without breaking 2387** backwards compatibility. ^(Note also that sqlite3_snprintf() 2388** returns a pointer to its buffer instead of the number of 2389** characters actually written into the buffer.)^ We admit that 2390** the number of characters written would be a more useful return 2391** value but we cannot change the implementation of sqlite3_snprintf() 2392** now without breaking compatibility. 2393** 2394** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2395** guarantees that the buffer is always zero-terminated. ^The first 2396** parameter "n" is the total size of the buffer, including space for 2397** the zero terminator. So the longest string that can be completely 2398** written will be n-1 characters. 2399** 2400** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2401** 2402** These routines all implement some additional formatting 2403** options that are useful for constructing SQL statements. 2404** All of the usual printf() formatting options apply. In addition, there 2405** is are "%q", "%Q", "%w" and "%z" options. 2406** 2407** ^(The %q option works like %s in that it substitutes a nul-terminated 2408** string from the argument list. But %q also doubles every '\'' character. 2409** %q is designed for use inside a string literal.)^ By doubling each '\'' 2410** character it escapes that character and allows it to be inserted into 2411** the string. 2412** 2413** For example, assume the string variable zText contains text as follows: 2414** 2415** <blockquote><pre> 2416** char *zText = "It's a happy day!"; 2417** </pre></blockquote> 2418** 2419** One can use this text in an SQL statement as follows: 2420** 2421** <blockquote><pre> 2422** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2423** sqlite3_exec(db, zSQL, 0, 0, 0); 2424** sqlite3_free(zSQL); 2425** </pre></blockquote> 2426** 2427** Because the %q format string is used, the '\'' character in zText 2428** is escaped and the SQL generated is as follows: 2429** 2430** <blockquote><pre> 2431** INSERT INTO table1 VALUES('It''s a happy day!') 2432** </pre></blockquote> 2433** 2434** This is correct. Had we used %s instead of %q, the generated SQL 2435** would have looked like this: 2436** 2437** <blockquote><pre> 2438** INSERT INTO table1 VALUES('It's a happy day!'); 2439** </pre></blockquote> 2440** 2441** This second example is an SQL syntax error. As a general rule you should 2442** always use %q instead of %s when inserting text into a string literal. 2443** 2444** ^(The %Q option works like %q except it also adds single quotes around 2445** the outside of the total string. Additionally, if the parameter in the 2446** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2447** single quotes).)^ So, for example, one could say: 2448** 2449** <blockquote><pre> 2450** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2451** sqlite3_exec(db, zSQL, 0, 0, 0); 2452** sqlite3_free(zSQL); 2453** </pre></blockquote> 2454** 2455** The code above will render a correct SQL statement in the zSQL 2456** variable even if the zText variable is a NULL pointer. 2457** 2458** ^(The "%w" formatting option is like "%q" except that it expects to 2459** be contained within double-quotes instead of single quotes, and it 2460** escapes the double-quote character instead of the single-quote 2461** character.)^ The "%w" formatting option is intended for safely inserting 2462** table and column names into a constructed SQL statement. 2463** 2464** ^(The "%z" formatting option works like "%s" but with the 2465** addition that after the string has been read and copied into 2466** the result, [sqlite3_free()] is called on the input string.)^ 2467*/ 2468char *sqlite3_mprintf(const char*,...); 2469char *sqlite3_vmprintf(const char*, va_list); 2470char *sqlite3_snprintf(int,char*,const char*, ...); 2471char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2472 2473/* 2474** CAPI3REF: Memory Allocation Subsystem 2475** 2476** The SQLite core uses these three routines for all of its own 2477** internal memory allocation needs. "Core" in the previous sentence 2478** does not include operating-system specific VFS implementation. The 2479** Windows VFS uses native malloc() and free() for some operations. 2480** 2481** ^The sqlite3_malloc() routine returns a pointer to a block 2482** of memory at least N bytes in length, where N is the parameter. 2483** ^If sqlite3_malloc() is unable to obtain sufficient free 2484** memory, it returns a NULL pointer. ^If the parameter N to 2485** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2486** a NULL pointer. 2487** 2488** ^The sqlite3_malloc64(N) routine works just like 2489** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2490** of a signed 32-bit integer. 2491** 2492** ^Calling sqlite3_free() with a pointer previously returned 2493** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2494** that it might be reused. ^The sqlite3_free() routine is 2495** a no-op if is called with a NULL pointer. Passing a NULL pointer 2496** to sqlite3_free() is harmless. After being freed, memory 2497** should neither be read nor written. Even reading previously freed 2498** memory might result in a segmentation fault or other severe error. 2499** Memory corruption, a segmentation fault, or other severe error 2500** might result if sqlite3_free() is called with a non-NULL pointer that 2501** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2502** 2503** ^The sqlite3_realloc(X,N) interface attempts to resize a 2504** prior memory allocation X to be at least N bytes. 2505** ^If the X parameter to sqlite3_realloc(X,N) 2506** is a NULL pointer then its behavior is identical to calling 2507** sqlite3_malloc(N). 2508** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2509** negative then the behavior is exactly the same as calling 2510** sqlite3_free(X). 2511** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2512** of at least N bytes in size or NULL if insufficient memory is available. 2513** ^If M is the size of the prior allocation, then min(N,M) bytes 2514** of the prior allocation are copied into the beginning of buffer returned 2515** by sqlite3_realloc(X,N) and the prior allocation is freed. 2516** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2517** prior allocation is not freed. 2518** 2519** ^The sqlite3_realloc64(X,N) interfaces works the same as 2520** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2521** of a 32-bit signed integer. 2522** 2523** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2524** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2525** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2526** ^The value returned by sqlite3_msize(X) might be larger than the number 2527** of bytes requested when X was allocated. ^If X is a NULL pointer then 2528** sqlite3_msize(X) returns zero. If X points to something that is not 2529** the beginning of memory allocation, or if it points to a formerly 2530** valid memory allocation that has now been freed, then the behavior 2531** of sqlite3_msize(X) is undefined and possibly harmful. 2532** 2533** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2534** sqlite3_malloc64(), and sqlite3_realloc64() 2535** is always aligned to at least an 8 byte boundary, or to a 2536** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2537** option is used. 2538** 2539** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2540** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2541** implementation of these routines to be omitted. That capability 2542** is no longer provided. Only built-in memory allocators can be used. 2543** 2544** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2545** the system malloc() and free() directly when converting 2546** filenames between the UTF-8 encoding used by SQLite 2547** and whatever filename encoding is used by the particular Windows 2548** installation. Memory allocation errors were detected, but 2549** they were reported back as [SQLITE_CANTOPEN] or 2550** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2551** 2552** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2553** must be either NULL or else pointers obtained from a prior 2554** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2555** not yet been released. 2556** 2557** The application must not read or write any part of 2558** a block of memory after it has been released using 2559** [sqlite3_free()] or [sqlite3_realloc()]. 2560*/ 2561void *sqlite3_malloc(int); 2562void *sqlite3_malloc64(sqlite3_uint64); 2563void *sqlite3_realloc(void*, int); 2564void *sqlite3_realloc64(void*, sqlite3_uint64); 2565void sqlite3_free(void*); 2566sqlite3_uint64 sqlite3_msize(void*); 2567 2568/* 2569** CAPI3REF: Memory Allocator Statistics 2570** 2571** SQLite provides these two interfaces for reporting on the status 2572** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2573** routines, which form the built-in memory allocation subsystem. 2574** 2575** ^The [sqlite3_memory_used()] routine returns the number of bytes 2576** of memory currently outstanding (malloced but not freed). 2577** ^The [sqlite3_memory_highwater()] routine returns the maximum 2578** value of [sqlite3_memory_used()] since the high-water mark 2579** was last reset. ^The values returned by [sqlite3_memory_used()] and 2580** [sqlite3_memory_highwater()] include any overhead 2581** added by SQLite in its implementation of [sqlite3_malloc()], 2582** but not overhead added by the any underlying system library 2583** routines that [sqlite3_malloc()] may call. 2584** 2585** ^The memory high-water mark is reset to the current value of 2586** [sqlite3_memory_used()] if and only if the parameter to 2587** [sqlite3_memory_highwater()] is true. ^The value returned 2588** by [sqlite3_memory_highwater(1)] is the high-water mark 2589** prior to the reset. 2590*/ 2591sqlite3_int64 sqlite3_memory_used(void); 2592sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2593 2594/* 2595** CAPI3REF: Pseudo-Random Number Generator 2596** 2597** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2598** select random [ROWID | ROWIDs] when inserting new records into a table that 2599** already uses the largest possible [ROWID]. The PRNG is also used for 2600** the build-in random() and randomblob() SQL functions. This interface allows 2601** applications to access the same PRNG for other purposes. 2602** 2603** ^A call to this routine stores N bytes of randomness into buffer P. 2604** ^The P parameter can be a NULL pointer. 2605** 2606** ^If this routine has not been previously called or if the previous 2607** call had N less than one or a NULL pointer for P, then the PRNG is 2608** seeded using randomness obtained from the xRandomness method of 2609** the default [sqlite3_vfs] object. 2610** ^If the previous call to this routine had an N of 1 or more and a 2611** non-NULL P then the pseudo-randomness is generated 2612** internally and without recourse to the [sqlite3_vfs] xRandomness 2613** method. 2614*/ 2615void sqlite3_randomness(int N, void *P); 2616 2617/* 2618** CAPI3REF: Compile-Time Authorization Callbacks 2619** METHOD: sqlite3 2620** 2621** ^This routine registers an authorizer callback with a particular 2622** [database connection], supplied in the first argument. 2623** ^The authorizer callback is invoked as SQL statements are being compiled 2624** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2625** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2626** points during the compilation process, as logic is being created 2627** to perform various actions, the authorizer callback is invoked to 2628** see if those actions are allowed. ^The authorizer callback should 2629** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2630** specific action but allow the SQL statement to continue to be 2631** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2632** rejected with an error. ^If the authorizer callback returns 2633** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2634** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2635** the authorizer will fail with an error message. 2636** 2637** When the callback returns [SQLITE_OK], that means the operation 2638** requested is ok. ^When the callback returns [SQLITE_DENY], the 2639** [sqlite3_prepare_v2()] or equivalent call that triggered the 2640** authorizer will fail with an error message explaining that 2641** access is denied. 2642** 2643** ^The first parameter to the authorizer callback is a copy of the third 2644** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2645** to the callback is an integer [SQLITE_COPY | action code] that specifies 2646** the particular action to be authorized. ^The third through sixth parameters 2647** to the callback are zero-terminated strings that contain additional 2648** details about the action to be authorized. 2649** 2650** ^If the action code is [SQLITE_READ] 2651** and the callback returns [SQLITE_IGNORE] then the 2652** [prepared statement] statement is constructed to substitute 2653** a NULL value in place of the table column that would have 2654** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2655** return can be used to deny an untrusted user access to individual 2656** columns of a table. 2657** ^If the action code is [SQLITE_DELETE] and the callback returns 2658** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2659** [truncate optimization] is disabled and all rows are deleted individually. 2660** 2661** An authorizer is used when [sqlite3_prepare | preparing] 2662** SQL statements from an untrusted source, to ensure that the SQL statements 2663** do not try to access data they are not allowed to see, or that they do not 2664** try to execute malicious statements that damage the database. For 2665** example, an application may allow a user to enter arbitrary 2666** SQL queries for evaluation by a database. But the application does 2667** not want the user to be able to make arbitrary changes to the 2668** database. An authorizer could then be put in place while the 2669** user-entered SQL is being [sqlite3_prepare | prepared] that 2670** disallows everything except [SELECT] statements. 2671** 2672** Applications that need to process SQL from untrusted sources 2673** might also consider lowering resource limits using [sqlite3_limit()] 2674** and limiting database size using the [max_page_count] [PRAGMA] 2675** in addition to using an authorizer. 2676** 2677** ^(Only a single authorizer can be in place on a database connection 2678** at a time. Each call to sqlite3_set_authorizer overrides the 2679** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2680** The authorizer is disabled by default. 2681** 2682** The authorizer callback must not do anything that will modify 2683** the database connection that invoked the authorizer callback. 2684** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2685** database connections for the meaning of "modify" in this paragraph. 2686** 2687** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2688** statement might be re-prepared during [sqlite3_step()] due to a 2689** schema change. Hence, the application should ensure that the 2690** correct authorizer callback remains in place during the [sqlite3_step()]. 2691** 2692** ^Note that the authorizer callback is invoked only during 2693** [sqlite3_prepare()] or its variants. Authorization is not 2694** performed during statement evaluation in [sqlite3_step()], unless 2695** as stated in the previous paragraph, sqlite3_step() invokes 2696** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2697*/ 2698int sqlite3_set_authorizer( 2699 sqlite3*, 2700 int (SQLITE_CALLBACK *xAuth)(void*,int,const char*,const char*,const char*, 2701 const char*), 2702 void *pUserData 2703); 2704 2705/* 2706** CAPI3REF: Authorizer Return Codes 2707** 2708** The [sqlite3_set_authorizer | authorizer callback function] must 2709** return either [SQLITE_OK] or one of these two constants in order 2710** to signal SQLite whether or not the action is permitted. See the 2711** [sqlite3_set_authorizer | authorizer documentation] for additional 2712** information. 2713** 2714** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2715** returned from the [sqlite3_vtab_on_conflict()] interface. 2716*/ 2717#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2718#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2719 2720/* 2721** CAPI3REF: Authorizer Action Codes 2722** 2723** The [sqlite3_set_authorizer()] interface registers a callback function 2724** that is invoked to authorize certain SQL statement actions. The 2725** second parameter to the callback is an integer code that specifies 2726** what action is being authorized. These are the integer action codes that 2727** the authorizer callback may be passed. 2728** 2729** These action code values signify what kind of operation is to be 2730** authorized. The 3rd and 4th parameters to the authorization 2731** callback function will be parameters or NULL depending on which of these 2732** codes is used as the second parameter. ^(The 5th parameter to the 2733** authorizer callback is the name of the database ("main", "temp", 2734** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2735** is the name of the inner-most trigger or view that is responsible for 2736** the access attempt or NULL if this access attempt is directly from 2737** top-level SQL code. 2738*/ 2739/******************************************* 3rd ************ 4th ***********/ 2740#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2741#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2742#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2743#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2744#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2745#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2746#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2747#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2748#define SQLITE_DELETE 9 /* Table Name NULL */ 2749#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2750#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2751#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2752#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2753#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2754#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2755#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2756#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2757#define SQLITE_INSERT 18 /* Table Name NULL */ 2758#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2759#define SQLITE_READ 20 /* Table Name Column Name */ 2760#define SQLITE_SELECT 21 /* NULL NULL */ 2761#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2762#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2763#define SQLITE_ATTACH 24 /* Filename NULL */ 2764#define SQLITE_DETACH 25 /* Database Name NULL */ 2765#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2766#define SQLITE_REINDEX 27 /* Index Name NULL */ 2767#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2768#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2769#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2770#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2771#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2772#define SQLITE_COPY 0 /* No longer used */ 2773#define SQLITE_RECURSIVE 33 /* NULL NULL */ 2774 2775/* 2776** CAPI3REF: Tracing And Profiling Functions 2777** METHOD: sqlite3 2778** 2779** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 2780** instead of the routines described here. 2781** 2782** These routines register callback functions that can be used for 2783** tracing and profiling the execution of SQL statements. 2784** 2785** ^The callback function registered by sqlite3_trace() is invoked at 2786** various times when an SQL statement is being run by [sqlite3_step()]. 2787** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2788** SQL statement text as the statement first begins executing. 2789** ^(Additional sqlite3_trace() callbacks might occur 2790** as each triggered subprogram is entered. The callbacks for triggers 2791** contain a UTF-8 SQL comment that identifies the trigger.)^ 2792** 2793** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2794** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2795** 2796** ^The callback function registered by sqlite3_profile() is invoked 2797** as each SQL statement finishes. ^The profile callback contains 2798** the original statement text and an estimate of wall-clock time 2799** of how long that statement took to run. ^The profile callback 2800** time is in units of nanoseconds, however the current implementation 2801** is only capable of millisecond resolution so the six least significant 2802** digits in the time are meaningless. Future versions of SQLite 2803** might provide greater resolution on the profiler callback. The 2804** sqlite3_profile() function is considered experimental and is 2805** subject to change in future versions of SQLite. 2806*/ 2807SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 2808 void(SQLITE_CALLBACK *xTrace)(void*,const char*), void*); 2809SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 2810 void(SQLITE_CALLBACK *xProfile)(void*,const char*,sqlite3_uint64), void*); 2811 2812/* 2813** CAPI3REF: SQL Trace Event Codes 2814** KEYWORDS: SQLITE_TRACE 2815** 2816** These constants identify classes of events that can be monitored 2817** using the [sqlite3_trace_v2()] tracing logic. The third argument 2818** to [sqlite3_trace_v2()] is an OR-ed combination of one or more of 2819** the following constants. ^The first argument to the trace callback 2820** is one of the following constants. 2821** 2822** New tracing constants may be added in future releases. 2823** 2824** ^A trace callback has four arguments: xCallback(T,C,P,X). 2825** ^The T argument is one of the integer type codes above. 2826** ^The C argument is a copy of the context pointer passed in as the 2827** fourth argument to [sqlite3_trace_v2()]. 2828** The P and X arguments are pointers whose meanings depend on T. 2829** 2830** <dl> 2831** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 2832** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 2833** first begins running and possibly at other times during the 2834** execution of the prepared statement, such as at the start of each 2835** trigger subprogram. ^The P argument is a pointer to the 2836** [prepared statement]. ^The X argument is a pointer to a string which 2837** is the unexpanded SQL text of the prepared statement or an SQL comment 2838** that indicates the invocation of a trigger. ^The callback can compute 2839** the same text that would have been returned by the legacy [sqlite3_trace()] 2840** interface by using the X argument when X begins with "--" and invoking 2841** [sqlite3_expanded_sql(P)] otherwise. 2842** 2843** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 2844** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 2845** information as is provided by the [sqlite3_profile()] callback. 2846** ^The P argument is a pointer to the [prepared statement] and the 2847** X argument points to a 64-bit integer which is the estimated of 2848** the number of nanosecond that the prepared statement took to run. 2849** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 2850** 2851** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 2852** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 2853** statement generates a single row of result. 2854** ^The P argument is a pointer to the [prepared statement] and the 2855** X argument is unused. 2856** 2857** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 2858** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 2859** connection closes. 2860** ^The P argument is a pointer to the [database connection] object 2861** and the X argument is unused. 2862** </dl> 2863*/ 2864#define SQLITE_TRACE_STMT 0x01 2865#define SQLITE_TRACE_PROFILE 0x02 2866#define SQLITE_TRACE_ROW 0x04 2867#define SQLITE_TRACE_CLOSE 0x08 2868 2869/* 2870** CAPI3REF: SQL Trace Hook 2871** METHOD: sqlite3 2872** 2873** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 2874** function X against [database connection] D, using property mask M 2875** and context pointer P. ^If the X callback is 2876** NULL or if the M mask is zero, then tracing is disabled. The 2877** M argument should be the bitwise OR-ed combination of 2878** zero or more [SQLITE_TRACE] constants. 2879** 2880** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 2881** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 2882** 2883** ^The X callback is invoked whenever any of the events identified by 2884** mask M occur. ^The integer return value from the callback is currently 2885** ignored, though this may change in future releases. Callback 2886** implementations should return zero to ensure future compatibility. 2887** 2888** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 2889** ^The T argument is one of the [SQLITE_TRACE] 2890** constants to indicate why the callback was invoked. 2891** ^The C argument is a copy of the context pointer. 2892** The P and X arguments are pointers whose meanings depend on T. 2893** 2894** The sqlite3_trace_v2() interface is intended to replace the legacy 2895** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 2896** are deprecated. 2897*/ 2898int sqlite3_trace_v2( 2899 sqlite3*, 2900 unsigned uMask, 2901 int(SQLITE_CALLBACK *xCallback)(unsigned,void*,void*,void*), 2902 void *pCtx 2903); 2904 2905/* 2906** CAPI3REF: Query Progress Callbacks 2907** METHOD: sqlite3 2908** 2909** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2910** function X to be invoked periodically during long running calls to 2911** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2912** database connection D. An example use for this 2913** interface is to keep a GUI updated during a large query. 2914** 2915** ^The parameter P is passed through as the only parameter to the 2916** callback function X. ^The parameter N is the approximate number of 2917** [virtual machine instructions] that are evaluated between successive 2918** invocations of the callback X. ^If N is less than one then the progress 2919** handler is disabled. 2920** 2921** ^Only a single progress handler may be defined at one time per 2922** [database connection]; setting a new progress handler cancels the 2923** old one. ^Setting parameter X to NULL disables the progress handler. 2924** ^The progress handler is also disabled by setting N to a value less 2925** than 1. 2926** 2927** ^If the progress callback returns non-zero, the operation is 2928** interrupted. This feature can be used to implement a 2929** "Cancel" button on a GUI progress dialog box. 2930** 2931** The progress handler callback must not do anything that will modify 2932** the database connection that invoked the progress handler. 2933** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2934** database connections for the meaning of "modify" in this paragraph. 2935** 2936*/ 2937void sqlite3_progress_handler(sqlite3*,int,int(SQLITE_CALLBACK *)(void*),void*); 2938 2939/* 2940** CAPI3REF: Opening A New Database Connection 2941** CONSTRUCTOR: sqlite3 2942** 2943** ^These routines open an SQLite database file as specified by the 2944** filename argument. ^The filename argument is interpreted as UTF-8 for 2945** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2946** order for sqlite3_open16(). ^(A [database connection] handle is usually 2947** returned in *ppDb, even if an error occurs. The only exception is that 2948** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2949** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2950** object.)^ ^(If the database is opened (and/or created) successfully, then 2951** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2952** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2953** an English language description of the error following a failure of any 2954** of the sqlite3_open() routines. 2955** 2956** ^The default encoding will be UTF-8 for databases created using 2957** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 2958** created using sqlite3_open16() will be UTF-16 in the native byte order. 2959** 2960** Whether or not an error occurs when it is opened, resources 2961** associated with the [database connection] handle should be released by 2962** passing it to [sqlite3_close()] when it is no longer required. 2963** 2964** The sqlite3_open_v2() interface works like sqlite3_open() 2965** except that it accepts two additional parameters for additional control 2966** over the new database connection. ^(The flags parameter to 2967** sqlite3_open_v2() can take one of 2968** the following three values, optionally combined with the 2969** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2970** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 2971** 2972** <dl> 2973** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2974** <dd>The database is opened in read-only mode. If the database does not 2975** already exist, an error is returned.</dd>)^ 2976** 2977** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2978** <dd>The database is opened for reading and writing if possible, or reading 2979** only if the file is write protected by the operating system. In either 2980** case the database must already exist, otherwise an error is returned.</dd>)^ 2981** 2982** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2983** <dd>The database is opened for reading and writing, and is created if 2984** it does not already exist. This is the behavior that is always used for 2985** sqlite3_open() and sqlite3_open16().</dd>)^ 2986** </dl> 2987** 2988** If the 3rd parameter to sqlite3_open_v2() is not one of the 2989** combinations shown above optionally combined with other 2990** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 2991** then the behavior is undefined. 2992** 2993** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2994** opens in the multi-thread [threading mode] as long as the single-thread 2995** mode has not been set at compile-time or start-time. ^If the 2996** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2997** in the serialized [threading mode] unless single-thread was 2998** previously selected at compile-time or start-time. 2999** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 3000** eligible to use [shared cache mode], regardless of whether or not shared 3001** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 3002** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 3003** participate in [shared cache mode] even if it is enabled. 3004** 3005** ^The fourth parameter to sqlite3_open_v2() is the name of the 3006** [sqlite3_vfs] object that defines the operating system interface that 3007** the new database connection should use. ^If the fourth parameter is 3008** a NULL pointer then the default [sqlite3_vfs] object is used. 3009** 3010** ^If the filename is ":memory:", then a private, temporary in-memory database 3011** is created for the connection. ^This in-memory database will vanish when 3012** the database connection is closed. Future versions of SQLite might 3013** make use of additional special filenames that begin with the ":" character. 3014** It is recommended that when a database filename actually does begin with 3015** a ":" character you should prefix the filename with a pathname such as 3016** "./" to avoid ambiguity. 3017** 3018** ^If the filename is an empty string, then a private, temporary 3019** on-disk database will be created. ^This private database will be 3020** automatically deleted as soon as the database connection is closed. 3021** 3022** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3023** 3024** ^If [URI filename] interpretation is enabled, and the filename argument 3025** begins with "file:", then the filename is interpreted as a URI. ^URI 3026** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3027** set in the fourth argument to sqlite3_open_v2(), or if it has 3028** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3029** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3030** As of SQLite version 3.7.7, URI filename interpretation is turned off 3031** by default, but future releases of SQLite might enable URI filename 3032** interpretation by default. See "[URI filenames]" for additional 3033** information. 3034** 3035** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3036** authority, then it must be either an empty string or the string 3037** "localhost". ^If the authority is not an empty string or "localhost", an 3038** error is returned to the caller. ^The fragment component of a URI, if 3039** present, is ignored. 3040** 3041** ^SQLite uses the path component of the URI as the name of the disk file 3042** which contains the database. ^If the path begins with a '/' character, 3043** then it is interpreted as an absolute path. ^If the path does not begin 3044** with a '/' (meaning that the authority section is omitted from the URI) 3045** then the path is interpreted as a relative path. 3046** ^(On windows, the first component of an absolute path 3047** is a drive specification (e.g. "C:").)^ 3048** 3049** [[core URI query parameters]] 3050** The query component of a URI may contain parameters that are interpreted 3051** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3052** SQLite and its built-in [VFSes] interpret the 3053** following query parameters: 3054** 3055** <ul> 3056** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3057** a VFS object that provides the operating system interface that should 3058** be used to access the database file on disk. ^If this option is set to 3059** an empty string the default VFS object is used. ^Specifying an unknown 3060** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3061** present, then the VFS specified by the option takes precedence over 3062** the value passed as the fourth parameter to sqlite3_open_v2(). 3063** 3064** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3065** "rwc", or "memory". Attempting to set it to any other value is 3066** an error)^. 3067** ^If "ro" is specified, then the database is opened for read-only 3068** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3069** third argument to sqlite3_open_v2(). ^If the mode option is set to 3070** "rw", then the database is opened for read-write (but not create) 3071** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3072** been set. ^Value "rwc" is equivalent to setting both 3073** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3074** set to "memory" then a pure [in-memory database] that never reads 3075** or writes from disk is used. ^It is an error to specify a value for 3076** the mode parameter that is less restrictive than that specified by 3077** the flags passed in the third parameter to sqlite3_open_v2(). 3078** 3079** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3080** "private". ^Setting it to "shared" is equivalent to setting the 3081** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3082** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3083** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3084** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3085** a URI filename, its value overrides any behavior requested by setting 3086** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3087** 3088** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3089** [powersafe overwrite] property does or does not apply to the 3090** storage media on which the database file resides. 3091** 3092** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3093** which if set disables file locking in rollback journal modes. This 3094** is useful for accessing a database on a filesystem that does not 3095** support locking. Caution: Database corruption might result if two 3096** or more processes write to the same database and any one of those 3097** processes uses nolock=1. 