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/*
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** 2001 September 15
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**
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** The author disclaims copyright to this source code. In place of
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** a legal notice, here is a blessing:
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**
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** May you do good and not evil.
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** May you find forgiveness for yourself and forgive others.
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** May you share freely, never taking more than you give.
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**
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*************************************************************************
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** This header file defines the interface that the SQLite library
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** presents to client programs. If a C-function, structure, datatype,
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** or constant definition does not appear in this file, then it is
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** not a published API of SQLite, is subject to change without
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** notice, and should not be referenced by programs that use SQLite.
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**
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** Some of the definitions that are in this file are marked as
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** "experimental". Experimental interfaces are normally new
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** features recently added to SQLite. We do not anticipate changes
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** to experimental interfaces but reserve the right to make minor changes
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** if experience from use "in the wild" suggest such changes are prudent.
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**
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** The official C-language API documentation for SQLite is derived
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** from comments in this file. This file is the authoritative source
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** on how SQLite interfaces are suppose to operate.
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**
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** The name of this file under configuration management is "sqlite.h.in".
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** The makefile makes some minor changes to this file (such as inserting
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** the version number) and changes its name to "sqlite3.h" as
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** part of the build process.
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*/
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#ifndef _SQLITE3_H_
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#define _SQLITE3_H_
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#include <stdarg.h> /* Needed for the definition of va_list */ |
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/*
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** Make sure we can call this stuff from C++.
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*/
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#ifdef __cplusplus
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extern "C" { |
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#endif
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/*
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** Add the ability to override 'extern'
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*/
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#ifndef SQLITE_EXTERN
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# define SQLITE_EXTERN extern |
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#endif
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#ifndef SQLITE_API
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# define SQLITE_API
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#endif
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/*
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** These no-op macros are used in front of interfaces to mark those
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** interfaces as either deprecated or experimental. New applications
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** should not use deprecated interfaces - they are support for backwards
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** compatibility only. Application writers should be aware that
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** experimental interfaces are subject to change in point releases.
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**
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** These macros used to resolve to various kinds of compiler magic that
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** would generate warning messages when they were used. But that
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** compiler magic ended up generating such a flurry of bug reports
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** that we have taken it all out and gone back to using simple
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** noop macros.
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*/
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#define SQLITE_DEPRECATED
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#define SQLITE_EXPERIMENTAL
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/*
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** Ensure these symbols were not defined by some previous header file.
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*/
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#ifdef SQLITE_VERSION
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# undef SQLITE_VERSION
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#endif
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#ifdef SQLITE_VERSION_NUMBER
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# undef SQLITE_VERSION_NUMBER
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#endif
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/*
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** CAPI3REF: Compile-Time Library Version Numbers
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**
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** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
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** evaluates to a string literal that is the SQLite version in the
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** format "X.Y.Z" where X is the major version number (always 3 for
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** SQLite3) and Y is the minor version number and Z is the release number.)^
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** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
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** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
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** numbers used in [SQLITE_VERSION].)^
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** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
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** be larger than the release from which it is derived. Either Y will
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** be held constant and Z will be incremented or else Y will be incremented
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** and Z will be reset to zero.
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**
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** Since version 3.6.18, SQLite source code has been stored in the
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** <a href="http://www.fossil-scm.org/">Fossil configuration management
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** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
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** a string which identifies a particular check-in of SQLite
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** within its configuration management system. ^The SQLITE_SOURCE_ID
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** string contains the date and time of the check-in (UTC) and an SHA1
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** hash of the entire source tree.
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**
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** See also: [sqlite3_libversion()],
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** [sqlite3_libversion_number()], [sqlite3_sourceid()],
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** [sqlite_version()] and [sqlite_source_id()].
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*/
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#define SQLITE_VERSION "3.8.3.1" |
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#define SQLITE_VERSION_NUMBER 3008003 |
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#define SQLITE_SOURCE_ID "2014-02-11 14:52:19 ea3317a4803d71d88183b29f1d3086f46d68a00e" |
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/*
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** CAPI3REF: Run-Time Library Version Numbers
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** KEYWORDS: sqlite3_version, sqlite3_sourceid
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**
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** These interfaces provide the same information as the [SQLITE_VERSION],
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** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
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** but are associated with the library instead of the header file. ^(Cautious
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** programmers might include assert() statements in their application to
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** verify that values returned by these interfaces match the macros in
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** the header, and thus insure that the application is
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** compiled with matching library and header files.
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**
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** <blockquote><pre>
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** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
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** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
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** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
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** </pre></blockquote>)^
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**
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** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
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** macro. ^The sqlite3_libversion() function returns a pointer to the
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** to the sqlite3_version[] string constant. The sqlite3_libversion()
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** function is provided for use in DLLs since DLL users usually do not have
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** direct access to string constants within the DLL. ^The
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** sqlite3_libversion_number() function returns an integer equal to
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** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns
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** a pointer to a string constant whose value is the same as the
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** [SQLITE_SOURCE_ID] C preprocessor macro.
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**
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** See also: [sqlite_version()] and [sqlite_source_id()].
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*/
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SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; |
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SQLITE_API const char *sqlite3_libversion(void); |
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SQLITE_API const char *sqlite3_sourceid(void); |
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SQLITE_API int sqlite3_libversion_number(void); |
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/*
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** CAPI3REF: Run-Time Library Compilation Options Diagnostics
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**
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** ^The sqlite3_compileoption_used() function returns 0 or 1
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** indicating whether the specified option was defined at
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** compile time. ^The SQLITE_ prefix may be omitted from the
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** option name passed to sqlite3_compileoption_used().
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**
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** ^The sqlite3_compileoption_get() function allows iterating
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** over the list of options that were defined at compile time by
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** returning the N-th compile time option string. ^If N is out of range,
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** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
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** prefix is omitted from any strings returned by
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** sqlite3_compileoption_get().
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**
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** ^Support for the diagnostic functions sqlite3_compileoption_used()
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** and sqlite3_compileoption_get() may be omitted by specifying the
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** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
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**
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** See also: SQL functions [sqlite_compileoption_used()] and
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** [sqlite_compileoption_get()] and the [compile_options pragma].
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*/
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#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
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SQLITE_API int sqlite3_compileoption_used(const char *zOptName); |
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SQLITE_API const char *sqlite3_compileoption_get(int N); |
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#endif
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/*
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** CAPI3REF: Test To See If The Library Is Threadsafe
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**
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** ^The sqlite3_threadsafe() function returns zero if and only if
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** SQLite was compiled with mutexing code omitted due to the
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** [SQLITE_THREADSAFE] compile-time option being set to 0.
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**
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** SQLite can be compiled with or without mutexes. When
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** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
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** are enabled and SQLite is threadsafe. When the
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** [SQLITE_THREADSAFE] macro is 0,
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** the mutexes are omitted. Without the mutexes, it is not safe
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** to use SQLite concurrently from more than one thread.
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**
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** Enabling mutexes incurs a measurable performance penalty.
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** So if speed is of utmost importance, it makes sense to disable
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** the mutexes. But for maximum safety, mutexes should be enabled.
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** ^The default behavior is for mutexes to be enabled.
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**
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** This interface can be used by an application to make sure that the
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** version of SQLite that it is linking against was compiled with
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** the desired setting of the [SQLITE_THREADSAFE] macro.
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**
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** This interface only reports on the compile-time mutex setting
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** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
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** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
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** can be fully or partially disabled using a call to [sqlite3_config()]
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** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
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** or [SQLITE_CONFIG_MUTEX]. ^(The return value of the
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** sqlite3_threadsafe() function shows only the compile-time setting of
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** thread safety, not any run-time changes to that setting made by
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** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
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** is unchanged by calls to sqlite3_config().)^
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**
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** See the [threading mode] documentation for additional information.
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*/
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SQLITE_API int sqlite3_threadsafe(void); |
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/*
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** CAPI3REF: Database Connection Handle
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** KEYWORDS: {database connection} {database connections}
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**
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** Each open SQLite database is represented by a pointer to an instance of
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** the opaque structure named "sqlite3". It is useful to think of an sqlite3
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** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
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** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
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** and [sqlite3_close_v2()] are its destructors. There are many other
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** interfaces (such as
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** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
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** [sqlite3_busy_timeout()] to name but three) that are methods on an
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** sqlite3 object.
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*/
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typedef struct sqlite3 sqlite3; |
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/*
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** CAPI3REF: 64-Bit Integer Types
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** KEYWORDS: sqlite_int64 sqlite_uint64
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**
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** Because there is no cross-platform way to specify 64-bit integer types
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** SQLite includes typedefs for 64-bit signed and unsigned integers.
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**
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** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
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** The sqlite_int64 and sqlite_uint64 types are supported for backwards
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** compatibility only.
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**
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** ^The sqlite3_int64 and sqlite_int64 types can store integer values
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** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
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** sqlite3_uint64 and sqlite_uint64 types can store integer values
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** between 0 and +18446744073709551615 inclusive.
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*/
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#ifdef SQLITE_INT64_TYPE
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typedef SQLITE_INT64_TYPE sqlite_int64;
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typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; |
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#elif defined(_MSC_VER) || defined(__BORLANDC__)
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typedef __int64 sqlite_int64;
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typedef unsigned __int64 sqlite_uint64; |
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#else
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typedef long long int sqlite_int64; |
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typedef unsigned long long int sqlite_uint64; |
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#endif
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typedef sqlite_int64 sqlite3_int64;
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typedef sqlite_uint64 sqlite3_uint64;
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/*
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** If compiling for a processor that lacks floating point support,
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** substitute integer for floating-point.
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*/
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#ifdef SQLITE_OMIT_FLOATING_POINT
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# define double sqlite3_int64 |
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#endif
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/*
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** CAPI3REF: Closing A Database Connection
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**
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** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
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** for the [sqlite3] object.
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** ^Calls to sqlite3_close() and sqlite3_close_v2() return SQLITE_OK if
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** the [sqlite3] object is successfully destroyed and all associated
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** resources are deallocated.
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**
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** ^If the database connection is associated with unfinalized prepared
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** statements or unfinished sqlite3_backup objects then sqlite3_close()
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** will leave the database connection open and return [SQLITE_BUSY].
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** ^If sqlite3_close_v2() is called with unfinalized prepared statements
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** and unfinished sqlite3_backups, then the database connection becomes
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** an unusable "zombie" which will automatically be deallocated when the
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** last prepared statement is finalized or the last sqlite3_backup is
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** finished. The sqlite3_close_v2() interface is intended for use with
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** host languages that are garbage collected, and where the order in which
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** destructors are called is arbitrary.
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**
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** Applications should [sqlite3_finalize | finalize] all [prepared statements],
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** [sqlite3_blob_close | close] all [BLOB handles], and
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** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
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** with the [sqlite3] object prior to attempting to close the object. ^If
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** sqlite3_close_v2() is called on a [database connection] that still has
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** outstanding [prepared statements], [BLOB handles], and/or
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** [sqlite3_backup] objects then it returns SQLITE_OK but the deallocation
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** of resources is deferred until all [prepared statements], [BLOB handles],
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** and [sqlite3_backup] objects are also destroyed.
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**
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** ^If an [sqlite3] object is destroyed while a transaction is open,
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** the transaction is automatically rolled back.
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**
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** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
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** must be either a NULL
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** pointer or an [sqlite3] object pointer obtained
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** from [sqlite3_open()], [sqlite3_open16()], or
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** [sqlite3_open_v2()], and not previously closed.
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** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
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** argument is a harmless no-op.
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*/
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SQLITE_API int sqlite3_close(sqlite3*);
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SQLITE_API int sqlite3_close_v2(sqlite3*);
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/*
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** The type for a callback function.
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** This is legacy and deprecated. It is included for historical
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** compatibility and is not documented.
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*/
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typedef int (*sqlite3_callback)(void*,int,char**, char**); |
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/*
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** CAPI3REF: One-Step Query Execution Interface
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**
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** The sqlite3_exec() interface is a convenience wrapper around
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** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
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** that allows an application to run multiple statements of SQL
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** without having to use a lot of C code.
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**
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** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
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** semicolon-separate SQL statements passed into its 2nd argument,
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** in the context of the [database connection] passed in as its 1st
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** argument. ^If the callback function of the 3rd argument to
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** sqlite3_exec() is not NULL, then it is invoked for each result row
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** coming out of the evaluated SQL statements. ^The 4th argument to
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** sqlite3_exec() is relayed through to the 1st argument of each
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** callback invocation. ^If the callback pointer to sqlite3_exec()
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** is NULL, then no callback is ever invoked and result rows are
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** ignored.
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**
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** ^If an error occurs while evaluating the SQL statements passed into
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** sqlite3_exec(), then execution of the current statement stops and
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** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
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** is not NULL then any error message is written into memory obtained
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** from [sqlite3_malloc()] and passed back through the 5th parameter.
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** To avoid memory leaks, the application should invoke [sqlite3_free()]
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** on error message strings returned through the 5th parameter of
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** of sqlite3_exec() after the error message string is no longer needed.
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** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
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** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
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** NULL before returning.
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**
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** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
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** routine returns SQLITE_ABORT without invoking the callback again and
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** without running any subsequent SQL statements.
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**
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** ^The 2nd argument to the sqlite3_exec() callback function is the
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** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
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** callback is an array of pointers to strings obtained as if from
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** [sqlite3_column_text()], one for each column. ^If an element of a
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** result row is NULL then the corresponding string pointer for the
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** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
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** sqlite3_exec() callback is an array of pointers to strings where each
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** entry represents the name of corresponding result column as obtained
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** from [sqlite3_column_name()].
|
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**
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** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
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** to an empty string, or a pointer that contains only whitespace and/or
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** SQL comments, then no SQL statements are evaluated and the database
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** is not changed.
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**
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** Restrictions:
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**
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** <ul>
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** <li> The application must insure that the 1st parameter to sqlite3_exec()
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** is a valid and open [database connection].
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** <li> The application must not close the [database connection] specified by
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** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
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** <li> The application must not modify the SQL statement text passed into
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** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
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** </ul>
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*/
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SQLITE_API int sqlite3_exec(
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sqlite3*, /* An open database */
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const char *sql, /* SQL to be evaluated */ |
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int (*callback)(void*,int,char**,char**), /* Callback function */ |
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void *, /* 1st argument to callback */ |
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char **errmsg /* Error msg written here */ |
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); |
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|
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/*
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** CAPI3REF: Result Codes
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** KEYWORDS: SQLITE_OK {error code} {error codes}
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** KEYWORDS: {result code} {result codes}
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**
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** Many SQLite functions return an integer result code from the set shown
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** here in order to indicate success or failure.
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**
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** New error codes may be added in future versions of SQLite.
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**
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** See also: [SQLITE_IOERR_READ | extended result codes],
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** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes].
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*/
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#define SQLITE_OK 0 /* Successful result */ |
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/* beginning-of-error-codes */
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#define SQLITE_ERROR 1 /* SQL error or missing database */ |
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#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ |
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#define SQLITE_PERM 3 /* Access permission denied */ |
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#define SQLITE_ABORT 4 /* Callback routine requested an abort */ |
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#define SQLITE_BUSY 5 /* The database file is locked */ |
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#define SQLITE_LOCKED 6 /* A table in the database is locked */ |
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#define SQLITE_NOMEM 7 /* A malloc() failed */ |
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#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ |
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#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ |
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#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ |
