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