3098** 3099** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3100** parameter that indicates that the database file is stored on 3101** read-only media. ^When immutable is set, SQLite assumes that the 3102** database file cannot be changed, even by a process with higher 3103** privilege, and so the database is opened read-only and all locking 3104** and change detection is disabled. Caution: Setting the immutable 3105** property on a database file that does in fact change can result 3106** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3107** See also: [SQLITE_IOCAP_IMMUTABLE]. 3108** 3109** </ul> 3110** 3111** ^Specifying an unknown parameter in the query component of a URI is not an 3112** error. Future versions of SQLite might understand additional query 3113** parameters. See "[query parameters with special meaning to SQLite]" for 3114** additional information. 3115** 3116** [[URI filename examples]] <h3>URI filename examples</h3> 3117** 3118** <table border="1" align=center cellpadding=5> 3119** <tr><th> URI filenames <th> Results 3120** <tr><td> file:data.db <td> 3121** Open the file "data.db" in the current directory. 3122** <tr><td> file:/home/fred/data.db<br> 3123** file:///home/fred/data.db <br> 3124** file://localhost/home/fred/data.db <br> <td> 3125** Open the database file "/home/fred/data.db". 3126** <tr><td> file://darkstar/home/fred/data.db <td> 3127** An error. "darkstar" is not a recognized authority. 3128** <tr><td style="white-space:nowrap"> 3129** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3130** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3131** C:. Note that the %20 escaping in this example is not strictly 3132** necessary - space characters can be used literally 3133** in URI filenames. 3134** <tr><td> file:data.db?mode=ro&cache=private <td> 3135** Open file "data.db" in the current directory for read-only access. 3136** Regardless of whether or not shared-cache mode is enabled by 3137** default, use a private cache. 3138** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3139** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3140** that uses dot-files in place of posix advisory locking. 3141** <tr><td> file:data.db?mode=readonly <td> 3142** An error. "readonly" is not a valid option for the "mode" parameter. 3143** </table> 3144** 3145** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3146** query components of a URI. A hexadecimal escape sequence consists of a 3147** percent sign - "%" - followed by exactly two hexadecimal digits 3148** specifying an octet value. ^Before the path or query components of a 3149** URI filename are interpreted, they are encoded using UTF-8 and all 3150** hexadecimal escape sequences replaced by a single byte containing the 3151** corresponding octet. If this process generates an invalid UTF-8 encoding, 3152** the results are undefined. 3153** 3154** <b>Note to Windows users:</b> The encoding used for the filename argument 3155** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3156** codepage is currently defined. Filenames containing international 3157** characters must be converted to UTF-8 prior to passing them into 3158** sqlite3_open() or sqlite3_open_v2(). 3159** 3160** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3161** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3162** features that require the use of temporary files may fail. 3163** 3164** See also: [sqlite3_temp_directory] 3165*/ 3166int sqlite3_open( 3167 const char *filename, /* Database filename (UTF-8) */ 3168 sqlite3 **ppDb /* OUT: SQLite db handle */ 3169); 3170int sqlite3_open16( 3171 const void *filename, /* Database filename (UTF-16) */ 3172 sqlite3 **ppDb /* OUT: SQLite db handle */ 3173); 3174int sqlite3_open_v2( 3175 const char *filename, /* Database filename (UTF-8) */ 3176 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3177 int flags, /* Flags */ 3178 const char *zVfs /* Name of VFS module to use */ 3179); 3180 3181/* 3182** CAPI3REF: Obtain Values For URI Parameters 3183** 3184** These are utility routines, useful to VFS implementations, that check 3185** to see if a database file was a URI that contained a specific query 3186** parameter, and if so obtains the value of that query parameter. 3187** 3188** If F is the database filename pointer passed into the xOpen() method of 3189** a VFS implementation when the flags parameter to xOpen() has one or 3190** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3191** P is the name of the query parameter, then 3192** sqlite3_uri_parameter(F,P) returns the value of the P 3193** parameter if it exists or a NULL pointer if P does not appear as a 3194** query parameter on F. If P is a query parameter of F 3195** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3196** a pointer to an empty string. 3197** 3198** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3199** parameter and returns true (1) or false (0) according to the value 3200** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3201** value of query parameter P is one of "yes", "true", or "on" in any 3202** case or if the value begins with a non-zero number. The 3203** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3204** query parameter P is one of "no", "false", or "off" in any case or 3205** if the value begins with a numeric zero. If P is not a query 3206** parameter on F or if the value of P is does not match any of the 3207** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3208** 3209** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3210** 64-bit signed integer and returns that integer, or D if P does not 3211** exist. If the value of P is something other than an integer, then 3212** zero is returned. 3213** 3214** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3215** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3216** is not a database file pathname pointer that SQLite passed into the xOpen 3217** VFS method, then the behavior of this routine is undefined and probably 3218** undesirable. 3219*/ 3220const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3221int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3222sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3223 3224 3225/* 3226** CAPI3REF: Error Codes And Messages 3227** METHOD: sqlite3 3228** 3229** ^If the most recent sqlite3_* API call associated with 3230** [database connection] D failed, then the sqlite3_errcode(D) interface 3231** returns the numeric [result code] or [extended result code] for that 3232** API call. 3233** If the most recent API call was successful, 3234** then the return value from sqlite3_errcode() is undefined. 3235** ^The sqlite3_extended_errcode() 3236** interface is the same except that it always returns the 3237** [extended result code] even when extended result codes are 3238** disabled. 3239** 3240** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3241** text that describes the error, as either UTF-8 or UTF-16 respectively. 3242** ^(Memory to hold the error message string is managed internally. 3243** The application does not need to worry about freeing the result. 3244** However, the error string might be overwritten or deallocated by 3245** subsequent calls to other SQLite interface functions.)^ 3246** 3247** ^The sqlite3_errstr() interface returns the English-language text 3248** that describes the [result code], as UTF-8. 3249** ^(Memory to hold the error message string is managed internally 3250** and must not be freed by the application)^. 3251** 3252** When the serialized [threading mode] is in use, it might be the 3253** case that a second error occurs on a separate thread in between 3254** the time of the first error and the call to these interfaces. 3255** When that happens, the second error will be reported since these 3256** interfaces always report the most recent result. To avoid 3257** this, each thread can obtain exclusive use of the [database connection] D 3258** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3259** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3260** all calls to the interfaces listed here are completed. 3261** 3262** If an interface fails with SQLITE_MISUSE, that means the interface 3263** was invoked incorrectly by the application. In that case, the 3264** error code and message may or may not be set. 3265*/ 3266int sqlite3_errcode(sqlite3 *db); 3267int sqlite3_extended_errcode(sqlite3 *db); 3268const char *sqlite3_errmsg(sqlite3*); 3269const void *sqlite3_errmsg16(sqlite3*); 3270const char *sqlite3_errstr(int); 3271 3272/* 3273** CAPI3REF: Prepared Statement Object 3274** KEYWORDS: {prepared statement} {prepared statements} 3275** 3276** An instance of this object represents a single SQL statement that 3277** has been compiled into binary form and is ready to be evaluated. 3278** 3279** Think of each SQL statement as a separate computer program. The 3280** original SQL text is source code. A prepared statement object 3281** is the compiled object code. All SQL must be converted into a 3282** prepared statement before it can be run. 3283** 3284** The life-cycle of a prepared statement object usually goes like this: 3285** 3286** <ol> 3287** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3288** <li> Bind values to [parameters] using the sqlite3_bind_*() 3289** interfaces. 3290** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3291** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3292** to step 2. Do this zero or more times. 3293** <li> Destroy the object using [sqlite3_finalize()]. 3294** </ol> 3295*/ 3296typedef struct sqlite3_stmt sqlite3_stmt; 3297 3298/* 3299** CAPI3REF: Run-time Limits 3300** METHOD: sqlite3 3301** 3302** ^(This interface allows the size of various constructs to be limited 3303** on a connection by connection basis. The first parameter is the 3304** [database connection] whose limit is to be set or queried. The 3305** second parameter is one of the [limit categories] that define a 3306** class of constructs to be size limited. The third parameter is the 3307** new limit for that construct.)^ 3308** 3309** ^If the new limit is a negative number, the limit is unchanged. 3310** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3311** [limits | hard upper bound] 3312** set at compile-time by a C preprocessor macro called 3313** [limits | SQLITE_MAX_<i>NAME</i>]. 3314** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3315** ^Attempts to increase a limit above its hard upper bound are 3316** silently truncated to the hard upper bound. 3317** 3318** ^Regardless of whether or not the limit was changed, the 3319** [sqlite3_limit()] interface returns the prior value of the limit. 3320** ^Hence, to find the current value of a limit without changing it, 3321** simply invoke this interface with the third parameter set to -1. 3322** 3323** Run-time limits are intended for use in applications that manage 3324** both their own internal database and also databases that are controlled 3325** by untrusted external sources. An example application might be a 3326** web browser that has its own databases for storing history and 3327** separate databases controlled by JavaScript applications downloaded 3328** off the Internet. The internal databases can be given the 3329** large, default limits. Databases managed by external sources can 3330** be given much smaller limits designed to prevent a denial of service 3331** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3332** interface to further control untrusted SQL. The size of the database 3333** created by an untrusted script can be contained using the 3334** [max_page_count] [PRAGMA]. 3335** 3336** New run-time limit categories may be added in future releases. 3337*/ 3338int sqlite3_limit(sqlite3*, int id, int newVal); 3339 3340/* 3341** CAPI3REF: Run-Time Limit Categories 3342** KEYWORDS: {limit category} {*limit categories} 3343** 3344** These constants define various performance limits 3345** that can be lowered at run-time using [sqlite3_limit()]. 3346** The synopsis of the meanings of the various limits is shown below. 3347** Additional information is available at [limits | Limits in SQLite]. 3348** 3349** <dl> 3350** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3351** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3352** 3353** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3354** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3355** 3356** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3357** <dd>The maximum number of columns in a table definition or in the 3358** result set of a [SELECT] or the maximum number of columns in an index 3359** or in an ORDER BY or GROUP BY clause.</dd>)^ 3360** 3361** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3362** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3363** 3364** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3365** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3366** 3367** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3368** <dd>The maximum number of instructions in a virtual machine program 3369** used to implement an SQL statement. This limit is not currently 3370** enforced, though that might be added in some future release of 3371** SQLite.</dd>)^ 3372** 3373** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3374** <dd>The maximum number of arguments on a function.</dd>)^ 3375** 3376** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3377** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3378** 3379** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3380** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3381** <dd>The maximum length of the pattern argument to the [LIKE] or 3382** [GLOB] operators.</dd>)^ 3383** 3384** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3385** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3386** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3387** 3388** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3389** <dd>The maximum depth of recursion for triggers.</dd>)^ 3390** 3391** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3392** <dd>The maximum number of auxiliary worker threads that a single 3393** [prepared statement] may start.</dd>)^ 3394** </dl> 3395*/ 3396#define SQLITE_LIMIT_LENGTH 0 3397#define SQLITE_LIMIT_SQL_LENGTH 1 3398#define SQLITE_LIMIT_COLUMN 2 3399#define SQLITE_LIMIT_EXPR_DEPTH 3 3400#define SQLITE_LIMIT_COMPOUND_SELECT 4 3401#define SQLITE_LIMIT_VDBE_OP 5 3402#define SQLITE_LIMIT_FUNCTION_ARG 6 3403#define SQLITE_LIMIT_ATTACHED 7 3404#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3405#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3406#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3407#define SQLITE_LIMIT_WORKER_THREADS 11 3408 3409/* 3410** CAPI3REF: Compiling An SQL Statement 3411** KEYWORDS: {SQL statement compiler} 3412** METHOD: sqlite3 3413** CONSTRUCTOR: sqlite3_stmt 3414** 3415** To execute an SQL query, it must first be compiled into a byte-code 3416** program using one of these routines. 3417** 3418** The first argument, "db", is a [database connection] obtained from a 3419** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3420** [sqlite3_open16()]. The database connection must not have been closed. 3421** 3422** The second argument, "zSql", is the statement to be compiled, encoded 3423** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 3424** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 3425** use UTF-16. 3426** 3427** ^If the nByte argument is negative, then zSql is read up to the 3428** first zero terminator. ^If nByte is positive, then it is the 3429** number of bytes read from zSql. ^If nByte is zero, then no prepared 3430** statement is generated. 3431** If the caller knows that the supplied string is nul-terminated, then 3432** there is a small performance advantage to passing an nByte parameter that 3433** is the number of bytes in the input string <i>including</i> 3434** the nul-terminator. 3435** 3436** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3437** past the end of the first SQL statement in zSql. These routines only 3438** compile the first statement in zSql, so *pzTail is left pointing to 3439** what remains uncompiled. 3440** 3441** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3442** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3443** to NULL. ^If the input text contains no SQL (if the input is an empty 3444** string or a comment) then *ppStmt is set to NULL. 3445** The calling procedure is responsible for deleting the compiled 3446** SQL statement using [sqlite3_finalize()] after it has finished with it. 3447** ppStmt may not be NULL. 3448** 3449** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3450** otherwise an [error code] is returned. 3451** 3452** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 3453** recommended for all new programs. The two older interfaces are retained 3454** for backwards compatibility, but their use is discouraged. 3455** ^In the "v2" interfaces, the prepared statement 3456** that is returned (the [sqlite3_stmt] object) contains a copy of the 3457** original SQL text. This causes the [sqlite3_step()] interface to 3458** behave differently in three ways: 3459** 3460** <ol> 3461** <li> 3462** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3463** always used to do, [sqlite3_step()] will automatically recompile the SQL 3464** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3465** retries will occur before sqlite3_step() gives up and returns an error. 3466** </li> 3467** 3468** <li> 3469** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3470** [error codes] or [extended error codes]. ^The legacy behavior was that 3471** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3472** and the application would have to make a second call to [sqlite3_reset()] 3473** in order to find the underlying cause of the problem. With the "v2" prepare 3474** interfaces, the underlying reason for the error is returned immediately. 3475** </li> 3476** 3477** <li> 3478** ^If the specific value bound to [parameter | host parameter] in the 3479** WHERE clause might influence the choice of query plan for a statement, 3480** then the statement will be automatically recompiled, as if there had been 3481** a schema change, on the first [sqlite3_step()] call following any change 3482** to the [sqlite3_bind_text | bindings] of that [parameter]. 3483** ^The specific value of WHERE-clause [parameter] might influence the 3484** choice of query plan if the parameter is the left-hand side of a [LIKE] 3485** or [GLOB] operator or if the parameter is compared to an indexed column 3486** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3487** </li> 3488** </ol> 3489*/ 3490int sqlite3_prepare( 3491 sqlite3 *db, /* Database handle */ 3492 const char *zSql, /* SQL statement, UTF-8 encoded */ 3493 int nByte, /* Maximum length of zSql in bytes. */ 3494 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3495 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3496); 3497int sqlite3_prepare_v2( 3498 sqlite3 *db, /* Database handle */ 3499 const char *zSql, /* SQL statement, UTF-8 encoded */ 3500 int nByte, /* Maximum length of zSql in bytes. */ 3501 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3502 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3503); 3504int sqlite3_prepare16( 3505 sqlite3 *db, /* Database handle */ 3506 const void *zSql, /* SQL statement, UTF-16 encoded */ 3507 int nByte, /* Maximum length of zSql in bytes. */ 3508 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3509 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3510); 3511int sqlite3_prepare16_v2( 3512 sqlite3 *db, /* Database handle */ 3513 const void *zSql, /* SQL statement, UTF-16 encoded */ 3514 int nByte, /* Maximum length of zSql in bytes. */ 3515 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3516 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3517); 3518 3519/* 3520** CAPI3REF: Retrieving Statement SQL 3521** METHOD: sqlite3_stmt 3522** 3523** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 3524** SQL text used to create [prepared statement] P if P was 3525** created by either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3526** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 3527** string containing the SQL text of prepared statement P with 3528** [bound parameters] expanded. 3529** 3530** ^(For example, if a prepared statement is created using the SQL 3531** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 3532** and parameter :xyz is unbound, then sqlite3_sql() will return 3533** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 3534** will return "SELECT 2345,NULL".)^ 3535** 3536** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 3537** is available to hold the result, or if the result would exceed the 3538** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 3539** 3540** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 3541** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 3542** option causes sqlite3_expanded_sql() to always return NULL. 3543** 3544** ^The string returned by sqlite3_sql(P) is managed by SQLite and is 3545** automatically freed when the prepared statement is finalized. 3546** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 3547** is obtained from [sqlite3_malloc()] and must be free by the application 3548** by passing it to [sqlite3_free()]. 3549*/ 3550const char *sqlite3_sql(sqlite3_stmt *pStmt); 3551char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 3552 3553/* 3554** CAPI3REF: Determine If An SQL Statement Writes The Database 3555** METHOD: sqlite3_stmt 3556** 3557** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3558** and only if the [prepared statement] X makes no direct changes to 3559** the content of the database file. 3560** 3561** Note that [application-defined SQL functions] or 3562** [virtual tables] might change the database indirectly as a side effect. 3563** ^(For example, if an application defines a function "eval()" that 3564** calls [sqlite3_exec()], then the following SQL statement would 3565** change the database file through side-effects: 3566** 3567** <blockquote><pre> 3568** SELECT eval('DELETE FROM t1') FROM t2; 3569** </pre></blockquote> 3570** 3571** But because the [SELECT] statement does not change the database file 3572** directly, sqlite3_stmt_readonly() would still return true.)^ 3573** 3574** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3575** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3576** since the statements themselves do not actually modify the database but 3577** rather they control the timing of when other statements modify the 3578** database. ^The [ATTACH] and [DETACH] statements also cause 3579** sqlite3_stmt_readonly() to return true since, while those statements 3580** change the configuration of a database connection, they do not make 3581** changes to the content of the database files on disk. 3582*/ 3583int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3584 3585/* 3586** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3587** METHOD: sqlite3_stmt 3588** 3589** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3590** [prepared statement] S has been stepped at least once using 3591** [sqlite3_step(S)] but has neither run to completion (returned 3592** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3593** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3594** interface returns false if S is a NULL pointer. If S is not a 3595** NULL pointer and is not a pointer to a valid [prepared statement] 3596** object, then the behavior is undefined and probably undesirable. 3597** 3598** This interface can be used in combination [sqlite3_next_stmt()] 3599** to locate all prepared statements associated with a database 3600** connection that are in need of being reset. This can be used, 3601** for example, in diagnostic routines to search for prepared 3602** statements that are holding a transaction open. 3603*/ 3604int sqlite3_stmt_busy(sqlite3_stmt*); 3605 3606/* 3607** CAPI3REF: Dynamically Typed Value Object 3608** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3609** 3610** SQLite uses the sqlite3_value object to represent all values 3611** that can be stored in a database table. SQLite uses dynamic typing 3612** for the values it stores. ^Values stored in sqlite3_value objects 3613** can be integers, floating point values, strings, BLOBs, or NULL. 3614** 3615** An sqlite3_value object may be either "protected" or "unprotected". 3616** Some interfaces require a protected sqlite3_value. Other interfaces 3617** will accept either a protected or an unprotected sqlite3_value. 3618** Every interface that accepts sqlite3_value arguments specifies 3619** whether or not it requires a protected sqlite3_value. The 3620** [sqlite3_value_dup()] interface can be used to construct a new 3621** protected sqlite3_value from an unprotected sqlite3_value. 3622** 3623** The terms "protected" and "unprotected" refer to whether or not 3624** a mutex is held. An internal mutex is held for a protected 3625** sqlite3_value object but no mutex is held for an unprotected 3626** sqlite3_value object. If SQLite is compiled to be single-threaded 3627** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3628** or if SQLite is run in one of reduced mutex modes 3629** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3630** then there is no distinction between protected and unprotected 3631** sqlite3_value objects and they can be used interchangeably. However, 3632** for maximum code portability it is recommended that applications 3633** still make the distinction between protected and unprotected 3634** sqlite3_value objects even when not strictly required. 3635** 3636** ^The sqlite3_value objects that are passed as parameters into the 3637** implementation of [application-defined SQL functions] are protected. 3638** ^The sqlite3_value object returned by 3639** [sqlite3_column_value()] is unprotected. 3640** Unprotected sqlite3_value objects may only be used with 3641** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3642** The [sqlite3_value_blob | sqlite3_value_type()] family of 3643** interfaces require protected sqlite3_value objects. 3644*/ 3645typedef struct Mem sqlite3_value; 3646 3647/* 3648** CAPI3REF: SQL Function Context Object 3649** 3650** The context in which an SQL function executes is stored in an 3651** sqlite3_context object. ^A pointer to an sqlite3_context object 3652** is always first parameter to [application-defined SQL functions]. 3653** The application-defined SQL function implementation will pass this 3654** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3655** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3656** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3657** and/or [sqlite3_set_auxdata()]. 3658*/ 3659typedef struct sqlite3_context sqlite3_context; 3660 3661/* 3662** CAPI3REF: Binding Values To Prepared Statements 3663** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3664** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3665** METHOD: sqlite3_stmt 3666** 3667** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3668** literals may be replaced by a [parameter] that matches one of following 3669** templates: 3670** 3671** <ul> 3672** <li> ? 3673** <li> ?NNN 3674** <li> :VVV 3675** <li> @VVV 3676** <li> $VVV 3677** </ul> 3678** 3679** In the templates above, NNN represents an integer literal, 3680** and VVV represents an alphanumeric identifier.)^ ^The values of these 3681** parameters (also called "host parameter names" or "SQL parameters") 3682** can be set using the sqlite3_bind_*() routines defined here. 3683** 3684** ^The first argument to the sqlite3_bind_*() routines is always 3685** a pointer to the [sqlite3_stmt] object returned from 3686** [sqlite3_prepare_v2()] or its variants. 3687** 3688** ^The second argument is the index of the SQL parameter to be set. 3689** ^The leftmost SQL parameter has an index of 1. ^When the same named 3690** SQL parameter is used more than once, second and subsequent 3691** occurrences have the same index as the first occurrence. 3692** ^The index for named parameters can be looked up using the 3693** [sqlite3_bind_parameter_index()] API if desired. ^The index 3694** for "?NNN" parameters is the value of NNN. 3695** ^The NNN value must be between 1 and the [sqlite3_limit()] 3696** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3697** 3698** ^The third argument is the value to bind to the parameter. 3699** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3700** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3701** is ignored and the end result is the same as sqlite3_bind_null(). 3702** 3703** ^(In those routines that have a fourth argument, its value is the 3704** number of bytes in the parameter. To be clear: the value is the 3705** number of <u>bytes</u> in the value, not the number of characters.)^ 3706** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3707** is negative, then the length of the string is 3708** the number of bytes up to the first zero terminator. 3709** If the fourth parameter to sqlite3_bind_blob() is negative, then 3710** the behavior is undefined. 3711** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3712** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3713** that parameter must be the byte offset 3714** where the NUL terminator would occur assuming the string were NUL 3715** terminated. If any NUL characters occur at byte offsets less than 3716** the value of the fourth parameter then the resulting string value will 3717** contain embedded NULs. The result of expressions involving strings 3718** with embedded NULs is undefined. 3719** 3720** ^The fifth argument to the BLOB and string binding interfaces 3721** is a destructor used to dispose of the BLOB or 3722** string after SQLite has finished with it. ^The destructor is called 3723** to dispose of the BLOB or string even if the call to bind API fails. 3724** ^If the fifth argument is 3725** the special value [SQLITE_STATIC], then SQLite assumes that the 3726** information is in static, unmanaged space and does not need to be freed. 3727** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3728** SQLite makes its own private copy of the data immediately, before 3729** the sqlite3_bind_*() routine returns. 3730** 3731** ^The sixth argument to sqlite3_bind_text64() must be one of 3732** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 3733** to specify the encoding of the text in the third parameter. If 3734** the sixth argument to sqlite3_bind_text64() is not one of the 3735** allowed values shown above, or if the text encoding is different 3736** from the encoding specified by the sixth parameter, then the behavior 3737** is undefined. 3738** 3739** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3740** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3741** (just an integer to hold its size) while it is being processed. 3742** Zeroblobs are intended to serve as placeholders for BLOBs whose 3743** content is later written using 3744** [sqlite3_blob_open | incremental BLOB I/O] routines. 3745** ^A negative value for the zeroblob results in a zero-length BLOB. 3746** 3747** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3748** for the [prepared statement] or with a prepared statement for which 3749** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3750** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3751** routine is passed a [prepared statement] that has been finalized, the 3752** result is undefined and probably harmful. 3753** 3754** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3755** ^Unbound parameters are interpreted as NULL. 3756** 3757** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3758** [error code] if anything goes wrong. 3759** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 3760** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 3761** [SQLITE_MAX_LENGTH]. 3762** ^[SQLITE_RANGE] is returned if the parameter 3763** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3764** 3765** See also: [sqlite3_bind_parameter_count()], 3766** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3767*/ 3768int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, 3769 void(SQLITE_CALLBACK *)(void*)); 3770int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 3771 void(SQLITE_CALLBACK *)(void*)); 3772int sqlite3_bind_double(sqlite3_stmt*, int, double); 3773int sqlite3_bind_int(sqlite3_stmt*, int, int); 3774int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3775int sqlite3_bind_null(sqlite3_stmt*, int); 3776int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int, 3777 void(SQLITE_CALLBACK *)(void*)); 3778int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, 3779 void(SQLITE_CALLBACK *)(void*)); 3780int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 3781 void(SQLITE_CALLBACK *)(void*), unsigned char encoding); 3782int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3783int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3784int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 3785 3786/* 3787** CAPI3REF: Number Of SQL Parameters 3788** METHOD: sqlite3_stmt 3789** 3790** ^This routine can be used to find the number of [SQL parameters] 3791** in a [prepared statement]. SQL parameters are tokens of the 3792** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3793** placeholders for values that are [sqlite3_bind_blob | bound] 3794** to the parameters at a later time. 3795** 3796** ^(This routine actually returns the index of the largest (rightmost) 3797** parameter. For all forms except ?NNN, this will correspond to the 3798** number of unique parameters. If parameters of the ?NNN form are used, 3799** there may be gaps in the list.)^ 3800** 3801** See also: [sqlite3_bind_blob|sqlite3_bind()], 3802** [sqlite3_bind_parameter_name()], and 3803** [sqlite3_bind_parameter_index()]. 3804*/ 3805int sqlite3_bind_parameter_count(sqlite3_stmt*); 3806 3807/* 3808** CAPI3REF: Name Of A Host Parameter 3809** METHOD: sqlite3_stmt 3810** 3811** ^The sqlite3_bind_parameter_name(P,N) interface returns 3812** the name of the N-th [SQL parameter] in the [prepared statement] P. 3813** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3814** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3815** respectively. 3816** In other words, the initial ":" or "$" or "@" or "?" 3817** is included as part of the name.)^ 3818** ^Parameters of the form "?" without a following integer have no name 3819** and are referred to as "nameless" or "anonymous parameters". 3820** 3821** ^The first host parameter has an index of 1, not 0. 3822** 3823** ^If the value N is out of range or if the N-th parameter is 3824** nameless, then NULL is returned. ^The returned string is 3825** always in UTF-8 encoding even if the named parameter was 3826** originally specified as UTF-16 in [sqlite3_prepare16()] or 3827** [sqlite3_prepare16_v2()]. 3828** 3829** See also: [sqlite3_bind_blob|sqlite3_bind()], 3830** [sqlite3_bind_parameter_count()], and 3831** [sqlite3_bind_parameter_index()]. 3832*/ 3833const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3834 3835/* 3836** CAPI3REF: Index Of A Parameter With A Given Name 3837** METHOD: sqlite3_stmt 3838** 3839** ^Return the index of an SQL parameter given its name. ^The 3840** index value returned is suitable for use as the second 3841** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3842** is returned if no matching parameter is found. ^The parameter 3843** name must be given in UTF-8 even if the original statement 3844** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3845** 3846** See also: [sqlite3_bind_blob|sqlite3_bind()], 3847** [sqlite3_bind_parameter_count()], and 3848** [sqlite3_bind_parameter_name()]. 3849*/ 3850int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3851 3852/* 3853** CAPI3REF: Reset All Bindings On A Prepared Statement 3854** METHOD: sqlite3_stmt 3855** 3856** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3857** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3858** ^Use this routine to reset all host parameters to NULL. 3859*/ 3860int sqlite3_clear_bindings(sqlite3_stmt*); 3861 3862/* 3863** CAPI3REF: Number Of Columns In A Result Set 3864** METHOD: sqlite3_stmt 3865** 3866** ^Return the number of columns in the result set returned by the 3867** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 3868** statement that does not return data (for example an [UPDATE]). 