412 |
#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ |
413 |
#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ |
414 |
#define SQLITE_FULL 13 /* Insertion failed because database is full */ |
415 |
#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ |
416 |
#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ |
417 |
#define SQLITE_EMPTY 16 /* Database is empty */ |
418 |
#define SQLITE_SCHEMA 17 /* The database schema changed */ |
419 |
#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ |
420 |
#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ |
421 |
#define SQLITE_MISMATCH 20 /* Data type mismatch */ |
422 |
#define SQLITE_MISUSE 21 /* Library used incorrectly */ |
423 |
#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ |
424 |
#define SQLITE_AUTH 23 /* Authorization denied */ |
425 |
#define SQLITE_FORMAT 24 /* Auxiliary database format error */ |
426 |
#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ |
427 |
#define SQLITE_NOTADB 26 /* File opened that is not a database file */ |
428 |
#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ |
429 |
#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ |
430 |
#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ |
431 |
#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ |
432 |
/* end-of-error-codes */
|
433 |
|
434 |
/*
|
435 |
** CAPI3REF: Extended Result Codes
|
436 |
** KEYWORDS: {extended error code} {extended error codes}
|
437 |
** KEYWORDS: {extended result code} {extended result codes}
|
438 |
**
|
439 |
** In its default configuration, SQLite API routines return one of 26 integer
|
440 |
** [SQLITE_OK | result codes]. However, experience has shown that many of
|
441 |
** these result codes are too coarse-grained. They do not provide as
|
442 |
** much information about problems as programmers might like. In an effort to
|
443 |
** address this, newer versions of SQLite (version 3.3.8 and later) include
|
444 |
** support for additional result codes that provide more detailed information
|
445 |
** about errors. The extended result codes are enabled or disabled
|
446 |
** on a per database connection basis using the
|
447 |
** [sqlite3_extended_result_codes()] API.
|
448 |
**
|
449 |
** Some of the available extended result codes are listed here.
|
450 |
** One may expect the number of extended result codes will increase
|
451 |
** over time. Software that uses extended result codes should expect
|
452 |
** to see new result codes in future releases of SQLite.
|
453 |
**
|
454 |
** The SQLITE_OK result code will never be extended. It will always
|
455 |
** be exactly zero.
|
456 |
*/
|
457 |
#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) |
458 |
#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) |
459 |
#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) |
460 |
#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) |
461 |
#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) |
462 |
#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) |
463 |
#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) |
464 |
#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) |
465 |
#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) |
466 |
#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) |
467 |
#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) |
468 |
#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) |
469 |
#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) |
470 |
#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) |
471 |
#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) |
472 |
#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) |
473 |
#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) |
474 |
#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) |
475 |
#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) |
476 |
#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) |
477 |
#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) |
478 |
#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) |
479 |
#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) |
480 |
#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) |
481 |
#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) |
482 |
#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) |
483 |
#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) |
484 |
#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) |
485 |
#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) |
486 |
#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) |
487 |
#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) |
488 |
#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) |
489 |
#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) |
490 |
#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) |
491 |
#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) |
492 |
#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) |
493 |
#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) |
494 |
#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) |
495 |
#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) |
496 |
#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) |
497 |
#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) |
498 |
#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) |
499 |
#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) |
500 |
#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) |
501 |
#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) |
502 |
#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) |
503 |
#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) |
504 |
#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) |
505 |
#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) |
506 |
#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) |
507 |
#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) |
508 |
#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) |
509 |
|
510 |
/*
|
511 |
** CAPI3REF: Flags For File Open Operations
|
512 |
**
|
513 |
** These bit values are intended for use in the
|
514 |
** 3rd parameter to the [sqlite3_open_v2()] interface and
|
515 |
** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
|
516 |
*/
|
517 |
#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ |
518 |
#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ |
519 |
#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ |
520 |
#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ |
521 |
#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ |
522 |
#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ |
523 |
#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ |
524 |
#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ |
525 |
#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ |
526 |
#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ |
527 |
#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ |
528 |
#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ |
529 |
#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ |
530 |
#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ |
531 |
#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ |
532 |
#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ |
533 |
#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ |
534 |
#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ |
535 |
#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ |
536 |
#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ |
537 |
|
538 |
/* Reserved: 0x00F00000 */
|
539 |
|
540 |
/*
|
541 |
** CAPI3REF: Device Characteristics
|
542 |
**
|
543 |
** The xDeviceCharacteristics method of the [sqlite3_io_methods]
|
544 |
** object returns an integer which is a vector of these
|
545 |
** bit values expressing I/O characteristics of the mass storage
|
546 |
** device that holds the file that the [sqlite3_io_methods]
|
547 |
** refers to.
|
548 |
**
|
549 |
** The SQLITE_IOCAP_ATOMIC property means that all writes of
|
550 |
** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
|
551 |
** mean that writes of blocks that are nnn bytes in size and
|
552 |
** are aligned to an address which is an integer multiple of
|
553 |
** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
|
554 |
** that when data is appended to a file, the data is appended
|
555 |
** first then the size of the file is extended, never the other
|
556 |
** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
|
557 |
** information is written to disk in the same order as calls
|
558 |
** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
|
559 |
** after reboot following a crash or power loss, the only bytes in a
|
560 |
** file that were written at the application level might have changed
|
561 |
** and that adjacent bytes, even bytes within the same sector are
|
562 |
** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
|
563 |
** flag indicate that a file cannot be deleted when open.
|
564 |
*/
|
565 |
#define SQLITE_IOCAP_ATOMIC 0x00000001 |
566 |
#define SQLITE_IOCAP_ATOMIC512 0x00000002 |
567 |
#define SQLITE_IOCAP_ATOMIC1K 0x00000004 |
568 |
#define SQLITE_IOCAP_ATOMIC2K 0x00000008 |
569 |
#define SQLITE_IOCAP_ATOMIC4K 0x00000010 |
570 |
#define SQLITE_IOCAP_ATOMIC8K 0x00000020 |
571 |
#define SQLITE_IOCAP_ATOMIC16K 0x00000040 |
572 |
#define SQLITE_IOCAP_ATOMIC32K 0x00000080 |
573 |
#define SQLITE_IOCAP_ATOMIC64K 0x00000100 |
574 |
#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 |
575 |
#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 |
576 |
#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 |
577 |
#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 |
578 |
|
579 |
/*
|
580 |
** CAPI3REF: File Locking Levels
|
581 |
**
|
582 |
** SQLite uses one of these integer values as the second
|
583 |
** argument to calls it makes to the xLock() and xUnlock() methods
|
584 |
** of an [sqlite3_io_methods] object.
|
585 |
*/
|
586 |
#define SQLITE_LOCK_NONE 0 |
587 |
#define SQLITE_LOCK_SHARED 1 |
588 |
#define SQLITE_LOCK_RESERVED 2 |
589 |
#define SQLITE_LOCK_PENDING 3 |
590 |
#define SQLITE_LOCK_EXCLUSIVE 4 |
591 |
|
592 |
/*
|
593 |
** CAPI3REF: Synchronization Type Flags
|
594 |
**
|
595 |
** When SQLite invokes the xSync() method of an
|
596 |
** [sqlite3_io_methods] object it uses a combination of
|
597 |
** these integer values as the second argument.
|
598 |
**
|
599 |
** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
|
600 |
** sync operation only needs to flush data to mass storage. Inode
|
601 |
** information need not be flushed. If the lower four bits of the flag
|
602 |
** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
|
603 |
** If the lower four bits equal SQLITE_SYNC_FULL, that means
|
604 |
** to use Mac OS X style fullsync instead of fsync().
|
605 |
**
|
606 |
** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
|
607 |
** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
|
608 |
** settings. The [synchronous pragma] determines when calls to the
|
609 |
** xSync VFS method occur and applies uniformly across all platforms.
|
610 |
** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
|
611 |
** energetic or rigorous or forceful the sync operations are and
|
612 |
** only make a difference on Mac OSX for the default SQLite code.
|
613 |
** (Third-party VFS implementations might also make the distinction
|
614 |
** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
|
615 |
** operating systems natively supported by SQLite, only Mac OSX
|
616 |
** cares about the difference.)
|
617 |
*/
|
618 |
#define SQLITE_SYNC_NORMAL 0x00002 |
619 |
#define SQLITE_SYNC_FULL 0x00003 |
620 |
#define SQLITE_SYNC_DATAONLY 0x00010 |
621 |
|
622 |
/*
|
623 |
** CAPI3REF: OS Interface Open File Handle
|
624 |
**
|
625 |
** An [sqlite3_file] object represents an open file in the
|
626 |
** [sqlite3_vfs | OS interface layer]. Individual OS interface
|
627 |
** implementations will
|
628 |
** want to subclass this object by appending additional fields
|
629 |
** for their own use. The pMethods entry is a pointer to an
|
630 |
** [sqlite3_io_methods] object that defines methods for performing
|
631 |
** I/O operations on the open file.
|
632 |
*/
|
633 |
typedef struct sqlite3_file sqlite3_file; |
634 |
struct sqlite3_file {
|
635 |
const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ |
636 |
}; |
637 |
|
638 |
/*
|
639 |
** CAPI3REF: OS Interface File Virtual Methods Object
|
640 |
**
|
641 |
** Every file opened by the [sqlite3_vfs.xOpen] method populates an
|
642 |
** [sqlite3_file] object (or, more commonly, a subclass of the
|
643 |
** [sqlite3_file] object) with a pointer to an instance of this object.
|
644 |
** This object defines the methods used to perform various operations
|
645 |
** against the open file represented by the [sqlite3_file] object.
|
646 |
**
|
647 |
** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
|
648 |
** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
|
649 |
** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
|
650 |
** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
|
651 |
** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
|
652 |
** to NULL.
|
653 |
**
|
654 |
** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
|
655 |
** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
|
656 |
** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
|
657 |
** flag may be ORed in to indicate that only the data of the file
|
658 |
** and not its inode needs to be synced.
|
659 |
**
|
660 |
** The integer values to xLock() and xUnlock() are one of
|
661 |
** <ul>
|
662 |
** <li> [SQLITE_LOCK_NONE],
|
663 |
** <li> [SQLITE_LOCK_SHARED],
|
664 |
** <li> [SQLITE_LOCK_RESERVED],
|
665 |
** <li> [SQLITE_LOCK_PENDING], or
|
666 |
** <li> [SQLITE_LOCK_EXCLUSIVE].
|
667 |
** </ul>
|
668 |
** xLock() increases the lock. xUnlock() decreases the lock.
|
669 |
** The xCheckReservedLock() method checks whether any database connection,
|
670 |
** either in this process or in some other process, is holding a RESERVED,
|
671 |
** PENDING, or EXCLUSIVE lock on the file. It returns true
|
672 |
** if such a lock exists and false otherwise.
|
673 |
**
|
674 |
** The xFileControl() method is a generic interface that allows custom
|
675 |
** VFS implementations to directly control an open file using the
|
676 |
** [sqlite3_file_control()] interface. The second "op" argument is an
|
677 |
** integer opcode. The third argument is a generic pointer intended to
|
678 |
** point to a structure that may contain arguments or space in which to
|
679 |
** write return values. Potential uses for xFileControl() might be
|
680 |
** functions to enable blocking locks with timeouts, to change the
|
681 |
** locking strategy (for example to use dot-file locks), to inquire
|
682 |
** about the status of a lock, or to break stale locks. The SQLite
|
683 |
** core reserves all opcodes less than 100 for its own use.
|
684 |
** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available.
|
685 |
** Applications that define a custom xFileControl method should use opcodes
|
686 |
** greater than 100 to avoid conflicts. VFS implementations should
|
687 |
** return [SQLITE_NOTFOUND] for file control opcodes that they do not
|
688 |
** recognize.
|
689 |
**
|
690 |
** The xSectorSize() method returns the sector size of the
|
691 |
** device that underlies the file. The sector size is the
|
692 |
** minimum write that can be performed without disturbing
|
693 |
** other bytes in the file. The xDeviceCharacteristics()
|
694 |
** method returns a bit vector describing behaviors of the
|
695 |
** underlying device:
|
696 |
**
|
697 |
** <ul>
|
698 |
** <li> [SQLITE_IOCAP_ATOMIC]
|
699 |
** <li> [SQLITE_IOCAP_ATOMIC512]
|
700 |
** <li> [SQLITE_IOCAP_ATOMIC1K]
|
701 |
** <li> [SQLITE_IOCAP_ATOMIC2K]
|
702 |
** <li> [SQLITE_IOCAP_ATOMIC4K]
|
703 |
** <li> [SQLITE_IOCAP_ATOMIC8K]
|
704 |
** <li> [SQLITE_IOCAP_ATOMIC16K]
|
705 |
** <li> [SQLITE_IOCAP_ATOMIC32K]
|
706 |
** <li> [SQLITE_IOCAP_ATOMIC64K]
|
707 |
** <li> [SQLITE_IOCAP_SAFE_APPEND]
|
708 |
** <li> [SQLITE_IOCAP_SEQUENTIAL]
|
709 |
** </ul>
|
710 |
**
|
711 |
** The SQLITE_IOCAP_ATOMIC property means that all writes of
|
712 |
** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
|
713 |
** mean that writes of blocks that are nnn bytes in size and
|
714 |
** are aligned to an address which is an integer multiple of
|
715 |
** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
|
716 |
** that when data is appended to a file, the data is appended
|
717 |
** first then the size of the file is extended, never the other
|
718 |
** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
|
719 |
** information is written to disk in the same order as calls
|
720 |
** to xWrite().
|
721 |
**
|
722 |
** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
|
723 |
** in the unread portions of the buffer with zeros. A VFS that
|
724 |
** fails to zero-fill short reads might seem to work. However,
|
725 |
** failure to zero-fill short reads will eventually lead to
|
726 |
** database corruption.
|
727 |
*/
|
728 |
typedef struct sqlite3_io_methods sqlite3_io_methods; |
729 |
struct sqlite3_io_methods {
|
730 |
int iVersion;
|
731 |
int (*xClose)(sqlite3_file*);
|
732 |
int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); |
733 |
int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); |
734 |
int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
|
735 |
int (*xSync)(sqlite3_file*, int flags); |
736 |
int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
|
737 |
int (*xLock)(sqlite3_file*, int); |
738 |
int (*xUnlock)(sqlite3_file*, int); |
739 |
int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); |
740 |
int (*xFileControl)(sqlite3_file*, int op, void *pArg); |
741 |
int (*xSectorSize)(sqlite3_file*);
|
742 |
int (*xDeviceCharacteristics)(sqlite3_file*);
|
743 |
/* Methods above are valid for version 1 */
|
744 |
int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); |
745 |
int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); |
746 |
void (*xShmBarrier)(sqlite3_file*);