3869** 3870** See also: [sqlite3_data_count()] 3871*/ 3872int sqlite3_column_count(sqlite3_stmt *pStmt); 3873 3874/* 3875** CAPI3REF: Column Names In A Result Set 3876** METHOD: sqlite3_stmt 3877** 3878** ^These routines return the name assigned to a particular column 3879** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3880** interface returns a pointer to a zero-terminated UTF-8 string 3881** and sqlite3_column_name16() returns a pointer to a zero-terminated 3882** UTF-16 string. ^The first parameter is the [prepared statement] 3883** that implements the [SELECT] statement. ^The second parameter is the 3884** column number. ^The leftmost column is number 0. 3885** 3886** ^The returned string pointer is valid until either the [prepared statement] 3887** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3888** reprepared by the first call to [sqlite3_step()] for a particular run 3889** or until the next call to 3890** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3891** 3892** ^If sqlite3_malloc() fails during the processing of either routine 3893** (for example during a conversion from UTF-8 to UTF-16) then a 3894** NULL pointer is returned. 3895** 3896** ^The name of a result column is the value of the "AS" clause for 3897** that column, if there is an AS clause. If there is no AS clause 3898** then the name of the column is unspecified and may change from 3899** one release of SQLite to the next. 3900*/ 3901const char *sqlite3_column_name(sqlite3_stmt*, int N); 3902const void *sqlite3_column_name16(sqlite3_stmt*, int N); 3903 3904/* 3905** CAPI3REF: Source Of Data In A Query Result 3906** METHOD: sqlite3_stmt 3907** 3908** ^These routines provide a means to determine the database, table, and 3909** table column that is the origin of a particular result column in 3910** [SELECT] statement. 3911** ^The name of the database or table or column can be returned as 3912** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3913** the database name, the _table_ routines return the table name, and 3914** the origin_ routines return the column name. 3915** ^The returned string is valid until the [prepared statement] is destroyed 3916** using [sqlite3_finalize()] or until the statement is automatically 3917** reprepared by the first call to [sqlite3_step()] for a particular run 3918** or until the same information is requested 3919** again in a different encoding. 3920** 3921** ^The names returned are the original un-aliased names of the 3922** database, table, and column. 3923** 3924** ^The first argument to these interfaces is a [prepared statement]. 3925** ^These functions return information about the Nth result column returned by 3926** the statement, where N is the second function argument. 3927** ^The left-most column is column 0 for these routines. 3928** 3929** ^If the Nth column returned by the statement is an expression or 3930** subquery and is not a column value, then all of these functions return 3931** NULL. ^These routine might also return NULL if a memory allocation error 3932** occurs. ^Otherwise, they return the name of the attached database, table, 3933** or column that query result column was extracted from. 3934** 3935** ^As with all other SQLite APIs, those whose names end with "16" return 3936** UTF-16 encoded strings and the other functions return UTF-8. 3937** 3938** ^These APIs are only available if the library was compiled with the 3939** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3940** 3941** If two or more threads call one or more of these routines against the same 3942** prepared statement and column at the same time then the results are 3943** undefined. 3944** 3945** If two or more threads call one or more 3946** [sqlite3_column_database_name | column metadata interfaces] 3947** for the same [prepared statement] and result column 3948** at the same time then the results are undefined. 3949*/ 3950const char *sqlite3_column_database_name(sqlite3_stmt*,int); 3951const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 3952const char *sqlite3_column_table_name(sqlite3_stmt*,int); 3953const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 3954const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 3955const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 3956 3957/* 3958** CAPI3REF: Declared Datatype Of A Query Result 3959** METHOD: sqlite3_stmt 3960** 3961** ^(The first parameter is a [prepared statement]. 3962** If this statement is a [SELECT] statement and the Nth column of the 3963** returned result set of that [SELECT] is a table column (not an 3964** expression or subquery) then the declared type of the table 3965** column is returned.)^ ^If the Nth column of the result set is an 3966** expression or subquery, then a NULL pointer is returned. 3967** ^The returned string is always UTF-8 encoded. 3968** 3969** ^(For example, given the database schema: 3970** 3971** CREATE TABLE t1(c1 VARIANT); 3972** 3973** and the following statement to be compiled: 3974** 3975** SELECT c1 + 1, c1 FROM t1; 3976** 3977** this routine would return the string "VARIANT" for the second result 3978** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3979** 3980** ^SQLite uses dynamic run-time typing. ^So just because a column 3981** is declared to contain a particular type does not mean that the 3982** data stored in that column is of the declared type. SQLite is 3983** strongly typed, but the typing is dynamic not static. ^Type 3984** is associated with individual values, not with the containers 3985** used to hold those values. 3986*/ 3987const char *sqlite3_column_decltype(sqlite3_stmt*,int); 3988const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 3989 3990/* 3991** CAPI3REF: Evaluate An SQL Statement 3992** METHOD: sqlite3_stmt 3993** 3994** After a [prepared statement] has been prepared using either 3995** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3996** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3997** must be called one or more times to evaluate the statement. 3998** 3999** The details of the behavior of the sqlite3_step() interface depend 4000** on whether the statement was prepared using the newer "v2" interface 4001** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 4002** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4003** new "v2" interface is recommended for new applications but the legacy 4004** interface will continue to be supported. 4005** 4006** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4007** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4008** ^With the "v2" interface, any of the other [result codes] or 4009** [extended result codes] might be returned as well. 4010** 4011** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4012** database locks it needs to do its job. ^If the statement is a [COMMIT] 4013** or occurs outside of an explicit transaction, then you can retry the 4014** statement. If the statement is not a [COMMIT] and occurs within an 4015** explicit transaction then you should rollback the transaction before 4016** continuing. 4017** 4018** ^[SQLITE_DONE] means that the statement has finished executing 4019** successfully. sqlite3_step() should not be called again on this virtual 4020** machine without first calling [sqlite3_reset()] to reset the virtual 4021** machine back to its initial state. 4022** 4023** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4024** is returned each time a new row of data is ready for processing by the 4025** caller. The values may be accessed using the [column access functions]. 4026** sqlite3_step() is called again to retrieve the next row of data. 4027** 4028** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4029** violation) has occurred. sqlite3_step() should not be called again on 4030** the VM. More information may be found by calling [sqlite3_errmsg()]. 4031** ^With the legacy interface, a more specific error code (for example, 4032** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4033** can be obtained by calling [sqlite3_reset()] on the 4034** [prepared statement]. ^In the "v2" interface, 4035** the more specific error code is returned directly by sqlite3_step(). 4036** 4037** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4038** Perhaps it was called on a [prepared statement] that has 4039** already been [sqlite3_finalize | finalized] or on one that had 4040** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4041** be the case that the same database connection is being used by two or 4042** more threads at the same moment in time. 4043** 4044** For all versions of SQLite up to and including 3.6.23.1, a call to 4045** [sqlite3_reset()] was required after sqlite3_step() returned anything 4046** other than [SQLITE_ROW] before any subsequent invocation of 4047** sqlite3_step(). Failure to reset the prepared statement using 4048** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4049** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 4050** calling [sqlite3_reset()] automatically in this circumstance rather 4051** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4052** break because any application that ever receives an SQLITE_MISUSE error 4053** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4054** can be used to restore the legacy behavior. 4055** 4056** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4057** API always returns a generic error code, [SQLITE_ERROR], following any 4058** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4059** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4060** specific [error codes] that better describes the error. 4061** We admit that this is a goofy design. The problem has been fixed 4062** with the "v2" interface. If you prepare all of your SQL statements 4063** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 4064** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4065** then the more specific [error codes] are returned directly 4066** by sqlite3_step(). The use of the "v2" interface is recommended. 4067*/ 4068int sqlite3_step(sqlite3_stmt*); 4069 4070/* 4071** CAPI3REF: Number of columns in a result set 4072** METHOD: sqlite3_stmt 4073** 4074** ^The sqlite3_data_count(P) interface returns the number of columns in the 4075** current row of the result set of [prepared statement] P. 4076** ^If prepared statement P does not have results ready to return 4077** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 4078** interfaces) then sqlite3_data_count(P) returns 0. 4079** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4080** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4081** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4082** will return non-zero if previous call to [sqlite3_step](P) returned 4083** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4084** where it always returns zero since each step of that multi-step 4085** pragma returns 0 columns of data. 4086** 4087** See also: [sqlite3_column_count()] 4088*/ 4089int sqlite3_data_count(sqlite3_stmt *pStmt); 4090 4091/* 4092** CAPI3REF: Fundamental Datatypes 4093** KEYWORDS: SQLITE_TEXT 4094** 4095** ^(Every value in SQLite has one of five fundamental datatypes: 4096** 4097** <ul> 4098** <li> 64-bit signed integer 4099** <li> 64-bit IEEE floating point number 4100** <li> string 4101** <li> BLOB 4102** <li> NULL 4103** </ul>)^ 4104** 4105** These constants are codes for each of those types. 4106** 4107** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4108** for a completely different meaning. Software that links against both 4109** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4110** SQLITE_TEXT. 4111*/ 4112#define SQLITE_INTEGER 1 4113#define SQLITE_FLOAT 2 4114#define SQLITE_BLOB 4 4115#define SQLITE_NULL 5 4116#ifdef SQLITE_TEXT 4117# undef SQLITE_TEXT 4118#else 4119# define SQLITE_TEXT 3 4120#endif 4121#define SQLITE3_TEXT 3 4122 4123/* 4124** CAPI3REF: Result Values From A Query 4125** KEYWORDS: {column access functions} 4126** METHOD: sqlite3_stmt 4127** 4128** ^These routines return information about a single column of the current 4129** result row of a query. ^In every case the first argument is a pointer 4130** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4131** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4132** and the second argument is the index of the column for which information 4133** should be returned. ^The leftmost column of the result set has the index 0. 4134** ^The number of columns in the result can be determined using 4135** [sqlite3_column_count()]. 4136** 4137** If the SQL statement does not currently point to a valid row, or if the 4138** column index is out of range, the result is undefined. 4139** These routines may only be called when the most recent call to 4140** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4141** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4142** If any of these routines are called after [sqlite3_reset()] or 4143** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4144** something other than [SQLITE_ROW], the results are undefined. 4145** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4146** are called from a different thread while any of these routines 4147** are pending, then the results are undefined. 4148** 4149** ^The sqlite3_column_type() routine returns the 4150** [SQLITE_INTEGER | datatype code] for the initial data type 4151** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4152** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 4153** returned by sqlite3_column_type() is only meaningful if no type 4154** conversions have occurred as described below. After a type conversion, 4155** the value returned by sqlite3_column_type() is undefined. Future 4156** versions of SQLite may change the behavior of sqlite3_column_type() 4157** following a type conversion. 4158** 4159** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4160** routine returns the number of bytes in that BLOB or string. 4161** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4162** the string to UTF-8 and then returns the number of bytes. 4163** ^If the result is a numeric value then sqlite3_column_bytes() uses 4164** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4165** the number of bytes in that string. 4166** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4167** 4168** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4169** routine returns the number of bytes in that BLOB or string. 4170** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4171** the string to UTF-16 and then returns the number of bytes. 4172** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4173** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4174** the number of bytes in that string. 4175** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4176** 4177** ^The values returned by [sqlite3_column_bytes()] and 4178** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4179** of the string. ^For clarity: the values returned by 4180** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4181** bytes in the string, not the number of characters. 4182** 4183** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4184** even empty strings, are always zero-terminated. ^The return 4185** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4186** 4187** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4188** [unprotected sqlite3_value] object. In a multithreaded environment, 4189** an unprotected sqlite3_value object may only be used safely with 4190** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4191** If the [unprotected sqlite3_value] object returned by 4192** [sqlite3_column_value()] is used in any other way, including calls 4193** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4194** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4195** 4196** These routines attempt to convert the value where appropriate. ^For 4197** example, if the internal representation is FLOAT and a text result 4198** is requested, [sqlite3_snprintf()] is used internally to perform the 4199** conversion automatically. ^(The following table details the conversions 4200** that are applied: 4201** 4202** <blockquote> 4203** <table border="1"> 4204** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4205** 4206** <tr><td> NULL <td> INTEGER <td> Result is 0 4207** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4208** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4209** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4210** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4211** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4212** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4213** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4214** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4215** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4216** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4217** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4218** <tr><td> TEXT <td> BLOB <td> No change 4219** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4220** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4221** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4222** </table> 4223** </blockquote>)^ 4224** 4225** Note that when type conversions occur, pointers returned by prior 4226** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4227** sqlite3_column_text16() may be invalidated. 4228** Type conversions and pointer invalidations might occur 4229** in the following cases: 4230** 4231** <ul> 4232** <li> The initial content is a BLOB and sqlite3_column_text() or 4233** sqlite3_column_text16() is called. A zero-terminator might 4234** need to be added to the string.</li> 4235** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4236** sqlite3_column_text16() is called. The content must be converted 4237** to UTF-16.</li> 4238** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4239** sqlite3_column_text() is called. The content must be converted 4240** to UTF-8.</li> 4241** </ul> 4242** 4243** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4244** not invalidate a prior pointer, though of course the content of the buffer 4245** that the prior pointer references will have been modified. Other kinds 4246** of conversion are done in place when it is possible, but sometimes they 4247** are not possible and in those cases prior pointers are invalidated. 4248** 4249** The safest policy is to invoke these routines 4250** in one of the following ways: 4251** 4252** <ul> 4253** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4254** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4255** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4256** </ul> 4257** 4258** In other words, you should call sqlite3_column_text(), 4259** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4260** into the desired format, then invoke sqlite3_column_bytes() or 4261** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4262** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4263** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4264** with calls to sqlite3_column_bytes(). 4265** 4266** ^The pointers returned are valid until a type conversion occurs as 4267** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4268** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4269** and BLOBs is freed automatically. Do <em>not</em> pass the pointers returned 4270** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4271** [sqlite3_free()]. 4272** 4273** ^(If a memory allocation error occurs during the evaluation of any 4274** of these routines, a default value is returned. The default value 4275** is either the integer 0, the floating point number 0.0, or a NULL 4276** pointer. Subsequent calls to [sqlite3_errcode()] will return 4277** [SQLITE_NOMEM].)^ 4278*/ 4279const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4280int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4281int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4282double sqlite3_column_double(sqlite3_stmt*, int iCol); 4283int sqlite3_column_int(sqlite3_stmt*, int iCol); 4284sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4285const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4286const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4287int sqlite3_column_type(sqlite3_stmt*, int iCol); 4288sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4289 4290/* 4291** CAPI3REF: Destroy A Prepared Statement Object 4292** DESTRUCTOR: sqlite3_stmt 4293** 4294** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4295** ^If the most recent evaluation of the statement encountered no errors 4296** or if the statement is never been evaluated, then sqlite3_finalize() returns 4297** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4298** sqlite3_finalize(S) returns the appropriate [error code] or 4299** [extended error code]. 4300** 4301** ^The sqlite3_finalize(S) routine can be called at any point during 4302** the life cycle of [prepared statement] S: 4303** before statement S is ever evaluated, after 4304** one or more calls to [sqlite3_reset()], or after any call 4305** to [sqlite3_step()] regardless of whether or not the statement has 4306** completed execution. 4307** 4308** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4309** 4310** The application must finalize every [prepared statement] in order to avoid 4311** resource leaks. It is a grievous error for the application to try to use 4312** a prepared statement after it has been finalized. Any use of a prepared 4313** statement after it has been finalized can result in undefined and 4314** undesirable behavior such as segfaults and heap corruption. 4315*/ 4316int sqlite3_finalize(sqlite3_stmt *pStmt); 4317 4318/* 4319** CAPI3REF: Reset A Prepared Statement Object 4320** METHOD: sqlite3_stmt 4321** 4322** The sqlite3_reset() function is called to reset a [prepared statement] 4323** object back to its initial state, ready to be re-executed. 4324** ^Any SQL statement variables that had values bound to them using 4325** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4326** Use [sqlite3_clear_bindings()] to reset the bindings. 4327** 4328** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4329** back to the beginning of its program. 4330** 4331** ^If the most recent call to [sqlite3_step(S)] for the 4332** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4333** or if [sqlite3_step(S)] has never before been called on S, 4334** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4335** 4336** ^If the most recent call to [sqlite3_step(S)] for the 4337** [prepared statement] S indicated an error, then 4338** [sqlite3_reset(S)] returns an appropriate [error code]. 4339** 4340** ^The [sqlite3_reset(S)] interface does not change the values 4341** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4342*/ 4343int sqlite3_reset(sqlite3_stmt *pStmt); 4344 4345/* 4346** CAPI3REF: Create Or Redefine SQL Functions 4347** KEYWORDS: {function creation routines} 4348** KEYWORDS: {application-defined SQL function} 4349** KEYWORDS: {application-defined SQL functions} 4350** METHOD: sqlite3 4351** 4352** ^These functions (collectively known as "function creation routines") 4353** are used to add SQL functions or aggregates or to redefine the behavior 4354** of existing SQL functions or aggregates. The only differences between 4355** these routines are the text encoding expected for 4356** the second parameter (the name of the function being created) 4357** and the presence or absence of a destructor callback for 4358** the application data pointer. 4359** 4360** ^The first parameter is the [database connection] to which the SQL 4361** function is to be added. ^If an application uses more than one database 4362** connection then application-defined SQL functions must be added 4363** to each database connection separately. 4364** 4365** ^The second parameter is the name of the SQL function to be created or 4366** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4367** representation, exclusive of the zero-terminator. ^Note that the name 4368** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4369** ^Any attempt to create a function with a longer name 4370** will result in [SQLITE_MISUSE] being returned. 4371** 4372** ^The third parameter (nArg) 4373** is the number of arguments that the SQL function or 4374** aggregate takes. ^If this parameter is -1, then the SQL function or 4375** aggregate may take any number of arguments between 0 and the limit 4376** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4377** parameter is less than -1 or greater than 127 then the behavior is 4378** undefined. 4379** 4380** ^The fourth parameter, eTextRep, specifies what 4381** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4382** its parameters. The application should set this parameter to 4383** [SQLITE_UTF16LE] if the function implementation invokes 4384** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4385** implementation invokes [sqlite3_value_text16be()] on an input, or 4386** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4387** otherwise. ^The same SQL function may be registered multiple times using 4388** different preferred text encodings, with different implementations for 4389** each encoding. 4390** ^When multiple implementations of the same function are available, SQLite 4391** will pick the one that involves the least amount of data conversion. 4392** 4393** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4394** to signal that the function will always return the same result given 4395** the same inputs within a single SQL statement. Most SQL functions are 4396** deterministic. The built-in [random()] SQL function is an example of a 4397** function that is not deterministic. The SQLite query planner is able to 4398** perform additional optimizations on deterministic functions, so use 4399** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4400** 4401** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4402** function can gain access to this pointer using [sqlite3_user_data()].)^ 4403** 4404** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4405** pointers to C-language functions that implement the SQL function or 4406** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4407** callback only; NULL pointers must be passed as the xStep and xFinal 4408** parameters. ^An aggregate SQL function requires an implementation of xStep 4409** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4410** SQL function or aggregate, pass NULL pointers for all three function 4411** callbacks. 4412** 4413** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4414** then it is destructor for the application data pointer. 4415** The destructor is invoked when the function is deleted, either by being 4416** overloaded or when the database connection closes.)^ 4417** ^The destructor is also invoked if the call to 4418** sqlite3_create_function_v2() fails. 4419** ^When the destructor callback of the tenth parameter is invoked, it 4420** is passed a single argument which is a copy of the application data 4421** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4422** 4423** ^It is permitted to register multiple implementations of the same 4424** functions with the same name but with either differing numbers of 4425** arguments or differing preferred text encodings. ^SQLite will use 4426** the implementation that most closely matches the way in which the 4427** SQL function is used. ^A function implementation with a non-negative 4428** nArg parameter is a better match than a function implementation with 4429** a negative nArg. ^A function where the preferred text encoding 4430** matches the database encoding is a better 4431** match than a function where the encoding is different. 4432** ^A function where the encoding difference is between UTF16le and UTF16be 4433** is a closer match than a function where the encoding difference is 4434** between UTF8 and UTF16. 4435** 4436** ^Built-in functions may be overloaded by new application-defined functions. 4437** 4438** ^An application-defined function is permitted to call other 4439** SQLite interfaces. However, such calls must not 4440** close the database connection nor finalize or reset the prepared 4441** statement in which the function is running. 4442*/ 4443int sqlite3_create_function( 4444 sqlite3 *db, 4445 const char *zFunctionName, 4446 int nArg, 4447 int eTextRep, 4448 void *pApp, 4449 void (SQLITE_CALLBACK *xFunc)(sqlite3_context*,int,sqlite3_value**), 4450 void (SQLITE_CALLBACK *xStep)(sqlite3_context*,int,sqlite3_value**), 4451 void (SQLITE_CALLBACK *xFinal)(sqlite3_context*) 4452); 4453int sqlite3_create_function16( 4454 sqlite3 *db, 4455 const void *zFunctionName, 4456 int nArg, 4457 int eTextRep, 4458 void *pApp, 4459 void (SQLITE_CALLBACK *xFunc)(sqlite3_context*,int,sqlite3_value**), 4460 void (SQLITE_CALLBACK *xStep)(sqlite3_context*,int,sqlite3_value**), 4461 void (SQLITE_CALLBACK *xFinal)(sqlite3_context*) 4462); 4463int sqlite3_create_function_v2( 4464 sqlite3 *db, 4465 const char *zFunctionName, 4466 int nArg, 4467 int eTextRep, 4468 void *pApp, 4469 void (SQLITE_CALLBACK *xFunc)(sqlite3_context*,int,sqlite3_value**), 4470 void (SQLITE_CALLBACK *xStep)(sqlite3_context*,int,sqlite3_value**), 4471 void (SQLITE_CALLBACK *xFinal)(sqlite3_context*), 4472 void (SQLITE_CALLBACK *xDestroy)(void*) 4473); 4474 4475/* 4476** CAPI3REF: Text Encodings 4477** 4478** These constant define integer codes that represent the various 4479** text encodings supported by SQLite. 4480*/ 4481#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4482#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4483#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4484#define SQLITE_UTF16 4 /* Use native byte order */ 4485#define SQLITE_ANY 5 /* Deprecated */ 4486#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4487 4488/* 4489** CAPI3REF: Function Flags 4490** 4491** These constants may be ORed together with the 4492** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4493** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4494** [sqlite3_create_function_v2()]. 4495*/ 4496#define SQLITE_DETERMINISTIC 0x800 4497 4498/* 4499** CAPI3REF: Deprecated Functions 4500** DEPRECATED 4501** 4502** These functions are [deprecated]. In order to maintain 4503** backwards compatibility with older code, these functions continue 4504** to be supported. However, new applications should avoid 4505** the use of these functions. To encourage programmers to avoid 4506** these functions, we will not explain what they do. 4507*/ 4508#ifndef SQLITE_OMIT_DEPRECATED 4509SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4510SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4511SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4512SQLITE_DEPRECATED int sqlite3_global_recover(void); 4513SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4514SQLITE_DEPRECATED int sqlite3_memory_alarm( 4515 void(SQLITE_CALLBACK *)(void*,sqlite3_int64,int), 4516 void*,sqlite3_int64); 4517#endif 4518 4519/* 4520** CAPI3REF: Obtaining SQL Values 4521** METHOD: sqlite3_value 4522** 4523** The C-language implementation of SQL functions and aggregates uses 4524** this set of interface routines to access the parameter values on 4525** the function or aggregate. 4526** 4527** The xFunc (for scalar functions) or xStep (for aggregates) parameters 4528** to [sqlite3_create_function()] and [sqlite3_create_function16()] 4529** define callbacks that implement the SQL functions and aggregates. 4530** The 3rd parameter to these callbacks is an array of pointers to 4531** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 4532** each parameter to the SQL function. These routines are used to 4533** extract values from the [sqlite3_value] objects. 4534** 4535** These routines work only with [protected sqlite3_value] objects. 4536** Any attempt to use these routines on an [unprotected sqlite3_value] 4537** object results in undefined behavior. 4538** 4539** ^These routines work just like the corresponding [column access functions] 4540** except that these routines take a single [protected sqlite3_value] object 4541** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4542** 4543** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4544** in the native byte-order of the host machine. ^The 4545** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4546** extract UTF-16 strings as big-endian and little-endian respectively. 4547** 4548** ^(The sqlite3_value_numeric_type() interface attempts to apply 4549** numeric affinity to the value. This means that an attempt is 4550** made to convert the value to an integer or floating point. If 4551** such a conversion is possible without loss of information (in other 4552** words, if the value is a string that looks like a number) 4553** then the conversion is performed. Otherwise no conversion occurs. 4554** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4555** 4556** Please pay particular attention to the fact that the pointer returned 4557** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4558** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4559** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4560** or [sqlite3_value_text16()]. 4561** 4562** These routines must be called from the same thread as 4563** the SQL function that supplied the [sqlite3_value*] parameters. 4564*/ 4565const void *sqlite3_value_blob(sqlite3_value*); 4566int sqlite3_value_bytes(sqlite3_value*); 4567int sqlite3_value_bytes16(sqlite3_value*); 4568double sqlite3_value_double(sqlite3_value*); 4569int sqlite3_value_int(sqlite3_value*); 4570sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4571const unsigned char *sqlite3_value_text(sqlite3_value*); 4572const void *sqlite3_value_text16(sqlite3_value*); 4573const void *sqlite3_value_text16le(sqlite3_value*); 4574const void *sqlite3_value_text16be(sqlite3_value*); 4575int sqlite3_value_type(sqlite3_value*); 4576int sqlite3_value_numeric_type(sqlite3_value*); 4577 4578/* 4579** CAPI3REF: Finding The Subtype Of SQL Values 4580** METHOD: sqlite3_value 4581** 4582** The sqlite3_value_subtype(V) function returns the subtype for 4583** an [application-defined SQL function] argument V. The subtype 4584** information can be used to pass a limited amount of context from 4585** one SQL function to another. Use the [sqlite3_result_subtype()] 4586** routine to set the subtype for the return value of an SQL function. 4587** 4588** SQLite makes no use of subtype itself. It merely passes the subtype 4589** from the result of one [application-defined SQL function] into the 4590** input of another. 4591*/ 4592unsigned int sqlite3_value_subtype(sqlite3_value*); 4593 4594/* 4595** CAPI3REF: Copy And Free SQL Values 4596** METHOD: sqlite3_value 4597** 4598** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 4599** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 4600** is a [protected sqlite3_value] object even if the input is not. 4601** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 4602** memory allocation fails. 4603** 4604** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 4605** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 4606** then sqlite3_value_free(V) is a harmless no-op. 4607*/ 4608sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 4609void sqlite3_value_free(sqlite3_value*); 4610 4611/* 4612** CAPI3REF: Obtain Aggregate Function Context 4613** METHOD: sqlite3_context 4614** 4615** Implementations of aggregate SQL functions use this 4616** routine to allocate memory for storing their state. 4617** 4618** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4619** for a particular aggregate function, SQLite 4620** allocates N of memory, zeroes out that memory, and returns a pointer 4621** to the new memory. ^On second and subsequent calls to 4622** sqlite3_aggregate_context() for the same aggregate function instance, 4623** the same buffer is returned. Sqlite3_aggregate_context() is normally 4624** called once for each invocation of the xStep callback and then one 4625** last time when the xFinal callback is invoked. ^(When no rows match 4626** an aggregate query, the xStep() callback of the aggregate function 4627** implementation is never called and xFinal() is called exactly once. 4628** In those cases, sqlite3_aggregate_context() might be called for the 4629** first time from within xFinal().)^ 4630** 4631** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4632** when first called if N is less than or equal to zero or if a memory 4633** allocate error occurs. 4634** 4635** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4636** determined by the N parameter on first successful call. Changing the 4637** value of N in subsequent call to sqlite3_aggregate_context() within 4638** the same aggregate function instance will not resize the memory 4639** allocation.)^ Within the xFinal callback, it is customary to set 4640** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4641** pointless memory allocations occur. 4642** 4643** ^SQLite automatically frees the memory allocated by 4644** sqlite3_aggregate_context() when the aggregate query concludes. 4645** 4646** The first parameter must be a copy of the 4647** [sqlite3_context | SQL function context] that is the first parameter 4648** to the xStep or xFinal callback routine that implements the aggregate 4649** function. 4650** 4651** This routine must be called from the same thread in which 4652** the aggregate SQL function is running. 4653*/ 4654void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4655 4656/* 4657** CAPI3REF: User Data For Functions 4658** METHOD: sqlite3_context 4659** 4660** ^The sqlite3_user_data() interface returns a copy of 4661** the pointer that was the pUserData parameter (the 5th parameter) 4662** of the [sqlite3_create_function()] 4663** and [sqlite3_create_function16()] routines that originally 4664** registered the application defined function. 4665** 4666** This routine must be called from the same thread in which 4667** the application-defined function is running. 4668*/ 4669void *sqlite3_user_data(sqlite3_context*); 4670 4671/* 4672** CAPI3REF: Database Connection For Functions 4673** METHOD: sqlite3_context 4674** 4675** ^The sqlite3_context_db_handle() interface returns a copy of 4676** the pointer to the [database connection] (the 1st parameter) 4677** of the [sqlite3_create_function()] 4678** and [sqlite3_create_function16()] routines that originally 4679** registered the application defined function. 4680*/ 4681sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 4682 4683/* 4684** CAPI3REF: Function Auxiliary Data 4685** METHOD: sqlite3_context 4686** 4687** These functions may be used by (non-aggregate) SQL functions to 4688** associate metadata with argument values. If the same value is passed to 4689** multiple invocations of the same SQL function during query execution, under 4690** some circumstances the associated metadata may be preserved. An example 4691** of where this might be useful is in a regular-expression matching 4692** function. The compiled version of the regular expression can be stored as 4693** metadata associated with the pattern string. 4694** Then as long as the pattern string remains the same, 4695** the compiled regular expression can be reused on multiple 4696** invocations of the same function. 4697** 4698** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4699** associated by the sqlite3_set_auxdata() function with the Nth argument 4700** value to the application-defined function. ^If there is no metadata 4701** associated with the function argument, this sqlite3_get_auxdata() interface 4702** returns a NULL pointer. 4703** 4704** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 4705** argument of the application-defined function. ^Subsequent 4706** calls to sqlite3_get_auxdata(C,N) return P from the most recent 4707** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 4708** NULL if the metadata has been discarded. 4709** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 4710** SQLite will invoke the destructor function X with parameter P exactly 4711** once, when the metadata is discarded. 4712** SQLite is free to discard the metadata at any time, including: <ul> 4713** <li> when the corresponding function parameter changes, or 4714** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 4715** SQL statement, or 4716** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or 4717** <li> during the original sqlite3_set_auxdata() call when a memory 4718** allocation error occurs. </ul>)^ 4719** 4720** Note the last bullet in particular. The destructor X in 4721** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 4722** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 4723** should be called near the end of the function implementation and the 4724** function implementation should not make any use of P after 4725** sqlite3_set_auxdata() has been called. 4726** 4727** ^(In practice, metadata is preserved between function calls for 4728** function parameters that are compile-time constants, including literal 4729** values and [parameters] and expressions composed from the same.)^ 4730** 4731** These routines must be called from the same thread in which 4732** the SQL function is running. 4733*/ 4734void *sqlite3_get_auxdata(sqlite3_context*, int N); 4735void sqlite3_set_auxdata(sqlite3_context*, int N, void*, 4736 void (SQLITE_CALLBACK *)(void*)); 4737 4738 4739/* 4740** CAPI3REF: Constants Defining Special Destructor Behavior 4741** 4742** These are special values for the destructor that is passed in as the 4743** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4744** argument is SQLITE_STATIC, it means that the content pointer is constant 4745** and will never change. It does not need to be destroyed. ^The 4746** SQLITE_TRANSIENT value means that the content will likely change in 4747** the near future and that SQLite should make its own private copy of 4748** the content before returning. 4749** 4750** The typedef is necessary to work around problems in certain 4751** C++ compilers. 4752*/ 4753typedef void (SQLITE_CALLBACK *sqlite3_destructor_type)(void*); 4754#define SQLITE_STATIC ((sqlite3_destructor_type)0) 4755#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4756 4757/* 4758** CAPI3REF: Setting The Result Of An SQL Function 4759** METHOD: sqlite3_context 4760** 4761** These routines are used by the xFunc or xFinal callbacks that 4762** implement SQL functions and aggregates. See 4763** [sqlite3_create_function()] and [sqlite3_create_function16()] 4764** for additional information. 4765** 4766** These functions work very much like the [parameter binding] family of 4767** functions used to bind values to host parameters in prepared statements. 4768** Refer to the [SQL parameter] documentation for additional information. 4769** 4770** ^The sqlite3_result_blob() interface sets the result from 4771** an application-defined function to be the BLOB whose content is pointed 4772** to by the second parameter and which is N bytes long where N is the 4773** third parameter. 4774** 4775** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 4776** interfaces set the result of the application-defined function to be 4777** a BLOB containing all zero bytes and N bytes in size. 4778** 4779** ^The sqlite3_result_double() interface sets the result from 4780** an application-defined function to be a floating point value specified 4781** by its 2nd argument. 4782** 4783** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4784** cause the implemented SQL function to throw an exception. 4785** ^SQLite uses the string pointed to by the 4786** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4787** as the text of an error message. ^SQLite interprets the error 4788** message string from sqlite3_result_error() as UTF-8. ^SQLite 4789** interprets the string from sqlite3_result_error16() as UTF-16 in native 4790** byte order. ^If the third parameter to sqlite3_result_error() 4791** or sqlite3_result_error16() is negative then SQLite takes as the error 4792** message all text up through the first zero character. 4793** ^If the third parameter to sqlite3_result_error() or 4794** sqlite3_result_error16() is non-negative then SQLite takes that many 4795** bytes (not characters) from the 2nd parameter as the error message. 4796** ^The sqlite3_result_error() and sqlite3_result_error16() 4797** routines make a private copy of the error message text before 4798** they return. Hence, the calling function can deallocate or 4799** modify the text after they return without harm. 4800** ^The sqlite3_result_error_code() function changes the error code 4801** returned by SQLite as a result of an error in a function. ^By default, 4802** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4803** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4804** 4805** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4806** error indicating that a string or BLOB is too long to represent. 4807** 4808** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4809** error indicating that a memory allocation failed. 4810** 4811** ^The sqlite3_result_int() interface sets the return value 4812** of the application-defined function to be the 32-bit signed integer 4813** value given in the 2nd argument. 4814** ^The sqlite3_result_int64() interface sets the return value 4815** of the application-defined function to be the 64-bit signed integer 4816** value given in the 2nd argument. 4817** 4818** ^The sqlite3_result_null() interface sets the return value 4819** of the application-defined function to be NULL. 4820** 4821** ^The sqlite3_result_text(), sqlite3_result_text16(), 4822** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4823** set the return value of the application-defined function to be 4824** a text string which is represented as UTF-8, UTF-16 native byte order, 4825** UTF-16 little endian, or UTF-16 big endian, respectively. 4826** ^The sqlite3_result_text64() interface sets the return value of an 4827** application-defined function to be a text string in an encoding 4828** specified by the fifth (and last) parameter, which must be one 4829** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 4830** ^SQLite takes the text result from the application from 4831** the 2nd parameter of the sqlite3_result_text* interfaces. 4832** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4833** is negative, then SQLite takes result text from the 2nd parameter 4834** through the first zero character. 4835** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4836** is non-negative, then as many bytes (not characters) of the text 4837** pointed to by the 2nd parameter are taken as the application-defined 4838** function result. If the 3rd parameter is non-negative, then it 4839** must be the byte offset into the string where the NUL terminator would 4840** appear if the string where NUL terminated. If any NUL characters occur 4841** in the string at a byte offset that is less than the value of the 3rd 4842** parameter, then the resulting string will contain embedded NULs and the 4843** result of expressions operating on strings with embedded NULs is undefined. 4844** ^If the 4th parameter to the sqlite3_result_text* interfaces 4845** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4846** function as the destructor on the text or BLOB result when it has 4847** finished using that result. 4848** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4849** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4850** assumes that the text or BLOB result is in constant space and does not 4851** copy the content of the parameter nor call a destructor on the content 4852** when it has finished using that result. 4853** ^If the 4th parameter to the sqlite3_result_text* interfaces 4854** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4855** then SQLite makes a copy of the result into space obtained from 4856** from [sqlite3_malloc()] before it returns. 4857** 4858** ^The sqlite3_result_value() interface sets the result of 4859** the application-defined function to be a copy of the 4860** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4861** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4862** so that the [sqlite3_value] specified in the parameter may change or 4863** be deallocated after sqlite3_result_value() returns without harm. 4864** ^A [protected sqlite3_value] object may always be used where an 4865** [unprotected sqlite3_value] object is required, so either 4866** kind of [sqlite3_value] object can be used with this interface. 4867** 4868** If these routines are called from within the different thread 4869** than the one containing the application-defined function that received 4870** the [sqlite3_context] pointer, the results are undefined. 4871*/ 4872void sqlite3_result_blob(sqlite3_context*, const void*, int, 4873 void(SQLITE_CALLBACK *)(void*)); 4874void sqlite3_result_blob64(sqlite3_context*,const void*, 4875 sqlite3_uint64,void(SQLITE_CALLBACK *)(void*)); 4876void sqlite3_result_double(sqlite3_context*, double); 4877void sqlite3_result_error(sqlite3_context*, const char*, int); 4878void sqlite3_result_error16(sqlite3_context*, const void*, int); 4879void sqlite3_result_error_toobig(sqlite3_context*); 4880void sqlite3_result_error_nomem(sqlite3_context*); 4881void sqlite3_result_error_code(sqlite3_context*, int); 4882void sqlite3_result_int(sqlite3_context*, int); 4883void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4884void sqlite3_result_null(sqlite3_context*); 4885void sqlite3_result_text(sqlite3_context*, const char*, int, 4886 void(SQLITE_CALLBACK *)(void*)); 4887void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 4888 void(SQLITE_CALLBACK *)(void*), 4889 unsigned char encoding); 4890void sqlite3_result_text16(sqlite3_context*, const void*, int, 4891 void(SQLITE_CALLBACK *)(void*)); 4892void sqlite3_result_text16le(sqlite3_context*, const void*, int, 4893 void(SQLITE_CALLBACK *)(void*)); 4894void sqlite3_result_text16be(sqlite3_context*, const void*, int, 4895 void(SQLITE_CALLBACK *)(void*)); 4896void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4897void sqlite3_result_zeroblob(sqlite3_context*, int n); 4898int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 4899 4900 4901/* 4902** CAPI3REF: Setting The Subtype Of An SQL Function 4903** METHOD: sqlite3_context 4904** 4905** The sqlite3_result_subtype(C,T) function causes the subtype of 4906** the result from the [application-defined SQL function] with 4907** [sqlite3_context] C to be the value T. Only the lower 8 bits 4908** of the subtype T are preserved in current versions of SQLite; 4909** higher order bits are discarded. 4910** The number of subtype bytes preserved by SQLite might increase 4911** in future releases of SQLite. 4912*/ 4913void sqlite3_result_subtype(sqlite3_context*,unsigned int); 4914 4915/* 4916** CAPI3REF: Define New Collating Sequences 4917** METHOD: sqlite3 4918** 4919** ^These functions add, remove, or modify a [collation] associated 4920** with the [database connection] specified as the first argument. 4921** 4922** ^The name of the collation is a UTF-8 string 4923** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4924** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4925** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4926** considered to be the same name. 4927** 4928** ^(The third argument (eTextRep) must be one of the constants: 4929** <ul> 4930** <li> [SQLITE_UTF8], 4931** <li> [SQLITE_UTF16LE], 4932** <li> [SQLITE_UTF16BE], 4933** <li> [SQLITE_UTF16], or 4934** <li> [SQLITE_UTF16_ALIGNED]. 4935** </ul>)^ 4936** ^The eTextRep argument determines the encoding of strings passed 4937** to the collating function callback, xCallback. 4938** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4939** force strings to be UTF16 with native byte order. 4940** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4941** on an even byte address. 4942** 4943** ^The fourth argument, pArg, is an application data pointer that is passed 4944** through as the first argument to the collating function callback. 4945** 4946** ^The fifth argument, xCallback, is a pointer to the collating function. 4947** ^Multiple collating functions can be registered using the same name but 4948** with different eTextRep parameters and SQLite will use whichever 4949** function requires the least amount of data transformation. 4950** ^If the xCallback argument is NULL then the collating function is 4951** deleted. ^When all collating functions having the same name are deleted, 4952** that collation is no longer usable. 4953** 4954** ^The collating function callback is invoked with a copy of the pArg 4955** application data pointer and with two strings in the encoding specified 4956** by the eTextRep argument. The collating function must return an 4957** integer that is negative, zero, or positive 4958** if the first string is less than, equal to, or greater than the second, 4959** respectively. A collating function must always return the same answer 4960** given the same inputs. If two or more collating functions are registered 4961** to the same collation name (using different eTextRep values) then all 4962** must give an equivalent answer when invoked with equivalent strings. 4963** The collating function must obey the following properties for all 4964** strings A, B, and C: 4965** 4966** <ol> 4967** <li> If A==B then B==A. 4968** <li> If A==B and B==C then A==C. 4969** <li> If A<B THEN B>A. 4970** <li> If A<B and B<C then A<C. 4971** </ol> 4972** 4973** If a collating function fails any of the above constraints and that 4974** collating function is registered and used, then the behavior of SQLite 4975** is undefined. 4976** 4977** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4978** with the addition that the xDestroy callback is invoked on pArg when 4979** the collating function is deleted. 4980** ^Collating functions are deleted when they are overridden by later 4981** calls to the collation creation functions or when the 4982** [database connection] is closed using [sqlite3_close()]. 4983** 4984** ^The xDestroy callback is <u>not</u> called if the 4985** sqlite3_create_collation_v2() function fails. Applications that invoke 4986** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 4987** check the return code and dispose of the application data pointer 4988** themselves rather than expecting SQLite to deal with it for them. 4989** This is different from every other SQLite interface. The inconsistency 4990** is unfortunate but cannot be changed without breaking backwards 4991** compatibility. 4992** 4993** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 4994*/ 4995int sqlite3_create_collation( 4996 sqlite3*, 4997 const char *zName, 4998 int eTextRep, 4999 void *pArg, 5000 int(SQLITE_CALLBACK *xCompare)(void*,int,const void*,int,const void*) 5001); 5002int sqlite3_create_collation_v2( 5003 sqlite3*, 5004 const char *zName, 5005 int eTextRep, 5006 void *pArg, 5007 int(SQLITE_CALLBACK *xCompare)(void*,int,const void*,int,const void*), 5008 void(SQLITE_CALLBACK *xDestroy)(void*) 5009); 5010int sqlite3_create_collation16( 5011 sqlite3*, 5012 const void *zName, 5013 int eTextRep, 5014 void *pArg, 5015 int(SQLITE_CALLBACK *xCompare)(void*,int,const void*,int,const void*) 5016); 5017 5018/* 5019** CAPI3REF: Collation Needed Callbacks 5020** METHOD: sqlite3 5021** 5022** ^To avoid having to register all collation sequences before a database 5023** can be used, a single callback function may be registered with the 5024** [database connection] to be invoked whenever an undefined collation 5025** sequence is required. 5026** 5027** ^If the function is registered using the sqlite3_collation_needed() API, 5028** then it is passed the names of undefined collation sequences as strings 5029** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5030** the names are passed as UTF-16 in machine native byte order. 5031** ^A call to either function replaces the existing collation-needed callback. 5032** 5033** ^(When the callback is invoked, the first argument passed is a copy 5034** of the second argument to sqlite3_collation_needed() or 5035** sqlite3_collation_needed16(). The second argument is the database 5036** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5037** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5038** sequence function required. The fourth parameter is the name of the 5039** required collation sequence.)^ 5040** 5041** The callback function should register the desired collation using 5042** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5043** [sqlite3_create_collation_v2()]. 5044*/ 5045int sqlite3_collation_needed( 5046 sqlite3*, 5047 void*, 5048 void(SQLITE_CALLBACK *)(void*,sqlite3*,int eTextRep,const char*) 5049); 5050int sqlite3_collation_needed16( 5051 sqlite3*, 5052 void*, 5053 void(SQLITE_CALLBACK *)(void*,sqlite3*,int eTextRep,const void*) 5054); 5055 5056#ifdef SQLITE_HAS_CODEC 5057/* 5058** Specify the key for an encrypted database. This routine should be 5059** called right after sqlite3_open(). 5060** 5061** The code to implement this API is not available in the public release 5062** of SQLite. 5063*/ 5064int sqlite3_key( 5065 sqlite3 *db, /* Database to be rekeyed */ 5066 const void *pKey, int nKey /* The key */ 5067); 5068int sqlite3_key_v2( 5069 sqlite3 *db, /* Database to be rekeyed */ 5070 const char *zDbName, /* Name of the database */ 5071 const void *pKey, int nKey /* The key */ 5072); 5073 5074/* 5075** Change the key on an open database. If the current database is not 5076** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5077** database is decrypted. 5078** 5079** The code to implement this API is not available in the public release 5080** of SQLite. 5081*/ 5082int sqlite3_rekey( 5083 sqlite3 *db, /* Database to be rekeyed */ 5084 const void *pKey, int nKey /* The new key */ 5085); 5086int sqlite3_rekey_v2( 5087 sqlite3 *db, /* Database to be rekeyed */ 5088 const char *zDbName, /* Name of the database */ 5089 const void *pKey, int nKey /* The new key */ 5090); 5091 5092/* 5093** Specify the activation key for a SEE database. Unless 5094** activated, none of the SEE routines will work. 5095*/ 5096void sqlite3_activate_see( 5097 const char *zPassPhrase /* Activation phrase */ 5098); 5099#endif 5100 5101#ifdef SQLITE_ENABLE_CEROD 5102/* 5103** Specify the activation key for a CEROD database. Unless 5104** activated, none of the CEROD routines will work. 5105*/ 5106void sqlite3_activate_cerod( 5107 const char *zPassPhrase /* Activation phrase */ 5108); 5109#endif 5110 5111/* 5112** CAPI3REF: Suspend Execution For A Short Time 5113** 5114** The sqlite3_sleep() function causes the current thread to suspend execution 5115** for at least a number of milliseconds specified in its parameter. 5116** 5117** If the operating system does not support sleep requests with 5118** millisecond time resolution, then the time will be rounded up to 5119** the nearest second. The number of milliseconds of sleep actually 5120** requested from the operating system is returned. 5121** 5122** ^SQLite implements this interface by calling the xSleep() 5123** method of the default [sqlite3_vfs] object. If the xSleep() method 5124** of the default VFS is not implemented correctly, or not implemented at 5125** all, then the behavior of sqlite3_sleep() may deviate from the description 5126** in the previous paragraphs. 5127*/ 5128int sqlite3_sleep(int); 5129 5130/* 5131** CAPI3REF: Name Of The Folder Holding Temporary Files 5132** 5133** ^(If this global variable is made to point to a string which is 5134** the name of a folder (a.k.a. directory), then all temporary files 5135** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5136** will be placed in that directory.)^ ^If this variable 5137** is a NULL pointer, then SQLite performs a search for an appropriate 5138** temporary file directory. 5139** 5140** Applications are strongly discouraged from using this global variable. 5141** It is required to set a temporary folder on Windows Runtime (WinRT). 5142** But for all other platforms, it is highly recommended that applications 5143** neither read nor write this variable. This global variable is a relic 5144** that exists for backwards compatibility of legacy applications and should 5145** be avoided in new projects. 5146** 5147** It is not safe to read or modify this variable in more than one 5148** thread at a time. It is not safe to read or modify this variable 5149** if a [database connection] is being used at the same time in a separate 5150** thread. 5151** It is intended that this variable be set once 5152** as part of process initialization and before any SQLite interface 5153** routines have been called and that this variable remain unchanged 5154** thereafter. 5155** 5156** ^The [temp_store_directory pragma] may modify this variable and cause 5157** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5158** the [temp_store_directory pragma] always assumes that any string 5159** that this variable points to is held in memory obtained from 5160** [sqlite3_malloc] and the pragma may attempt to free that memory 5161** using [sqlite3_free]. 5162** Hence, if this variable is modified directly, either it should be 5163** made NULL or made to point to memory obtained from [sqlite3_malloc] 5164** or else the use of the [temp_store_directory pragma] should be avoided. 5165** Except when requested by the [temp_store_directory pragma], SQLite 5166** does not free the memory that sqlite3_temp_directory points to. If 5167** the application wants that memory to be freed, it must do 5168** so itself, taking care to only do so after all [database connection] 5169** objects have been destroyed. 5170** 5171** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5172** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5173** features that require the use of temporary files may fail. Here is an 5174** example of how to do this using C++ with the Windows Runtime: 5175** 5176** <blockquote><pre> 5177** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5178** TemporaryFolder->Path->Data(); 5179** char zPathBuf[MAX_PATH + 1]; 5180** memset(zPathBuf, 0, sizeof(zPathBuf)); 5181** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5182** NULL, NULL); 5183** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5184** </pre></blockquote> 5185*/ 5186SQLITE_EXTERN char *sqlite3_temp_directory; 5187 5188/* 5189** CAPI3REF: Name Of The Folder Holding Database Files 5190** 5191** ^(If this global variable is made to point to a string which is 5192** the name of a folder (a.k.a. directory), then all database files 5193** specified with a relative pathname and created or accessed by 5194** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5195** to be relative to that directory.)^ ^If this variable is a NULL 5196** pointer, then SQLite assumes that all database files specified 5197** with a relative pathname are relative to the current directory 5198** for the process. Only the windows VFS makes use of this global 5199** variable; it is ignored by the unix VFS. 5200** 5201** Changing the value of this variable while a database connection is 5202** open can result in a corrupt database. 5203** 5204** It is not safe to read or modify this variable in more than one 5205** thread at a time. It is not safe to read or modify this variable 5206** if a [database connection] is being used at the same time in a separate 5207** thread. 5208** It is intended that this variable be set once 5209** as part of process initialization and before any SQLite interface 5210** routines have been called and that this variable remain unchanged 5211** thereafter. 5212** 5213** ^The [data_store_directory pragma] may modify this variable and cause 5214** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5215** the [data_store_directory pragma] always assumes that any string 5216** that this variable points to is held in memory obtained from 5217** [sqlite3_malloc] and the pragma may attempt to free that memory 5218** using [sqlite3_free]. 5219** Hence, if this variable is modified directly, either it should be 5220** made NULL or made to point to memory obtained from [sqlite3_malloc] 5221** or else the use of the [data_store_directory pragma] should be avoided. 5222*/ 5223SQLITE_EXTERN char *sqlite3_data_directory; 5224 5225/* 5226** CAPI3REF: Test For Auto-Commit Mode 5227** KEYWORDS: {autocommit mode} 5228** METHOD: sqlite3 5229** 5230** ^The sqlite3_get_autocommit() interface returns non-zero or 5231** zero if the given database connection is or is not in autocommit mode, 5232** respectively. ^Autocommit mode is on by default. 5233** ^Autocommit mode is disabled by a [BEGIN] statement. 5234** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5235** 5236** If certain kinds of errors occur on a statement within a multi-statement 5237** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5238** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5239** transaction might be rolled back automatically. The only way to 5240** find out whether SQLite automatically rolled back the transaction after 5241** an error is to use this function. 5242** 5243** If another thread changes the autocommit status of the database 5244** connection while this routine is running, then the return value 5245** is undefined. 5246*/ 5247int sqlite3_get_autocommit(sqlite3*); 5248 5249/* 5250** CAPI3REF: Find The Database Handle Of A Prepared Statement 5251** METHOD: sqlite3_stmt 5252** 5253** ^The sqlite3_db_handle interface returns the [database connection] handle 5254** to which a [prepared statement] belongs. ^The [database connection] 5255** returned by sqlite3_db_handle is the same [database connection] 5256** that was the first argument 5257** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5258** create the statement in the first place. 5259*/ 5260sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 5261 5262/* 5263** CAPI3REF: Return The Filename For A Database Connection 5264** METHOD: sqlite3 5265** 5266** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5267** associated with database N of connection D. ^The main database file 5268** has the name "main". If there is no attached database N on the database 5269** connection D, or if database N is a temporary or in-memory database, then 5270** a NULL pointer is returned. 5271** 5272** ^The filename returned by this function is the output of the 5273** xFullPathname method of the [VFS]. ^In other words, the filename 5274** will be an absolute pathname, even if the filename used 5275** to open the database originally was a URI or relative pathname. 5276*/ 5277const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5278 5279/* 5280** CAPI3REF: Determine if a database is read-only 5281** METHOD: sqlite3 5282** 5283** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5284** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5285** the name of a database on connection D. 5286*/ 5287int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5288 5289/* 5290** CAPI3REF: Find the next prepared statement 5291** METHOD: sqlite3 5292** 5293** ^This interface returns a pointer to the next [prepared statement] after 5294** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5295** then this interface returns a pointer to the first prepared statement 5296** associated with the database connection pDb. ^If no prepared statement 5297** satisfies the conditions of this routine, it returns NULL. 5298** 5299** The [database connection] pointer D in a call to 5300** [sqlite3_next_stmt(D,S)] must refer to an open database 5301** connection and in particular must not be a NULL pointer. 5302*/ 5303sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5304 5305/* 5306** CAPI3REF: Commit And Rollback Notification Callbacks 5307** METHOD: sqlite3 5308** 5309** ^The sqlite3_commit_hook() interface registers a callback 5310** function to be invoked whenever a transaction is [COMMIT | committed]. 5311** ^Any callback set by a previous call to sqlite3_commit_hook() 5312** for the same database connection is overridden. 5313** ^The sqlite3_rollback_hook() interface registers a callback 5314** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5315** ^Any callback set by a previous call to sqlite3_rollback_hook() 5316** for the same database connection is overridden. 5317** ^The pArg argument is passed through to the callback. 5318** ^If the callback on a commit hook function returns non-zero, 5319** then the commit is converted into a rollback. 5320** 5321** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5322** return the P argument from the previous call of the same function 5323** on the same [database connection] D, or NULL for 5324** the first call for each function on D. 5325** 5326** The commit and rollback hook callbacks are not reentrant. 5327** The callback implementation must not do anything that will modify 5328** the database connection that invoked the callback. Any actions 5329** to modify the database connection must be deferred until after the 5330** completion of the [sqlite3_step()] call that triggered the commit 5331** or rollback hook in the first place. 5332** Note that running any other SQL statements, including SELECT statements, 5333** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5334** the database connections for the meaning of "modify" in this paragraph. 5335** 5336** ^Registering a NULL function disables the callback. 5337** 5338** ^When the commit hook callback routine returns zero, the [COMMIT] 5339** operation is allowed to continue normally. ^If the commit hook 5340** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5341** ^The rollback hook is invoked on a rollback that results from a commit 5342** hook returning non-zero, just as it would be with any other rollback. 5343** 5344** ^For the purposes of this API, a transaction is said to have been 5345** rolled back if an explicit "ROLLBACK" statement is executed, or 5346** an error or constraint causes an implicit rollback to occur. 5347** ^The rollback callback is not invoked if a transaction is 5348** automatically rolled back because the database connection is closed. 5349** 5350** See also the [sqlite3_update_hook()] interface. 5351*/ 5352void *sqlite3_commit_hook(sqlite3*, int(SQLITE_CALLBACK *)(void*), void*); 5353void *sqlite3_rollback_hook(sqlite3*, void(SQLITE_CALLBACK *)(void *), void*); 5354 5355/* 5356** CAPI3REF: Data Change Notification Callbacks 5357** METHOD: sqlite3 5358** 5359** ^The sqlite3_update_hook() interface registers a callback function 5360** with the [database connection] identified by the first argument 5361** to be invoked whenever a row is updated, inserted or deleted in 5362** a [rowid table]. 5363** ^Any callback set by a previous call to this function 5364** for the same database connection is overridden. 5365** 5366** ^The second argument is a pointer to the function to invoke when a 5367** row is updated, inserted or deleted in a rowid table. 5368** ^The first argument to the callback is a copy of the third argument 5369** to sqlite3_update_hook(). 5370** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5371** or [SQLITE_UPDATE], depending on the operation that caused the callback 5372** to be invoked. 5373** ^The third and fourth arguments to the callback contain pointers to the 5374** database and table name containing the affected row. 5375** ^The final callback parameter is the [rowid] of the row. 5376** ^In the case of an update, this is the [rowid] after the update takes place. 5377** 5378** ^(The update hook is not invoked when internal system tables are 5379** modified (i.e. sqlite_master and sqlite_sequence).)