|
747 |
int (*xShmUnmap)(sqlite3_file*, int deleteFlag); |
748 |
/* Methods above are valid for version 2 */
|
749 |
int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); |
750 |
int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); |
751 |
/* Methods above are valid for version 3 */
|
752 |
/* Additional methods may be added in future releases */
|
753 |
}; |
754 |
|
755 |
/*
|
756 |
** CAPI3REF: Standard File Control Opcodes
|
757 |
**
|
758 |
** These integer constants are opcodes for the xFileControl method
|
759 |
** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
|
760 |
** interface.
|
761 |
**
|
762 |
** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
|
763 |
** opcode causes the xFileControl method to write the current state of
|
764 |
** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
|
765 |
** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
|
766 |
** into an integer that the pArg argument points to. This capability
|
767 |
** is used during testing and only needs to be supported when SQLITE_TEST
|
768 |
** is defined.
|
769 |
** <ul>
|
770 |
** <li>[[SQLITE_FCNTL_SIZE_HINT]]
|
771 |
** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
|
772 |
** layer a hint of how large the database file will grow to be during the
|
773 |
** current transaction. This hint is not guaranteed to be accurate but it
|
774 |
** is often close. The underlying VFS might choose to preallocate database
|
775 |
** file space based on this hint in order to help writes to the database
|
776 |
** file run faster.
|
777 |
**
|
778 |
** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
|
779 |
** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
|
780 |
** extends and truncates the database file in chunks of a size specified
|
781 |
** by the user. The fourth argument to [sqlite3_file_control()] should
|
782 |
** point to an integer (type int) containing the new chunk-size to use
|
783 |
** for the nominated database. Allocating database file space in large
|
784 |
** chunks (say 1MB at a time), may reduce file-system fragmentation and
|
785 |
** improve performance on some systems.
|
786 |
**
|
787 |
** <li>[[SQLITE_FCNTL_FILE_POINTER]]
|
788 |
** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
|
789 |
** to the [sqlite3_file] object associated with a particular database
|
790 |
** connection. See the [sqlite3_file_control()] documentation for
|
791 |
** additional information.
|
792 |
**
|
793 |
** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
|
794 |
** No longer in use.
|
795 |
**
|
796 |
** <li>[[SQLITE_FCNTL_SYNC]]
|
797 |
** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
|
798 |
** sent to the VFS immediately before the xSync method is invoked on a
|
799 |
** database file descriptor. Or, if the xSync method is not invoked
|
800 |
** because the user has configured SQLite with
|
801 |
** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
|
802 |
** of the xSync method. In most cases, the pointer argument passed with
|
803 |
** this file-control is NULL. However, if the database file is being synced
|
804 |
** as part of a multi-database commit, the argument points to a nul-terminated
|
805 |
** string containing the transactions master-journal file name. VFSes that
|
806 |
** do not need this signal should silently ignore this opcode. Applications
|
807 |
** should not call [sqlite3_file_control()] with this opcode as doing so may
|
808 |
** disrupt the operation of the specialized VFSes that do require it.
|
809 |
**
|
810 |
** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
|
811 |
** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
|
812 |
** and sent to the VFS after a transaction has been committed immediately
|
813 |
** but before the database is unlocked. VFSes that do not need this signal
|
814 |
** should silently ignore this opcode. Applications should not call
|
815 |
** [sqlite3_file_control()] with this opcode as doing so may disrupt the
|
816 |
** operation of the specialized VFSes that do require it.
|
817 |
**
|
818 |
** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
|
819 |
** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
|
820 |
** retry counts and intervals for certain disk I/O operations for the
|
821 |
** windows [VFS] in order to provide robustness in the presence of
|
822 |
** anti-virus programs. By default, the windows VFS will retry file read,
|
823 |
** file write, and file delete operations up to 10 times, with a delay
|
824 |
** of 25 milliseconds before the first retry and with the delay increasing
|
825 |
** by an additional 25 milliseconds with each subsequent retry. This
|
826 |
** opcode allows these two values (10 retries and 25 milliseconds of delay)
|
827 |
** to be adjusted. The values are changed for all database connections
|
828 |
** within the same process. The argument is a pointer to an array of two
|
829 |
** integers where the first integer i the new retry count and the second
|
830 |
** integer is the delay. If either integer is negative, then the setting
|
831 |
** is not changed but instead the prior value of that setting is written
|
832 |
** into the array entry, allowing the current retry settings to be
|
833 |
** interrogated. The zDbName parameter is ignored.
|
834 |
**
|
835 |
** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
|
836 |
** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
|
837 |
** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
|
838 |
** write ahead log and shared memory files used for transaction control
|
839 |
** are automatically deleted when the latest connection to the database
|
840 |
** closes. Setting persistent WAL mode causes those files to persist after
|
841 |
** close. Persisting the files is useful when other processes that do not
|
842 |
** have write permission on the directory containing the database file want
|
843 |
** to read the database file, as the WAL and shared memory files must exist
|
844 |
** in order for the database to be readable. The fourth parameter to
|
845 |
** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
|
846 |
** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
|
847 |
** WAL mode. If the integer is -1, then it is overwritten with the current
|
848 |
** WAL persistence setting.
|
849 |
**
|
850 |
** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
|
851 |
** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
|
852 |
** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
|
853 |
** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
|
854 |
** xDeviceCharacteristics methods. The fourth parameter to
|
855 |
** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
|
856 |
** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
|
857 |
** mode. If the integer is -1, then it is overwritten with the current
|
858 |
** zero-damage mode setting.
|
859 |
**
|
860 |
** <li>[[SQLITE_FCNTL_OVERWRITE]]
|
861 |
** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
|
862 |
** a write transaction to indicate that, unless it is rolled back for some
|
863 |
** reason, the entire database file will be overwritten by the current
|
864 |
** transaction. This is used by VACUUM operations.
|
865 |
**
|
866 |
** <li>[[SQLITE_FCNTL_VFSNAME]]
|
867 |
** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
|
868 |
** all [VFSes] in the VFS stack. The names are of all VFS shims and the
|
869 |
** final bottom-level VFS are written into memory obtained from
|
870 |
** [sqlite3_malloc()] and the result is stored in the char* variable
|
871 |
** that the fourth parameter of [sqlite3_file_control()] points to.
|
872 |
** The caller is responsible for freeing the memory when done. As with
|
873 |
** all file-control actions, there is no guarantee that this will actually
|
874 |
** do anything. Callers should initialize the char* variable to a NULL
|
875 |
** pointer in case this file-control is not implemented. This file-control
|
876 |
** is intended for diagnostic use only.
|
877 |
**
|
878 |
** <li>[[SQLITE_FCNTL_PRAGMA]]
|
879 |
** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
|
880 |
** file control is sent to the open [sqlite3_file] object corresponding
|
881 |
** to the database file to which the pragma statement refers. ^The argument
|
882 |
** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
|
883 |
** pointers to strings (char**) in which the second element of the array
|
884 |
** is the name of the pragma and the third element is the argument to the
|
885 |
** pragma or NULL if the pragma has no argument. ^The handler for an
|
886 |
** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
|
887 |
** of the char** argument point to a string obtained from [sqlite3_mprintf()]
|
888 |
** or the equivalent and that string will become the result of the pragma or
|
889 |
** the error message if the pragma fails. ^If the
|
890 |
** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
|
891 |
** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
|
892 |
** file control returns [SQLITE_OK], then the parser assumes that the
|
893 |
** VFS has handled the PRAGMA itself and the parser generates a no-op
|
894 |
** prepared statement. ^If the [SQLITE_FCNTL_PRAGMA] file control returns
|
895 |
** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
|
896 |
** that the VFS encountered an error while handling the [PRAGMA] and the
|
897 |
** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
|
898 |
** file control occurs at the beginning of pragma statement analysis and so
|
899 |
** it is able to override built-in [PRAGMA] statements.
|
900 |
**
|
901 |
** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
|
902 |
** ^The [SQLITE_FCNTL_BUSYHANDLER]
|
903 |
** file-control may be invoked by SQLite on the database file handle
|
904 |
** shortly after it is opened in order to provide a custom VFS with access
|
905 |
** to the connections busy-handler callback. The argument is of type (void **)
|
906 |
** - an array of two (void *) values. The first (void *) actually points
|
907 |
** to a function of type (int (*)(void *)). In order to invoke the connections
|
908 |
** busy-handler, this function should be invoked with the second (void *) in
|
909 |
** the array as the only argument. If it returns non-zero, then the operation
|
910 |
** should be retried. If it returns zero, the custom VFS should abandon the
|
911 |
** current operation.
|
912 |
**
|
913 |
** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
|
914 |
** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
|
915 |
** to have SQLite generate a
|
916 |
** temporary filename using the same algorithm that is followed to generate
|
917 |
** temporary filenames for TEMP tables and other internal uses. The
|
918 |
** argument should be a char** which will be filled with the filename
|
919 |
** written into memory obtained from [sqlite3_malloc()]. The caller should
|
920 |
** invoke [sqlite3_free()] on the result to avoid a memory leak.
|
921 |
**
|
922 |
** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
|
923 |
** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
|
924 |
** maximum number of bytes that will be used for memory-mapped I/O.
|
925 |
** The argument is a pointer to a value of type sqlite3_int64 that
|
926 |
** is an advisory maximum number of bytes in the file to memory map. The
|
927 |
** pointer is overwritten with the old value. The limit is not changed if
|
928 |
** the value originally pointed to is negative, and so the current limit
|
929 |
** can be queried by passing in a pointer to a negative number. This
|
930 |
** file-control is used internally to implement [PRAGMA mmap_size].
|
931 |
**
|
932 |
** <li>[[SQLITE_FCNTL_TRACE]]
|
933 |
** The [SQLITE_FCNTL_TRACE] file control provides advisory information
|
934 |
** to the VFS about what the higher layers of the SQLite stack are doing.
|
935 |
** This file control is used by some VFS activity tracing [shims].
|
936 |
** The argument is a zero-terminated string. Higher layers in the
|
937 |
** SQLite stack may generate instances of this file control if
|
938 |
** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
|
939 |
**
|
940 |
** <li>[[SQLITE_FCNTL_HAS_MOVED]]
|
941 |
** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
|
942 |
** pointer to an integer and it writes a boolean into that integer depending
|
943 |
** on whether or not the file has been renamed, moved, or deleted since it
|
944 |
** was first opened.
|
945 |
**
|
946 |
** </ul>
|
947 |
*/
|
948 |
#define SQLITE_FCNTL_LOCKSTATE 1 |
949 |
#define SQLITE_GET_LOCKPROXYFILE 2 |
950 |
#define SQLITE_SET_LOCKPROXYFILE 3 |
951 |
#define SQLITE_LAST_ERRNO 4 |
952 |
#define SQLITE_FCNTL_SIZE_HINT 5 |
953 |
#define SQLITE_FCNTL_CHUNK_SIZE 6 |
954 |
#define SQLITE_FCNTL_FILE_POINTER 7 |
955 |
#define SQLITE_FCNTL_SYNC_OMITTED 8 |
956 |
#define SQLITE_FCNTL_WIN32_AV_RETRY 9 |
957 |
#define SQLITE_FCNTL_PERSIST_WAL 10 |
958 |
#define SQLITE_FCNTL_OVERWRITE 11 |
959 |
#define SQLITE_FCNTL_VFSNAME 12 |
960 |
#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 |
961 |
#define SQLITE_FCNTL_PRAGMA 14 |
962 |
#define SQLITE_FCNTL_BUSYHANDLER 15 |
963 |
#define SQLITE_FCNTL_TEMPFILENAME 16 |
964 |
#define SQLITE_FCNTL_MMAP_SIZE 18 |
965 |
#define SQLITE_FCNTL_TRACE 19 |
966 |
#define SQLITE_FCNTL_HAS_MOVED 20 |
967 |
#define SQLITE_FCNTL_SYNC 21 |
968 |
#define SQLITE_FCNTL_COMMIT_PHASETWO 22 |
969 |
|
970 |
/*
|
971 |
** CAPI3REF: Mutex Handle
|
972 |
**
|
973 |
** The mutex module within SQLite defines [sqlite3_mutex] to be an
|
974 |
** abstract type for a mutex object. The SQLite core never looks
|
975 |
** at the internal representation of an [sqlite3_mutex]. It only
|
976 |
** deals with pointers to the [sqlite3_mutex] object.
|
977 |
**
|
978 |
** Mutexes are created using [sqlite3_mutex_alloc()].
|
979 |
*/
|
980 |
typedef struct sqlite3_mutex sqlite3_mutex; |
981 |
|
982 |
/*
|
983 |
** CAPI3REF: OS Interface Object
|
984 |
**
|
985 |
** An instance of the sqlite3_vfs object defines the interface between
|
986 |
** the SQLite core and the underlying operating system. The "vfs"
|
987 |
** in the name of the object stands for "virtual file system". See
|
988 |
** the [VFS | VFS documentation] for further information.
|
989 |
**
|
990 |
** The value of the iVersion field is initially 1 but may be larger in
|
991 |
** future versions of SQLite. Additional fields may be appended to this
|
992 |
** object when the iVersion value is increased. Note that the structure
|
993 |
** of the sqlite3_vfs object changes in the transaction between
|
994 |
** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not
|
995 |
** modified.
|
996 |
**
|
997 |
** The szOsFile field is the size of the subclassed [sqlite3_file]
|
998 |
** structure used by this VFS. mxPathname is the maximum length of
|
999 |
** a pathname in this VFS.
|
1000 |
**
|
1001 |
** Registered sqlite3_vfs objects are kept on a linked list formed by
|
1002 |
** the pNext pointer. The [sqlite3_vfs_register()]
|
1003 |
** and [sqlite3_vfs_unregister()] interfaces manage this list
|
1004 |
** in a thread-safe way. The [sqlite3_vfs_find()] interface
|
1005 |
** searches the list. Neither the application code nor the VFS
|
1006 |
** implementation should use the pNext pointer.
|
1007 |
**
|
1008 |
** The pNext field is the only field in the sqlite3_vfs
|
1009 |
** structure that SQLite will ever modify. SQLite will only access
|
1010 |
** or modify this field while holding a particular static mutex.
|
1011 |
** The application should never modify anything within the sqlite3_vfs
|
1012 |
** object once the object has been registered.
|
1013 |
**
|
1014 |
** The zName field holds the name of the VFS module. The name must
|
1015 |
** be unique across all VFS modules.
|
1016 |
**
|
1017 |
** [[sqlite3_vfs.xOpen]]
|
1018 |
** ^SQLite guarantees that the zFilename parameter to xOpen
|
1019 |
** is either a NULL pointer or string obtained
|
1020 |
** from xFullPathname() with an optional suffix added.
|
1021 |
** ^If a suffix is added to the zFilename parameter, it will
|
1022 |
** consist of a single "-" character followed by no more than
|
1023 |
** 11 alphanumeric and/or "-" characters.
|
1024 |
** ^SQLite further guarantees that
|
1025 |
** the string will be valid and unchanged until xClose() is
|
1026 |
** called. Because of the previous sentence,
|
1027 |
** the [sqlite3_file] can safely store a pointer to the
|
1028 |
** filename if it needs to remember the filename for some reason.
|
1029 |
** If the zFilename parameter to xOpen is a NULL pointer then xOpen
|
1030 |
** must invent its own temporary name for the file. ^Whenever the
|
1031 |
** xFilename parameter is NULL it will also be the case that the
|
1032 |
** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
|
1033 |
**
|
1034 |
** The flags argument to xOpen() includes all bits set in
|
1035 |
** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
|
1036 |
** or [sqlite3_open16()] is used, then flags includes at least
|
1037 |
** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
|
1038 |
** If xOpen() opens a file read-only then it sets *pOutFlags to
|
1039 |
** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
|
1040 |
**
|
1041 |
** ^(SQLite will also add one of the following flags to the xOpen()
|
1042 |
** call, depending on the object being opened:
|
1043 |
**
|
1044 |
** <ul>
|
1045 |
** <li> [SQLITE_OPEN_MAIN_DB]
|
1046 |
** <li> [SQLITE_OPEN_MAIN_JOURNAL]
|
1047 |
** <li> [SQLITE_OPEN_TEMP_DB]
|
1048 |
** <li> [SQLITE_OPEN_TEMP_JOURNAL]
|
1049 |
** <li> [SQLITE_OPEN_TRANSIENT_DB]
|
1050 |
** <li> [SQLITE_OPEN_SUBJOURNAL]
|
1051 |
** <li> [SQLITE_OPEN_MASTER_JOURNAL]
|
1052 |
** <li> [SQLITE_OPEN_WAL]
|
1053 |
** </ul>)^
|
1054 |
**
|
1055 |
** The file I/O implementation can use the object type flags to
|
1056 |
** change the way it deals with files. For example, an application
|
1057 |
** that does not care about crash recovery or rollback might make
|
1058 |
** the open of a journal file a no-op. Writes to this journal would
|
1059 |
** also be no-ops, and any attempt to read the journal would return
|
1060 |
** SQLITE_IOERR. Or the implementation might recognize that a database
|
1061 |
** file will be doing page-aligned sector reads and writes in a random
|
1062 |
** order and set up its I/O subsystem accordingly.
|
1063 |
**
|
1064 |
** SQLite might also add one of the following flags to the xOpen method:
|
1065 |
**
|
1066 |
** <ul>
|
1067 |
** <li> [SQLITE_OPEN_DELETEONCLOSE]
|
1068 |
** <li> [SQLITE_OPEN_EXCLUSIVE]
|
1069 |
** </ul>
|
1070 |
**
|
1071 |
** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
|
1072 |
** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
|
1073 |
** will be set for TEMP databases and their journals, transient
|
1074 |
** databases, and subjournals.
|
1075 |
**
|
1076 |
** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
|
1077 |
** with the [SQLITE_OPEN_CREATE] flag, which are both directly
|
1078 |
** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
|
1079 |
** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
|
1080 |
** SQLITE_OPEN_CREATE, is used to indicate that file should always
|
1081 |
** be created, and that it is an error if it already exists.
|
1082 |
** It is <i>not</i> used to indicate the file should be opened
|
1083 |
** for exclusive access.
|
1084 |
**
|
1085 |
** ^At least szOsFile bytes of memory are allocated by SQLite
|
1086 |
** to hold the [sqlite3_file] structure passed as the third
|
1087 |
** argument to xOpen. The xOpen method does not have to
|
1088 |
** allocate the structure; it should just fill it in. Note that
|
1089 |
** the xOpen method must set the sqlite3_file.pMethods to either
|
1090 |
** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
|
1091 |
** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
|
1092 |
** element will be valid after xOpen returns regardless of the success
|
1093 |
** or failure of the xOpen call.
|
1094 |
**
|
1095 |
** [[sqlite3_vfs.xAccess]]
|
1096 |
** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
|
1097 |
** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
|
1098 |
** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
|
1099 |
** to test whether a file is at least readable. The file can be a
|
1100 |
** directory.
|
1101 |
**
|
1102 |
** ^SQLite will always allocate at least mxPathname+1 bytes for the
|
1103 |
** output buffer xFullPathname. The exact size of the output buffer
|
1104 |
** is also passed as a parameter to both methods. If the output buffer
|
1105 |
** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
|
1106 |
** handled as a fatal error by SQLite, vfs implementations should endeavor
|
1107 |
** to prevent this by setting mxPathname to a sufficiently large value.
|
1108 |
**
|
1109 |
** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
|
1110 |
** interfaces are not strictly a part of the filesystem, but they are
|
1111 |
** included in the VFS structure for completeness.
|
1112 |
** The xRandomness() function attempts to return nBytes bytes
|
1113 |
** of good-quality randomness into zOut. The return value is
|
1114 |
** the actual number of bytes of randomness obtained.
|
1115 |
** The xSleep() method causes the calling thread to sleep for at
|
1116 |
** least the number of microseconds given. ^The xCurrentTime()
|
1117 |
** method returns a Julian Day Number for the current date and time as
|
1118 |
** a floating point value.
|
1119 |
** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
|
1120 |
** Day Number multiplied by 86400000 (the number of milliseconds in
|
1121 |
** a 24-hour day).
|
1122 |
** ^SQLite will use the xCurrentTimeInt64() method to get the current
|
1123 |
** date and time if that method is available (if iVersion is 2 or
|
1124 |
** greater and the function pointer is not NULL) and will fall back
|
1125 |
** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
|
1126 |
**
|
1127 |
** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
|
1128 |
** are not used by the SQLite core. These optional interfaces are provided
|
1129 |
** by some VFSes to facilitate testing of the VFS code. By overriding
|
1130 |
** system calls with functions under its control, a test program can
|
1131 |
** simulate faults and error conditions that would otherwise be difficult
|
1132 |
** or impossible to induce. The set of system calls that can be overridden
|
1133 |
** varies from one VFS to another, and from one version of the same VFS to the
|
1134 |
** next. Applications that use these interfaces must be prepared for any
|
1135 |
** or all of these interfaces to be NULL or for their behavior to change
|
1136 |
** from one release to the next. Applications must not attempt to access
|
1137 |
** any of these methods if the iVersion of the VFS is less than 3.
|
1138 |
*/
|
1139 |
typedef struct sqlite3_vfs sqlite3_vfs; |
1140 |
typedef void (*sqlite3_syscall_ptr)(void); |
1141 |
struct sqlite3_vfs {
|
1142 |
int iVersion; /* Structure version number (currently 3) */ |
1143 |
int szOsFile; /* Size of subclassed sqlite3_file */ |
1144 |
int mxPathname; /* Maximum file pathname length */ |
1145 |
sqlite3_vfs *pNext; /* Next registered VFS */
|
1146 |
const char *zName; /* Name of this virtual file system */ |
1147 |
void *pAppData; /* Pointer to application-specific data */ |
1148 |
int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, |
1149 |
int flags, int *pOutFlags); |
1150 |
int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); |
1151 |
int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); |
1152 |
int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); |
1153 |
void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); |
1154 |
void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); |
1155 |
void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); |
1156 |
void (*xDlClose)(sqlite3_vfs*, void*); |
1157 |
int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); |
1158 |
int (*xSleep)(sqlite3_vfs*, int microseconds); |
1159 |
int (*xCurrentTime)(sqlite3_vfs*, double*); |
1160 |
int (*xGetLastError)(sqlite3_vfs*, int, char *); |
1161 |
/*
|
1162 |
** The methods above are in version 1 of the sqlite_vfs object
|
1163 |
** definition. Those that follow are added in version 2 or later
|