^ 5380** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5381** 5382** ^In the current implementation, the update hook 5383** is not invoked when duplication rows are deleted because of an 5384** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5385** invoked when rows are deleted using the [truncate optimization]. 5386** The exceptions defined in this paragraph might change in a future 5387** release of SQLite. 5388** 5389** The update hook implementation must not do anything that will modify 5390** the database connection that invoked the update hook. Any actions 5391** to modify the database connection must be deferred until after the 5392** completion of the [sqlite3_step()] call that triggered the update hook. 5393** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5394** database connections for the meaning of "modify" in this paragraph. 5395** 5396** ^The sqlite3_update_hook(D,C,P) function 5397** returns the P argument from the previous call 5398** on the same [database connection] D, or NULL for 5399** the first call on D. 5400** 5401** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 5402** and [sqlite3_preupdate_hook()] interfaces. 5403*/ 5404void *sqlite3_update_hook( 5405 sqlite3*, 5406 void(SQLITE_CALLBACK *)(void *,int ,char const *,char const *,sqlite3_int64), 5407 void* 5408); 5409 5410/* 5411** CAPI3REF: Enable Or Disable Shared Pager Cache 5412** 5413** ^(This routine enables or disables the sharing of the database cache 5414** and schema data structures between [database connection | connections] 5415** to the same database. Sharing is enabled if the argument is true 5416** and disabled if the argument is false.)^ 5417** 5418** ^Cache sharing is enabled and disabled for an entire process. 5419** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 5420** sharing was enabled or disabled for each thread separately. 5421** 5422** ^(The cache sharing mode set by this interface effects all subsequent 5423** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5424** Existing database connections continue use the sharing mode 5425** that was in effect at the time they were opened.)^ 5426** 5427** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5428** successfully. An [error code] is returned otherwise.)^ 5429** 5430** ^Shared cache is disabled by default. But this might change in 5431** future releases of SQLite. Applications that care about shared 5432** cache setting should set it explicitly. 5433** 5434** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5435** and will always return SQLITE_MISUSE. On those systems, 5436** shared cache mode should be enabled per-database connection via 5437** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5438** 5439** This interface is threadsafe on processors where writing a 5440** 32-bit integer is atomic. 5441** 5442** See Also: [SQLite Shared-Cache Mode] 5443*/ 5444int sqlite3_enable_shared_cache(int); 5445 5446/* 5447** CAPI3REF: Attempt To Free Heap Memory 5448** 5449** ^The sqlite3_release_memory() interface attempts to free N bytes 5450** of heap memory by deallocating non-essential memory allocations 5451** held by the database library. Memory used to cache database 5452** pages to improve performance is an example of non-essential memory. 5453** ^sqlite3_release_memory() returns the number of bytes actually freed, 5454** which might be more or less than the amount requested. 5455** ^The sqlite3_release_memory() routine is a no-op returning zero 5456** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5457** 5458** See also: [sqlite3_db_release_memory()] 5459*/ 5460int sqlite3_release_memory(int); 5461 5462/* 5463** CAPI3REF: Free Memory Used By A Database Connection 5464** METHOD: sqlite3 5465** 5466** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5467** memory as possible from database connection D. Unlike the 5468** [sqlite3_release_memory()] interface, this interface is in effect even 5469** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5470** omitted. 5471** 5472** See also: [sqlite3_release_memory()] 5473*/ 5474int sqlite3_db_release_memory(sqlite3*); 5475 5476/* 5477** CAPI3REF: Impose A Limit On Heap Size 5478** 5479** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5480** soft limit on the amount of heap memory that may be allocated by SQLite. 5481** ^SQLite strives to keep heap memory utilization below the soft heap 5482** limit by reducing the number of pages held in the page cache 5483** as heap memory usages approaches the limit. 5484** ^The soft heap limit is "soft" because even though SQLite strives to stay 5485** below the limit, it will exceed the limit rather than generate 5486** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5487** is advisory only. 5488** 5489** ^The return value from sqlite3_soft_heap_limit64() is the size of 5490** the soft heap limit prior to the call, or negative in the case of an 5491** error. ^If the argument N is negative 5492** then no change is made to the soft heap limit. Hence, the current 5493** size of the soft heap limit can be determined by invoking 5494** sqlite3_soft_heap_limit64() with a negative argument. 5495** 5496** ^If the argument N is zero then the soft heap limit is disabled. 5497** 5498** ^(The soft heap limit is not enforced in the current implementation 5499** if one or more of following conditions are true: 5500** 5501** <ul> 5502** <li> The soft heap limit is set to zero. 5503** <li> Memory accounting is disabled using a combination of the 5504** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5505** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5506** <li> An alternative page cache implementation is specified using 5507** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5508** <li> The page cache allocates from its own memory pool supplied 5509** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5510** from the heap. 5511** </ul>)^ 5512** 5513** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 5514** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5515** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5516** the soft heap limit is enforced on every memory allocation. Without 5517** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5518** when memory is allocated by the page cache. Testing suggests that because 5519** the page cache is the predominate memory user in SQLite, most 5520** applications will achieve adequate soft heap limit enforcement without 5521** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5522** 5523** The circumstances under which SQLite will enforce the soft heap limit may 5524** changes in future releases of SQLite. 5525*/ 5526sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 5527 5528/* 5529** CAPI3REF: Deprecated Soft Heap Limit Interface 5530** DEPRECATED 5531** 5532** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5533** interface. This routine is provided for historical compatibility 5534** only. All new applications should use the 5535** [sqlite3_soft_heap_limit64()] interface rather than this one. 5536*/ 5537SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 5538 5539 5540/* 5541** CAPI3REF: Extract Metadata About A Column Of A Table 5542** METHOD: sqlite3 5543** 5544** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 5545** information about column C of table T in database D 5546** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 5547** interface returns SQLITE_OK and fills in the non-NULL pointers in 5548** the final five arguments with appropriate values if the specified 5549** column exists. ^The sqlite3_table_column_metadata() interface returns 5550** SQLITE_ERROR and if the specified column does not exist. 5551** ^If the column-name parameter to sqlite3_table_column_metadata() is a 5552** NULL pointer, then this routine simply checks for the existance of the 5553** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 5554** does not. 5555** 5556** ^The column is identified by the second, third and fourth parameters to 5557** this function. ^(The second parameter is either the name of the database 5558** (i.e. "main", "temp", or an attached database) containing the specified 5559** table or NULL.)^ ^If it is NULL, then all attached databases are searched 5560** for the table using the same algorithm used by the database engine to 5561** resolve unqualified table references. 5562** 5563** ^The third and fourth parameters to this function are the table and column 5564** name of the desired column, respectively. 5565** 5566** ^Metadata is returned by writing to the memory locations passed as the 5th 5567** and subsequent parameters to this function. ^Any of these arguments may be 5568** NULL, in which case the corresponding element of metadata is omitted. 5569** 5570** ^(<blockquote> 5571** <table border="1"> 5572** <tr><th> Parameter <th> Output<br>Type <th> Description 5573** 5574** <tr><td> 5th <td> const char* <td> Data type 5575** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5576** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5577** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5578** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5579** </table> 5580** </blockquote>)^ 5581** 5582** ^The memory pointed to by the character pointers returned for the 5583** declaration type and collation sequence is valid until the next 5584** call to any SQLite API function. 5585** 5586** ^If the specified table is actually a view, an [error code] is returned. 5587** 5588** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 5589** is not a [WITHOUT ROWID] table and an 5590** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5591** parameters are set for the explicitly declared column. ^(If there is no 5592** [INTEGER PRIMARY KEY] column, then the outputs 5593** for the [rowid] are set as follows: 5594** 5595** <pre> 5596** data type: "INTEGER" 5597** collation sequence: "BINARY" 5598** not null: 0 5599** primary key: 1 5600** auto increment: 0 5601** </pre>)^ 5602** 5603** ^This function causes all database schemas to be read from disk and 5604** parsed, if that has not already been done, and returns an error if 5605** any errors are encountered while loading the schema. 5606*/ 5607int sqlite3_table_column_metadata( 5608 sqlite3 *db, /* Connection handle */ 5609 const char *zDbName, /* Database name or NULL */ 5610 const char *zTableName, /* Table name */ 5611 const char *zColumnName, /* Column name */ 5612 char const **pzDataType, /* OUTPUT: Declared data type */ 5613 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5614 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5615 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5616 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5617); 5618 5619/* 5620** CAPI3REF: Load An Extension 5621** METHOD: sqlite3 5622** 5623** ^This interface loads an SQLite extension library from the named file. 5624** 5625** ^The sqlite3_load_extension() interface attempts to load an 5626** [SQLite extension] library contained in the file zFile. If 5627** the file cannot be loaded directly, attempts are made to load 5628** with various operating-system specific extensions added. 5629** So for example, if "samplelib" cannot be loaded, then names like 5630** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5631** be tried also. 5632** 5633** ^The entry point is zProc. 5634** ^(zProc may be 0, in which case SQLite will try to come up with an 5635** entry point name on its own. It first tries "sqlite3_extension_init". 5636** If that does not work, it constructs a name "sqlite3_X_init" where the 5637** X is consists of the lower-case equivalent of all ASCII alphabetic 5638** characters in the filename from the last "/" to the first following 5639** "." and omitting any initial "lib".)^ 5640** ^The sqlite3_load_extension() interface returns 5641** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5642** ^If an error occurs and pzErrMsg is not 0, then the 5643** [sqlite3_load_extension()] interface shall attempt to 5644** fill *pzErrMsg with error message text stored in memory 5645** obtained from [sqlite3_malloc()]. The calling function 5646** should free this memory by calling [sqlite3_free()]. 5647** 5648** ^Extension loading must be enabled using 5649** [sqlite3_enable_load_extension()] or 5650** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 5651** prior to calling this API, 5652** otherwise an error will be returned. 5653** 5654** <b>Security warning:</b> It is recommended that the 5655** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 5656** interface. The use of the [sqlite3_enable_load_extension()] interface 5657** should be avoided. This will keep the SQL function [load_extension()] 5658** disabled and prevent SQL injections from giving attackers 5659** access to extension loading capabilities. 5660** 5661** See also the [load_extension() SQL function]. 5662*/ 5663int sqlite3_load_extension( 5664 sqlite3 *db, /* Load the extension into this database connection */ 5665 const char *zFile, /* Name of the shared library containing extension */ 5666 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5667 char **pzErrMsg /* Put error message here if not 0 */ 5668); 5669 5670/* 5671** CAPI3REF: Enable Or Disable Extension Loading 5672** METHOD: sqlite3 5673** 5674** ^So as not to open security holes in older applications that are 5675** unprepared to deal with [extension loading], and as a means of disabling 5676** [extension loading] while evaluating user-entered SQL, the following API 5677** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5678** 5679** ^Extension loading is off by default. 5680** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5681** to turn extension loading on and call it with onoff==0 to turn 5682** it back off again. 5683** 5684** ^This interface enables or disables both the C-API 5685** [sqlite3_load_extension()] and the SQL function [load_extension()]. 5686** Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 5687** to enable or disable only the C-API. 5688** 5689** <b>Security warning:</b> It is recommended that extension loading 5690** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 5691** rather than this interface, so the [load_extension()] SQL function 5692** remains disabled. This will prevent SQL injections from giving attackers 5693** access to extension loading capabilities. 5694*/ 5695int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5696 5697/* 5698** CAPI3REF: Automatically Load Statically Linked Extensions 5699** 5700** ^This interface causes the xEntryPoint() function to be invoked for 5701** each new [database connection] that is created. The idea here is that 5702** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5703** that is to be automatically loaded into all new database connections. 5704** 5705** ^(Even though the function prototype shows that xEntryPoint() takes 5706** no arguments and returns void, SQLite invokes xEntryPoint() with three 5707** arguments and expects and integer result as if the signature of the 5708** entry point where as follows: 5709** 5710** <blockquote><pre> 5711** int xEntryPoint( 5712** sqlite3 *db, 5713** const char **pzErrMsg, 5714** const struct sqlite3_api_routines *pThunk 5715** ); 5716** </pre></blockquote>)^ 5717** 5718** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5719** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5720** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5721** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5722** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5723** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5724** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5725** 5726** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5727** on the list of automatic extensions is a harmless no-op. ^No entry point 5728** will be called more than once for each database connection that is opened. 5729** 5730** See also: [sqlite3_reset_auto_extension()] 5731** and [sqlite3_cancel_auto_extension()] 5732*/ 5733int sqlite3_auto_extension(void (SQLITE_CALLBACK *xEntryPoint)(void)); 5734 5735/* 5736** CAPI3REF: Cancel Automatic Extension Loading 5737** 5738** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 5739** initialization routine X that was registered using a prior call to 5740** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 5741** routine returns 1 if initialization routine X was successfully 5742** unregistered and it returns 0 if X was not on the list of initialization 5743** routines. 5744*/ 5745int sqlite3_cancel_auto_extension(void (SQLITE_CALLBACK *xEntryPoint)(void)); 5746 5747/* 5748** CAPI3REF: Reset Automatic Extension Loading 5749** 5750** ^This interface disables all automatic extensions previously 5751** registered using [sqlite3_auto_extension()]. 5752*/ 5753void sqlite3_reset_auto_extension(void); 5754 5755/* 5756** The interface to the virtual-table mechanism is currently considered 5757** to be experimental. The interface might change in incompatible ways. 5758** If this is a problem for you, do not use the interface at this time. 5759** 5760** When the virtual-table mechanism stabilizes, we will declare the 5761** interface fixed, support it indefinitely, and remove this comment. 5762*/ 5763 5764/* 5765** Structures used by the virtual table interface 5766*/ 5767typedef struct sqlite3_vtab sqlite3_vtab; 5768typedef struct sqlite3_index_info sqlite3_index_info; 5769typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5770typedef struct sqlite3_module sqlite3_module; 5771 5772/* 5773** CAPI3REF: Virtual Table Object 5774** KEYWORDS: sqlite3_module {virtual table module} 5775** 5776** This structure, sometimes called a "virtual table module", 5777** defines the implementation of a [virtual tables]. 5778** This structure consists mostly of methods for the module. 5779** 5780** ^A virtual table module is created by filling in a persistent 5781** instance of this structure and passing a pointer to that instance 5782** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5783** ^The registration remains valid until it is replaced by a different 5784** module or until the [database connection] closes. The content 5785** of this structure must not change while it is registered with 5786** any database connection. 5787*/ 5788struct sqlite3_module { 5789 int iVersion; 5790 int (SQLITE_CALLBACK *xCreate)(sqlite3*, void *pAux, 5791 int argc, const char *const*argv, 5792 sqlite3_vtab **ppVTab, char**); 5793 int (SQLITE_CALLBACK *xConnect)(sqlite3*, void *pAux, 5794 int argc, const char *const*argv, 5795 sqlite3_vtab **ppVTab, char**); 5796 int (SQLITE_CALLBACK *xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5797 int (SQLITE_CALLBACK *xDisconnect)(sqlite3_vtab *pVTab); 5798 int (SQLITE_CALLBACK *xDestroy)(sqlite3_vtab *pVTab); 5799 int (SQLITE_CALLBACK *xOpen)(sqlite3_vtab *pVTab, 5800 sqlite3_vtab_cursor **ppCursor); 5801 int (SQLITE_CALLBACK *xClose)(sqlite3_vtab_cursor*); 5802 int (SQLITE_CALLBACK *xFilter)(sqlite3_vtab_cursor*, 5803 int idxNum, const char *idxStr, 5804 int argc, sqlite3_value **argv); 5805 int (SQLITE_CALLBACK *xNext)(sqlite3_vtab_cursor*); 5806 int (SQLITE_CALLBACK *xEof)(sqlite3_vtab_cursor*); 5807 int (SQLITE_CALLBACK *xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5808 int (SQLITE_CALLBACK *xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5809 int (SQLITE_CALLBACK *xUpdate)(sqlite3_vtab *, int, sqlite3_value **, 5810 sqlite3_int64 *); 5811 int (SQLITE_CALLBACK *xBegin)(sqlite3_vtab *pVTab); 5812 int (SQLITE_CALLBACK *xSync)(sqlite3_vtab *pVTab); 5813 int (SQLITE_CALLBACK *xCommit)(sqlite3_vtab *pVTab); 5814 int (SQLITE_CALLBACK *xRollback)(sqlite3_vtab *pVTab); 5815 int (SQLITE_CALLBACK *xFindFunction)(sqlite3_vtab *pVtab, 5816 int nArg, const char *zName, 5817 void (SQLITE_CALLBACK **pxFunc)(sqlite3_context*,int,sqlite3_value**), 5818 void **ppArg); 5819 int (SQLITE_CALLBACK *xRename)(sqlite3_vtab *pVtab, const char *zNew); 5820 /* The methods above are in version 1 of the sqlite_module object. Those 5821 ** below are for version 2 and greater. */ 5822 int (SQLITE_CALLBACK *xSavepoint)(sqlite3_vtab *pVTab, int); 5823 int (SQLITE_CALLBACK *xRelease)(sqlite3_vtab *pVTab, int); 5824 int (SQLITE_CALLBACK *xRollbackTo)(sqlite3_vtab *pVTab, int); 5825}; 5826 5827/* 5828** CAPI3REF: Virtual Table Indexing Information 5829** KEYWORDS: sqlite3_index_info 5830** 5831** The sqlite3_index_info structure and its substructures is used as part 5832** of the [virtual table] interface to 5833** pass information into and receive the reply from the [xBestIndex] 5834** method of a [virtual table module]. The fields under **Inputs** are the 5835** inputs to xBestIndex and are read-only. xBestIndex inserts its 5836** results into the **Outputs** fields. 5837** 5838** ^(The aConstraint[] array records WHERE clause constraints of the form: 5839** 5840** <blockquote>column OP expr</blockquote> 5841** 5842** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5843** stored in aConstraint[].op using one of the 5844** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5845** ^(The index of the column is stored in 5846** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5847** expr on the right-hand side can be evaluated (and thus the constraint 5848** is usable) and false if it cannot.)^ 5849** 5850** ^The optimizer automatically inverts terms of the form "expr OP column" 5851** and makes other simplifications to the WHERE clause in an attempt to 5852** get as many WHERE clause terms into the form shown above as possible. 5853** ^The aConstraint[] array only reports WHERE clause terms that are 5854** relevant to the particular virtual table being queried. 5855** 5856** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5857** ^Each term of aOrderBy records a column of the ORDER BY clause. 5858** 5859** The colUsed field indicates which columns of the virtual table may be 5860** required by the current scan. Virtual table columns are numbered from 5861** zero in the order in which they appear within the CREATE TABLE statement 5862** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 5863** the corresponding bit is set within the colUsed mask if the column may be 5864** required by SQLite. If the table has at least 64 columns and any column 5865** to the right of the first 63 is required, then bit 63 of colUsed is also 5866** set. In other words, column iCol may be required if the expression 5867** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 5868** non-zero. 5869** 5870** The [xBestIndex] method must fill aConstraintUsage[] with information 5871** about what parameters to pass to xFilter. ^If argvIndex>0 then 5872** the right-hand side of the corresponding aConstraint[] is evaluated 5873** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5874** is true, then the constraint is assumed to be fully handled by the 5875** virtual table and is not checked again by SQLite.)^ 5876** 5877** ^The idxNum and idxPtr values are recorded and passed into the 5878** [xFilter] method. 5879** ^[sqlite3_free()] is used to free idxPtr if and only if 5880** needToFreeIdxPtr is true. 5881** 5882** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5883** the correct order to satisfy the ORDER BY clause so that no separate 5884** sorting step is required. 5885** 5886** ^The estimatedCost value is an estimate of the cost of a particular 5887** strategy. A cost of N indicates that the cost of the strategy is similar 5888** to a linear scan of an SQLite table with N rows. A cost of log(N) 5889** indicates that the expense of the operation is similar to that of a 5890** binary search on a unique indexed field of an SQLite table with N rows. 5891** 5892** ^The estimatedRows value is an estimate of the number of rows that 5893** will be returned by the strategy. 5894** 5895** The xBestIndex method may optionally populate the idxFlags field with a 5896** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 5897** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 5898** assumes that the strategy may visit at most one row. 5899** 5900** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 5901** SQLite also assumes that if a call to the xUpdate() method is made as 5902** part of the same statement to delete or update a virtual table row and the 5903** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 5904** any database changes. In other words, if the xUpdate() returns 5905** SQLITE_CONSTRAINT, the database contents must be exactly as they were 5906** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 5907** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 5908** the xUpdate method are automatically rolled back by SQLite. 5909** 5910** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 5911** structure for SQLite version 3.8.2. If a virtual table extension is 5912** used with an SQLite version earlier than 3.8.2, the results of attempting 5913** to read or write the estimatedRows field are undefined (but are likely 5914** to included crashing the application). The estimatedRows field should 5915** therefore only be used if [sqlite3_libversion_number()] returns a 5916** value greater than or equal to 3008002. Similarly, the idxFlags field 5917** was added for version 3.9.0. It may therefore only be used if 5918** sqlite3_libversion_number() returns a value greater than or equal to 5919** 3009000. 5920*/ 5921struct sqlite3_index_info { 5922 /* Inputs */ 5923 int nConstraint; /* Number of entries in aConstraint */ 5924 struct sqlite3_index_constraint { 5925 int iColumn; /* Column constrained. -1 for ROWID */ 5926 unsigned char op; /* Constraint operator */ 5927 unsigned char usable; /* True if this constraint is usable */ 5928 int iTermOffset; /* Used internally - xBestIndex should ignore */ 5929 } *aConstraint; /* Table of WHERE clause constraints */ 5930 int nOrderBy; /* Number of terms in the ORDER BY clause */ 5931 struct sqlite3_index_orderby { 5932 int iColumn; /* Column number */ 5933 unsigned char desc; /* True for DESC. False for ASC. */ 5934 } *aOrderBy; /* The ORDER BY clause */ 5935 /* Outputs */ 5936 struct sqlite3_index_constraint_usage { 5937 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5938 unsigned char omit; /* Do not code a test for this constraint */ 5939 } *aConstraintUsage; 5940 int idxNum; /* Number used to identify the index */ 5941 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5942 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5943 int orderByConsumed; /* True if output is already ordered */ 5944 double estimatedCost; /* Estimated cost of using this index */ 5945 /* Fields below are only available in SQLite 3.8.2 and later */ 5946 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 5947 /* Fields below are only available in SQLite 3.9.0 and later */ 5948 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 5949 /* Fields below are only available in SQLite 3.10.0 and later */ 5950 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 5951}; 5952 5953/* 5954** CAPI3REF: Virtual Table Scan Flags 5955*/ 5956#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 5957 5958/* 5959** CAPI3REF: Virtual Table Constraint Operator Codes 5960** 5961** These macros defined the allowed values for the 5962** [sqlite3_index_info].aConstraint[].op field. Each value represents 5963** an operator that is part of a constraint term in the wHERE clause of 5964** a query that uses a [virtual table]. 5965*/ 5966#define SQLITE_INDEX_CONSTRAINT_EQ 2 5967#define SQLITE_INDEX_CONSTRAINT_GT 4 5968#define SQLITE_INDEX_CONSTRAINT_LE 8 5969#define SQLITE_INDEX_CONSTRAINT_LT 16 5970#define SQLITE_INDEX_CONSTRAINT_GE 32 5971#define SQLITE_INDEX_CONSTRAINT_MATCH 64 5972#define SQLITE_INDEX_CONSTRAINT_LIKE 65 5973#define SQLITE_INDEX_CONSTRAINT_GLOB 66 5974#define SQLITE_INDEX_CONSTRAINT_REGEXP 67 5975 5976/* 5977** CAPI3REF: Register A Virtual Table Implementation 5978** METHOD: sqlite3 5979** 5980** ^These routines are used to register a new [virtual table module] name. 5981** ^Module names must be registered before 5982** creating a new [virtual table] using the module and before using a 5983** preexisting [virtual table] for the module. 5984** 5985** ^The module name is registered on the [database connection] specified 5986** by the first parameter. ^The name of the module is given by the 5987** second parameter. ^The third parameter is a pointer to 5988** the implementation of the [virtual table module]. ^The fourth 5989** parameter is an arbitrary client data pointer that is passed through 5990** into the [xCreate] and [xConnect] methods of the virtual table module 5991** when a new virtual table is be being created or reinitialized. 5992** 5993** ^The sqlite3_create_module_v2() interface has a fifth parameter which 5994** is a pointer to a destructor for the pClientData. ^SQLite will 5995** invoke the destructor function (if it is not NULL) when SQLite 5996** no longer needs the pClientData pointer. ^The destructor will also 5997** be invoked if the call to sqlite3_create_module_v2() fails. 5998** ^The sqlite3_create_module() 5999** interface is equivalent to sqlite3_create_module_v2() with a NULL 6000** destructor. 6001*/ 6002int sqlite3_create_module( 6003 sqlite3 *db, /* SQLite connection to register module with */ 6004 const char *zName, /* Name of the module */ 6005 const sqlite3_module *p, /* Methods for the module */ 6006 void *pClientData /* Client data for xCreate/xConnect */ 6007); 6008int sqlite3_create_module_v2( 6009 sqlite3 *db, /* SQLite connection to register module with */ 6010 const char *zName, /* Name of the module */ 6011 const sqlite3_module *p, /* Methods for the module */ 6012 void *pClientData, /* Client data for xCreate/xConnect */ 6013 void(SQLITE_CALLBACK *xDestroy)(void*) /* Module destructor function */ 6014); 6015 6016/* 6017** CAPI3REF: Virtual Table Instance Object 6018** KEYWORDS: sqlite3_vtab 6019** 6020** Every [virtual table module] implementation uses a subclass 6021** of this object to describe a particular instance 6022** of the [virtual table]. Each subclass will 6023** be tailored to the specific needs of the module implementation. 6024** The purpose of this superclass is to define certain fields that are 6025** common to all module implementations. 6026** 6027** ^Virtual tables methods can set an error message by assigning a 6028** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6029** take care that any prior string is freed by a call to [sqlite3_free()] 6030** prior to assigning a new string to zErrMsg. ^After the error message 6031** is delivered up to the client application, the string will be automatically 6032** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6033*/ 6034struct sqlite3_vtab { 6035 const sqlite3_module *pModule; /* The module for this virtual table */ 6036 int nRef; /* Number of open cursors */ 6037 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6038 /* Virtual table implementations will typically add additional fields */ 6039}; 6040 6041/* 6042** CAPI3REF: Virtual Table Cursor Object 6043** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6044** 6045** Every [virtual table module] implementation uses a subclass of the 6046** following structure to describe cursors that point into the 6047** [virtual table] and are used 6048** to loop through the virtual table. Cursors are created using the 6049** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6050** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6051** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6052** of the module. Each module implementation will define 6053** the content of a cursor structure to suit its own needs. 6054** 6055** This superclass exists in order to define fields of the cursor that 6056** are common to all implementations. 6057*/ 6058struct sqlite3_vtab_cursor { 6059 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6060 /* Virtual table implementations will typically add additional fields */ 6061}; 6062 6063/* 6064** CAPI3REF: Declare The Schema Of A Virtual Table 6065** 6066** ^The [xCreate] and [xConnect] methods of a 6067** [virtual table module] call this interface 6068** to declare the format (the names and datatypes of the columns) of 6069** the virtual tables they implement. 6070*/ 6071int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6072 6073/* 6074** CAPI3REF: Overload A Function For A Virtual Table 6075** METHOD: sqlite3 6076** 6077** ^(Virtual tables can provide alternative implementations of functions 6078** using the [xFindFunction] method of the [virtual table module]. 6079** But global versions of those functions 6080** must exist in order to be overloaded.)^ 6081** 6082** ^(This API makes sure a global version of a function with a particular 6083** name and number of parameters exists. If no such function exists 6084** before this API is called, a new function is created.)^ ^The implementation 6085** of the new function always causes an exception to be thrown. So 6086** the new function is not good for anything by itself. Its only 6087** purpose is to be a placeholder function that can be overloaded 6088** by a [virtual table]. 6089*/ 6090int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6091 6092/* 6093** The interface to the virtual-table mechanism defined above (back up 6094** to a comment remarkably similar to this one) is currently considered 6095** to be experimental. The interface might change in incompatible ways. 6096** If this is a problem for you, do not use the interface at this time. 6097** 6098** When the virtual-table mechanism stabilizes, we will declare the 6099** interface fixed, support it indefinitely, and remove this comment. 6100*/ 6101 6102/* 6103** CAPI3REF: A Handle To An Open BLOB 6104** KEYWORDS: {BLOB handle} {BLOB handles} 6105** 6106** An instance of this object represents an open BLOB on which 6107** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6108** ^Objects of this type are created by [sqlite3_blob_open()] 6109** and destroyed by [sqlite3_blob_close()]. 6110** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6111** can be used to read or write small subsections of the BLOB. 6112** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6113*/ 6114typedef struct sqlite3_blob sqlite3_blob; 6115 6116/* 6117** CAPI3REF: Open A BLOB For Incremental I/O 6118** METHOD: sqlite3 6119** CONSTRUCTOR: sqlite3_blob 6120** 6121** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6122** in row iRow, column zColumn, table zTable in database zDb; 6123** in other words, the same BLOB that would be selected by: 6124** 6125** <pre> 6126** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 6127** </pre>)^ 6128** 6129** ^(Parameter zDb is not the filename that contains the database, but 6130** rather the symbolic name of the database. For attached databases, this is 6131** the name that appears after the AS keyword in the [ATTACH] statement. 6132** For the main database file, the database name is "main". For TEMP 6133** tables, the database name is "temp".)^ 6134** 6135** ^If the flags parameter is non-zero, then the BLOB is opened for read 6136** and write access. ^If the flags parameter is zero, the BLOB is opened for 6137** read-only access. 6138** 6139** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 6140** in *ppBlob. Otherwise an [error code] is returned and, unless the error 6141** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 6142** the API is not misused, it is always safe to call [sqlite3_blob_close()] 6143** on *ppBlob after this function it returns. 6144** 6145** This function fails with SQLITE_ERROR if any of the following are true: 6146** <ul> 6147** <li> ^(Database zDb does not exist)^, 6148** <li> ^(Table zTable does not exist within database zDb)^, 6149** <li> ^(Table zTable is a WITHOUT ROWID table)^, 6150** <li> ^(Column zColumn does not exist)^, 6151** <li> ^(Row iRow is not present in the table)^, 6152** <li> ^(The specified column of row iRow contains a value that is not 6153** a TEXT or BLOB value)^, 6154** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 6155** constraint and the blob is being opened for read/write access)^, 6156** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 6157** column zColumn is part of a [child key] definition and the blob is 6158** being opened for read/write access)^. 6159** </ul> 6160** 6161** ^Unless it returns SQLITE_MISUSE, this function sets the 6162** [database connection] error code and message accessible via 6163** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6164** 6165** 6166** ^(If the row that a BLOB handle points to is modified by an 6167** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 6168** then the BLOB handle is marked as "expired". 6169** This is true if any column of the row is changed, even a column 6170** other than the one the BLOB handle is open on.)^ 6171** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 6172** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 6173** ^(Changes written into a BLOB prior to the BLOB expiring are not 6174** rolled back by the expiration of the BLOB. Such changes will eventually 6175** commit if the transaction continues to completion.)^ 6176** 6177** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 6178** the opened blob. ^The size of a blob may not be changed by this 6179** interface. Use the [UPDATE] SQL command to change the size of a 6180** blob. 6181** 6182** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 6183** and the built-in [zeroblob] SQL function may be used to create a 6184** zero-filled blob to read or write using the incremental-blob interface. 6185** 6186** To avoid a resource leak, every open [BLOB handle] should eventually 6187** be released by a call to [sqlite3_blob_close()]. 6188*/ 6189int sqlite3_blob_open( 6190 sqlite3*, 6191 const char *zDb, 6192 const char *zTable, 6193 const char *zColumn, 6194 sqlite3_int64 iRow, 6195 int flags, 6196 sqlite3_blob **ppBlob 6197); 6198 6199/* 6200** CAPI3REF: Move a BLOB Handle to a New Row 6201** METHOD: sqlite3_blob 6202** 6203** ^This function is used to move an existing blob handle so that it points 6204** to a different row of the same database table. ^The new row is identified 6205** by the rowid value passed as the second argument. Only the row can be 6206** changed. ^The database, table and column on which the blob handle is open 6207** remain the same. Moving an existing blob handle to a new row can be 6208** faster than closing the existing handle and opening a new one. 6209** 6210** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6211** it must exist and there must be either a blob or text value stored in 6212** the nominated column.)^ ^If the new row is not present in the table, or if 6213** it does not contain a blob or text value, or if another error occurs, an 6214** SQLite error code is returned and the blob handle is considered aborted. 6215** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6216** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6217** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6218** always returns zero. 6219** 6220** ^This function sets the database handle error code and message. 6221*/ 6222int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6223 6224/* 6225** CAPI3REF: Close A BLOB Handle 6226** DESTRUCTOR: sqlite3_blob 6227** 6228** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6229** unconditionally. Even if this routine returns an error code, the 6230** handle is still closed.)^ 6231** 6232** ^If the blob handle being closed was opened for read-write access, and if 6233** the database is in auto-commit mode and there are no other open read-write 6234** blob handles or active write statements, the current transaction is 6235** committed. ^If an error occurs while committing the transaction, an error 6236** code is returned and the transaction rolled back. 6237** 6238** Calling this function with an argument that is not a NULL pointer or an 6239** open blob handle results in undefined behaviour. ^Calling this routine 6240** with a null pointer (such as would be returned by a failed call to 6241** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6242** is passed a valid open blob handle, the values returned by the 6243** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6244*/ 6245int sqlite3_blob_close(sqlite3_blob *); 6246 6247/* 6248** CAPI3REF: Return The Size Of An Open BLOB 6249** METHOD: sqlite3_blob 6250** 6251** ^Returns the size in bytes of the BLOB accessible via the 6252** successfully opened [BLOB handle] in its only argument. ^The 6253** incremental blob I/O routines can only read or overwriting existing 6254** blob content; they cannot change the size of a blob. 6255** 6256** This routine only works on a [BLOB handle] which has been created 6257** by a prior successful call to [sqlite3_blob_open()] and which has not 6258** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6259** to this routine results in undefined and probably undesirable behavior. 6260*/ 6261int sqlite3_blob_bytes(sqlite3_blob *); 6262 6263/* 6264** CAPI3REF: Read Data From A BLOB Incrementally 6265** METHOD: sqlite3_blob 6266** 6267** ^(This function is used to read data from an open [BLOB handle] into a 6268** caller-supplied buffer. N bytes of data are copied into buffer Z 6269** from the open BLOB, starting at offset iOffset.)^ 6270** 6271** ^If offset iOffset is less than N bytes from the end of the BLOB, 6272** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6273** less than zero, [SQLITE_ERROR] is returned and no data is read. 6274** ^The size of the blob (and hence the maximum value of N+iOffset) 6275** can be determined using the [sqlite3_blob_bytes()] interface. 6276** 6277** ^An attempt to read from an expired [BLOB handle] fails with an 6278** error code of [SQLITE_ABORT]. 6279** 6280** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6281** Otherwise, an [error code] or an [extended error code] is returned.)^ 6282** 6283** This routine only works on a [BLOB handle] which has been created 6284** by a prior successful call to [sqlite3_blob_open()] and which has not 6285** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6286** to this routine results in undefined and probably undesirable behavior. 6287** 6288** See also: [sqlite3_blob_write()]. 6289*/ 6290int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6291 6292/* 6293** CAPI3REF: Write Data Into A BLOB Incrementally 6294** METHOD: sqlite3_blob 6295** 6296** ^(This function is used to write data into an open [BLOB handle] from a 6297** caller-supplied buffer. N bytes of data are copied from the buffer Z 6298** into the open BLOB, starting at offset iOffset.)^ 6299** 6300** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6301** Otherwise, an [error code] or an [extended error code] is returned.)^ 6302** ^Unless SQLITE_MISUSE is returned, this function sets the 6303** [database connection] error code and message accessible via 6304** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6305** 6306** ^If the [BLOB handle] passed as the first argument was not opened for 6307** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6308** this function returns [SQLITE_READONLY]. 6309** 6310** This function may only modify the contents of the BLOB; it is 6311** not possible to increase the size of a BLOB using this API. 6312** ^If offset iOffset is less than N bytes from the end of the BLOB, 6313** [SQLITE_ERROR] is returned and no data is written. The size of the 6314** BLOB (and hence the maximum value of N+iOffset) can be determined 6315** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 6316** than zero [SQLITE_ERROR] is returned and no data is written. 6317** 6318** ^An attempt to write to an expired [BLOB handle] fails with an 6319** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 6320** before the [BLOB handle] expired are not rolled back by the 6321** expiration of the handle, though of course those changes might 6322** have been overwritten by the statement that expired the BLOB handle 6323** or by other independent statements. 6324** 6325** This routine only works on a [BLOB handle] which has been created 6326** by a prior successful call to [sqlite3_blob_open()] and which has not 6327** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6328** to this routine results in undefined and probably undesirable behavior. 6329** 6330** See also: [sqlite3_blob_read()]. 6331*/ 6332int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 6333 6334/* 6335** CAPI3REF: Virtual File System Objects 6336** 6337** A virtual filesystem (VFS) is an [sqlite3_vfs] object 6338** that SQLite uses to interact 6339** with the underlying operating system. Most SQLite builds come with a 6340** single default VFS that is appropriate for the host computer. 6341** New VFSes can be registered and existing VFSes can be unregistered. 6342** The following interfaces are provided. 6343** 6344** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 6345** ^Names are case sensitive. 6346** ^Names are zero-terminated UTF-8 strings. 6347** ^If there is no match, a NULL pointer is returned. 6348** ^If zVfsName is NULL then the default VFS is returned. 6349** 6350** ^New VFSes are registered with sqlite3_vfs_register(). 6351** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6352** ^The same VFS can be registered multiple times without injury. 6353** ^To make an existing VFS into the default VFS, register it again 6354** with the makeDflt flag set. If two different VFSes with the 6355** same name are registered, the behavior is undefined. If a 6356** VFS is registered with a name that is NULL or an empty string, 6357** then the behavior is undefined. 6358** 6359** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6360** ^(If the default VFS is unregistered, another VFS is chosen as 6361** the default. The choice for the new VFS is arbitrary.)^ 6362*/ 6363sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 6364int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6365int sqlite3_vfs_unregister(sqlite3_vfs*); 6366 6367/* 6368** CAPI3REF: Mutexes 6369** 6370** The SQLite core uses these routines for thread 6371** synchronization. Though they are intended for internal 6372** use by SQLite, code that links against SQLite is 6373** permitted to use any of these routines. 6374** 6375** The SQLite source code contains multiple implementations 6376** of these mutex routines. An appropriate implementation 6377** is selected automatically at compile-time. The following 6378** implementations are available in the SQLite core: 6379** 6380** <ul> 6381** <li> SQLITE_MUTEX_PTHREADS 6382** <li> SQLITE_MUTEX_W32 6383** <li> SQLITE_MUTEX_NOOP 6384** </ul> 6385** 6386** The SQLITE_MUTEX_NOOP implementation is a set of routines 6387** that does no real locking and is appropriate for use in 6388** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6389** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6390** and Windows. 6391** 6392** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6393** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6394** implementation is included with the library. In this case the 6395** application must supply a custom mutex implementation using the 6396** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6397** before calling sqlite3_initialize() or any other public sqlite3_ 6398** function that calls sqlite3_initialize(). 6399** 6400** ^The sqlite3_mutex_alloc() routine allocates a new 6401** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6402** routine returns NULL if it is unable to allocate the requested 6403** mutex. The argument to sqlite3_mutex_alloc() must one of these 6404** integer constants: 6405** 6406** <ul> 6407** <li> SQLITE_MUTEX_FAST 6408** <li> SQLITE_MUTEX_RECURSIVE 6409** <li> SQLITE_MUTEX_STATIC_MASTER 6410** <li> SQLITE_MUTEX_STATIC_MEM 6411** <li> SQLITE_MUTEX_STATIC_OPEN 6412** <li> SQLITE_MUTEX_STATIC_PRNG 6413** <li> SQLITE_MUTEX_STATIC_LRU 6414** <li> SQLITE_MUTEX_STATIC_PMEM 6415** <li> SQLITE_MUTEX_STATIC_APP1 6416** <li> SQLITE_MUTEX_STATIC_APP2 6417** <li> SQLITE_MUTEX_STATIC_APP3 6418** <li> SQLITE_MUTEX_STATIC_VFS1 6419** <li> SQLITE_MUTEX_STATIC_VFS2 6420** <li> SQLITE_MUTEX_STATIC_VFS3 6421** </ul> 6422** 6423** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6424** cause sqlite3_mutex_alloc() to create 6425** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6426** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6427** The mutex implementation does not need to make a distinction 6428** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6429** not want to. SQLite will only request a recursive mutex in 6430** cases where it really needs one. If a faster non-recursive mutex 6431** implementation is available on the host platform, the mutex subsystem 6432** might return such a mutex in response to SQLITE_MUTEX_FAST. 6433** 6434** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6435** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6436** a pointer to a static preexisting mutex. ^Nine static mutexes are 6437** used by the current version of SQLite. Future versions of SQLite 6438** may add additional static mutexes. Static mutexes are for internal 6439** use by SQLite only. Applications that use SQLite mutexes should 6440** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6441** SQLITE_MUTEX_RECURSIVE. 6442** 6443** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6444** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6445** returns a different mutex on every call. ^For the static 6446** mutex types, the same mutex is returned on every call that has 6447** the same type number. 6448** 6449** ^The sqlite3_mutex_free() routine deallocates a previously 6450** allocated dynamic mutex. Attempting to deallocate a static 6451** mutex results in undefined behavior. 6452** 6453** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6454** to enter a mutex. ^If another thread is already within the mutex, 6455** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6456** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6457** upon successful entry. ^(Mutexes created using 6458** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6459** In such cases, the 6460** mutex must be exited an equal number of times before another thread 6461** can enter.)^ If the same thread tries to enter any mutex other 6462** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6463** 6464** ^(Some systems (for example, Windows 95) do not support the operation 6465** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6466** will always return SQLITE_BUSY. The SQLite core only ever uses 6467** sqlite3_mutex_try() as an optimization so this is acceptable 6468** behavior.)^ 6469** 6470** ^The sqlite3_mutex_leave() routine exits a mutex that was 6471** previously entered by the same thread. The behavior 6472** is undefined if the mutex is not currently entered by the 6473** calling thread or is not currently allocated. 6474** 6475** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6476** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6477** behave as no-ops. 6478** 6479** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6480*/ 6481sqlite3_mutex *sqlite3_mutex_alloc(int); 6482void sqlite3_mutex_free(sqlite3_mutex*); 6483void sqlite3_mutex_enter(sqlite3_mutex*); 6484int sqlite3_mutex_try(sqlite3_mutex*); 6485void sqlite3_mutex_leave(sqlite3_mutex*); 6486 6487/* 6488** CAPI3REF: Mutex Methods Object 6489** 6490** An instance of this structure defines the low-level routines 6491** used to allocate and use mutexes. 6492** 6493** Usually, the default mutex implementations provided by SQLite are 6494** sufficient, however the application has the option of substituting a custom 6495** implementation for specialized deployments or systems for which SQLite 6496** does not provide a suitable implementation. In this case, the application 6497** creates and populates an instance of this structure to pass 6498** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6499** Additionally, an instance of this structure can be used as an 6500** output variable when querying the system for the current mutex 6501** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6502** 6503** ^The xMutexInit method defined by this structure is invoked as 6504** part of system initialization by the sqlite3_initialize() function. 6505** ^The xMutexInit routine is called by SQLite exactly once for each 6506** effective call to [sqlite3_initialize()]. 6507** 6508** ^The xMutexEnd method defined by this structure is invoked as 6509** part of system shutdown by the sqlite3_shutdown() function. The 6510** implementation of this method is expected to release all outstanding 6511** resources obtained by the mutex methods implementation, especially 6512** those obtained by the xMutexInit method. ^The xMutexEnd() 6513** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6514** 6515** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6516** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6517** xMutexNotheld) implement the following interfaces (respectively): 6518** 6519** <ul> 6520** <li> [sqlite3_mutex_alloc()] </li> 6521** <li> [sqlite3_mutex_free()] </li> 6522** <li> [sqlite3_mutex_enter()] </li> 6523** <li> [sqlite3_mutex_try()] </li> 6524** <li> [sqlite3_mutex_leave()] </li> 6525** <li> [sqlite3_mutex_held()] </li> 6526** <li> [sqlite3_mutex_notheld()] </li> 6527** </ul>)^ 6528** 6529** The only difference is that the public sqlite3_XXX functions enumerated 6530** above silently ignore any invocations that pass a NULL pointer instead 6531** of a valid mutex handle. The implementations of the methods defined 6532** by this structure are not required to handle this case, the results 6533** of passing a NULL pointer instead of a valid mutex handle are undefined 6534** (i.e. it is acceptable to provide an implementation that segfaults if 6535** it is passed a NULL pointer). 6536** 6537** The xMutexInit() method must be threadsafe. It must be harmless to 6538** invoke xMutexInit() multiple times within the same process and without 6539** intervening calls to xMutexEnd(). Second and subsequent calls to 6540** xMutexInit() must be no-ops. 6541** 6542** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 6543** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 6544** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 6545** memory allocation for a fast or recursive mutex. 6546** 6547** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 6548** called, but only if the prior call to xMutexInit returned SQLITE_OK. 6549** If xMutexInit fails in any way, it is expected to clean up after itself 6550** prior to returning. 6551*/ 6552typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6553struct sqlite3_mutex_methods { 6554 int (SQLITE_CALLBACK *xMutexInit)(void); 6555 int (SQLITE_CALLBACK *xMutexEnd)(void); 6556 sqlite3_mutex *(SQLITE_CALLBACK *xMutexAlloc)(int); 6557 void (SQLITE_CALLBACK *xMutexFree)(sqlite3_mutex *); 6558 void (SQLITE_CALLBACK *xMutexEnter)(sqlite3_mutex *); 6559 int (SQLITE_CALLBACK *xMutexTry)(sqlite3_mutex *); 6560 void (SQLITE_CALLBACK *xMutexLeave)(sqlite3_mutex *); 6561 int (SQLITE_CALLBACK *xMutexHeld)(sqlite3_mutex *); 6562 int (SQLITE_CALLBACK *xMutexNotheld)(sqlite3_mutex *); 6563}; 6564 6565/* 6566** CAPI3REF: Mutex Verification Routines 6567** 6568** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 6569** are intended for use inside assert() statements. The SQLite core 6570** never uses these routines except inside an assert() and applications 6571** are advised to follow the lead of the core. The SQLite core only 6572** provides implementations for these routines when it is compiled 6573** with the SQLITE_DEBUG flag. External mutex implementations 6574** are only required to provide these routines if SQLITE_DEBUG is 6575** defined and if NDEBUG is not defined. 6576** 6577** These routines should return true if the mutex in their argument 6578** is held or not held, respectively, by the calling thread. 6579** 6580** The implementation is not required to provide versions of these 6581** routines that actually work. If the implementation does not provide working 6582** versions of these routines, it should at least provide stubs that always 6583** return true so that one does not get spurious assertion failures. 6584** 6585** If the argument to sqlite3_mutex_held() is a NULL pointer then 6586** the routine should return 1. This seems counter-intuitive since 6587** clearly the mutex cannot be held if it does not exist. But 6588** the reason the mutex does not exist is because the build is not 6589** using mutexes. And we do not want the assert() containing the 6590** call to sqlite3_mutex_held() to fail, so a non-zero return is 6591** the appropriate thing to do. The sqlite3_mutex_notheld() 6592** interface should also return 1 when given a NULL pointer. 6593*/ 6594#ifndef NDEBUG 6595int sqlite3_mutex_held(sqlite3_mutex*); 6596int sqlite3_mutex_notheld(sqlite3_mutex*); 6597#endif 6598 6599/* 6600** CAPI3REF: Mutex Types 6601** 6602** The [sqlite3_mutex_alloc()] interface takes a single argument 6603** which is one of these integer constants. 6604** 6605** The set of static mutexes may change from one SQLite release to the 6606** next. Applications that override the built-in mutex logic must be 6607** prepared to accommodate additional static mutexes. 6608*/ 6609#define SQLITE_MUTEX_FAST 0 6610#define SQLITE_MUTEX_RECURSIVE 1 6611#define SQLITE_MUTEX_STATIC_MASTER 2 6612#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6613#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6614#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6615#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 6616#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6617#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6618#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6619#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 6620#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 6621#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 6622#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 6623#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 6624#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 6625 6626/* 6627** CAPI3REF: Retrieve the mutex for a database connection 6628** METHOD: sqlite3 6629** 6630** ^This interface returns a pointer the [sqlite3_mutex] object that 6631** serializes access to the [database connection] given in the argument 6632** when the [threading mode] is Serialized. 6633** ^If the [threading mode] is Single-thread or Multi-thread then this 6634** routine returns a NULL pointer. 6635*/ 6636sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 6637 6638/* 6639** CAPI3REF: Low-Level Control Of Database Files 6640** METHOD: sqlite3 6641** 6642** ^The [sqlite3_file_control()] interface makes a direct call to the 6643** xFileControl method for the [sqlite3_io_methods] object associated 6644** with a particular database identified by the second argument. ^The 6645** name of the database is "main" for the main database or "temp" for the 6646** TEMP database, or the name that appears after the AS keyword for 6647** databases that are added using the [ATTACH] SQL command. 6648** ^A NULL pointer can be used in place of "main" to refer to the 6649** main database file. 6650** ^The third and fourth parameters to this routine 6651** are passed directly through to the second and third parameters of 6652** the xFileControl method. ^The return value of the xFileControl 6653** method becomes the return value of this routine. 6654** 6655** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 6656** a pointer to the underlying [sqlite3_file] object to be written into 6657** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 6658** case is a short-circuit path which does not actually invoke the 6659** underlying sqlite3_io_methods.xFileControl method. 6660** 6661** ^If the second parameter (zDbName) does not match the name of any 6662** open database file, then SQLITE_ERROR is returned. ^This error 6663** code is not remembered and will not be recalled by [sqlite3_errcode()] 6664** or [sqlite3_errmsg()]. The underlying xFileControl method might 6665** also return SQLITE_ERROR. There is no way to distinguish between 6666** an incorrect zDbName and an SQLITE_ERROR return from the underlying 6667** xFileControl method. 6668** 6669** See also: [SQLITE_FCNTL_LOCKSTATE] 6670*/ 6671int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 6672 6673/* 6674** CAPI3REF: Testing Interface 6675** 6676** ^The sqlite3_test_control() interface is used to read out internal 6677** state of SQLite and to inject faults into SQLite for testing 6678** purposes. ^The first parameter is an operation code that determines 6679** the number, meaning, and operation of all subsequent parameters. 6680** 6681** This interface is not for use by applications. It exists solely 6682** for verifying the correct operation of the SQLite library. Depending 6683** on how the SQLite library is compiled, this interface might not exist. 6684** 6685** The details of the operation codes, their meanings, the parameters 6686** they take, and what they do are all subject to change without notice. 6687** Unlike most of the SQLite API, this function is not guaranteed to 6688** operate consistently from one release to the next. 6689*/ 6690int sqlite3_test_control(int op, ...); 6691 6692/* 6693** CAPI3REF: Testing Interface Operation Codes 6694** 6695** These constants are the valid operation code parameters used 6696** as the first argument to [sqlite3_test_control()]. 6697** 6698** These parameters and their meanings are subject to change 6699** without notice. These values are for testing purposes only. 6700** Applications should not use any of these parameters or the 6701** [sqlite3_test_control()] interface. 6702*/ 6703#define SQLITE_TESTCTRL_FIRST 5 6704#define SQLITE_TESTCTRL_PRNG_SAVE 5 6705#define SQLITE_TESTCTRL_PRNG_RESTORE 6 6706#define SQLITE_TESTCTRL_PRNG_RESET 7 6707#define SQLITE_TESTCTRL_BITVEC_TEST 8 6708#define SQLITE_TESTCTRL_FAULT_INSTALL 9 6709#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 6710#define SQLITE_TESTCTRL_PENDING_BYTE 11 6711#define SQLITE_TESTCTRL_ASSERT 12 6712#define SQLITE_TESTCTRL_ALWAYS 13 6713#define SQLITE_TESTCTRL_RESERVE 14 6714#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 6715#define SQLITE_TESTCTRL_ISKEYWORD 16 6716#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 6717#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 6718#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 6719#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 6720#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 6721#define SQLITE_TESTCTRL_BYTEORDER 22 6722#define SQLITE_TESTCTRL_ISINIT 23 6723#define SQLITE_TESTCTRL_SORTER_MMAP 24 6724#define SQLITE_TESTCTRL_IMPOSTER 25 6725#define SQLITE_TESTCTRL_LAST 25 6726 6727/* 6728** CAPI3REF: SQLite Runtime Status 6729** 6730** ^These interfaces are used to retrieve runtime status information 6731** about the performance of SQLite, and optionally to reset various 6732** highwater marks. ^The first argument is an integer code for 6733** the specific parameter to measure. ^(Recognized integer codes 6734** are of the form [status parameters | SQLITE_STATUS_...].)^ 6735** ^The current value of the parameter is returned into *pCurrent. 6736** ^The highest recorded value is returned in *pHighwater. ^If the 6737** resetFlag is true, then the highest record value is reset after 6738** *pHighwater is written. ^(Some parameters do not record the highest 6739** value. For those parameters 6740** nothing is written into *pHighwater and the resetFlag is ignored.)^ 6741** ^(Other parameters record only the highwater mark and not the current 6742** value. For these latter parameters nothing is written into *pCurrent.)^ 6743** 6744** ^The sqlite3_status() and sqlite3_status64() routines return 6745** SQLITE_OK on success and a non-zero [error code] on failure. 6746** 6747** If either the current value or the highwater mark is too large to 6748** be represented by a 32-bit integer, then the values returned by 6749** sqlite3_status() are undefined. 6750** 6751** See also: [sqlite3_db_status()] 6752*/ 6753int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 6754int sqlite3_status64( 6755 int op, 6756 sqlite3_int64 *pCurrent, 6757 sqlite3_int64 *pHighwater, 6758 int resetFlag 6759); 6760 6761 6762/* 6763** CAPI3REF: Status Parameters 6764** KEYWORDS: {status parameters} 6765** 6766** These integer constants designate various run-time status parameters 6767** that can be returned by [sqlite3_status()]. 6768** 6769** <dl> 6770** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 6771** <dd>This parameter is the current amount of memory checked out 6772** using [sqlite3_malloc()], either directly or indirectly. The 6773** figure includes calls made to [sqlite3_malloc()] by the application 6774** and internal memory usage by the SQLite library. Scratch memory 6775** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 6776** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 6777** this parameter. The amount returned is the sum of the allocation 6778** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 6779** 6780** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 6781** <dd>This parameter records the largest memory allocation request 6782** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 6783** internal equivalents). Only the value returned in the 6784** *pHighwater parameter to [sqlite3_status()] is of interest. 6785** The value written into the *pCurrent parameter is undefined.</dd>)^ 6786** 6787** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 6788** <dd>This parameter records the number of separate memory allocations 6789** currently checked out.</dd>)^ 6790** 6791** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 6792** <dd>This parameter returns the number of pages used out of the 6793** [pagecache memory allocator] that was configured using 6794** [SQLITE_CONFIG_PAGECACHE]. The 6795** value returned is in pages, not in bytes.</dd>)^ 6796** 6797** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 6798** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6799** <dd>This parameter returns the number of bytes of page cache 6800** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 6801** buffer and where forced to overflow to [sqlite3_malloc()]. The 6802** returned value includes allocations that overflowed because they 6803** where too large (they were larger than the "sz" parameter to 6804** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 6805** no space was left in the page cache.</dd>)^ 6806** 6807** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 6808** <dd>This parameter records the largest memory allocation request 6809** handed to [pagecache memory allocator]. Only the value returned in the 6810** *pHighwater parameter to [sqlite3_status()] is of interest. 6811** The value written into the *pCurrent parameter is undefined.</dd>)^ 6812** 6813** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 6814** <dd>This parameter returns the number of allocations used out of the 6815** [scratch memory allocator] configured using 6816** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6817** in bytes. Since a single thread may only have one scratch allocation 6818** outstanding at time, this parameter also reports the number of threads 6819** using scratch memory at the same time.</dd>)^ 6820** 6821** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6822** <dd>This parameter returns the number of bytes of scratch memory 6823** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 6824** buffer and where forced to overflow to [sqlite3_malloc()]. The values 6825** returned include overflows because the requested allocation was too 6826** larger (that is, because the requested allocation was larger than the 6827** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 6828** slots were available. 6829** </dd>)^ 6830** 6831** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6832** <dd>This parameter records the largest memory allocation request 6833** handed to [scratch memory allocator]. Only the value returned in the 6834** *pHighwater parameter to [sqlite3_status()] is of interest. 6835** The value written into the *pCurrent parameter is undefined.</dd>)^ 6836** 6837** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6838** <dd>The *pHighwater parameter records the deepest parser stack. 6839** The *pCurrent value is undefined. The *pHighwater value is only 6840** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6841** </dl> 6842** 6843** New status parameters may be added from time to time. 6844*/ 6845#define SQLITE_STATUS_MEMORY_USED 0 6846#define SQLITE_STATUS_PAGECACHE_USED 1 6847#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6848#define SQLITE_STATUS_SCRATCH_USED 3 6849#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6850#define SQLITE_STATUS_MALLOC_SIZE 5 6851#define SQLITE_STATUS_PARSER_STACK 6 6852#define SQLITE_STATUS_PAGECACHE_SIZE 7 6853#define SQLITE_STATUS_SCRATCH_SIZE 8 6854#define SQLITE_STATUS_MALLOC_COUNT 9 6855 6856/* 6857** CAPI3REF: Database Connection Status 6858** METHOD: sqlite3 6859** 6860** ^This interface is used to retrieve runtime status information 6861** about a single [database connection]. ^The first argument is the 6862** database connection object to be interrogated. ^The second argument 6863** is an integer constant, taken from the set of 6864** [SQLITE_DBSTATUS options], that 6865** determines the parameter to interrogate. The set of 6866** [SQLITE_DBSTATUS options] is likely 6867** to grow in future releases of SQLite. 6868** 6869** ^The current value of the requested parameter is written into *pCur 6870** and the highest instantaneous value is written into *pHiwtr. ^If 6871** the resetFlg is true, then the highest instantaneous value is 6872** reset back down to the current value. 6873** 6874** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 6875** non-zero [error code] on failure. 6876** 6877** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 6878*/ 6879int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 6880 6881/* 6882** CAPI3REF: Status Parameters for database connections 6883** KEYWORDS: {SQLITE_DBSTATUS options} 6884** 6885** These constants are the available integer "verbs" that can be passed as 6886** the second argument to the [sqlite3_db_status()] interface. 6887** 6888** New verbs may be added in future releases of SQLite. Existing verbs 6889** might be discontinued. Applications should check the return code from 6890** [sqlite3_db_status()] to make sure that the call worked. 6891** The [sqlite3_db_status()] interface will return a non-zero error code 6892** if a discontinued or unsupported verb is invoked. 6893** 6894** <dl> 6895** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6896** <dd>This parameter returns the number of lookaside memory slots currently 6897** checked out.</dd>)^ 6898** 6899** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6900** <dd>This parameter returns the number malloc attempts that were 6901** satisfied using lookaside memory. Only the high-water value is meaningful; 6902** the current value is always zero.)^ 6903** 6904** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6905** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6906** <dd>This parameter returns the number malloc attempts that might have 6907** been satisfied using lookaside memory but failed due to the amount of 6908** memory requested being larger than the lookaside slot size. 6909** Only the high-water value is meaningful; 6910** the current value is always zero.)^ 6911** 6912** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6913** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6914** <dd>This parameter returns the number malloc attempts that might have 6915** been satisfied using lookaside memory but failed due to all lookaside 6916** memory already being in use. 6917** Only the high-water value is meaningful; 6918** the current value is always zero.)