1164 |
*/
|
1165 |
int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
|
1166 |
/*
|
1167 |
** The methods above are in versions 1 and 2 of the sqlite_vfs object.
|
1168 |
** Those below are for version 3 and greater.
|
1169 |
*/
|
1170 |
int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); |
1171 |
sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); |
1172 |
const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); |
1173 |
/*
|
1174 |
** The methods above are in versions 1 through 3 of the sqlite_vfs object.
|
1175 |
** New fields may be appended in figure versions. The iVersion
|
1176 |
** value will increment whenever this happens.
|
1177 |
*/
|
1178 |
}; |
1179 |
|
1180 |
/*
|
1181 |
** CAPI3REF: Flags for the xAccess VFS method
|
1182 |
**
|
1183 |
** These integer constants can be used as the third parameter to
|
1184 |
** the xAccess method of an [sqlite3_vfs] object. They determine
|
1185 |
** what kind of permissions the xAccess method is looking for.
|
1186 |
** With SQLITE_ACCESS_EXISTS, the xAccess method
|
1187 |
** simply checks whether the file exists.
|
1188 |
** With SQLITE_ACCESS_READWRITE, the xAccess method
|
1189 |
** checks whether the named directory is both readable and writable
|
1190 |
** (in other words, if files can be added, removed, and renamed within
|
1191 |
** the directory).
|
1192 |
** The SQLITE_ACCESS_READWRITE constant is currently used only by the
|
1193 |
** [temp_store_directory pragma], though this could change in a future
|
1194 |
** release of SQLite.
|
1195 |
** With SQLITE_ACCESS_READ, the xAccess method
|
1196 |
** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
|
1197 |
** currently unused, though it might be used in a future release of
|
1198 |
** SQLite.
|
1199 |
*/
|
1200 |
#define SQLITE_ACCESS_EXISTS 0 |
1201 |
#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ |
1202 |
#define SQLITE_ACCESS_READ 2 /* Unused */ |
1203 |
|
1204 |
/*
|
1205 |
** CAPI3REF: Flags for the xShmLock VFS method
|
1206 |
**
|
1207 |
** These integer constants define the various locking operations
|
1208 |
** allowed by the xShmLock method of [sqlite3_io_methods]. The
|
1209 |
** following are the only legal combinations of flags to the
|
1210 |
** xShmLock method:
|
1211 |
**
|
1212 |
** <ul>
|
1213 |
** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
|
1214 |
** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
|
1215 |
** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
|
1216 |
** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
|
1217 |
** </ul>
|
1218 |
**
|
1219 |
** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
|
1220 |
** was given no the corresponding lock.
|
1221 |
**
|
1222 |
** The xShmLock method can transition between unlocked and SHARED or
|
1223 |
** between unlocked and EXCLUSIVE. It cannot transition between SHARED
|
1224 |
** and EXCLUSIVE.
|
1225 |
*/
|
1226 |
#define SQLITE_SHM_UNLOCK 1 |
1227 |
#define SQLITE_SHM_LOCK 2 |
1228 |
#define SQLITE_SHM_SHARED 4 |
1229 |
#define SQLITE_SHM_EXCLUSIVE 8 |
1230 |
|
1231 |
/*
|
1232 |
** CAPI3REF: Maximum xShmLock index
|
1233 |
**
|
1234 |
** The xShmLock method on [sqlite3_io_methods] may use values
|
1235 |
** between 0 and this upper bound as its "offset" argument.
|
1236 |
** The SQLite core will never attempt to acquire or release a
|
1237 |
** lock outside of this range
|
1238 |
*/
|
1239 |
#define SQLITE_SHM_NLOCK 8 |
1240 |
|
1241 |
|
1242 |
/*
|
1243 |
** CAPI3REF: Initialize The SQLite Library
|
1244 |
**
|
1245 |
** ^The sqlite3_initialize() routine initializes the
|
1246 |
** SQLite library. ^The sqlite3_shutdown() routine
|
1247 |
** deallocates any resources that were allocated by sqlite3_initialize().
|
1248 |
** These routines are designed to aid in process initialization and
|
1249 |
** shutdown on embedded systems. Workstation applications using
|
1250 |
** SQLite normally do not need to invoke either of these routines.
|
1251 |
**
|
1252 |
** A call to sqlite3_initialize() is an "effective" call if it is
|
1253 |
** the first time sqlite3_initialize() is invoked during the lifetime of
|
1254 |
** the process, or if it is the first time sqlite3_initialize() is invoked
|
1255 |
** following a call to sqlite3_shutdown(). ^(Only an effective call
|
1256 |
** of sqlite3_initialize() does any initialization. All other calls
|
1257 |
** are harmless no-ops.)^
|
1258 |
**
|
1259 |
** A call to sqlite3_shutdown() is an "effective" call if it is the first
|
1260 |
** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
|
1261 |
** an effective call to sqlite3_shutdown() does any deinitialization.
|
1262 |
** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
|
1263 |
**
|
1264 |
** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
|
1265 |
** is not. The sqlite3_shutdown() interface must only be called from a
|
1266 |
** single thread. All open [database connections] must be closed and all
|
1267 |
** other SQLite resources must be deallocated prior to invoking
|
1268 |
** sqlite3_shutdown().
|
1269 |
**
|
1270 |
** Among other things, ^sqlite3_initialize() will invoke
|
1271 |
** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
|
1272 |
** will invoke sqlite3_os_end().
|
1273 |
**
|
1274 |
** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
|
1275 |
** ^If for some reason, sqlite3_initialize() is unable to initialize
|
1276 |
** the library (perhaps it is unable to allocate a needed resource such
|
1277 |
** as a mutex) it returns an [error code] other than [SQLITE_OK].
|
1278 |
**
|
1279 |
** ^The sqlite3_initialize() routine is called internally by many other
|
1280 |
** SQLite interfaces so that an application usually does not need to
|
1281 |
** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
|
1282 |
** calls sqlite3_initialize() so the SQLite library will be automatically
|
1283 |
** initialized when [sqlite3_open()] is called if it has not be initialized
|
1284 |
** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
|
1285 |
** compile-time option, then the automatic calls to sqlite3_initialize()
|
1286 |
** are omitted and the application must call sqlite3_initialize() directly
|
1287 |
** prior to using any other SQLite interface. For maximum portability,
|
1288 |
** it is recommended that applications always invoke sqlite3_initialize()
|
1289 |
** directly prior to using any other SQLite interface. Future releases
|
1290 |
** of SQLite may require this. In other words, the behavior exhibited
|
1291 |
** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
|
1292 |
** default behavior in some future release of SQLite.
|
1293 |
**
|
1294 |
** The sqlite3_os_init() routine does operating-system specific
|
1295 |
** initialization of the SQLite library. The sqlite3_os_end()
|
1296 |
** routine undoes the effect of sqlite3_os_init(). Typical tasks
|
1297 |
** performed by these routines include allocation or deallocation
|
1298 |
** of static resources, initialization of global variables,
|
1299 |
** setting up a default [sqlite3_vfs] module, or setting up
|
1300 |
** a default configuration using [sqlite3_config()].
|
1301 |
**
|
1302 |
** The application should never invoke either sqlite3_os_init()
|
1303 |
** or sqlite3_os_end() directly. The application should only invoke
|
1304 |
** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
|
1305 |
** interface is called automatically by sqlite3_initialize() and
|
1306 |
** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
|
1307 |
** implementations for sqlite3_os_init() and sqlite3_os_end()
|
1308 |
** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
|
1309 |
** When [custom builds | built for other platforms]
|
1310 |
** (using the [SQLITE_OS_OTHER=1] compile-time
|
1311 |
** option) the application must supply a suitable implementation for
|
1312 |
** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
|
1313 |
** implementation of sqlite3_os_init() or sqlite3_os_end()
|
1314 |
** must return [SQLITE_OK] on success and some other [error code] upon
|
1315 |
** failure.
|
1316 |
*/
|
1317 |
SQLITE_API int sqlite3_initialize(void); |
1318 |
SQLITE_API int sqlite3_shutdown(void); |
1319 |
SQLITE_API int sqlite3_os_init(void); |
1320 |
SQLITE_API int sqlite3_os_end(void); |
1321 |
|
1322 |
/*
|
1323 |
** CAPI3REF: Configuring The SQLite Library
|
1324 |
**
|
1325 |
** The sqlite3_config() interface is used to make global configuration
|
1326 |
** changes to SQLite in order to tune SQLite to the specific needs of
|
1327 |
** the application. The default configuration is recommended for most
|
1328 |
** applications and so this routine is usually not necessary. It is
|
1329 |
** provided to support rare applications with unusual needs.
|
1330 |
**
|
1331 |
** The sqlite3_config() interface is not threadsafe. The application
|
1332 |
** must insure that no other SQLite interfaces are invoked by other
|
1333 |
** threads while sqlite3_config() is running. Furthermore, sqlite3_config()
|
1334 |
** may only be invoked prior to library initialization using
|
1335 |
** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
|
1336 |
** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
|
1337 |
** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
|
1338 |
** Note, however, that ^sqlite3_config() can be called as part of the
|
1339 |
** implementation of an application-defined [sqlite3_os_init()].
|
1340 |
**
|
1341 |
** The first argument to sqlite3_config() is an integer
|
1342 |
** [configuration option] that determines
|
1343 |
** what property of SQLite is to be configured. Subsequent arguments
|
1344 |
** vary depending on the [configuration option]
|
1345 |
** in the first argument.
|
1346 |
**
|
1347 |
** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
|
1348 |
** ^If the option is unknown or SQLite is unable to set the option
|
1349 |
** then this routine returns a non-zero [error code].
|
1350 |
*/
|
1351 |
SQLITE_API int sqlite3_config(int, ...); |
1352 |
|
1353 |
/*
|
1354 |
** CAPI3REF: Configure database connections
|
1355 |
**
|
1356 |
** The sqlite3_db_config() interface is used to make configuration
|
1357 |
** changes to a [database connection]. The interface is similar to
|
1358 |
** [sqlite3_config()] except that the changes apply to a single
|
1359 |
** [database connection] (specified in the first argument).
|
1360 |
**
|
1361 |
** The second argument to sqlite3_db_config(D,V,...) is the
|
1362 |
** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
|
1363 |
** that indicates what aspect of the [database connection] is being configured.
|
1364 |
** Subsequent arguments vary depending on the configuration verb.
|
1365 |
**
|
1366 |
** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
|
1367 |
** the call is considered successful.
|
1368 |
*/
|
1369 |
SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); |
1370 |
|
1371 |
/*
|
1372 |
** CAPI3REF: Memory Allocation Routines
|
1373 |
**
|
1374 |
** An instance of this object defines the interface between SQLite
|
1375 |
** and low-level memory allocation routines.
|
1376 |
**
|
1377 |
** This object is used in only one place in the SQLite interface.
|
1378 |
** A pointer to an instance of this object is the argument to
|
1379 |
** [sqlite3_config()] when the configuration option is
|
1380 |
** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
|
1381 |
** By creating an instance of this object
|
1382 |
** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
|
1383 |
** during configuration, an application can specify an alternative
|
1384 |
** memory allocation subsystem for SQLite to use for all of its
|
1385 |
** dynamic memory needs.
|
1386 |
**
|
1387 |
** Note that SQLite comes with several [built-in memory allocators]
|
1388 |
** that are perfectly adequate for the overwhelming majority of applications
|
1389 |
** and that this object is only useful to a tiny minority of applications
|
1390 |
** with specialized memory allocation requirements. This object is
|
1391 |
** also used during testing of SQLite in order to specify an alternative
|
1392 |
** memory allocator that simulates memory out-of-memory conditions in
|
1393 |
** order to verify that SQLite recovers gracefully from such
|
1394 |
** conditions.
|
1395 |
**
|
1396 |
** The xMalloc, xRealloc, and xFree methods must work like the
|
1397 |
** malloc(), realloc() and free() functions from the standard C library.
|
1398 |
** ^SQLite guarantees that the second argument to
|
1399 |
** xRealloc is always a value returned by a prior call to xRoundup.
|
1400 |
**
|
1401 |
** xSize should return the allocated size of a memory allocation
|
1402 |
** previously obtained from xMalloc or xRealloc. The allocated size
|
1403 |
** is always at least as big as the requested size but may be larger.
|
1404 |
**
|
1405 |
** The xRoundup method returns what would be the allocated size of
|
1406 |
** a memory allocation given a particular requested size. Most memory
|
1407 |
** allocators round up memory allocations at least to the next multiple
|
1408 |
** of 8. Some allocators round up to a larger multiple or to a power of 2.
|
1409 |
** Every memory allocation request coming in through [sqlite3_malloc()]
|
1410 |
** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
|
1411 |
** that causes the corresponding memory allocation to fail.
|
1412 |
**
|
1413 |
** The xInit method initializes the memory allocator. For example,
|
1414 |
** it might allocate any require mutexes or initialize internal data
|
1415 |
** structures. The xShutdown method is invoked (indirectly) by
|
1416 |
** [sqlite3_shutdown()] and should deallocate any resources acquired
|
1417 |
** by xInit. The pAppData pointer is used as the only parameter to
|
1418 |
** xInit and xShutdown.
|
1419 |
**
|
1420 |
** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
|
1421 |
** the xInit method, so the xInit method need not be threadsafe. The
|
1422 |
** xShutdown method is only called from [sqlite3_shutdown()] so it does
|
1423 |
** not need to be threadsafe either. For all other methods, SQLite
|
1424 |
** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
|
1425 |
** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
|
1426 |
** it is by default) and so the methods are automatically serialized.
|
1427 |
** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
|
1428 |
** methods must be threadsafe or else make their own arrangements for
|
1429 |
** serialization.
|
1430 |
**
|
1431 |
** SQLite will never invoke xInit() more than once without an intervening
|
1432 |
** call to xShutdown().
|
1433 |
*/
|
1434 |
typedef struct sqlite3_mem_methods sqlite3_mem_methods; |
1435 |
struct sqlite3_mem_methods {
|
1436 |
void *(*xMalloc)(int); /* Memory allocation function */ |
1437 |
void (*xFree)(void*); /* Free a prior allocation */ |
1438 |
void *(*xRealloc)(void*,int); /* Resize an allocation */ |
1439 |
int (*xSize)(void*); /* Return the size of an allocation */ |
1440 |
int (*xRoundup)(int); /* Round up request size to allocation size */ |
1441 |
int (*xInit)(void*); /* Initialize the memory allocator */ |
1442 |
void (*xShutdown)(void*); /* Deinitialize the memory allocator */ |
1443 |
void *pAppData; /* Argument to xInit() and xShutdown() */ |
1444 |
}; |
1445 |
|
1446 |
/*
|
1447 |
** CAPI3REF: Configuration Options
|
1448 |
** KEYWORDS: {configuration option}
|
1449 |
**
|
1450 |
** These constants are the available integer configuration options that
|
1451 |
** can be passed as the first argument to the [sqlite3_config()] interface.
|
1452 |
**
|
1453 |
** New configuration options may be added in future releases of SQLite.
|
1454 |
** Existing configuration options might be discontinued. Applications
|
1455 |
** should check the return code from [sqlite3_config()] to make sure that
|
1456 |
** the call worked. The [sqlite3_config()] interface will return a
|
1457 |
** non-zero [error code] if a discontinued or unsupported configuration option
|
1458 |
** is invoked.
|
1459 |
**
|
1460 |
** <dl>
|
1461 |
** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
|
1462 |
** <dd>There are no arguments to this option. ^This option sets the
|
1463 |
** [threading mode] to Single-thread. In other words, it disables
|
1464 |
** all mutexing and puts SQLite into a mode where it can only be used
|
1465 |
** by a single thread. ^If SQLite is compiled with
|
1466 |
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
|
1467 |
** it is not possible to change the [threading mode] from its default
|
1468 |
** value of Single-thread and so [sqlite3_config()] will return
|
1469 |
** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
|
1470 |
** configuration option.</dd>
|
1471 |
**
|
1472 |
** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
|
1473 |
** <dd>There are no arguments to this option. ^This option sets the
|
1474 |
** [threading mode] to Multi-thread. In other words, it disables
|
1475 |
** mutexing on [database connection] and [prepared statement] objects.
|
1476 |
** The application is responsible for serializing access to
|
1477 |
** [database connections] and [prepared statements]. But other mutexes
|
1478 |
** are enabled so that SQLite will be safe to use in a multi-threaded
|
1479 |
** environment as long as no two threads attempt to use the same
|
1480 |
** [database connection] at the same time. ^If SQLite is compiled with
|
1481 |
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
|
1482 |
** it is not possible to set the Multi-thread [threading mode] and
|
1483 |
** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
|
1484 |
** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
|
1485 |
**
|
1486 |
** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
|
1487 |
** <dd>There are no arguments to this option. ^This option sets the
|
1488 |
** [threading mode] to Serialized. In other words, this option enables
|
1489 |
** all mutexes including the recursive
|
1490 |
** mutexes on [database connection] and [prepared statement] objects.
|
1491 |
** In this mode (which is the default when SQLite is compiled with
|
1492 |
** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
|
1493 |
** to [database connections] and [prepared statements] so that the
|
1494 |
** application is free to use the same [database connection] or the
|
1495 |
** same [prepared statement] in different threads at the same time.
|
1496 |
** ^If SQLite is compiled with
|
1497 |
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
|
1498 |
** it is not possible to set the Serialized [threading mode] and
|
1499 |
** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
|
1500 |
** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
|
1501 |
**
|
1502 |
** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
|
1503 |
** <dd> ^(This option takes a single argument which is a pointer to an
|
1504 |
** instance of the [sqlite3_mem_methods] structure. The argument specifies
|
1505 |
** alternative low-level memory allocation routines to be used in place of
|
1506 |
** the memory allocation routines built into SQLite.)^ ^SQLite makes
|
1507 |
** its own private copy of the content of the [sqlite3_mem_methods] structure
|
1508 |
** before the [sqlite3_config()] call returns.</dd>
|
1509 |
**
|
1510 |
** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
|
1511 |
** <dd> ^(This option takes a single argument which is a pointer to an
|
1512 |
** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods]
|
1513 |
** structure is filled with the currently defined memory allocation routines.)^
|
1514 |
** This option can be used to overload the default memory allocation
|
1515 |
** routines with a wrapper that simulations memory allocation failure or
|
1516 |
** tracks memory usage, for example. </dd>
|
1517 |
**
|
1518 |
** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
|
1519 |
** <dd> ^This option takes single argument of type int, interpreted as a
|
1520 |
** boolean, which enables or disables the collection of memory allocation
|
1521 |
** statistics. ^(When memory allocation statistics are disabled, the
|
1522 |
** following SQLite interfaces become non-operational:
|
1523 |
** <ul>
|
1524 |
** <li> [sqlite3_memory_used()]
|
1525 |
** <li> [sqlite3_memory_highwater()]
|
1526 |
** <li> [sqlite3_soft_heap_limit64()]
|
1527 |
** <li> [sqlite3_status()]
|
1528 |
** </ul>)^
|
1529 |
** ^Memory allocation statistics are enabled by default unless SQLite is
|
1530 |
** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
|
1531 |
** allocation statistics are disabled by default.
|
1532 |
** </dd>
|
1533 |
**
|
1534 |
** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
|
1535 |
** <dd> ^This option specifies a static memory buffer that SQLite can use for
|
1536 |
** scratch memory. There are three arguments: A pointer an 8-byte
|
1537 |
** aligned memory buffer from which the scratch allocations will be
|
1538 |
** drawn, the size of each scratch allocation (sz),
|
1539 |
** and the maximum number of scratch allocations (N). The sz
|
1540 |
** argument must be a multiple of 16.
|
1541 |
** The first argument must be a pointer to an 8-byte aligned buffer
|
1542 |
** of at least sz*N bytes of memory.
|
1543 |
** ^SQLite will use no more than two scratch buffers per thread. So
|
1544 |
** N should be set to twice the expected maximum number of threads.
|
1545 |
** ^SQLite will never require a scratch buffer that is more than 6
|
1546 |
** times the database page size. ^If SQLite needs needs additional
|
1547 |
** scratch memory beyond what is provided by this configuration option, then
|
1548 |
** [sqlite3_malloc()] will be used to obtain the memory needed.</dd>
|
1549 |
**
|
1550 |
** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
|
1551 |
** <dd> ^This option specifies a static memory buffer that SQLite can use for
|
1552 |
** the database page cache with the default page cache implementation.
|
1553 |
** This configuration should not be used if an application-define page
|
1554 |
** cache implementation is loaded using the SQLITE_CONFIG_PCACHE2 option.
|
1555 |
** There are three arguments to this option: A pointer to 8-byte aligned
|
1556 |
** memory, the size of each page buffer (sz), and the number of pages (N).
|
1557 |
** The sz argument should be the size of the largest database page
|
1558 |
** (a power of two between 512 and 32768) plus a little extra for each
|
1559 |
** page header. ^The page header size is 20 to 40 bytes depending on
|
1560 |
** the host architecture. ^It is harmless, apart from the wasted memory,
|
1561 |
** to make sz a little too large. The first
|
1562 |
** argument should point to an allocation of at least sz*N bytes of memory.
|
1563 |
** ^SQLite will use the memory provided by the first argument to satisfy its
|
1564 |
** memory needs for the first N pages that it adds to cache. ^If additional
|
1565 |
** page cache memory is needed beyond what is provided by this option, then
|
1566 |
** SQLite goes to [sqlite3_malloc()] for the additional storage space.
|
1567 |
** The pointer in the first argument must
|
1568 |
** be aligned to an 8-byte boundary or subsequent behavior of SQLite
|
1569 |
** will be undefined.</dd>
|
1570 |
**
|
1571 |
** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
|
1572 |
** <dd> ^This option specifies a static memory buffer that SQLite will use
|
1573 |
** for all of its dynamic memory allocation needs beyond those provided
|
1574 |
** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE].
|
1575 |
** There are three arguments: An 8-byte aligned pointer to the memory,
|
1576 |
** the number of bytes in the memory buffer, and the minimum allocation size.
|
1577 |
** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
|
1578 |
** to using its default memory allocator (the system malloc() implementation),
|
1579 |
** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
|
1580 |
** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or
|
1581 |
** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory
|
1582 |
** allocator is engaged to handle all of SQLites memory allocation needs.
|
1583 |
** The first pointer (the memory pointer) must be aligned to an 8-byte
|
1584 |
** boundary or subsequent behavior of SQLite will be undefined.
|
1585 |