^ 6919** 6920** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6921** <dd>This parameter returns the approximate number of bytes of heap 6922** memory used by all pager caches associated with the database connection.)^ 6923** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6924** 6925** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 6926** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 6927** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 6928** pager cache is shared between two or more connections the bytes of heap 6929** memory used by that pager cache is divided evenly between the attached 6930** connections.)^ In other words, if none of the pager caches associated 6931** with the database connection are shared, this request returns the same 6932** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 6933** shared, the value returned by this call will be smaller than that returned 6934** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 6935** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 6936** 6937** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 6938** <dd>This parameter returns the approximate number of bytes of heap 6939** memory used to store the schema for all databases associated 6940** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 6941** ^The full amount of memory used by the schemas is reported, even if the 6942** schema memory is shared with other database connections due to 6943** [shared cache mode] being enabled. 6944** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 6945** 6946** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 6947** <dd>This parameter returns the approximate number of bytes of heap 6948** and lookaside memory used by all prepared statements associated with 6949** the database connection.)^ 6950** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 6951** </dd> 6952** 6953** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 6954** <dd>This parameter returns the number of pager cache hits that have 6955** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 6956** is always 0. 6957** </dd> 6958** 6959** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 6960** <dd>This parameter returns the number of pager cache misses that have 6961** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 6962** is always 0. 6963** </dd> 6964** 6965** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 6966** <dd>This parameter returns the number of dirty cache entries that have 6967** been written to disk. Specifically, the number of pages written to the 6968** wal file in wal mode databases, or the number of pages written to the 6969** database file in rollback mode databases. Any pages written as part of 6970** transaction rollback or database recovery operations are not included. 6971** If an IO or other error occurs while writing a page to disk, the effect 6972** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 6973** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 6974** </dd> 6975** 6976** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 6977** <dd>This parameter returns zero for the current value if and only if 6978** all foreign key constraints (deferred or immediate) have been 6979** resolved.)^ ^The highwater mark is always 0. 6980** </dd> 6981** </dl> 6982*/ 6983#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 6984#define SQLITE_DBSTATUS_CACHE_USED 1 6985#define SQLITE_DBSTATUS_SCHEMA_USED 2 6986#define SQLITE_DBSTATUS_STMT_USED 3 6987#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 6988#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 6989#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 6990#define SQLITE_DBSTATUS_CACHE_HIT 7 6991#define SQLITE_DBSTATUS_CACHE_MISS 8 6992#define SQLITE_DBSTATUS_CACHE_WRITE 9 6993#define SQLITE_DBSTATUS_DEFERRED_FKS 10 6994#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 6995#define SQLITE_DBSTATUS_MAX 11 /* Largest defined DBSTATUS */ 6996 6997 6998/* 6999** CAPI3REF: Prepared Statement Status 7000** METHOD: sqlite3_stmt 7001** 7002** ^(Each prepared statement maintains various 7003** [SQLITE_STMTSTATUS counters] that measure the number 7004** of times it has performed specific operations.)^ These counters can 7005** be used to monitor the performance characteristics of the prepared 7006** statements. For example, if the number of table steps greatly exceeds 7007** the number of table searches or result rows, that would tend to indicate 7008** that the prepared statement is using a full table scan rather than 7009** an index. 7010** 7011** ^(This interface is used to retrieve and reset counter values from 7012** a [prepared statement]. The first argument is the prepared statement 7013** object to be interrogated. The second argument 7014** is an integer code for a specific [SQLITE_STMTSTATUS counter] 7015** to be interrogated.)^ 7016** ^The current value of the requested counter is returned. 7017** ^If the resetFlg is true, then the counter is reset to zero after this 7018** interface call returns. 7019** 7020** See also: [sqlite3_status()] and [sqlite3_db_status()]. 7021*/ 7022int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 7023 7024/* 7025** CAPI3REF: Status Parameters for prepared statements 7026** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 7027** 7028** These preprocessor macros define integer codes that name counter 7029** values associated with the [sqlite3_stmt_status()] interface. 7030** The meanings of the various counters are as follows: 7031** 7032** <dl> 7033** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 7034** <dd>^This is the number of times that SQLite has stepped forward in 7035** a table as part of a full table scan. Large numbers for this counter 7036** may indicate opportunities for performance improvement through 7037** careful use of indices.</dd> 7038** 7039** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 7040** <dd>^This is the number of sort operations that have occurred. 7041** A non-zero value in this counter may indicate an opportunity to 7042** improvement performance through careful use of indices.</dd> 7043** 7044** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 7045** <dd>^This is the number of rows inserted into transient indices that 7046** were created automatically in order to help joins run faster. 7047** A non-zero value in this counter may indicate an opportunity to 7048** improvement performance by adding permanent indices that do not 7049** need to be reinitialized each time the statement is run.</dd> 7050** 7051** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 7052** <dd>^This is the number of virtual machine operations executed 7053** by the prepared statement if that number is less than or equal 7054** to 2147483647. The number of virtual machine operations can be 7055** used as a proxy for the total work done by the prepared statement. 7056** If the number of virtual machine operations exceeds 2147483647 7057** then the value returned by this statement status code is undefined. 7058** </dd> 7059** </dl> 7060*/ 7061#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 7062#define SQLITE_STMTSTATUS_SORT 2 7063#define SQLITE_STMTSTATUS_AUTOINDEX 3 7064#define SQLITE_STMTSTATUS_VM_STEP 4 7065 7066/* 7067** CAPI3REF: Custom Page Cache Object 7068** 7069** The sqlite3_pcache type is opaque. It is implemented by 7070** the pluggable module. The SQLite core has no knowledge of 7071** its size or internal structure and never deals with the 7072** sqlite3_pcache object except by holding and passing pointers 7073** to the object. 7074** 7075** See [sqlite3_pcache_methods2] for additional information. 7076*/ 7077typedef struct sqlite3_pcache sqlite3_pcache; 7078 7079/* 7080** CAPI3REF: Custom Page Cache Object 7081** 7082** The sqlite3_pcache_page object represents a single page in the 7083** page cache. The page cache will allocate instances of this 7084** object. Various methods of the page cache use pointers to instances 7085** of this object as parameters or as their return value. 7086** 7087** See [sqlite3_pcache_methods2] for additional information. 7088*/ 7089typedef struct sqlite3_pcache_page sqlite3_pcache_page; 7090struct sqlite3_pcache_page { 7091 void *pBuf; /* The content of the page */ 7092 void *pExtra; /* Extra information associated with the page */ 7093}; 7094 7095/* 7096** CAPI3REF: Application Defined Page Cache. 7097** KEYWORDS: {page cache} 7098** 7099** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 7100** register an alternative page cache implementation by passing in an 7101** instance of the sqlite3_pcache_methods2 structure.)^ 7102** In many applications, most of the heap memory allocated by 7103** SQLite is used for the page cache. 7104** By implementing a 7105** custom page cache using this API, an application can better control 7106** the amount of memory consumed by SQLite, the way in which 7107** that memory is allocated and released, and the policies used to 7108** determine exactly which parts of a database file are cached and for 7109** how long. 7110** 7111** The alternative page cache mechanism is an 7112** extreme measure that is only needed by the most demanding applications. 7113** The built-in page cache is recommended for most uses. 7114** 7115** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 7116** internal buffer by SQLite within the call to [sqlite3_config]. Hence 7117** the application may discard the parameter after the call to 7118** [sqlite3_config()] returns.)^ 7119** 7120** [[the xInit() page cache method]] 7121** ^(The xInit() method is called once for each effective 7122** call to [sqlite3_initialize()])^ 7123** (usually only once during the lifetime of the process). ^(The xInit() 7124** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 7125** The intent of the xInit() method is to set up global data structures 7126** required by the custom page cache implementation. 7127** ^(If the xInit() method is NULL, then the 7128** built-in default page cache is used instead of the application defined 7129** page cache.)^ 7130** 7131** [[the xShutdown() page cache method]] 7132** ^The xShutdown() method is called by [sqlite3_shutdown()]. 7133** It can be used to clean up 7134** any outstanding resources before process shutdown, if required. 7135** ^The xShutdown() method may be NULL. 7136** 7137** ^SQLite automatically serializes calls to the xInit method, 7138** so the xInit method need not be threadsafe. ^The 7139** xShutdown method is only called from [sqlite3_shutdown()] so it does 7140** not need to be threadsafe either. All other methods must be threadsafe 7141** in multithreaded applications. 7142** 7143** ^SQLite will never invoke xInit() more than once without an intervening 7144** call to xShutdown(). 7145** 7146** [[the xCreate() page cache methods]] 7147** ^SQLite invokes the xCreate() method to construct a new cache instance. 7148** SQLite will typically create one cache instance for each open database file, 7149** though this is not guaranteed. ^The 7150** first parameter, szPage, is the size in bytes of the pages that must 7151** be allocated by the cache. ^szPage will always a power of two. ^The 7152** second parameter szExtra is a number of bytes of extra storage 7153** associated with each page cache entry. ^The szExtra parameter will 7154** a number less than 250. SQLite will use the 7155** extra szExtra bytes on each page to store metadata about the underlying 7156** database page on disk. The value passed into szExtra depends 7157** on the SQLite version, the target platform, and how SQLite was compiled. 7158** ^The third argument to xCreate(), bPurgeable, is true if the cache being 7159** created will be used to cache database pages of a file stored on disk, or 7160** false if it is used for an in-memory database. The cache implementation 7161** does not have to do anything special based with the value of bPurgeable; 7162** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 7163** never invoke xUnpin() except to deliberately delete a page. 7164** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 7165** false will always have the "discard" flag set to true. 7166** ^Hence, a cache created with bPurgeable false will 7167** never contain any unpinned pages. 7168** 7169** [[the xCachesize() page cache method]] 7170** ^(The xCachesize() method may be called at any time by SQLite to set the 7171** suggested maximum cache-size (number of pages stored by) the cache 7172** instance passed as the first argument. This is the value configured using 7173** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 7174** parameter, the implementation is not required to do anything with this 7175** value; it is advisory only. 7176** 7177** [[the xPagecount() page cache methods]] 7178** The xPagecount() method must return the number of pages currently 7179** stored in the cache, both pinned and unpinned. 7180** 7181** [[the xFetch() page cache methods]] 7182** The xFetch() method locates a page in the cache and returns a pointer to 7183** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 7184** The pBuf element of the returned sqlite3_pcache_page object will be a 7185** pointer to a buffer of szPage bytes used to store the content of a 7186** single database page. The pExtra element of sqlite3_pcache_page will be 7187** a pointer to the szExtra bytes of extra storage that SQLite has requested 7188** for each entry in the page cache. 7189** 7190** The page to be fetched is determined by the key. ^The minimum key value 7191** is 1. After it has been retrieved using xFetch, the page is considered 7192** to be "pinned". 7193** 7194** If the requested page is already in the page cache, then the page cache 7195** implementation must return a pointer to the page buffer with its content 7196** intact. If the requested page is not already in the cache, then the 7197** cache implementation should use the value of the createFlag 7198** parameter to help it determined what action to take: 7199** 7200** <table border=1 width=85% align=center> 7201** <tr><th> createFlag <th> Behavior when page is not already in cache 7202** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 7203** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 7204** Otherwise return NULL. 7205** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 7206** NULL if allocating a new page is effectively impossible. 7207** </table> 7208** 7209** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 7210** will only use a createFlag of 2 after a prior call with a createFlag of 1 7211** failed.)^ In between the to xFetch() calls, SQLite may 7212** attempt to unpin one or more cache pages by spilling the content of 7213** pinned pages to disk and synching the operating system disk cache. 7214** 7215** [[the xUnpin() page cache method]] 7216** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 7217** as its second argument. If the third parameter, discard, is non-zero, 7218** then the page must be evicted from the cache. 7219** ^If the discard parameter is 7220** zero, then the page may be discarded or retained at the discretion of 7221** page cache implementation. ^The page cache implementation 7222** may choose to evict unpinned pages at any time. 7223** 7224** The cache must not perform any reference counting. A single 7225** call to xUnpin() unpins the page regardless of the number of prior calls 7226** to xFetch(). 7227** 7228** [[the xRekey() page cache methods]] 7229** The xRekey() method is used to change the key value associated with the 7230** page passed as the second argument. If the cache 7231** previously contains an entry associated with newKey, it must be 7232** discarded. ^Any prior cache entry associated with newKey is guaranteed not 7233** to be pinned. 7234** 7235** When SQLite calls the xTruncate() method, the cache must discard all 7236** existing cache entries with page numbers (keys) greater than or equal 7237** to the value of the iLimit parameter passed to xTruncate(). If any 7238** of these pages are pinned, they are implicitly unpinned, meaning that 7239** they can be safely discarded. 7240** 7241** [[the xDestroy() page cache method]] 7242** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 7243** All resources associated with the specified cache should be freed. ^After 7244** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 7245** handle invalid, and will not use it with any other sqlite3_pcache_methods2 7246** functions. 7247** 7248** [[the xShrink() page cache method]] 7249** ^SQLite invokes the xShrink() method when it wants the page cache to 7250** free up as much of heap memory as possible. The page cache implementation 7251** is not obligated to free any memory, but well-behaved implementations should 7252** do their best. 7253*/ 7254typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 7255struct sqlite3_pcache_methods2 { 7256 int iVersion; 7257 void *pArg; 7258 int (SQLITE_CALLBACK *xInit)(void*); 7259 void (SQLITE_CALLBACK *xShutdown)(void*); 7260 sqlite3_pcache *(SQLITE_CALLBACK *xCreate)(int szPage, int szExtra, 7261 int bPurgeable); 7262 void (SQLITE_CALLBACK *xCachesize)(sqlite3_pcache*, int nCachesize); 7263 int (SQLITE_CALLBACK *xPagecount)(sqlite3_pcache*); 7264 sqlite3_pcache_page *(SQLITE_CALLBACK *xFetch)(sqlite3_pcache*, unsigned key, 7265 int createFlag); 7266 void (SQLITE_CALLBACK *xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, 7267 int discard); 7268 void (SQLITE_CALLBACK *xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 7269 unsigned oldKey, unsigned newKey); 7270 void (SQLITE_CALLBACK *xTruncate)(sqlite3_pcache*, unsigned iLimit); 7271 void (SQLITE_CALLBACK *xDestroy)(sqlite3_pcache*); 7272 void (SQLITE_CALLBACK *xShrink)(sqlite3_pcache*); 7273}; 7274 7275/* 7276** This is the obsolete pcache_methods object that has now been replaced 7277** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 7278** retained in the header file for backwards compatibility only. 7279*/ 7280typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 7281struct sqlite3_pcache_methods { 7282 void *pArg; 7283 int (SQLITE_CALLBACK *xInit)(void*); 7284 void (SQLITE_CALLBACK *xShutdown)(void*); 7285 sqlite3_pcache *(SQLITE_CALLBACK *xCreate)(int szPage, int bPurgeable); 7286 void (SQLITE_CALLBACK *xCachesize)(sqlite3_pcache*, int nCachesize); 7287 int (SQLITE_CALLBACK *xPagecount)(sqlite3_pcache*); 7288 void *(SQLITE_CALLBACK *xFetch)(sqlite3_pcache*, unsigned key, 7289 int createFlag); 7290 void (SQLITE_CALLBACK *xUnpin)(sqlite3_pcache*, void*, int discard); 7291 void (SQLITE_CALLBACK *xRekey)(sqlite3_pcache*, void*, unsigned oldKey, 7292 unsigned newKey); 7293 void (SQLITE_CALLBACK *xTruncate)(sqlite3_pcache*, unsigned iLimit); 7294 void (SQLITE_CALLBACK *xDestroy)(sqlite3_pcache*); 7295}; 7296 7297 7298/* 7299** CAPI3REF: Online Backup Object 7300** 7301** The sqlite3_backup object records state information about an ongoing 7302** online backup operation. ^The sqlite3_backup object is created by 7303** a call to [sqlite3_backup_init()] and is destroyed by a call to 7304** [sqlite3_backup_finish()]. 7305** 7306** See Also: [Using the SQLite Online Backup API] 7307*/ 7308typedef struct sqlite3_backup sqlite3_backup; 7309 7310/* 7311** CAPI3REF: Online Backup API. 7312** 7313** The backup API copies the content of one database into another. 7314** It is useful either for creating backups of databases or 7315** for copying in-memory databases to or from persistent files. 7316** 7317** See Also: [Using the SQLite Online Backup API] 7318** 7319** ^SQLite holds a write transaction open on the destination database file 7320** for the duration of the backup operation. 7321** ^The source database is read-locked only while it is being read; 7322** it is not locked continuously for the entire backup operation. 7323** ^Thus, the backup may be performed on a live source database without 7324** preventing other database connections from 7325** reading or writing to the source database while the backup is underway. 7326** 7327** ^(To perform a backup operation: 7328** <ol> 7329** <li><b>sqlite3_backup_init()</b> is called once to initialize the 7330** backup, 7331** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 7332** the data between the two databases, and finally 7333** <li><b>sqlite3_backup_finish()</b> is called to release all resources 7334** associated with the backup operation. 7335** </ol>)^ 7336** There should be exactly one call to sqlite3_backup_finish() for each 7337** successful call to sqlite3_backup_init(). 7338** 7339** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 7340** 7341** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 7342** [database connection] associated with the destination database 7343** and the database name, respectively. 7344** ^The database name is "main" for the main database, "temp" for the 7345** temporary database, or the name specified after the AS keyword in 7346** an [ATTACH] statement for an attached database. 7347** ^The S and M arguments passed to 7348** sqlite3_backup_init(D,N,S,M) identify the [database connection] 7349** and database name of the source database, respectively. 7350** ^The source and destination [database connections] (parameters S and D) 7351** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 7352** an error. 7353** 7354** ^A call to sqlite3_backup_init() will fail, returning NULL, if 7355** there is already a read or read-write transaction open on the 7356** destination database. 7357** 7358** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 7359** returned and an error code and error message are stored in the 7360** destination [database connection] D. 7361** ^The error code and message for the failed call to sqlite3_backup_init() 7362** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 7363** [sqlite3_errmsg16()] functions. 7364** ^A successful call to sqlite3_backup_init() returns a pointer to an 7365** [sqlite3_backup] object. 7366** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 7367** sqlite3_backup_finish() functions to perform the specified backup 7368** operation. 7369** 7370** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 7371** 7372** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 7373** the source and destination databases specified by [sqlite3_backup] object B. 7374** ^If N is negative, all remaining source pages are copied. 7375** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 7376** are still more pages to be copied, then the function returns [SQLITE_OK]. 7377** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 7378** from source to destination, then it returns [SQLITE_DONE]. 7379** ^If an error occurs while running sqlite3_backup_step(B,N), 7380** then an [error code] is returned. ^As well as [SQLITE_OK] and 7381** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 7382** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 7383** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 7384** 7385** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 7386** <ol> 7387** <li> the destination database was opened read-only, or 7388** <li> the destination database is using write-ahead-log journaling 7389** and the destination and source page sizes differ, or 7390** <li> the destination database is an in-memory database and the 7391** destination and source page sizes differ. 7392** </ol>)^ 7393** 7394** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 7395** the [sqlite3_busy_handler | busy-handler function] 7396** is invoked (if one is specified). ^If the 7397** busy-handler returns non-zero before the lock is available, then 7398** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 7399** sqlite3_backup_step() can be retried later. ^If the source 7400** [database connection] 7401** is being used to write to the source database when sqlite3_backup_step() 7402** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 7403** case the call to sqlite3_backup_step() can be retried later on. ^(If 7404** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 7405** [SQLITE_READONLY] is returned, then 7406** there is no point in retrying the call to sqlite3_backup_step(). These 7407** errors are considered fatal.)^ The application must accept 7408** that the backup operation has failed and pass the backup operation handle 7409** to the sqlite3_backup_finish() to release associated resources. 7410** 7411** ^The first call to sqlite3_backup_step() obtains an exclusive lock 7412** on the destination file. ^The exclusive lock is not released until either 7413** sqlite3_backup_finish() is called or the backup operation is complete 7414** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 7415** sqlite3_backup_step() obtains a [shared lock] on the source database that 7416** lasts for the duration of the sqlite3_backup_step() call. 7417** ^Because the source database is not locked between calls to 7418** sqlite3_backup_step(), the source database may be modified mid-way 7419** through the backup process. ^If the source database is modified by an 7420** external process or via a database connection other than the one being 7421** used by the backup operation, then the backup will be automatically 7422** restarted by the next call to sqlite3_backup_step(). ^If the source 7423** database is modified by the using the same database connection as is used 7424** by the backup operation, then the backup database is automatically 7425** updated at the same time. 7426** 7427** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 7428** 7429** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 7430** application wishes to abandon the backup operation, the application 7431** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 7432** ^The sqlite3_backup_finish() interfaces releases all 7433** resources associated with the [sqlite3_backup] object. 7434** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 7435** active write-transaction on the destination database is rolled back. 7436** The [sqlite3_backup] object is invalid 7437** and may not be used following a call to sqlite3_backup_finish(). 7438** 7439** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 7440** sqlite3_backup_step() errors occurred, regardless or whether or not 7441** sqlite3_backup_step() completed. 7442** ^If an out-of-memory condition or IO error occurred during any prior 7443** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 7444** sqlite3_backup_finish() returns the corresponding [error code]. 7445** 7446** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 7447** is not a permanent error and does not affect the return value of 7448** sqlite3_backup_finish(). 7449** 7450** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 7451** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 7452** 7453** ^The sqlite3_backup_remaining() routine returns the number of pages still 7454** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 7455** ^The sqlite3_backup_pagecount() routine returns the total number of pages 7456** in the source database at the conclusion of the most recent 7457** sqlite3_backup_step(). 7458** ^(The values returned by these functions are only updated by 7459** sqlite3_backup_step(). If the source database is modified in a way that 7460** changes the size of the source database or the number of pages remaining, 7461** those changes are not reflected in the output of sqlite3_backup_pagecount() 7462** and sqlite3_backup_remaining() until after the next 7463** sqlite3_backup_step().)^ 7464** 7465** <b>Concurrent Usage of Database Handles</b> 7466** 7467** ^The source [database connection] may be used by the application for other 7468** purposes while a backup operation is underway or being initialized. 7469** ^If SQLite is compiled and configured to support threadsafe database 7470** connections, then the source database connection may be used concurrently 7471** from within other threads. 7472** 7473** However, the application must guarantee that the destination 7474** [database connection] is not passed to any other API (by any thread) after 7475** sqlite3_backup_init() is called and before the corresponding call to 7476** sqlite3_backup_finish(). SQLite does not currently check to see 7477** if the application incorrectly accesses the destination [database connection] 7478** and so no error code is reported, but the operations may malfunction 7479** nevertheless. Use of the destination database connection while a 7480** backup is in progress might also also cause a mutex deadlock. 7481** 7482** If running in [shared cache mode], the application must 7483** guarantee that the shared cache used by the destination database 7484** is not accessed while the backup is running. In practice this means 7485** that the application must guarantee that the disk file being 7486** backed up to is not accessed by any connection within the process, 7487** not just the specific connection that was passed to sqlite3_backup_init(). 7488** 7489** The [sqlite3_backup] object itself is partially threadsafe. Multiple 7490** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 7491** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 7492** APIs are not strictly speaking threadsafe. If they are invoked at the 7493** same time as another thread is invoking sqlite3_backup_step() it is 7494** possible that they return invalid values. 7495*/ 7496sqlite3_backup *sqlite3_backup_init( 7497 sqlite3 *pDest, /* Destination database handle */ 7498 const char *zDestName, /* Destination database name */ 7499 sqlite3 *pSource, /* Source database handle */ 7500 const char *zSourceName /* Source database name */ 7501); 7502int sqlite3_backup_step(sqlite3_backup *p, int nPage); 7503int sqlite3_backup_finish(sqlite3_backup *p); 7504int sqlite3_backup_remaining(sqlite3_backup *p); 7505int sqlite3_backup_pagecount(sqlite3_backup *p); 7506 7507/* 7508** CAPI3REF: Unlock Notification 7509** METHOD: sqlite3 7510** 7511** ^When running in shared-cache mode, a database operation may fail with 7512** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 7513** individual tables within the shared-cache cannot be obtained. See 7514** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 7515** ^This API may be used to register a callback that SQLite will invoke 7516** when the connection currently holding the required lock relinquishes it. 7517** ^This API is only available if the library was compiled with the 7518** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 7519** 7520** See Also: [Using the SQLite Unlock Notification Feature]. 7521** 7522** ^Shared-cache locks are released when a database connection concludes 7523** its current transaction, either by committing it or rolling it back. 7524** 7525** ^When a connection (known as the blocked connection) fails to obtain a 7526** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 7527** identity of the database connection (the blocking connection) that 7528** has locked the required resource is stored internally. ^After an 7529** application receives an SQLITE_LOCKED error, it may call the 7530** sqlite3_unlock_notify() method with the blocked connection handle as 7531** the first argument to register for a callback that will be invoked 7532** when the blocking connections current transaction is concluded. ^The 7533** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 7534** call that concludes the blocking connections transaction. 7535** 7536** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 7537** there is a chance that the blocking connection will have already 7538** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 7539** If this happens, then the specified callback is invoked immediately, 7540** from within the call to sqlite3_unlock_notify().)^ 7541** 7542** ^If the blocked connection is attempting to obtain a write-lock on a 7543** shared-cache table, and more than one other connection currently holds 7544** a read-lock on the same table, then SQLite arbitrarily selects one of 7545** the other connections to use as the blocking connection. 7546** 7547** ^(There may be at most one unlock-notify callback registered by a 7548** blocked connection. If sqlite3_unlock_notify() is called when the 7549** blocked connection already has a registered unlock-notify callback, 7550** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 7551** called with a NULL pointer as its second argument, then any existing 7552** unlock-notify callback is canceled. ^The blocked connections 7553** unlock-notify callback may also be canceled by closing the blocked 7554** connection using [sqlite3_close()]. 7555** 7556** The unlock-notify callback is not reentrant. If an application invokes 7557** any sqlite3_xxx API functions from within an unlock-notify callback, a 7558** crash or deadlock may be the result. 7559** 7560** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 7561** returns SQLITE_OK. 7562** 7563** <b>Callback Invocation Details</b> 7564** 7565** When an unlock-notify callback is registered, the application provides a 7566** single void* pointer that is passed to the callback when it is invoked. 7567** However, the signature of the callback function allows SQLite to pass 7568** it an array of void* context pointers. The first argument passed to 7569** an unlock-notify callback is a pointer to an array of void* pointers, 7570** and the second is the number of entries in the array. 7571** 7572** When a blocking connections transaction is concluded, there may be 7573** more than one blocked connection that has registered for an unlock-notify 7574** callback. ^If two or more such blocked connections have specified the 7575** same callback function, then instead of invoking the callback function 7576** multiple times, it is invoked once with the set of void* context pointers 7577** specified by the blocked connections bundled together into an array. 7578** This gives the application an opportunity to prioritize any actions 7579** related to the set of unblocked database connections. 7580** 7581** <b>Deadlock Detection</b> 7582** 7583** Assuming that after registering for an unlock-notify callback a 7584** database waits for the callback to be issued before taking any further 7585** action (a reasonable assumption), then using this API may cause the 7586** application to deadlock. For example, if connection X is waiting for 7587** connection Y's transaction to be concluded, and similarly connection 7588** Y is waiting on connection X's transaction, then neither connection 7589** will proceed and the system may remain deadlocked indefinitely. 7590** 7591** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 7592** detection. ^If a given call to sqlite3_unlock_notify() would put the 7593** system in a deadlocked state, then SQLITE_LOCKED is returned and no 7594** unlock-notify callback is registered. The system is said to be in 7595** a deadlocked state if connection A has registered for an unlock-notify 7596** callback on the conclusion of connection B's transaction, and connection 7597** B has itself registered for an unlock-notify callback when connection 7598** A's transaction is concluded. ^Indirect deadlock is also detected, so 7599** the system is also considered to be deadlocked if connection B has 7600** registered for an unlock-notify callback on the conclusion of connection 7601** C's transaction, where connection C is waiting on connection A. ^Any 7602** number of levels of indirection are allowed. 7603** 7604** <b>The "DROP TABLE" Exception</b> 7605** 7606** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 7607** always appropriate to call sqlite3_unlock_notify(). There is however, 7608** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 7609** SQLite checks if there are any currently executing SELECT statements 7610** that belong to the same connection. If there are, SQLITE_LOCKED is 7611** returned. In this case there is no "blocking connection", so invoking 7612** sqlite3_unlock_notify() results in the unlock-notify callback being 7613** invoked immediately. If the application then re-attempts the "DROP TABLE" 7614** or "DROP INDEX" query, an infinite loop might be the result. 7615** 7616** One way around this problem is to check the extended error code returned 7617** by an sqlite3_step() call. ^(If there is a blocking connection, then the 7618** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 7619** the special "DROP TABLE/INDEX" case, the extended error code is just 7620** SQLITE_LOCKED.)^ 7621*/ 7622int sqlite3_unlock_notify( 7623 sqlite3 *pBlocked, /* Waiting connection */ 7624 void (SQLITE_CALLBACK *xNotify)(void **apArg, int nArg), /* Callback func */ 7625 void *pNotifyArg /* Argument to pass to xNotify */ 7626); 7627 7628 7629/* 7630** CAPI3REF: String Comparison 7631** 7632** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 7633** and extensions to compare the contents of two buffers containing UTF-8 7634** strings in a case-independent fashion, using the same definition of "case 7635** independence" that SQLite uses internally when comparing identifiers. 7636*/ 7637int sqlite3_stricmp(const char *, const char *); 7638int sqlite3_strnicmp(const char *, const char *, int); 7639 7640/* 7641** CAPI3REF: String Globbing 7642* 7643** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 7644** string X matches the [GLOB] pattern P. 7645** ^The definition of [GLOB] pattern matching used in 7646** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 7647** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 7648** is case sensitive. 7649** 7650** Note that this routine returns zero on a match and non-zero if the strings 7651** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7652** 7653** See also: [sqlite3_strlike()]. 7654*/ 7655int sqlite3_strglob(const char *zGlob, const char *zStr); 7656 7657/* 7658** CAPI3REF: String LIKE Matching 7659* 7660** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 7661** string X matches the [LIKE] pattern P with escape character E. 7662** ^The definition of [LIKE] pattern matching used in 7663** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 7664** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 7665** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 7666** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 7667** insensitive - equivalent upper and lower case ASCII characters match 7668** one another. 7669** 7670** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 7671** only ASCII characters are case folded. 7672** 7673** Note that this routine returns zero on a match and non-zero if the strings 7674** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7675** 7676** See also: [sqlite3_strglob()]. 7677*/ 7678int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 7679 7680/* 7681** CAPI3REF: Error Logging Interface 7682** 7683** ^The [sqlite3_log()] interface writes a message into the [error log] 7684** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 7685** ^If logging is enabled, the zFormat string and subsequent arguments are 7686** used with [sqlite3_snprintf()] to generate the final output string. 7687** 7688** The sqlite3_log() interface is intended for use by extensions such as 7689** virtual tables, collating functions, and SQL functions. While there is 7690** nothing to prevent an application from calling sqlite3_log(), doing so 7691** is considered bad form. 7692** 7693** The zFormat string must not be NULL. 7694** 7695** To avoid deadlocks and other threading problems, the sqlite3_log() routine 7696** will not use dynamically allocated memory. The log message is stored in 7697** a fixed-length buffer on the stack. If the log message is longer than 7698** a few hundred characters, it will be truncated to the length of the 7699** buffer. 7700*/ 7701void sqlite3_log(int iErrCode, const char *zFormat, ...); 7702 7703/* 7704** CAPI3REF: Write-Ahead Log Commit Hook 7705** METHOD: sqlite3 7706** 7707** ^The [sqlite3_wal_hook()] function is used to register a callback that 7708** is invoked each time data is committed to a database in wal mode. 7709** 7710** ^(The callback is invoked by SQLite after the commit has taken place and 7711** the associated write-lock on the database released)^, so the implementation 7712** may read, write or [checkpoint] the database as required. 7713** 7714** ^The first parameter passed to the callback function when it is invoked 7715** is a copy of the third parameter passed to sqlite3_wal_hook() when 7716** registering the callback. ^The second is a copy of the database handle. 7717** ^The third parameter is the name of the database that was written to - 7718** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 7719** is the number of pages currently in the write-ahead log file, 7720** including those that were just committed. 7721** 7722** The callback function should normally return [SQLITE_OK]. ^If an error 7723** code is returned, that error will propagate back up through the 7724** SQLite code base to cause the statement that provoked the callback 7725** to report an error, though the commit will have still occurred. If the 7726** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 7727** that does not correspond to any valid SQLite error code, the results 7728** are undefined. 7729** 7730** A single database handle may have at most a single write-ahead log callback 7731** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 7732** previously registered write-ahead log callback. ^Note that the 7733** [sqlite3_wal_autocheckpoint()] interface and the 7734** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 7735** overwrite any prior [sqlite3_wal_hook()] settings. 7736*/ 7737void *sqlite3_wal_hook( 7738 sqlite3*, 7739 int(SQLITE_CALLBACK *)(void *,sqlite3*,const char*,int), 7740 void* 7741); 7742 7743/* 7744** CAPI3REF: Configure an auto-checkpoint 7745** METHOD: sqlite3 7746** 7747** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 7748** [sqlite3_wal_hook()] that causes any database on [database connection] D 7749** to automatically [checkpoint] 7750** after committing a transaction if there are N or 7751** more frames in the [write-ahead log] file. ^Passing zero or 7752** a negative value as the nFrame parameter disables automatic 7753** checkpoints entirely. 7754** 7755** ^The callback registered by this function replaces any existing callback 7756** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 7757** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 7758** configured by this function. 7759** 7760** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 7761** from SQL. 7762** 7763** ^Checkpoints initiated by this mechanism are 7764** [sqlite3_wal_checkpoint_v2|PASSIVE]. 7765** 7766** ^Every new [database connection] defaults to having the auto-checkpoint 7767** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 7768** pages. The use of this interface 7769** is only necessary if the default setting is found to be suboptimal 7770** for a particular application. 7771*/ 7772int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 7773 7774/* 7775** CAPI3REF: Checkpoint a database 7776** METHOD: sqlite3 7777** 7778** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 7779** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 7780** 7781** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 7782** [write-ahead log] for database X on [database connection] D to be 7783** transferred into the database file and for the write-ahead log to 7784** be reset. See the [checkpointing] documentation for addition 7785** information. 7786** 7787** This interface used to be the only way to cause a checkpoint to 7788** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 7789** interface was added. This interface is retained for backwards 7790** compatibility and as a convenience for applications that need to manually 7791** start a callback but which do not need the full power (and corresponding 7792** complication) of [sqlite3_wal_checkpoint_v2()]. 7793*/ 7794int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 7795 7796/* 7797** CAPI3REF: Checkpoint a database 7798** METHOD: sqlite3 7799** 7800** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 7801** operation on database X of [database connection] D in mode M. Status 7802** information is written back into integers pointed to by L and C.)^ 7803** ^(The M parameter must be a valid [checkpoint mode]:)^ 7804** 7805** <dl> 7806** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 7807** ^Checkpoint as many frames as possible without waiting for any database 7808** readers or writers to finish, then sync the database file if all frames 7809** in the log were checkpointed. ^The [busy-handler callback] 7810** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 7811** ^On the other hand, passive mode might leave the checkpoint unfinished 7812** if there are concurrent readers or writers. 7813** 7814** <dt>SQLITE_CHECKPOINT_FULL<dd> 7815** ^This mode blocks (it invokes the 7816** [sqlite3_busy_handler|busy-handler callback]) until there is no 7817** database writer and all readers are reading from the most recent database 7818** snapshot. ^It then checkpoints all frames in the log file and syncs the 7819** database file. ^This mode blocks new database writers while it is pending, 7820** but new database readers are allowed to continue unimpeded. 7821** 7822** <dt>SQLITE_CHECKPOINT_RESTART<dd> 7823** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 7824** that after checkpointing the log file it blocks (calls the 7825** [busy-handler callback]) 7826** until all readers are reading from the database file only. ^This ensures 7827** that the next writer will restart the log file from the beginning. 7828** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 7829** database writer attempts while it is pending, but does not impede readers. 7830** 7831** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 7832** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 7833** addition that it also truncates the log file to zero bytes just prior 7834** to a successful return. 7835** </dl> 7836** 7837** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 7838** the log file or to -1 if the checkpoint could not run because 7839** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 7840** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 7841** log file (including any that were already checkpointed before the function 7842** was called) or to -1 if the checkpoint could not run due to an error or 7843** because the database is not in WAL mode. ^Note that upon successful 7844** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 7845** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 7846** 7847** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 7848** any other process is running a checkpoint operation at the same time, the 7849** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 7850** busy-handler configured, it will not be invoked in this case. 7851** 7852** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 7853** exclusive "writer" lock on the database file. ^If the writer lock cannot be 7854** obtained immediately, and a busy-handler is configured, it is invoked and 7855** the writer lock retried until either the busy-handler returns 0 or the lock 7856** is successfully obtained. ^The busy-handler is also invoked while waiting for 7857** database readers as described above. ^If the busy-handler returns 0 before 7858** the writer lock is obtained or while waiting for database readers, the 7859** checkpoint operation proceeds from that point in the same way as 7860** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 7861** without blocking any further. ^SQLITE_BUSY is returned in this case. 7862** 7863** ^If parameter zDb is NULL or points to a zero length string, then the 7864** specified operation is attempted on all WAL databases [attached] to 7865** [database connection] db. In this case the 7866** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 7867** an SQLITE_BUSY error is encountered when processing one or more of the 7868** attached WAL databases, the operation is still attempted on any remaining 7869** attached databases and SQLITE_BUSY is returned at the end. ^If any other 7870** error occurs while processing an attached database, processing is abandoned 7871** and the error code is returned to the caller immediately. ^If no error 7872** (SQLITE_BUSY or otherwise) is encountered while processing the attached 7873** databases, SQLITE_OK is returned. 7874** 7875** ^If database zDb is the name of an attached database that is not in WAL 7876** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 7877** zDb is not NULL (or a zero length string) and is not the name of any 7878** attached database, SQLITE_ERROR is returned to the caller. 7879** 7880** ^Unless it returns SQLITE_MISUSE, 7881** the sqlite3_wal_checkpoint_v2() interface 7882** sets the error information that is queried by 7883** [sqlite3_errcode()] and [sqlite3_errmsg()]. 7884** 7885** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 7886** from SQL. 7887*/ 7888int sqlite3_wal_checkpoint_v2( 7889 sqlite3 *db, /* Database handle */ 7890 const char *zDb, /* Name of attached database (or NULL) */ 7891 int eMode, /* SQLITE_CHECKPOINT_* value */ 7892 int *pnLog, /* OUT: Size of WAL log in frames */ 7893 int *pnCkpt /* OUT: Total number of frames checkpointed */ 7894); 7895 7896/* 7897** CAPI3REF: Checkpoint Mode Values 7898** KEYWORDS: {checkpoint mode} 7899** 7900** These constants define all valid values for the "checkpoint mode" passed 7901** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 7902** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 7903** meaning of each of these checkpoint modes. 7904*/ 7905#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 7906#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 7907#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 7908#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 7909 7910/* 7911** CAPI3REF: Virtual Table Interface Configuration 7912** 7913** This function may be called by either the [xConnect] or [xCreate] method 7914** of a [virtual table] implementation to configure 7915** various facets of the virtual table interface. 7916** 7917** If this interface is invoked outside the context of an xConnect or 7918** xCreate virtual table method then the behavior is undefined. 7919** 7920** At present, there is only one option that may be configured using 7921** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 7922** may be added in the future. 7923*/ 7924int sqlite3_vtab_config(sqlite3*, int op, ...); 7925 7926/* 7927** CAPI3REF: Virtual Table Configuration Options 7928** 7929** These macros define the various options to the 7930** [sqlite3_vtab_config()] interface that [virtual table] implementations 7931** can use to customize and optimize their behavior. 7932** 7933** <dl> 7934** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 7935** <dd>Calls of the form 7936** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 7937** where X is an integer. If X is zero, then the [virtual table] whose 7938** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 7939** support constraints. In this configuration (which is the default) if 7940** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 7941** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 7942** specified as part of the users SQL statement, regardless of the actual 7943** ON CONFLICT mode specified. 7944** 7945** If X is non-zero, then the virtual table implementation guarantees 7946** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 7947** any modifications to internal or persistent data structures have been made. 7948** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 7949** is able to roll back a statement or database transaction, and abandon 7950** or continue processing the current SQL statement as appropriate. 7951** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 7952** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 7953** had been ABORT. 7954** 7955** Virtual table implementations that are required to handle OR REPLACE 7956** must do so within the [xUpdate] method. If a call to the 7957** [sqlite3_vtab_on_conflict()] function indicates that the current ON 7958** CONFLICT policy is REPLACE, the virtual table implementation should 7959** silently replace the appropriate rows within the xUpdate callback and 7960** return SQLITE_OK. Or, if this is not possible, it may return 7961** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 7962** constraint handling. 7963** </dl> 7964*/ 7965#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 7966 7967/* 7968** CAPI3REF: Determine The Virtual Table Conflict Policy 7969** 7970** This function may only be called from within a call to the [xUpdate] method 7971** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 7972** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 7973** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 7974** of the SQL statement that triggered the call to the [xUpdate] method of the 7975** [virtual table]. 7976*/ 7977int sqlite3_vtab_on_conflict(sqlite3 *); 7978 7979/* 7980** CAPI3REF: Conflict resolution modes 7981** KEYWORDS: {conflict resolution mode} 7982** 7983** These constants are returned by [sqlite3_vtab_on_conflict()] to 7984** inform a [virtual table] implementation what the [ON CONFLICT] mode 7985** is for the SQL statement being evaluated. 7986** 7987** Note that the [SQLITE_IGNORE] constant is also used as a potential 7988** return value from the [sqlite3_set_authorizer()] callback and that 7989** [SQLITE_ABORT] is also a [result code]. 7990*/ 7991#define SQLITE_ROLLBACK 1 7992/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 7993#define SQLITE_FAIL 3 7994/* #define SQLITE_ABORT 4 // Also an error code */ 7995#define SQLITE_REPLACE 5 7996 7997/* 7998** CAPI3REF: Prepared Statement Scan Status Opcodes 7999** KEYWORDS: {scanstatus options} 8000** 8001** The following constants can be used for the T parameter to the 8002** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 8003** different metric for sqlite3_stmt_scanstatus() to return. 8004** 8005** When the value returned to V is a string, space to hold that string is 8006** managed by the prepared statement S and will be automatically freed when 8007** S is finalized. 8008** 8009** <dl> 8010** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 8011** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 8012** set to the total number of times that the X-th loop has run.</dd> 8013** 8014** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 8015** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 8016** to the total number of rows examined by all iterations of the X-th loop.</dd> 8017** 8018** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 8019** <dd>^The "double" variable pointed to by the T parameter will be set to the 8020** query planner's estimate for the average number of rows output from each 8021** iteration of the X-th loop. If the query planner's estimates was accurate, 8022** then this value will approximate the quotient NVISIT/NLOOP and the 8023** product of this value for all prior loops with the same SELECTID will 8024** be the NLOOP value for the current loop. 8025** 8026** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 8027** <dd>^The "const char *" variable pointed to by the T parameter will be set 8028** to a zero-terminated UTF-8 string containing the name of the index or table 8029** used for the X-th loop. 8030** 8031** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 8032** <dd>^The "const char *" variable pointed to by the T parameter will be set 8033** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 8034** description for the X-th loop. 8035** 8036** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 8037** <dd>^The "int" variable pointed to by the T parameter will be set to the 8038** "select-id" for the X-th loop. The select-id identifies which query or 8039** subquery the loop is part of. The main query has a select-id of zero. 8040** The select-id is the same value as is output in the first column 8041** of an [EXPLAIN QUERY PLAN] query. 8042** </dl> 8043*/ 8044#define SQLITE_SCANSTAT_NLOOP 0 8045#define SQLITE_SCANSTAT_NVISIT 1 8046#define SQLITE_SCANSTAT_EST 2 8047#define SQLITE_SCANSTAT_NAME 3 8048#define SQLITE_SCANSTAT_EXPLAIN 4 8049#define SQLITE_SCANSTAT_SELECTID 5 8050 8051/* 8052** CAPI3REF: Prepared Statement Scan Status 8053** METHOD: sqlite3_stmt 8054** 8055** This interface returns information about the predicted and measured 8056** performance for pStmt. Advanced applications can use this 8057** interface to compare the predicted and the measured performance and 8058** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 8059** 8060** Since this interface is expected to be rarely used, it is only 8061** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 8062** compile-time option. 8063** 8064** The "iScanStatusOp" parameter determines which status information to return. 8065** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 8066** of this interface is undefined. 8067** ^The requested measurement is written into a variable pointed to by 8068** the "pOut" parameter. 8069** Parameter "idx" identifies the specific loop to retrieve statistics for. 8070** Loops are numbered starting from zero. ^If idx is out of range - less than 8071** zero or greater than or equal to the total number of loops used to implement 8072** the statement - a non-zero value is returned and the variable that pOut 8073** points to is unchanged. 8074** 8075** ^Statistics might not be available for all loops in all statements. ^In cases 8076** where there exist loops with no available statistics, this function behaves 8077** as if the loop did not exist - it returns non-zero and leave the variable 8078** that pOut points to unchanged. 8079** 8080** See also: [sqlite3_stmt_scanstatus_reset()] 8081*/ 8082int sqlite3_stmt_scanstatus( 8083 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 8084 int idx, /* Index of loop to report on */ 8085 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 8086 void *pOut /* Result written here */ 8087); 8088 8089/* 8090** CAPI3REF: Zero Scan-Status Counters 8091** METHOD: sqlite3_stmt 8092** 8093** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 8094** 8095** This API is only available if the library is built with pre-processor 8096** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 8097*/ 8098void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 8099 8100/* 8101** CAPI3REF: Flush caches to disk mid-transaction 8102** 8103** ^If a write-transaction is open on [database connection] D when the 8104** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 8105** pages in the pager-cache that are not currently in use are written out 8106** to disk. A dirty page may be in use if a database cursor created by an 8107** active SQL statement is reading from it, or if it is page 1 of a database 8108** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 8109** interface flushes caches for all schemas - "main", "temp", and 8110** any [attached] databases. 8111** 8112** ^If this function needs to obtain extra database locks before dirty pages 8113** can be flushed to disk, it does so. ^If those locks cannot be obtained 8114** immediately and there is a busy-handler callback configured, it is invoked 8115** in the usual manner. ^If the required lock still cannot be obtained, then 8116** the database is skipped and an attempt made to flush any dirty pages 8117** belonging to the next (if any) database. ^If any databases are skipped 8118** because locks cannot be obtained, but no other error occurs, this 8119** function returns SQLITE_BUSY. 8120** 8121** ^If any other error occurs while flushing dirty pages to disk (for 8122** example an IO error or out-of-memory condition), then processing is 8123** abandoned and an SQLite [error code] is returned to the caller immediately. 8124** 8125** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 8126** 8127** ^This function does not set the database handle error code or message 8128** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 8129*/ 8130int sqlite3_db_cacheflush(sqlite3*); 8131 8132/* 8133** CAPI3REF: The pre-update hook. 8134** 8135** ^These interfaces are only available if SQLite is compiled using the 8136** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 8137** 8138** ^The [sqlite3_preupdate_hook()] interface registers a callback function 8139** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 8140** on a [rowid table]. 8141** ^At most one preupdate hook may be registered at a time on a single 8142** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 8143** the previous setting. 8144** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 8145** with a NULL pointer as the second parameter. 8146** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 8147** the first parameter to callbacks. 8148** 8149** ^The preupdate hook only fires for changes to [rowid tables]; the preupdate 8150** hook is not invoked for changes to [virtual tables] or [WITHOUT ROWID] 8151** tables. 8152** 8153** ^The second parameter to the preupdate callback is a pointer to 8154** the [database connection] that registered the preupdate hook. 8155** ^The third parameter to the preupdate callback is one of the constants 8156** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to indentify the 8157** kind of update operation that is about to occur. 8158** ^(The fourth parameter to the preupdate callback is the name of the 8159** database within the database connection that is being modified. This 8160** will be "main" for the main database or "temp" for TEMP tables or 8161** the name given after the AS keyword in the [ATTACH] statement for attached 8162** databases.)^ 8163** ^The fifth parameter to the preupdate callback is the name of the 8164** table that is being modified. 8165** ^The sixth parameter to the preupdate callback is the initial [rowid] of the 8166** row being changes for SQLITE_UPDATE and SQLITE_DELETE changes and is 8167** undefined for SQLITE_INSERT changes. 8168** ^The seventh parameter to the preupdate callback is the final [rowid] of 8169** the row being changed for SQLITE_UPDATE and SQLITE_INSERT changes and is 8170** undefined for SQLITE_DELETE changes. 8171** 8172** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 8173** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 8174** provide additional information about a preupdate event. These routines 8175** may only be called from within a preupdate callback. Invoking any of 8176** these routines from outside of a preupdate callback or with a 8177** [database connection] pointer that is different from the one supplied 8178** to the preupdate callback results in undefined and probably undesirable 8179** behavior. 8180** 8181** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 8182** in the row that is being inserted, updated, or deleted. 8183** 8184** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 8185** a [protected sqlite3_value] that contains the value of the Nth column of 8186** the table row before it is updated. The N parameter must be between 0 8187** and one less than the number of columns or the behavior will be 8188** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 8189** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 8190** behavior is undefined. The [sqlite3_value] that P points to 8191** will be destroyed when the preupdate callback returns. 8192** 8193** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 8194** a [protected sqlite3_value] that contains the value of the Nth column of 8195** the table row after it is updated. The N parameter must be between 0 8196** and one less than the number of columns or the behavior will be 8197** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 8198** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 8199** behavior is undefined. The [sqlite3_value] that P points to 8200** will be destroyed when the preupdate callback returns. 8201** 8202** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 8203** callback was invoked as a result of a direct insert, update, or delete 8204** operation; or 1 for inserts, updates, or deletes invoked by top-level 8205** triggers; or 2 for changes resulting from triggers called by top-level 8206** triggers; and so forth. 8207** 8208** See also: [sqlite3_update_hook()] 8209*/ 8210SQLITE_EXPERIMENTAL void *sqlite3_preupdate_hook( 8211 sqlite3 *db, 8212 void(SQLITE_CALLBACK *xPreUpdate)( 8213 void *pCtx, /* Copy of third arg to preupdate_hook() */ 8214 sqlite3 *db, /* Database handle */ 8215 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 8216 char const *zDb, /* Database name */ 8217 char const *zName, /* Table name */ 8218 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 8219 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 8220 ), 8221 void* 8222); 8223SQLITE_EXPERIMENTAL int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 8224SQLITE_EXPERIMENTAL int sqlite3_preupdate_count(sqlite3 *); 8225SQLITE_EXPERIMENTAL int sqlite3_preupdate_depth(sqlite3 *); 8226SQLITE_EXPERIMENTAL int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 8227 8228/* 8229** CAPI3REF: Low-level system error code 8230** 8231** ^Attempt to return the underlying operating system error code or error 8232** number that caused the most recent I/O error or failure to open a file. 8233** The return value is OS-dependent. For example, on unix systems, after 8234** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 8235** called to get back the underlying "errno" that caused the problem, such 8236** as ENOSPC, EAUTH, EISDIR, and so forth. 8237*/ 8238int sqlite3_system_errno(sqlite3*); 8239 8240/* 8241** CAPI3REF: Database Snapshot 8242** KEYWORDS: {snapshot} 8243** EXPERIMENTAL 8244** 8245** An instance of the snapshot object records the state of a [WAL mode] 8246** database for some specific point in history. 8247** 8248** In [WAL mode], multiple [database connections] that are open on the 8249** same database file can each be reading a different historical version 8250** of the database file. When a [database connection] begins a read 8251** transaction, that connection sees an unchanging copy of the database 8252** as it existed for the point in time when the transaction first started. 8253** Subsequent changes to the database from other connections are not seen 8254** by the reader until a new read transaction is started. 8255** 8256** The sqlite3_snapshot object records state information about an historical 8257** version of the database file so that it is possible to later open a new read 8258** transaction that sees that historical version of the database rather than 8259** the most recent version. 8260** 8261** The constructor for this object is [sqlite3_snapshot_get()]. The 8262** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer 8263** to an historical snapshot (if possible). The destructor for 8264** sqlite3_snapshot objects is [sqlite3_snapshot_free()]. 8265*/ 8266typedef struct sqlite3_snapshot sqlite3_snapshot; 8267 8268/* 8269** CAPI3REF: Record A Database Snapshot 8270** EXPERIMENTAL 8271** 8272** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 8273** new [sqlite3_snapshot] object that records the current state of 8274** schema S in database connection D. ^On success, the 8275** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 8276** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 8277** ^If schema S of [database connection] D is not a [WAL mode] database 8278** that is in a read transaction, then [sqlite3_snapshot_get(D,S,P)] 8279** leaves the *P value unchanged and returns an appropriate [error code]. 8280** 8281** The [sqlite3_snapshot] object returned from a successful call to 8282** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 8283** to avoid a memory leak. 8284** 8285** The [sqlite3_snapshot_get()] interface is only available when the 8286** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8287*/ 8288SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 8289 sqlite3 *db, 8290 const char *zSchema, 8291 sqlite3_snapshot **ppSnapshot 8292); 8293 8294/* 8295** CAPI3REF: Start a read transaction on an historical snapshot 8296** EXPERIMENTAL 8297** 8298** ^The [sqlite3_snapshot_open(D,S,P)] interface starts a 8299** read transaction for schema S of 8300** [database connection] D such that the read transaction 8301** refers to historical [snapshot] P, rather than the most 8302** recent change to the database. 8303** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success 8304** or an appropriate [error code] if it fails. 8305** 8306** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be 8307** the first operation following the [BEGIN] that takes the schema S 8308** out of [autocommit mode]. 8309** ^In other words, schema S must not currently be in 8310** a transaction for [sqlite3_snapshot_open(D,S,P)] to work, but the 8311** database connection D must be out of [autocommit mode]. 8312** ^A [snapshot] will fail to open if it has been overwritten by a 8313** [checkpoint]. 8314** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 8315** database connection D does not know that the database file for 8316** schema S is in [WAL mode]. A database connection might not know 8317** that the database file is in [WAL mode] if there has been no prior 8318** I/O on that database connection, or if the database entered [WAL mode] 8319** after the most recent I/O on the database connection.)^ 8320** (Hint: Run "[PRAGMA application_id]" against a newly opened 8321** database connection in order to make it ready to use snapshots.) 8322** 8323** The [sqlite3_snapshot_open()] interface is only available when the 8324** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8325*/ 8326SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 8327 sqlite3 *db, 8328 const char *zSchema, 8329 sqlite3_snapshot *pSnapshot 8330); 8331 8332/* 8333** CAPI3REF: Destroy a snapshot 8334** EXPERIMENTAL 8335** 8336** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 8337** The application must eventually free every [sqlite3_snapshot] object 8338** using this routine to avoid a memory leak. 8339** 8340** The [sqlite3_snapshot_free()] interface is only available when the 8341** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8342*/ 8343SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 8344 8345/* 8346** CAPI3REF: Compare the ages of two snapshot handles. 8347** EXPERIMENTAL 8348** 8349** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 8350** of two valid snapshot handles. 8351** 8352** If the two snapshot handles are not associated with the same database 8353** file, the result of the comparison is undefined. 8354** 8355** Additionally, the result of the comparison is only valid if both of the 8356** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 8357** last time the wal file was deleted. The wal file is deleted when the 8358** database is changed back to rollback mode or when the number of database 8359** clients drops to zero. If either snapshot handle was obtained before the 8360** wal file was last deleted, the value returned by this function 8361** is undefined. 8362** 8363** Otherwise, this API returns a negative value if P1 refers to an older 8364** snapshot than P2, zero if the two handles refer to the same database 8365** snapshot, and a positive value if P1 is a newer snapshot than P2. 8366*/ 8367SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 8368 sqlite3_snapshot *p1, 8369 sqlite3_snapshot *p2 8370); 8371 8372/* 8373** Undo the hack that converts floating point types to integer for 8374** builds on processors without floating point support. 8375*/ 8376#ifdef SQLITE_OMIT_FLOATING_POINT 8377# undef double 8378#endif 8379 8380#ifdef __cplusplus 8381} /* End of the 'extern "C"' block */ 8382#endif 8383#endif /* SQLITE3_H */ 8384