** The minimum allocation size is capped at 2**12. Reasonable values
|
1586 |
** for the minimum allocation size are 2**5 through 2**8.</dd>
|
1587 |
**
|
1588 |
** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
|
1589 |
** <dd> ^(This option takes a single argument which is a pointer to an
|
1590 |
** instance of the [sqlite3_mutex_methods] structure. The argument specifies
|
1591 |
** alternative low-level mutex routines to be used in place
|
1592 |
** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the
|
1593 |
** content of the [sqlite3_mutex_methods] structure before the call to
|
1594 |
** [sqlite3_config()] returns. ^If SQLite is compiled with
|
1595 |
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
|
1596 |
** the entire mutexing subsystem is omitted from the build and hence calls to
|
1597 |
** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
|
1598 |
** return [SQLITE_ERROR].</dd>
|
1599 |
**
|
1600 |
** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
|
1601 |
** <dd> ^(This option takes a single argument which is a pointer to an
|
1602 |
** instance of the [sqlite3_mutex_methods] structure. The
|
1603 |
** [sqlite3_mutex_methods]
|
1604 |
** structure is filled with the currently defined mutex routines.)^
|
1605 |
** This option can be used to overload the default mutex allocation
|
1606 |
** routines with a wrapper used to track mutex usage for performance
|
1607 |
** profiling or testing, for example. ^If SQLite is compiled with
|
1608 |
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
|
1609 |
** the entire mutexing subsystem is omitted from the build and hence calls to
|
1610 |
** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
|
1611 |
** return [SQLITE_ERROR].</dd>
|
1612 |
**
|
1613 |
** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
|
1614 |
** <dd> ^(This option takes two arguments that determine the default
|
1615 |
** memory allocation for the lookaside memory allocator on each
|
1616 |
** [database connection]. The first argument is the
|
1617 |
** size of each lookaside buffer slot and the second is the number of
|
1618 |
** slots allocated to each database connection.)^ ^(This option sets the
|
1619 |
** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
|
1620 |
** verb to [sqlite3_db_config()] can be used to change the lookaside
|
1621 |
** configuration on individual connections.)^ </dd>
|
1622 |
**
|
1623 |
** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
|
1624 |
** <dd> ^(This option takes a single argument which is a pointer to
|
1625 |
** an [sqlite3_pcache_methods2] object. This object specifies the interface
|
1626 |
** to a custom page cache implementation.)^ ^SQLite makes a copy of the
|
1627 |
** object and uses it for page cache memory allocations.</dd>
|
1628 |
**
|
1629 |
** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
|
1630 |
** <dd> ^(This option takes a single argument which is a pointer to an
|
1631 |
** [sqlite3_pcache_methods2] object. SQLite copies of the current
|
1632 |
** page cache implementation into that object.)^ </dd>
|
1633 |
**
|
1634 |
** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
|
1635 |
** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
|
1636 |
** global [error log].
|
1637 |
** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
|
1638 |
** function with a call signature of void(*)(void*,int,const char*),
|
1639 |
** and a pointer to void. ^If the function pointer is not NULL, it is
|
1640 |
** invoked by [sqlite3_log()] to process each logging event. ^If the
|
1641 |
** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
|
1642 |
** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
|
1643 |
** passed through as the first parameter to the application-defined logger
|
1644 |
** function whenever that function is invoked. ^The second parameter to
|
1645 |
** the logger function is a copy of the first parameter to the corresponding
|
1646 |
** [sqlite3_log()] call and is intended to be a [result code] or an
|
1647 |
** [extended result code]. ^The third parameter passed to the logger is
|
1648 |
** log message after formatting via [sqlite3_snprintf()].
|
1649 |
** The SQLite logging interface is not reentrant; the logger function
|
1650 |
** supplied by the application must not invoke any SQLite interface.
|
1651 |
** In a multi-threaded application, the application-defined logger
|
1652 |
** function must be threadsafe. </dd>
|
1653 |
**
|
1654 |
** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
|
1655 |
** <dd>^(This option takes a single argument of type int. If non-zero, then
|
1656 |
** URI handling is globally enabled. If the parameter is zero, then URI handling
|
1657 |
** is globally disabled.)^ ^If URI handling is globally enabled, all filenames
|
1658 |
** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or
|
1659 |
** specified as part of [ATTACH] commands are interpreted as URIs, regardless
|
1660 |
** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
|
1661 |
** connection is opened. ^If it is globally disabled, filenames are
|
1662 |
** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
|
1663 |
** database connection is opened. ^(By default, URI handling is globally
|
1664 |
** disabled. The default value may be changed by compiling with the
|
1665 |
** [SQLITE_USE_URI] symbol defined.)^
|
1666 |
**
|
1667 |
** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
|
1668 |
** <dd>^This option takes a single integer argument which is interpreted as
|
1669 |
** a boolean in order to enable or disable the use of covering indices for
|
1670 |
** full table scans in the query optimizer. ^The default setting is determined
|
1671 |
** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
|
1672 |
** if that compile-time option is omitted.
|
1673 |
** The ability to disable the use of covering indices for full table scans
|
1674 |
** is because some incorrectly coded legacy applications might malfunction
|
1675 |
** when the optimization is enabled. Providing the ability to
|
1676 |
** disable the optimization allows the older, buggy application code to work
|
1677 |
** without change even with newer versions of SQLite.
|
1678 |
**
|
1679 |
** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
|
1680 |
** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
|
1681 |
** <dd> These options are obsolete and should not be used by new code.
|
1682 |
** They are retained for backwards compatibility but are now no-ops.
|
1683 |
** </dd>
|
1684 |
**
|
1685 |
** [[SQLITE_CONFIG_SQLLOG]]
|
1686 |
** <dt>SQLITE_CONFIG_SQLLOG
|
1687 |
** <dd>This option is only available if sqlite is compiled with the
|
1688 |
** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
|
1689 |
** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
|
1690 |
** The second should be of type (void*). The callback is invoked by the library
|
1691 |
** in three separate circumstances, identified by the value passed as the
|
1692 |
** fourth parameter. If the fourth parameter is 0, then the database connection
|
1693 |
** passed as the second argument has just been opened. The third argument
|
1694 |
** points to a buffer containing the name of the main database file. If the
|
1695 |
** fourth parameter is 1, then the SQL statement that the third parameter
|
1696 |
** points to has just been executed. Or, if the fourth parameter is 2, then
|
1697 |
** the connection being passed as the second parameter is being closed. The
|
1698 |
** third parameter is passed NULL In this case. An example of using this
|
1699 |
** configuration option can be seen in the "test_sqllog.c" source file in
|
1700 |
** the canonical SQLite source tree.</dd>
|
1701 |
**
|
1702 |
** [[SQLITE_CONFIG_MMAP_SIZE]]
|
1703 |
** <dt>SQLITE_CONFIG_MMAP_SIZE
|
1704 |
** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
|
1705 |
** that are the default mmap size limit (the default setting for
|
1706 |
** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
|
1707 |
** ^The default setting can be overridden by each database connection using
|
1708 |
** either the [PRAGMA mmap_size] command, or by using the
|
1709 |
** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
|
1710 |
** cannot be changed at run-time. Nor may the maximum allowed mmap size
|
1711 |
** exceed the compile-time maximum mmap size set by the
|
1712 |
** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
|
1713 |
** ^If either argument to this option is negative, then that argument is
|
1714 |
** changed to its compile-time default.
|
1715 |
**
|
1716 |
** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
|
1717 |
** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
|
1718 |
** <dd>^This option is only available if SQLite is compiled for Windows
|
1719 |
** with the [SQLITE_WIN32_MALLOC] pre-processor macro defined.
|
1720 |
** SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
|
1721 |
** that specifies the maximum size of the created heap.
|
1722 |
** </dl>
|
1723 |
*/
|
1724 |
#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ |
1725 |
#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ |
1726 |
#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ |
1727 |
#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ |
1728 |
#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ |
1729 |
#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ |
1730 |
#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ |
1731 |
#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ |
1732 |
#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ |
1733 |
#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ |
1734 |
#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ |
1735 |
/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
|
1736 |
#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ |
1737 |
#define SQLITE_CONFIG_PCACHE 14 /* no-op */ |
1738 |
#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ |
1739 |
#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ |
1740 |
#define SQLITE_CONFIG_URI 17 /* int */ |
1741 |
#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ |
1742 |
#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ |
1743 |
#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ |
1744 |
#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ |
1745 |
#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ |
1746 |
#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ |
1747 |
|
1748 |
/*
|
1749 |
** CAPI3REF: Database Connection Configuration Options
|
1750 |
**
|
1751 |
** These constants are the available integer configuration options that
|
1752 |
** can be passed as the second argument to the [sqlite3_db_config()] interface.
|
1753 |
**
|
1754 |
** New configuration options may be added in future releases of SQLite.
|
1755 |
** Existing configuration options might be discontinued. Applications
|
1756 |
** should check the return code from [sqlite3_db_config()] to make sure that
|
1757 |
** the call worked. ^The [sqlite3_db_config()] interface will return a
|
1758 |
** non-zero [error code] if a discontinued or unsupported configuration option
|
1759 |
** is invoked.
|
1760 |
**
|
1761 |
** <dl>
|
1762 |
** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
|
1763 |
** <dd> ^This option takes three additional arguments that determine the
|
1764 |
** [lookaside memory allocator] configuration for the [database connection].
|
1765 |
** ^The first argument (the third parameter to [sqlite3_db_config()] is a
|
1766 |
** pointer to a memory buffer to use for lookaside memory.
|
1767 |
** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
|
1768 |
** may be NULL in which case SQLite will allocate the
|
1769 |
** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
|
1770 |
** size of each lookaside buffer slot. ^The third argument is the number of
|
1771 |
** slots. The size of the buffer in the first argument must be greater than
|
1772 |
** or equal to the product of the second and third arguments. The buffer
|
1773 |
** must be aligned to an 8-byte boundary. ^If the second argument to
|
1774 |
** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
|
1775 |
** rounded down to the next smaller multiple of 8. ^(The lookaside memory
|
1776 |
** configuration for a database connection can only be changed when that
|
1777 |
** connection is not currently using lookaside memory, or in other words
|
1778 |
** when the "current value" returned by
|
1779 |
** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
|
1780 |
** Any attempt to change the lookaside memory configuration when lookaside
|
1781 |
** memory is in use leaves the configuration unchanged and returns
|
1782 |
** [SQLITE_BUSY].)^</dd>
|
1783 |
**
|
1784 |
** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
|
1785 |
** <dd> ^This option is used to enable or disable the enforcement of
|
1786 |
** [foreign key constraints]. There should be two additional arguments.
|
1787 |
** The first argument is an integer which is 0 to disable FK enforcement,
|
1788 |
** positive to enable FK enforcement or negative to leave FK enforcement
|
1789 |
** unchanged. The second parameter is a pointer to an integer into which
|
1790 |
** is written 0 or 1 to indicate whether FK enforcement is off or on
|
1791 |
** following this call. The second parameter may be a NULL pointer, in
|
1792 |
** which case the FK enforcement setting is not reported back. </dd>
|
1793 |
**
|
1794 |
** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
|
1795 |
** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
|
1796 |
** There should be two additional arguments.
|
1797 |
** The first argument is an integer which is 0 to disable triggers,
|
1798 |
** positive to enable triggers or negative to leave the setting unchanged.
|
1799 |
** The second parameter is a pointer to an integer into which
|
1800 |
** is written 0 or 1 to indicate whether triggers are disabled or enabled
|
1801 |
** following this call. The second parameter may be a NULL pointer, in
|
1802 |
** which case the trigger setting is not reported back. </dd>
|
1803 |
**
|
1804 |
** </dl>
|
1805 |
*/
|
1806 |
#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ |
1807 |
#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ |
1808 |
#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ |
1809 |
|
1810 |
|
1811 |
/*
|
1812 |
** CAPI3REF: Enable Or Disable Extended Result Codes
|
1813 |
**
|
1814 |
** ^The sqlite3_extended_result_codes() routine enables or disables the
|
1815 |
** [extended result codes] feature of SQLite. ^The extended result
|
1816 |
** codes are disabled by default for historical compatibility.
|
1817 |
*/
|
1818 |
SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); |
1819 |
|
1820 |
/*
|
1821 |
** CAPI3REF: Last Insert Rowid
|
1822 |
**
|
1823 |
** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
|
1824 |
** has a unique 64-bit signed
|
1825 |
** integer key called the [ROWID | "rowid"]. ^The rowid is always available
|
1826 |
** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
|
1827 |
** names are not also used by explicitly declared columns. ^If
|
1828 |
** the table has a column of type [INTEGER PRIMARY KEY] then that column
|
1829 |
** is another alias for the rowid.
|
1830 |
**
|
1831 |
** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the
|
1832 |
** most recent successful [INSERT] into a rowid table or [virtual table]
|
1833 |
** on database connection D.
|
1834 |
** ^Inserts into [WITHOUT ROWID] tables are not recorded.
|
1835 |
** ^If no successful [INSERT]s into rowid tables
|
1836 |
** have ever occurred on the database connection D,
|
1837 |
** then sqlite3_last_insert_rowid(D) returns zero.
|
1838 |
**
|
1839 |
** ^(If an [INSERT] occurs within a trigger or within a [virtual table]
|
1840 |
** method, then this routine will return the [rowid] of the inserted
|
1841 |
** row as long as the trigger or virtual table method is running.
|
1842 |
** But once the trigger or virtual table method ends, the value returned
|
1843 |
** by this routine reverts to what it was before the trigger or virtual
|
1844 |
** table method began.)^
|
1845 |
**
|
1846 |
** ^An [INSERT] that fails due to a constraint violation is not a
|
1847 |
** successful [INSERT] and does not change the value returned by this
|
1848 |
** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
|
1849 |
** and INSERT OR ABORT make no changes to the return value of this
|
1850 |
** routine when their insertion fails. ^(When INSERT OR REPLACE
|
1851 |
** encounters a constraint violation, it does not fail. The
|
1852 |
** INSERT continues to completion after deleting rows that caused
|
1853 |
** the constraint problem so INSERT OR REPLACE will always change
|
1854 |
** the return value of this interface.)^
|
1855 |
**
|
1856 |
** ^For the purposes of this routine, an [INSERT] is considered to
|
1857 |
** be successful even if it is subsequently rolled back.
|
1858 |
**
|
1859 |
** This function is accessible to SQL statements via the
|
1860 |
** [last_insert_rowid() SQL function].
|
1861 |
**
|
1862 |
** If a separate thread performs a new [INSERT] on the same
|
1863 |
** database connection while the [sqlite3_last_insert_rowid()]
|
1864 |
** function is running and thus changes the last insert [rowid],
|
1865 |
** then the value returned by [sqlite3_last_insert_rowid()] is
|
1866 |
** unpredictable and might not equal either the old or the new
|
1867 |
** last insert [rowid].
|
1868 |
*/
|
1869 |
SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); |
1870 |
|
1871 |
/*
|
1872 |
** CAPI3REF: Count The Number Of Rows Modified
|
1873 |
**
|
1874 |
** ^This function returns the number of database rows that were changed
|
1875 |
** or inserted or deleted by the most recently completed SQL statement
|
1876 |
** on the [database connection] specified by the first parameter.
|
1877 |
** ^(Only changes that are directly specified by the [INSERT], [UPDATE],
|
1878 |
** or [DELETE] statement are counted. Auxiliary changes caused by
|
1879 |
** triggers or [foreign key actions] are not counted.)^ Use the
|
1880 |
** [sqlite3_total_changes()] function to find the total number of changes
|
1881 |
** including changes caused by triggers and foreign key actions.
|
1882 |
**
|
1883 |
** ^Changes to a view that are simulated by an [INSTEAD OF trigger]
|
1884 |
** are not counted. Only real table changes are counted.
|
1885 |
**
|
1886 |
** ^(A "row change" is a change to a single row of a single table
|
1887 |
** caused by an INSERT, DELETE, or UPDATE statement. Rows that
|
1888 |
** are changed as side effects of [REPLACE] constraint resolution,
|
1889 |
** rollback, ABORT processing, [DROP TABLE], or by any other
|
1890 |
** mechanisms do not count as direct row changes.)^
|
1891 |
**
|
1892 |
** A "trigger context" is a scope of execution that begins and
|
1893 |
** ends with the script of a [CREATE TRIGGER | trigger].
|
1894 |
** Most SQL statements are
|
1895 |
** evaluated outside of any trigger. This is the "top level"
|
1896 |
** trigger context. If a trigger fires from the top level, a
|
1897 |
** new trigger context is entered for the duration of that one
|
1898 |
** trigger. Subtriggers create subcontexts for their duration.
|
1899 |
**
|
1900 |
** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does
|
1901 |
** not create a new trigger context.
|
1902 |
**
|
1903 |
** ^This function returns the number of direct row changes in the
|
1904 |
** most recent INSERT, UPDATE, or DELETE statement within the same
|
1905 |
** trigger context.
|
1906 |
**
|
1907 |
** ^Thus, when called from the top level, this function returns the
|
1908 |
** number of changes in the most recent INSERT, UPDATE, or DELETE
|
1909 |
** that also occurred at the top level. ^(Within the body of a trigger,
|
1910 |
** the sqlite3_changes() interface can be called to find the number of
|
1911 |
** changes in the most recently completed INSERT, UPDATE, or DELETE
|
1912 |
** statement within the body of the same trigger.
|
1913 |
** However, the number returned does not include changes
|
1914 |
** caused by subtriggers since those have their own context.)^
|
1915 |
**
|
1916 |
** See also the [sqlite3_total_changes()] interface, the
|
1917 |
** [count_changes pragma], and the [changes() SQL function].
|
1918 |
**
|
1919 |
** If a separate thread makes changes on the same database connection
|
1920 |
** while [sqlite3_changes()] is running then the value returned
|
1921 |
** is unpredictable and not meaningful.
|
1922 |
*/
|
1923 |
SQLITE_API int sqlite3_changes(sqlite3*);
|
1924 |
|
1925 |
/*
|
1926 |
** CAPI3REF: Total Number Of Rows Modified
|
1927 |
**
|
1928 |
** ^This function returns the number of row changes caused by [INSERT],
|
1929 |
** [UPDATE] or [DELETE] statements since the [database connection] was opened.
|
1930 |
** ^(The count returned by sqlite3_total_changes() includes all changes
|
1931 |
** from all [CREATE TRIGGER | trigger] contexts and changes made by
|
1932 |
** [foreign key actions]. However,
|
1933 |
** the count does not include changes used to implement [REPLACE] constraints,
|
1934 |
** do rollbacks or ABORT processing, or [DROP TABLE] processing. The
|
1935 |
** count does not include rows of views that fire an [INSTEAD OF trigger],
|
1936 |
** though if the INSTEAD OF trigger makes changes of its own, those changes
|
1937 |
** are counted.)^
|
1938 |
** ^The sqlite3_total_changes() function counts the changes as soon as
|
1939 |
** the statement that makes them is completed (when the statement handle
|
1940 |
** is passed to [sqlite3_reset()] or [sqlite3_finalize()]).
|
1941 |
**
|
1942 |
** See also the [sqlite3_changes()] interface, the
|
1943 |
** [count_changes pragma], and the [total_changes() SQL function].
|
1944 |
**
|
1945 |
** If a separate thread makes changes on the same database connection
|
1946 |
** while [sqlite3_total_changes()] is running then the value
|
1947 |
** returned is unpredictable and not meaningful.
|
1948 |
*/
|
1949 |
SQLITE_API int sqlite3_total_changes(sqlite3*);
|
1950 |
|
1951 |
/*
|
1952 |
** CAPI3REF: Interrupt A Long-Running Query
|
1953 |
**
|
1954 |
** ^This function causes any pending database operation to abort and
|
1955 |
** return at its earliest opportunity. This routine is typically
|
1956 |
** called in response to a user action such as pressing "Cancel"
|
1957 |
** or Ctrl-C where the user wants a long query operation to halt
|
1958 |
** immediately.
|
1959 |
**
|
1960 |
** ^It is safe to call this routine from a thread different from the
|
1961 |
** thread that is currently running the database operation. But it
|
1962 |
** is not safe to call this routine with a [database connection] that
|
1963 |
** is closed or might close before sqlite3_interrupt() returns.
|
1964 |
**
|
1965 |
** ^If an SQL operation is very nearly finished at the time when
|
1966 |
** sqlite3_interrupt() is called, then it might not have an opportunity
|
1967 |
** to be interrupted and might continue to completion.
|
1968 |
**
|
1969 |
** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
|
1970 |
** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
|
1971 |
** that is inside an explicit transaction, then the entire transaction
|
1972 |
** will be rolled back automatically.
|
1973 |
**
|
1974 |
** ^The sqlite3_interrupt(D) call is in effect until all currently running
|
1975 |
** SQL statements on [database connection] D complete. ^Any new SQL statements
|
1976 |
** that are started after the sqlite3_interrupt() call and before the
|
1977 |
** running statements reaches zero are interrupted as if they had been
|
1978 |
** running prior to the sqlite3_interrupt() call. ^New SQL statements
|
1979 |
** that are started after the running statement count reaches zero are
|
1980 |
** not effected by the sqlite3_interrupt().
|
1981 |
** ^A call to sqlite3_interrupt(D) that occurs when there are no running
|
1982 |
** SQL statements is a no-op and has no effect on SQL statements
|
1983 |
** that are started after the sqlite3_interrupt() call returns.
|
1984 |
**
|
1985 |
** If the database connection closes while [sqlite3_interrupt()]
|
1986 |
** is running then bad things will likely happen.
|
1987 |
*/
|
1988 |
SQLITE_API void sqlite3_interrupt(sqlite3*);
|
1989 |
|
1990 |
/*
|
1991 |
** CAPI3REF: Determine If An SQL Statement Is Complete
|
1992 |
**
|
1993 |
** These routines are useful during command-line input to determine if the
|
1994 |
** currently entered text seems to form a complete SQL statement or
|
1995 |
** if additional input is needed before sending the text into
|
1996 |
** SQLite for parsing. ^These routines return 1 if the input string
|
1997 |
** appears to be a complete SQL statement. ^A statement is judged to be
|
1998 |
** complete if it ends with a semicolon token and is not a prefix of a
|
1999 |
** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
|
2000 |
** string literals or quoted identifier names or comments are not
|
2001 |
** independent tokens (they are part of the token in which they are
|
2002 |
** embedded) and thus do not count as a statement terminator. ^Whitespace
|
2003 |
** and comments that follow the final semicolon are ignored.
|
2004 |
**
|
2005 |
** ^These routines return 0 if the statement is incomplete. ^If a
|
2006 |
** memory allocation fails, then SQLITE_NOMEM is returned.
|
2007 |
**
|
2008 |
** ^These routines do not parse the SQL statements thus
|
2009 |
** will not detect syntactically incorrect SQL.
|
2010 |
**
|
2011 |
** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
|
2012 |
** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
|
2013 |
** automatically by sqlite3_complete16(). If that initialization fails,
|
2014 |
** then the return value from sqlite3_complete16() will be non-zero
|
2015 |
** regardless of whether or not the input SQL is complete.)^
|
2016 |
**
|
2017 |
** The input to [sqlite3_complete()] must be a zero-terminated
|
2018 |
** UTF-8 string.
|
2019 |
**
|
2020 |
** The input to [sqlite3_complete16()] must be a zero-terminated
|
2021 |
** UTF-16 string in native byte order.
|
2022 |
*/
|
2023 |
SQLITE_API int sqlite3_complete(const char *sql); |
2024 |
SQLITE_API int sqlite3_complete16(const void *sql); |
2025 |
|
2026 |
/*
|
2027 |
** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
|
2028 |
**
|
2029 |
** ^This routine sets a callback function that might be invoked whenever
|
2030 |
** an attempt is made to open a database table that another thread
|
2031 |
** or process has locked.
|
2032 |
**
|
2033 |
** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]
|
2034 |
** is returned immediately upon encountering the lock. ^If the busy callback
|
2035 |
** is not NULL, then the callback might be invoked with two arguments.
|
2036 |
**
|
2037 |
** ^The first argument to the busy handler is a copy of the void* pointer which
|
2038 |
** is the third argument to sqlite3_busy_handler(). ^The second argument to
|
2039 |
** the busy handler callback is the number of times that the busy handler has
|
2040 |
** been invoked for this locking event. ^If the
|
2041 |
** busy callback returns 0, then no additional attempts are made to
|
2042 |
** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.
|
2043 |
** ^If the callback returns non-zero, then another attempt
|
2044 |
** is made to open the database for reading and the cycle repeats.
|
2045 |
**
|
2046 |
** The presence of a busy handler does not guarantee that it will be invoked
|
2047 |
** when there is lock contention. ^If SQLite determines that invoking the busy
|
2048 |
** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
|
2049 |
** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler.
|
2050 |
** Consider a scenario where one process is holding a read lock that
|
2051 |
** it is trying to promote to a reserved lock and
|
2052 |
** a second process is holding a reserved lock that it is trying
|
2053 |
** to promote to an exclusive lock. The first process cannot proceed
|
2054 |
** because it is blocked by the second and the second process cannot
|
2055 |
** proceed because it is blocked by the first. If both processes
|
2056 |
** invoke the busy handlers, neither will make any progress. Therefore,
|
2057 |
** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
|
2058 |
** will induce the first process to release its read lock and allow
|
2059 |
** the second process to proceed.
|
2060 |
**
|
2061 |
** ^The default busy callback is NULL.
|
2062 |
**
|
2063 |
** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED]
|
2064 |
** when SQLite is in the middle of a large transaction where all the
|
2065 |
** changes will not fit into the in-memory cache. SQLite will
|
2066 |
** already hold a RESERVED lock on the database file, but it needs
|
2067 |
** to promote this lock to EXCLUSIVE so that it can spill cache
|
2068 |
** pages into the database file without harm to concurrent
|
2069 |
** readers. ^If it is unable to promote the lock, then the in-memory
|
2070 |
** cache will be left in an inconsistent state and so the error
|
2071 |
** code is promoted from the relatively benign [SQLITE_BUSY] to
|
2072 |
** the more severe [SQLITE_IOERR_BLOCKED]. ^This error code promotion
|
2073 |
** forces an automatic rollback of the changes. See the
|
2074 |
** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError">
|
2075 |
** CorruptionFollowingBusyError</a> wiki page for a discussion of why
|
2076 |
** this is important.
|
2077 |
**
|
2078 |
** ^(There can only be a single busy handler defined for each
|
2079 |
** [database connection]. Setting a new busy handler clears any
|
2080 |
** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
|
2081 |
** will also set or clear the busy handler.
|
2082 |
**
|
2083 |
** The busy callback should not take any actions which modify the
|
2084 |
** database connection that invoked the busy handler. Any such actions
|
2085 |
** result in undefined behavior.
|
2086 |
**
|
2087 |
** A busy handler must not close the database connection
|
2088 |
** or [prepared statement] that invoked the busy handler.
|
2089 |
*/
|
2090 |
SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); |
2091 |
|
2092 |
/*
|
2093 |
** CAPI3REF: Set A Busy Timeout
|
2094 |
**
|
2095 |
** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
|
2096 |
** for a specified amount of time when a table is locked. ^The handler
|
2097 |
** will sleep multiple times until at least "ms" milliseconds of sleeping
|
2098 |
** have accumulated. ^After at least "ms" milliseconds of sleeping,
|
2099 |
** the handler returns 0 which causes [sqlite3_step()] to return
|
2100 |
** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
|
2101 |
**
|
2102 |
** ^Calling this routine with an argument less than or equal to zero
|
2103 |
** turns off all busy handlers.
|
2104 |
**
|
2105 |
** ^(There can only be a single busy handler for a particular
|
2106 |
** [database connection] any any given moment. If another busy handler
|
2107 |
** was defined (using [sqlite3_busy_handler()]) prior to calling
|
2108 |
** this routine, that other busy handler is cleared.)^
|
2109 |
*/
|
2110 |
SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); |
2111 |
|
2112 |
/*
|
2113 |
** CAPI3REF: Convenience Routines For Running Queries
|
2114 |
**
|
2115 |
** This is a legacy interface that is preserved for backwards compatibility.
|
2116 |
** Use of this interface is not recommended.
|
2117 |
**
|
2118 |
** Definition: A <b>result table</b> is memory data structure created by the
|
2119 |
** [sqlite3_get_table()] interface. A result table records the
|
2120 |
** complete query results from one or more queries.
|
2121 |
**
|
2122 |
** The table conceptually has a number of rows and columns. But
|
2123 |
** these numbers are not part of the result table itself. These
|
2124 |
** numbers are obtained separately. Let N be the number of rows
|
2125 |
** and M be the number of columns.
|
2126 |
**
|
2127 |
** A result table is an array of pointers to zero-terminated UTF-8 strings.
|
2128 |
** There are (N+1)*M elements in the array. The first M pointers point
|
2129 |
** to zero-terminated strings that contain the names of the columns.
|
2130 |
** The remaining entries all point to query results. NULL values result
|
2131 |
** in NULL pointers. All other values are in their UTF-8 zero-terminated
|
2132 |
** string representation as returned by [sqlite3_column_text()].
|
2133 |
**
|
2134 |
** A result table might consist of one or more memory allocations.
|
2135 |
** It is not safe to pass a result table directly to [sqlite3_free()].
|
2136 |
** A result table should be deallocated using [sqlite3_free_table()].
|
2137 |
**
|
2138 |
** ^(As an example of the result table format, suppose a query result
|
2139 |
** is as follows:
|
2140 |
**
|
2141 |
** <blockquote><pre>
|
2142 |
** Name | Age
|
2143 |
** -----------------------
|
2144 |
** Alice | 43
|
2145 |
** Bob | 28
|
2146 |
** Cindy | 21
|
2147 |
** </pre></blockquote>
|
2148 |
**
|
2149 |
** There are two column (M==2) and three rows (N==3). Thus the
|
2150 |
** result table has 8 entries. Suppose the result table is stored
|
2151 |
** in an array names azResult. Then azResult holds this content:
|
2152 |
**
|
2153 |
** <blockquote><pre>
|
2154 |
** azResult[0] = "Name";
|
2155 |
** azResult[1] = "Age";
|
2156 |
** azResult[2] = "Alice";
|
2157 |
** azResult[3] = "43";
|
2158 |
** azResult[4] = "Bob";
|
2159 |
** azResult[5] = "28";
|
2160 |
** azResult[6] = "Cindy";
|
2161 |
** azResult[7] = "21";
|
2162 |
** </pre></blockquote>)^
|
2163 |
**
|
2164 |
** ^The sqlite3_get_table() function evaluates one or more
|
2165 |
** semicolon-separated SQL statements in the zero-terminated UTF-8
|
2166 |
** string of its 2nd parameter and returns a result table to the
|
2167 |
** pointer given in its 3rd parameter.
|
2168 |
**
|
2169 |
** After the application has finished with the result from sqlite3_get_table(),
|
2170 |
** it must pass the result table pointer to sqlite3_free_table() in order to
|
2171 |
** release the memory that was malloced. Because of the way the
|
2172 |
** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
|
2173 |
** function must not try to call [sqlite3_free()] directly. Only
|
2174 |
** [sqlite3_free_table()] is able to release the memory properly and safely.
|
2175 |
**
|
2176 |
** The sqlite3_get_table() interface is implemented as a wrapper around
|
2177 |
** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
|
2178 |
** to any internal data structures of SQLite. It uses only the public
|
2179 |
** interface defined here. As a consequence, errors that occur in the
|
2180 |
** wrapper layer outside of the internal [sqlite3_exec()] call are not
|
2181 |
** reflected in subsequent calls to [sqlite3_errcode()] or
|
2182 |
** [sqlite3_errmsg()].
|
2183 |
*/
|
2184 |
SQLITE_API int sqlite3_get_table(
|
2185 |
sqlite3 *db, /* An open database */
|
2186 |
const char *zSql, /* SQL to be evaluated */ |
2187 |
char ***pazResult, /* Results of the query */ |
2188 |
int *pnRow, /* Number of result rows written here */ |
2189 |
int *pnColumn, /* Number of result columns written here */ |
2190 |
char **pzErrmsg /* Error msg written here */ |
2191 |
); |
2192 |
SQLITE_API void sqlite3_free_table(char **result); |
2193 |
|
2194 |
/*
|
2195 |
** CAPI3REF: Formatted String Printing Functions
|
2196 |
**
|
2197 |
** These routines are work-alikes of the "printf()" family of functions
|
2198 |
** from the standard C library.
|
2199 |
**
|
2200 |
** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
|
2201 |
** results into memory obtained from [sqlite3_malloc()].
|
2202 |
** The strings returned by these two routines should be
|
2203 |
** released by [sqlite3_free()]. ^Both routines return a
|
2204 |
** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
|
2205 |
** memory to hold the resulting string.
|
2206 |
**
|
2207 |
** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
|
2208 |
** the standard C library. The result is written into the
|
2209 |
** buffer supplied as the second parameter whose size is given by
|
2210 |
** the first parameter. Note that the order of the
|
2211 |
** first two parameters is reversed from snprintf().)^ This is an
|
2212 |
** historical accident that cannot be fixed without breaking
|
2213 |
** backwards compatibility. ^(Note also that sqlite3_snprintf()
|
2214 |
** returns a pointer to its buffer instead of the number of
|
2215 |
** characters actually written into the buffer.)^ We admit that
|
2216 |
** the number of characters written would be a more useful return
|
2217 |
** value but we cannot change the implementation of sqlite3_snprintf()
|
2218 |
** now without breaking compatibility.
|
2219 |
**
|
2220 |
** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
|
2221 |
** guarantees that the buffer is always zero-terminated. ^The first
|
2222 |
** parameter "n" is the total size of the buffer, including space for
|
2223 |
** the zero terminator. So the longest string that can be completely
|
2224 |
** written will be n-1 characters.
|
2225 |
**
|
2226 |
** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
|
2227 |
**
|
2228 |
** These routines all implement some additional formatting
|
2229 |
** options that are useful for constructing SQL statements.
|
2230 |
** All of the usual printf() formatting options apply. In addition, there
|
2231 |
** is are "%q", "%Q", and "%z" options.
|
2232 |
**
|
2233 |
** ^(The %q option works like %s in that it substitutes a nul-terminated
|
2234 |
** string from the argument list. But %q also doubles every '\'' character.
|
2235 |
** %q is designed for use inside a string literal.)^ By doubling each '\''
|
2236 |
** character it escapes that character and allows it to be inserted into
|
2237 |
** the string.
|
2238 |
**
|
2239 |
** For example, assume the string variable zText contains text as follows:
|
2240 |
**
|
2241 |
** <blockquote><pre>
|
2242 |
** char *zText = "It's a happy day!";
|
2243 |
** </pre></blockquote>
|
2244 |
**
|
2245 |
** One can use this text in an SQL statement as follows:
|
2246 |
**
|
2247 |
** <blockquote><pre>
|
2248 |
** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
|
2249 |
** sqlite3_exec(db, zSQL, 0, 0, 0);
|
2250 |
** sqlite3_free(zSQL);
|
2251 |
** </pre></blockquote>
|
2252 |
**
|
2253 |
** Because the %q format string is used, the '\'' character in zText
|
2254 |
** is escaped and the SQL generated is as follows:
|
2255 |
**
|
2256 |
** <blockquote><pre>
|
2257 |
** INSERT INTO table1 VALUES('It''s a happy day!')
|
2258 |
** </pre></blockquote>
|
2259 |
**
|
2260 |
** This is correct. Had we used %s instead of %q, the generated SQL
|
2261 |
** would have looked like this:
|
2262 |
**
|
2263 |
** <blockquote><pre>
|
2264 |
** INSERT INTO table1 VALUES('It's a happy day!');
|
2265 |
** </pre></blockquote>
|
2266 |
**
|
2267 |
** This second example is an SQL syntax error. As a general rule you should
|
2268 |
** always use %q instead of %s when inserting text into a string literal.
|
2269 |
**
|
2270 |
** ^(The %Q option works like %q except it also adds single quotes around
|
2271 |
** the outside of the total string. Additionally, if the parameter in the
|
2272 |
** argument list is a NULL pointer, %Q substitutes the text "NULL" (without
|
2273 |
** single quotes).)^ So, for example, one could say:
|
2274 |
**
|
2275 |
** <blockquote><pre>
|
2276 |
** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
|
2277 |
** sqlite3_exec(db, zSQL, 0, 0, 0);
|
2278 |
** sqlite3_free(zSQL);
|
2279 |
** </pre></blockquote>
|
2280 |
**
|
2281 |
** The code above will render a correct SQL statement in the zSQL
|
2282 |
** variable even if the zText variable is a NULL pointer.
|
2283 |
**
|
2284 |
** ^(The "%z" formatting option works like "%s" but with the
|
2285 |
** addition that after the string has been read and copied into
|
2286 |
** the result, [sqlite3_free()] is called on the input string.)^
|
2287 |
*/
|
2288 |
SQLITE_API char *sqlite3_mprintf(const char*,...); |
2289 |
SQLITE_API char *sqlite3_vmprintf(const char*, va_list); |
2290 |
SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); |
2291 |
SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); |
2292 |
|
2293 |
/*
|
2294 |
** CAPI3REF: Memory Allocation Subsystem
|
2295 |
**
|
2296 |
** The SQLite core uses these three routines for all of its own
|
2297 |
** internal memory allocation needs. "Core" in the previous sentence
|
2298 |
** does not include operating-system specific VFS implementation. The
|
2299 |
** Windows VFS uses native malloc() and free() for some operations.
|
2300 |
**
|
2301 |
** ^The sqlite3_malloc() routine returns a pointer to a block
|
2302 |
** of memory at least N bytes in length, where N is the parameter.
|
2303 |
** ^If sqlite3_malloc() is unable to obtain sufficient free
|
2304 |
** memory, it returns a NULL pointer. ^If the parameter N to
|
2305 |
** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
|
2306 |
** a NULL pointer.
|
2307 |
**
|
2308 |
** ^Calling sqlite3_free() with a pointer previously returned
|
2309 |
** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
|
2310 |
** that it might be reused. ^The sqlite3_free() routine is
|
2311 |
** a no-op if is called with a NULL pointer. Passing a NULL pointer
|
2312 |
** to sqlite3_free() is harmless. After being freed, memory
|
2313 |
** should neither be read nor written. Even reading previously freed
|
2314 |
** memory might result in a segmentation fault or other severe error.
|
2315 |
** Memory corruption, a segmentation fault, or other severe error
|
2316 |
** might result if sqlite3_free() is called with a non-NULL pointer that
|
2317 |
** was not obtained from sqlite3_malloc() or sqlite3_realloc().
|
2318 |
**
|
2319 |
** ^(The sqlite3_realloc() interface attempts to resize a
|
2320 |
** prior memory allocation to be at least N bytes, where N is the
|
2321 |
** second parameter. The memory allocation to be resized is the first
|
2322 |
** parameter.)^ ^ If the first parameter to sqlite3_realloc()
|
2323 |
** is a NULL pointer then its behavior is identical to calling
|
2324 |
** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc().
|
2325 |
** ^If the second parameter to sqlite3_realloc() is zero or
|
2326 |
** negative then the behavior is exactly the same as calling
|
2327 |
** sqlite3_free(P) where P is the first parameter to sqlite3_realloc().
|
2328 |
** ^sqlite3_realloc() returns a pointer to a memory allocation
|
2329 |
** of at least N bytes in size or NULL if sufficient memory is unavailable.
|
2330 |
** ^If M is the size of the prior allocation, then min(N,M) bytes
|
2331 |
** of the prior allocation are copied into the beginning of buffer returned
|
2332 |
** by sqlite3_realloc() and the prior allocation is freed.
|
2333 |
** ^If sqlite3_realloc() returns NULL, then the prior allocation
|
2334 |
** is not freed.
|
2335 |
**
|
2336 |
** ^The memory returned by sqlite3_malloc() and sqlite3_realloc()
|
2337 |
** is always aligned to at least an 8 byte boundary, or to a
|
2338 |
** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
|
2339 |
** option is used.
|
2340 |
**
|
2341 |
** In SQLite version 3.5.0 and 3.5.1, it was possible to define
|
2342 |
** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
|
2343 |
** implementation of these routines to be omitted. That capability
|
2344 |
** is no longer provided. Only built-in memory allocators can be used.
|
2345 |
**
|
2346 |
** Prior to SQLite version 3.7.10, the Windows OS interface layer called
|
2347 |
** the system malloc() and free() directly when converting
|
2348 |
** filenames between the UTF-8 encoding used by SQLite
|
2349 |
** and whatever filename encoding is used by the particular Windows
|
2350 |
** installation. Memory allocation errors were detected, but
|
2351 |
** they were reported back as [SQLITE_CANTOPEN] or
|
2352 |
** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
|
2353 |
**
|
2354 |
** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
|
2355 |
** must be either NULL or else pointers obtained from a prior
|
2356 |
** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
|
2357 |
** not yet been released.
|
2358 |
**
|
2359 |
** The application must not read or write any part of
|
2360 |
** a block of memory after it has been released using
|
2361 |
** [sqlite3_free()] or [sqlite3_realloc()].
|
2362 |
*/
|
2363 |
SQLITE_API void *sqlite3_malloc(int); |
2364 |
SQLITE_API void *sqlite3_realloc(void*, int); |
2365 |
SQLITE_API void sqlite3_free(void*); |
2366 |
|
2367 |
/*
|
2368 |
** CAPI3REF: Memory Allocator Statistics
|
2369 |
**
|
2370 |
** SQLite provides these two interfaces for reporting on the status
|
2371 |
** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
|
2372 |
** routines, which form the built-in memory allocation subsystem.
|
2373 |
**
|
2374 |
** ^The [sqlite3_memory_used()] routine returns the number of bytes
|
2375 |
** of memory currently outstanding (malloced but not freed).
|
2376 |
** ^The [sqlite3_memory_highwater()] routine returns the maximum
|
2377 |
** value of [sqlite3_memory_used()] since the high-water mark
|
2378 |
** was last reset. ^The values returned by [sqlite3_memory_used()] and
|
2379 |
** [sqlite3_memory_highwater()] include any overhead
|
2380 |
** added by SQLite in its implementation of [sqlite3_malloc()],
|
2381 |
** but not overhead added by the any underlying system library
|
2382 |
** routines that [sqlite3_malloc()] may call.
|
2383 |
**
|
2384 |
** ^The memory high-water mark is reset to the current value of
|
2385 |
** [sqlite3_memory_used()] if and only if the parameter to
|
2386 |
** [sqlite3_memory_highwater()] is true. ^The value returned
|
2387 |
** by [sqlite3_memory_highwater(1)] is the high-water mark
|
2388 |
** prior to the reset.
|
2389 |
*/
|
2390 |
SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
|
2391 |
SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
|
2392 |
|
2393 |
/*
|
2394 |
** CAPI3REF: Pseudo-Random Number Generator
|
2395 |
**
|
2396 |
** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
|
2397 |
** select random [ROWID | ROWIDs] when inserting new records into a table that
|
2398 |
** already uses the largest possible [ROWID]. The PRNG is also used for
|
2399 |
** the build-in random() and randomblob() SQL functions. This interface allows
|
2400 |
** applications to access the same PRNG for other purposes.
|
2401 |
**
|
2402 |
** ^A call to this routine stores N bytes of randomness into buffer P.
|
2403 |
** ^If N is less than one, then P can be a NULL pointer.
|
2404 |
**
|
2405 |
** ^If this routine has not been previously called or if the previous
|
2406 |
** call had N less than one, then the PRNG is seeded using randomness
|
2407 |
** obtained from the xRandomness method of the default [sqlite3_vfs] object.
|
2408 |
** ^If the previous call to this routine had an N of 1 or more then
|
2409 |
** the pseudo-randomness is generated
|
2410 |
** internally and without recourse to the [sqlite3_vfs] xRandomness
|
2411 |
** method.
|
2412 |
*/
|
2413 |
SQLITE_API void sqlite3_randomness(int N, void *P); |
2414 |
|
2415 |
/*
|
2416 |
** CAPI3REF: Compile-Time Authorization Callbacks
|
2417 |
**
|
2418 |
** ^This routine registers an authorizer callback with a particular
|
2419 |
** [database connection], supplied in the first argument.
|
2420 |
** ^The authorizer callback is invoked as SQL statements are being compiled
|
2421 |
** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
|
2422 |
** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various
|
2423 |
** points during the compilation process, as logic is being created
|
2424 |
** to perform various actions, the authorizer callback is invoked to
|
2425 |
** see if those actions are allowed. ^The authorizer callback should
|
2426 |
** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
|
2427 |
** specific action but allow the SQL statement to continue to be
|
2428 |
** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
|
2429 |
** rejected with an error. ^If the authorizer callback returns
|
2430 |
** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
|
2431 |
** then the [sqlite3_prepare_v2()] or equivalent call that triggered
|
2432 |
** the authorizer will fail with an error message.
|
2433 |
**
|
2434 |
** When the callback returns [SQLITE_OK], that means the operation
|
2435 |
** requested is ok. ^When the callback returns [SQLITE_DENY], the
|
2436 |
** [sqlite3_prepare_v2()] or equivalent call that triggered the
|
2437 |
** authorizer will fail with an error message explaining that
|
2438 |
** access is denied.
|
2439 |
**
|
2440 |
** ^The first parameter to the authorizer callback is a copy of the third
|
2441 |
** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
|
2442 |
** to the callback is an integer [SQLITE_COPY | action code] that specifies
|
2443 |
** the particular action to be authorized. ^The third through sixth parameters
|
2444 |
** to the callback are zero-terminated strings that contain additional
|
2445 |
** details about the action to be authorized.
|
2446 |
**
|
2447 |
** ^If the action code is [SQLITE_READ]
|
2448 |
** and the callback returns [SQLITE_IGNORE] then the
|
2449 |
** [prepared statement] statement is constructed to substitute
|
2450 |
** a NULL value in place of the table column that would have
|
2451 |
** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
|
2452 |
** return can be used to deny an untrusted user access to individual
|
2453 |
** columns of a table.
|
2454 |
** ^If the action code is [SQLITE_DELETE] and the callback returns
|
2455 |
** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
|
2456 |
** [truncate optimization] is disabled and all rows are deleted individually.
|
2457 |
**
|
2458 |
** An authorizer is used when [sqlite3_prepare | preparing]
|
2459 |
** SQL statements from an untrusted source, to ensure that the SQL statements
|
2460 |
** do not try to access data they are not allowed to see, or that they do not
|
2461 |
** try to execute malicious statements that damage the database. For
|
2462 |
** example, an application may allow a user to enter arbitrary
|
2463 |
** SQL queries for evaluation by a database. But the application does
|
2464 |
** not want the user to be able to make arbitrary changes to the
|
2465 |
** database. An authorizer could then be put in place while the
|
2466 |
** user-entered SQL is being [sqlite3_prepare | prepared] that
|
2467 |
** disallows everything except [SELECT] statements.
|
2468 |
**
|
2469 |
** Applications that need to process SQL from untrusted sources
|
2470 |
** might also consider lowering resource limits using [sqlite3_limit()]
|
2471 |
** and limiting database size using the [max_page_count] [PRAGMA]
|
2472 |
** in addition to using an authorizer.
|
2473 |
**
|
2474 |
** ^(Only a single authorizer can be in place on a database connection
|
2475 |
** at a time. Each call to sqlite3_set_authorizer overrides the
|
2476 |
** previous call.)^ ^Disable the authorizer by installing a NULL callback.
|
2477 |
** The authorizer is disabled by default.
|
2478 |
**
|
2479 |
** The authorizer callback must not do anything that will modify
|
2480 |
** the database connection that invoked the authorizer callback.
|
2481 |
** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
|
2482 |
** database connections for the meaning of "modify" in this paragraph.
|
2483 |
**
|
2484 |
** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
|
2485 |
** statement might be re-prepared during [sqlite3_step()] due to a
|
2486 |
** schema change. Hence, the application should ensure that the
|
2487 |
** correct authorizer callback remains in place during the [sqlite3_step()].
|
2488 |
**
|
2489 |
** ^Note that the authorizer callback is invoked only during
|
2490 |
** [sqlite3_prepare()] or its variants. Authorization is not
|
2491 |
** performed during statement evaluation in [sqlite3_step()], unless
|
2492 |
** as stated in the previous paragraph, sqlite3_step() invokes
|
2493 |
** sqlite3_prepare_v2() to reprepare a statement after a schema change.
|
2494 |
*/
|
2495 |
SQLITE_API int sqlite3_set_authorizer(
|
2496 |
sqlite3*, |
2497 |
int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), |
2498 |
void *pUserData
|
2499 |
); |
2500 |
|
2501 |
/*
|
2502 |
** CAPI3REF: Authorizer Return Codes
|
2503 |
**
|
2504 |
** The [sqlite3_set_authorizer | authorizer callback function] must
|
2505 |
** return either [SQLITE_OK] or one of these two constants in order
|
2506 |
** to signal SQLite whether or not the action is permitted. See the
|
2507 |
** [sqlite3_set_authorizer | authorizer documentation] for additional
|
2508 |
** information.
|
2509 |
**
|
2510 |
** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code]
|
2511 |
** from the [sqlite3_vtab_on_conflict()] interface.
|
2512 |
*/
|
2513 |
#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ |
2514 |
#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ |
2515 |
|
2516 |
/*
|
2517 |
** CAPI3REF: Authorizer Action Codes
|
2518 |
**
|
2519 |
** The [sqlite3_set_authorizer()] interface registers a callback function
|
2520 |
** that is invoked to authorize certain SQL statement actions. The
|
2521 |
** second parameter to the callback is an integer code that specifies
|
2522 |
** what action is being authorized. These are the integer action codes that
|
2523 |
** the authorizer callback may be passed.
|
2524 |
**
|
2525 |
** These action code values signify what kind of operation is to be
|
2526 |
** authorized. The 3rd and 4th parameters to the authorization
|
2527 |
** callback function will be parameters or NULL depending on which of these
|
2528 |
** codes is used as the second parameter. ^(The 5th parameter to the
|
2529 |
** authorizer callback is the name of the database ("main", "temp",
|
2530 |
** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
|
2531 |
** is the name of the inner-most trigger or view that is responsible for
|
2532 |
** the access attempt or NULL if this access attempt is directly from
|
2533 |
** top-level SQL code.
|
2534 |
*/
|
2535 |
/******************************************* 3rd ************ 4th ***********/
|
2536 |
#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ |
2537 |
#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ |
2538 |
#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ |
2539 |
#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ |
2540 |
#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ |
2541 |
#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ |
2542 |
#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ |
2543 |
#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ |
2544 |
#define SQLITE_DELETE 9 /* Table Name NULL */ |
2545 |
#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ |
2546 |
#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ |
2547 |
#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ |
2548 |
#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ |
2549 |
#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ |
2550 |
#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ |
2551 |
#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ |
2552 |
#define SQLITE_DROP_VIEW 17 /* View Name NULL */ |
2553 |
#define SQLITE_INSERT 18 /* Table Name NULL */ |
2554 |
#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ |
2555 |
#define SQLITE_READ 20 /* Table Name Column Name */ |
2556 |
#define SQLITE_SELECT 21 /* NULL NULL */ |
2557 |
#define SQLITE_TRANSACTION 22 /* Operation NULL */ |
2558 |
#define SQLITE_UPDATE 23 /* Table Name Column Name */ |
2559 |
#define SQLITE_ATTACH 24 /* Filename NULL */ |
2560 |
#define SQLITE_DETACH 25 /* Database Name NULL */ |
2561 |
#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ |
2562 |
#define SQLITE_REINDEX 27 /* Index Name NULL */ |
2563 |
#define SQLITE_ANALYZE 28 /* Table Name NULL */ |
2564 |
#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ |
2565 |
#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ |
2566 |
#define SQLITE_FUNCTION 31 /* NULL Function Name */ |
2567 |
#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ |
2568 |
#define SQLITE_COPY 0 /* No longer used */ |
2569 |
#define SQLITE_RECURSIVE 33 /* NULL NULL */ |
2570 |
|
2571 |
/*
|
2572 |
** CAPI3REF: Tracing And Profiling Functions
|
2573 |
**
|
2574 |
** These routines register callback functions that can be used for
|
2575 |
** tracing and profiling the execution of SQL statements.
|
2576 |
**
|
2577 |
** ^The callback function registered by sqlite3_trace() is invoked at
|
2578 |
** various times when an SQL statement is being run by [sqlite3_step()].
|
2579 |
** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
|
2580 |
** SQL statement text as the statement first begins executing.
|
2581 |
** ^(Additional sqlite3_trace() callbacks might occur
|
2582 |
** as each triggered subprogram is entered. The callbacks for triggers
|
2583 |
** contain a UTF-8 SQL comment that identifies the trigger.)^
|
2584 |
**
|
2585 |
** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
|
2586 |
** the length of [bound parameter] expansion in the output of sqlite3_trace().
|
2587 |
**
|
2588 |
** ^The callback function registered by sqlite3_profile() is invoked
|
2589 |
** as each SQL statement finishes. ^The profile callback contains
|
2590 |
** the original statement text and an estimate of wall-clock time
|
2591 |
** of how long that statement took to run. ^The profile callback
|
2592 |
** time is in units of nanoseconds, however the current implementation
|
2593 |
** is only capable of millisecond resolution so the six least significant
|
2594 |
** digits in the time are meaningless. Future versions of SQLite
|
2595 |
** might provide greater resolution on the profiler callback. The
|
2596 |
** sqlite3_profile() function is considered experimental and is
|
2597 |
** subject to change in future versions of SQLite.
|
2598 |
*/
|
2599 |
SQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); |
2600 |
SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*,
|
2601 |
void(*xProfile)(void*,const char*,sqlite3_uint64), void*); |
2602 |
|
2603 |
/*
|
2604 |
** CAPI3REF: Query Progress Callbacks
|
2605 |
**
|
2606 |
** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
|
2607 |
** function X to be invoked periodically during long running calls to
|
2608 |
** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
|
2609 |
** database connection D. An example use for this
|
2610 |
** interface is to keep a GUI updated during a large query.
|
2611 |
**
|
2612 |
** ^The parameter P is passed through as the only parameter to the
|
2613 |
** callback function X. ^The parameter N is the approximate number of
|
2614 |
** [virtual machine instructions] that are evaluated between successive
|
2615 |
** invocations of the callback X. ^If N is less than one then the progress
|
2616 |
** handler is disabled.
|
2617 |
**
|
2618 |
** ^Only a single progress handler may be defined at one time per
|
2619 |
** [database connection]; setting a new progress handler cancels the
|
2620 |
** old one. ^Setting parameter X to NULL disables the progress handler.
|
2621 |
** ^The progress handler is also disabled by setting N to a value less
|
2622 |
** than 1.
|
2623 |
**
|
2624 |
** ^If the progress callback returns non-zero, the operation is
|
2625 |
** interrupted. This feature can be used to implement a
|
2626 |
** "Cancel" button on a GUI progress dialog box.
|
2627 |
**
|
2628 |
** The progress handler callback must not do anything that will modify
|
2629 |
** the database connection that invoked the progress handler.
|
2630 |
** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
|
2631 |
** database connections for the meaning of "modify" in this paragraph.
|
2632 |
**
|
2633 |
*/
|
2634 |
SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); |
2635 |
|
2636 |
/*
|
2637 |
** CAPI3REF: Opening A New Database Connection
|
2638 |
**
|
2639 |
** ^These routines open an SQLite database file as specified by the
|
2640 |
** filename argument. ^The filename argument is interpreted as UTF-8 for
|
2641 |
** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
|
2642 |
** order for sqlite3_open16(). ^(A [database connection] handle is usually
|
2643 |
** returned in *ppDb, even if an error occurs. The only exception is that
|
2644 |
** if SQLite is unable to allocate memory to hold the [sqlite3] object,
|
2645 |
** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
|
2646 |
** object.)^ ^(If the database is opened (and/or created) successfully, then
|
2647 |
** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
|
2648 |
** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
|
2649 |
** an English language description of the error following a failure of any
|
2650 |
** of the sqlite3_open() routines.
|
2651 |
**
|
2652 |
** ^The default encoding for the database will be UTF-8 if
|
2653 |
** sqlite3_open() or sqlite3_open_v2() is called and
|
2654 |
** UTF-16 in the native byte order if sqlite3_open16() is used.
|
2655 |
**
|
2656 |
** Whether or not an error occurs when it is opened, resources
|
2657 |
** associated with the [database connection] handle should be released by
|
2658 |
** passing it to [sqlite3_close()] when it is no longer required.
|
2659 |
**
|
2660 |
** The sqlite3_open_v2() interface works like sqlite3_open()
|
2661 |
** except that it accepts two additional parameters for additional control
|
2662 |
** over the new database connection. ^(The flags parameter to
|
2663 |
** sqlite3_open_v2() can take one of
|
2664 |
** the following three values, optionally combined with the
|
2665 |
** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],
|
2666 |
** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^
|
2667 |
**
|
2668 |
** <dl>
|
2669 |
** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
|
2670 |
** <dd>The database is opened in read-only mode. If the database does not
|
2671 |
** already exist, an error is returned.</dd>)^
|
2672 |
**
|
2673 |
** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
|
2674 |
** <dd>The database is opened for reading and writing if possible, or reading
|
2675 |
** only if the file is write protected by the operating system. In either
|
2676 |
** case the database must already exist, otherwise an error is returned.</dd>)^
|
2677 |
**
|
2678 |
** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
|
2679 |
** <dd>The database is opened for reading and writing, and is created if
|
2680 |
** it does not already exist. This is the behavior that is always used for
|
2681 |
** sqlite3_open() and sqlite3_open16().</dd>)^
|
2682 |
** </dl>
|
2683 |
**
|
2684 |
** If the 3rd parameter to sqlite3_open_v2() is not one of the
|
2685 |
** combinations shown above optionally combined with other
|
2686 |
** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
|
2687 |
** then the behavior is undefined.
|
2688 |
**
|
2689 |
** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
|
2690 |
** opens in the multi-thread [threading mode] as long as the single-thread
|
2691 |
** mode has not been set at compile-time or start-time. ^If the
|
2692 |
** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
|
2693 |
** in the serialized [threading mode] unless single-thread was
|
2694 |
** previously selected at compile-time or start-time.
|
2695 |
** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
|
2696 |
** eligible to use [shared cache mode], regardless of whether or not shared
|
2697 |
** cache is enabled using [sqlite3_enable_shared_cache()]. ^The
|
2698 |
** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
|
2699 |
** participate in [shared cache mode] even if it is enabled.
|
2700 |
**
|
2701 |
** ^The fourth parameter to sqlite3_open_v2() is the name of the
|
2702 |
** [sqlite3_vfs] object that defines the operating system interface that
|
2703 |
** the new database connection should use. ^If the fourth parameter is
|
2704 |
** a NULL pointer then the default [sqlite3_vfs] object is used.
|
2705 |
**
|
2706 |
** ^If the filename is ":memory:", then a private, temporary in-memory database
|
2707 |
** is created for the connection. ^This in-memory database will vanish when
|
2708 |
** the database connection is closed. Future versions of SQLite might
|
2709 |
** make use of additional special filenames that begin with the ":" character.
|
2710 |
** It is recommended that when a database filename actually does begin with
|
2711 |
** a ":" character you should prefix the filename with a pathname such as
|
2712 |
** "./" to avoid ambiguity.
|
2713 |
**
|
2714 |
** ^If the filename is an empty string, then a private, temporary
|
2715 |
** on-disk database will be created. ^This private database will be
|
2716 |
** automatically deleted as soon as the database connection is closed.
|
2717 |
**
|
2718 |
** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
|
2719 |
**
|
2720 |
** ^If [URI filename] interpretation is enabled, and the filename argument
|
2721 |
** begins with "file:", then the filename is interpreted as a URI. ^URI
|
2722 |
** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
|
2723 |
** set in the fourth argument to sqlite3_open_v2(), or if it has
|
2724 |
** been enabled globally using the [SQLITE_CONFIG_URI] option with the
|
2725 |
** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
|
2726 |
** As of SQLite version 3.7.7, URI filename interpretation is turned off
|
2727 |
** by default, but future releases of SQLite might enable URI filename
|
2728 |
** interpretation by default. See "[URI filenames]" for additional
|
2729 |
** information.
|
2730 |
**
|
2731 |
** URI filenames are parsed according to RFC 3986. ^If the URI contains an
|
2732 |
** authority, then it must be either an empty string or the string
|
2733 |
** "localhost". ^If the authority is not an empty string or "localhost", an
|
2734 |
** error is returned to the caller. ^The fragment component of a URI, if
|
2735 |
** present, is ignored.
|
2736 |
**
|
2737 |
** ^SQLite uses the path component of the URI as the name of the disk file
|
2738 |
** which contains the database. ^If the path begins with a '/' character,
|
2739 |
** then it is interpreted as an absolute path. ^If the path does not begin
|
2740 |
** with a '/' (meaning that the authority section is omitted from the URI)
|
2741 |
** then the path is interpreted as a relative path.
|
2742 |
** ^On windows, the first component of an absolute path
|
2743 |
** is a drive specification (e.g. "C:").
|
2744 |
**
|
2745 |
** [[core URI query parameters]]
|
2746 |
** The query component of a URI may contain parameters that are interpreted
|
2747 |
** either by SQLite itself, or by a [VFS | custom VFS implementation].
|
2748 |
** SQLite interprets the following three query parameters:
|
2749 |
**
|
2750 |
** <ul>
|
2751 |
** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
|
2752 |
** a VFS object that provides the operating system interface that should
|
2753 |
** be used to access the database file on disk. ^If this option is set to
|
2754 |
** an empty string the default VFS object is used. ^Specifying an unknown
|
2755 |
** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
|
2756 |
** present, then the VFS specified by the option takes precedence over
|
2757 |
** the value passed as the fourth parameter to sqlite3_open_v2().
|
2758 |
**
|
2759 |
** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
|
2760 |
** "rwc", or "memory". Attempting to set it to any other value is
|
2761 |
** an error)^.
|
2762 |
** ^If "ro" is specified, then the database is opened for read-only
|
2763 |
** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
|
2764 |
** third argument to sqlite3_open_v2(). ^If the mode option is set to
|
2765 |
** "rw", then the database is opened for read-write (but not create)
|
2766 |
** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
|
2767 |
** been set. ^Value "rwc" is equivalent to setting both
|
2768 |
** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
|
2769 |
** set to "memory" then a pure [in-memory database] that never reads
|
2770 |
** or writes from disk is used. ^It is an error to specify a value for
|
2771 |
** the mode parameter that is less restrictive than that specified by
|
2772 |
** the flags passed in the third parameter to sqlite3_open_v2().
|
2773 |
**
|
2774 |
** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
|
2775 |
** "private". ^Setting it to "shared" is equivalent to setting the
|
2776 |
** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
|
2777 |
** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
|
2778 |
** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
|
2779 |
** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
|
2780 |
** a URI filename, its value overrides any behavior requested by setting
|
2781 |
** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
|
2782 |
** </ul>
|
2783 |
**
|
2784 |
** ^Specifying an unknown parameter in the query component of a URI is not an
|
2785 |
** error. Future versions of SQLite might understand additional query
|
2786 |
** parameters. See "[query parameters with special meaning to SQLite]" for
|
2787 |
** additional information.
|
2788 |
**
|
2789 |
** [[URI filename examples]] <h3>URI filename examples</h3>
|
2790 |
**
|
2791 |
** <table border="1" align=center cellpadding=5>
|
2792 |
** <tr><th> URI filenames <th> Results
|
2793 |
** <tr><td> file:data.db <td>
|
2794 |
** Open the file "data.db" in the current directory.
|
2795 |
** <tr><td> file:/home/fred/data.db<br>
|
2796 |
** file:///home/fred/data.db <br>
|
2797 |
** file://localhost/home/fred/data.db <br> <td>
|
2798 |
** Open the database file "/home/fred/data.db".
|
2799 |
** <tr><td> file://darkstar/home/fred/data.db <td>
|
2800 |
** An error. "darkstar" is not a recognized authority.
|
2801 |
** <tr><td style="white-space:nowrap">
|
2802 |
** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
|
2803 |
** <td> Windows only: Open the file "data.db" on fred's desktop on drive
|
2804 |
** C:. Note that the %20 escaping in this example is not strictly
|
2805 |
** necessary - space characters can be used literally
|
2806 |
** in URI filenames.
|
2807 |
** <tr><td> file:data.db?mode=ro&cache=private <td>
|
2808 |
** Open file "data.db" in the current directory for read-only access.
|
2809 |
** Regardless of whether or not shared-cache mode is enabled by
|
2810 |
** default, use a private cache.
|
2811 |
** <tr><td> file:/home/fred/data.db?vfs=unix-nolock <td>
|
2812 |
** Open file "/home/fred/data.db". Use the special VFS "unix-nolock".
|
2813 |
** <tr><td> file:data.db?mode=readonly <td>
|
2814 |
** An error. "readonly" is not a valid option for the "mode" parameter.
|
2815 |
** </table>
|
2816 |
**
|
2817 |
** ^URI hexadecimal escape sequences (%HH) are supported within the path and
|
2818 |
** query components of a URI. A hexadecimal escape sequence consists of a
|
2819 |
** percent sign - "%" - followed by exactly two hexadecimal digits
|
2820 |
** specifying an octet value. ^Before the path or query components of a
|
2821 |
** URI filename are interpreted, they are encoded using UTF-8 and all
|
2822 |
** hexadecimal escape sequences replaced by a single byte containing the
|
2823 |
** corresponding octet. If this process generates an invalid UTF-8 encoding,
|
2824 |
** the results are undefined.
|
2825 |
**
|
2826 |
** <b>Note to Windows users:</b> The encoding used for the filename argument
|
2827 |
** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
|
2828 |
** codepage is currently defined. Filenames containing international
|
2829 |
** characters must be converted to UTF-8 prior to passing them into
|
2830 |
** sqlite3_open() or sqlite3_open_v2().
|
2831 |
**
|
2832 |
** <b>Note to Windows Runtime users:</b> The temporary directory must be set
|
2833 |
** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
|
2834 |
** features that require the use of temporary files may fail.
|
2835 |
**
|
2836 |
** See also: [sqlite3_temp_directory]
|
2837 |
*/
|
2838 |
SQLITE_API int sqlite3_open(
|
2839 |
const char *filename, /* Database filename (UTF-8) */ |
2840 |
sqlite3 **ppDb /* OUT: SQLite db handle */
|
2841 |
); |
2842 |
SQLITE_API int sqlite3_open16(
|
2843 |
const void *filename, /* Database filename (UTF-16) */ |
2844 |
sqlite3 **ppDb /* OUT: SQLite db handle */
|
2845 |
); |
2846 |
SQLITE_API int sqlite3_open_v2(
|
2847 |
const char *filename, /* Database filename (UTF-8) */ |
2848 |
sqlite3 **ppDb, /* OUT: SQLite db handle */
|
2849 |
int flags, /* Flags */ |
2850 |
const char *zVfs /* Name of VFS module to use */ |
2851 |
); |
2852 |
|
2853 |
/*
|
2854 |
** CAPI3REF: Obtain Values For URI Parameters
|
2855 |
**
|
2856 |
** These are utility routines, useful to VFS implementations, that check
|
2857 |
** to see if a database file was a URI that contained a specific query
|
2858 |
** parameter, and if so obtains the value of that query parameter.
|
2859 |
**
|
2860 |
** If F is the database filename pointer passed into the xOpen() method of
|
2861 |
** a VFS implementation when the flags parameter to xOpen() has one or
|
2862 |
** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and
|
2863 |
** P is the name of the query parameter, then
|
2864 |
** sqlite3_uri_parameter(F,P) returns the value of the P
|
2865 |
** parameter if it exists or a NULL pointer if P does not appear as a
|
2866 |
** query parameter on F. If P is a query parameter of F
|
2867 |
** has no explicit value, then sqlite3_uri_parameter(F,P) returns
|
2868 |
** a pointer to an empty string.
|
2869 |
**
|
2870 |
** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
|
2871 |
** parameter and returns true (1) or false (0) according to the value
|
2872 |
** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
|
2873 |
** value of query parameter P is one of "yes", "true", or "on" in any
|
2874 |
** case or if the value begins with a non-zero number. The
|
2875 |
** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
|
2876 |
** query parameter P is one of "no", "false", or "off" in any case or
|
2877 |
** if the value begins with a numeric zero. If P is not a query
|
2878 |
** parameter on F or if the value of P is does not match any of the
|
2879 |
** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
|
2880 |
**
|
2881 |
** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
|
2882 |
** 64-bit signed integer and returns that integer, or D if P does not
|
2883 |
** exist. If the value of P is something other than an integer, then
|
2884 |
** zero is returned.
|
2885 |
**
|
2886 |
** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
|
2887 |
** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
|
2888 |
** is not a database file pathname pointer that SQLite passed into the xOpen
|
2889 |
** VFS method, then the behavior of this routine is undefined and probably
|
2890 |
** undesirable.
|
2891 |
*/
|
2892 |
SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); |
2893 |
SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); |
2894 |
SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); |
2895 |
|
2896 |
|
2897 |
/*
|
2898 |
** CAPI3REF: Error Codes And Messages
|
2899 |
**
|
2900 |
** ^The sqlite3_errcode() interface returns the numeric [result code] or
|
2901 |
** [extended result code] for the most recent failed sqlite3_* API call
|
2902 |
** associated with a [database connection]. If a prior API call failed
|
2903 |
** but the most recent API call succeeded, the return value from
|
2904 |
** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode()
|
2905 |
** interface is the same except that it always returns the
|
2906 |
** [extended result code] even when extended result codes are
|
2907 |
** disabled.
|
2908 |
**
|
2909 |
** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
|
2910 |
** text that describes the error, as either UTF-8 or UTF-16 respectively.
|
2911 |
** ^(Memory to hold the error message string is managed internally.
|
2912 |
** The application does not need to worry about freeing the result.
|
2913 |
** However, the error string might be overwritten or deallocated by
|
2914 |
** subsequent calls to other SQLite interface functions.)^
|
2915 |
**
|
2916 |
** ^The sqlite3_errstr() interface returns the English-language text
|
2917 |
** that describes the [result code], as UTF-8.
|
2918 |
** ^(Memory to hold the error message string is managed internally
|
2919 |
** and must not be freed by the application)^.
|
2920 |
**
|
2921 |
** When the serialized [threading mode] is in use, it might be the
|
2922 |
** case that a second error occurs on a separate thread in between
|
2923 |
** the time of the first error and the call to these interfaces.
|
2924 |
** When that happens, the second error will be reported since these
|
2925 |
** interfaces always report the most recent result. To avoid
|
2926 |
** this, each thread can obtain exclusive use of the [database connection] D
|
2927 |
** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
|
2928 |
** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
|
2929 |
** all calls to the interfaces listed here are completed.
|
2930 |
**
|
2931 |
** If an interface fails with SQLITE_MISUSE, that means the interface
|
2932 |
** was invoked incorrectly by the application. In that case, the
|
2933 |
** error code and message may or may not be set.
|
2934 |
*/
|
2935 |
SQLITE_API int sqlite3_errcode(sqlite3 *db);
|
2936 |
SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
|
2937 |
SQLITE_API const char *sqlite3_errmsg(sqlite3*); |
2938 |
SQLITE_API const void *sqlite3_errmsg16(sqlite3*); |
2939 |
SQLITE_API const char *sqlite3_errstr(int); |
2940 |
|
2941 |
/*
|
2942 |
** CAPI3REF: SQL Statement Object
|
2943 |
** KEYWORDS: {prepared statement} {prepared statements}
|
2944 |
**
|
2945 |
** An instance of this object represents a single SQL statement.
|
2946 |
** This object is variously known as a "prepared statement" or a
|
2947 |
** "compiled SQL statement" or simply as a "statement".
|
2948 |
**
|
2949 |
** The life of a statement object goes something like this:
|
2950 |
**
|
2951 |
** <ol>
|
2952 |
** <li> Create the object using [sqlite3_prepare_v2()] or a related
|
2953 |
** function.
|
2954 |
** <li> Bind values to [host parameters] using the sqlite3_bind_*()
|
2955 |
** interfaces.
|
2956 |
** <li> Run the SQL by calling [sqlite3_step()] one or more times.
|
2957 |
** <li> Reset the statement using [sqlite3_reset()] then go back
|
2958 |
** to step 2. Do this zero or more times.
|
2959 |
** <li> Destroy the object using [sqlite3_finalize()].
|
2960 |
** </ol>
|
2961 |
**
|
2962 |
** Refer to documentation on individual methods above for additional
|
2963 |
** information.
|
2964 |
*/
|
2965 |
typedef struct sqlite3_stmt sqlite3_stmt; |
2966 |
|
2967 |
/*
|
2968 |
** CAPI3REF: Run-time Limits
|
2969 |
**
|
2970 |
** ^(This interface allows the size of various constructs to be limited
|
2971 |
** on a connection by connection basis. The first parameter is the
|
2972 |
** [database connection] whose limit is to be set or queried. The
|
2973 |
** second parameter is one of the [limit categories] that define a
|
2974 |
** class of constructs to be size limited. The third parameter is the
|
2975 |
** new limit for that construct.)^
|
2976 |
**
|
2977 |
** ^If the new limit is a negative number, the limit is unchanged.
|
2978 |
** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
|
2979 |
** [limits | hard upper bound]
|
2980 |
** set at compile-time by a C preprocessor macro called
|
2981 |
** [limits | SQLITE_MAX_<i>NAME</i>].
|
2982 |
** (The "_LIMIT_" in the name is changed to "_MAX_".))^
|
2983 |
** ^Attempts to increase a limit above its hard upper bound are
|
2984 |
** silently truncated to the hard upper bound.
|
2985 |
**
|
2986 |
** ^Regardless of whether or not the limit was changed, the
|
2987 |
** [sqlite3_limit()] interface returns the prior value of the limit.
|
2988 |
** ^Hence, to find the current value of a limit without changing it,
|
2989 |
** simply invoke this interface with the third parameter set to -1.
|
2990 |
**
|
2991 |
** Run-time limits are intended for use in applications that manage
|
2992 |
** both their own internal database and also databases that are controlled
|
2993 |
** by untrusted external sources. An example application might be a
|
2994 |
** web browser that has its own databases for storing history and
|
2995 |
** separate databases controlled by JavaScript applications downloaded
|
2996 |
** off the Internet. The internal databases can be given the
|
2997 |
** large, default limits. Databases managed by external sources can
|
2998 |
** be given much smaller limits designed to prevent a denial of service
|
2999 |
** attack. Developers might also want to use the [sqlite3_set_authorizer()]
|
3000 |
** interface to further control untrusted SQL. The size of the database
|
3001 |
** created by an untrusted script can be contained using the
|
3002 |
** [max_page_count] [PRAGMA].
|
3003 |
**
|
3004 |
** New run-time limit categories may be added in future releases.
|
3005 |
*/
|
3006 |
SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); |
3007 |
|
3008 |
/*
|
3009 |
** CAPI3REF: Run-Time Limit Categories
|
3010 |
** KEYWORDS: {limit category} {*limit categories}
|
3011 |
**
|
3012 |
** These constants define various performance limits
|
3013 |
** that can be lowered at run-time using [sqlite3_limit()].
|
3014 |
** The synopsis of the meanings of the various limits is shown below.
|
3015 |
** Additional information is available at [limits | Limits in SQLite].
|
3016 |
**
|
3017 |
** <dl>
|
3018 |
** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
|
3019 |
** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
|
3020 |
**
|
3021 |
** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
|
3022 |
** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
|
3023 |
**
|
3024 |
** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
|
3025 |
** <dd>The maximum number of columns in a table definition or in the
|
3026 |
** result set of a [SELECT] or the maximum number of columns in an index
|
3027 |
** or in an ORDER BY or GROUP BY clause.</dd>)^
|
3028 |
**
|
3029 |
** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
|
3030 |
** <dd>The maximum depth of the parse tree on any expression.</dd>)^
|
3031 |
**
|
3032 |
** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
|
3033 |
** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
|
3034 |
**
|
3035 |
** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
|
3036 |
** <dd>The maximum number of instructions in a virtual machine program
|
3037 |
** used to implement an SQL statement. This limit is not currently
|
3038 |
** enforced, though that might be added in some future release of
|
3039 |
** SQLite.</dd>)^
|
3040 |
**
|
3041 |
** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
|
3042 |
** <dd>The maximum number of arguments on a function.</dd>)^
|
3043 |
**
|
3044 |
** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
|
3045 |
** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
|
3046 |
**
|
3047 |
** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
|
3048 |
** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
|
3049 |
** <dd>The maximum length of the pattern argument to the [LIKE] or
|
3050 |
** [GLOB] operators.</dd>)^
|
3051 |
**
|
3052 |
** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
|
3053 |
** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
|
3054 |
** <dd>The maximum index number of any [parameter] in an SQL statement.)^
|
3055 |
**
|
3056 |
** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
|
3057 |
** <dd>The maximum depth of recursion for triggers.</dd>)^
|
3058 |
** </dl>
|
3059 |
*/
|
3060 |
#define SQLITE_LIMIT_LENGTH 0 |
3061 |
#define SQLITE_LIMIT_SQL_LENGTH 1 |
3062 |
#define SQLITE_LIMIT_COLUMN 2 |
3063 |
#define SQLITE_LIMIT_EXPR_DEPTH 3 |
3064 |
#define SQLITE_LIMIT_COMPOUND_SELECT 4 |
3065 |
#define SQLITE_LIMIT_VDBE_OP 5 |
3066 |
#define SQLITE_LIMIT_FUNCTION_ARG 6 |
3067 |
#define SQLITE_LIMIT_ATTACHED 7 |
3068 |
#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 |
3069 |
#define SQLITE_LIMIT_VARIABLE_NUMBER 9 |
3070 |
#define SQLITE_LIMIT_TRIGGER_DEPTH 10 |
3071 |
|
3072 |
/*
|
3073 |
** CAPI3REF: Compiling An SQL Statement
|
3074 |
** KEYWORDS: {SQL statement compiler}
|
3075 |
**
|
3076 |
** To execute an SQL query, it must first be compiled into a byte-code
|
3077 |
** program using one of these routines.
|
3078 |
**
|
3079 |
** The first argument, "db", is a [database connection] obtained from a
|
3080 |
** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
|
3081 |
** [sqlite3_open16()]. The database connection must not have been closed.
|
3082 |
**
|
3083 |
** The second argument, "zSql", is the statement to be compiled, encoded
|
3084 |
** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2()
|
3085 |
** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()
|
3086 |
** use UTF-16.
|
3087 |
**
|
3088 |
** ^If the nByte argument is less than zero, then zSql is read up to the
|
3089 |
** first zero terminator. ^If nByte is non-negative, then it is the maximum
|
3090 |
** number of bytes read from zSql. ^When nByte is non-negative, the
|
3091 |
** zSql string ends at either the first '\000' or '\u0000' character or
|
3092 |
** the nByte-th byte, whichever comes first. If the caller knows
|
3093 |
** that the supplied string is nul-terminated, then there is a small
|
3094 |
** performance advantage to be gained by passing an nByte parameter that
|
3095 |
** is equal to the number of bytes in the input string <i>including</i>
|
3096 |
** the nul-terminator bytes as this saves SQLite from having to
|
3097 |
** make a copy of the input string.
|
3098 |
**
|
3099 |
** ^If pzTail is not NULL then *pzTail is made to point to the first byte
|
3100 |
** past the end of the first SQL statement in zSql. These routines only
|
3101 |
** compile the first statement in zSql, so *pzTail is left pointing to
|
3102 |
** what remains uncompiled.
|
3103 |
**
|
3104 |
** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
|
3105 |
** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
|
3106 |
** to NULL. ^If the input text contains no SQL (if the input is an empty
|
3107 |
** string or a comment) then *ppStmt is set to NULL.
|
3108 |
** The calling procedure is responsible for deleting the compiled
|
3109 |
** SQL statement using [sqlite3_finalize()] after it has finished with it.
|
3110 |
** ppStmt may not be NULL.
|
3111 |
**
|
3112 |
** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
|
3113 |
** otherwise an [error code] is returned.
|
3114 |
**
|
3115 |
** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
|
3116 |
** recommended for all new programs. The two older interfaces are retained
|
3117 |
** for backwards compatibility, but their use is discouraged.
|
3118 |
** ^In the "v2" interfaces, the prepared statement
|
3119 |
** that is returned (the [sqlite3_stmt] object) contains a copy of the
|
3120 |
** original SQL text. This causes the [sqlite3_step()] interface to
|
3121 |
** behave differently in three ways:
|
3122 |
**
|
3123 |
** <ol>
|
3124 |
** <li>
|
3125 |
** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
|
3126 |
** always used to do, [sqlite3_step()] will automatically recompile the SQL
|
3127 |
** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
|
3128 |
** retries will occur before sqlite3_step() gives up and returns an error.
|
3129 |
** </li>
|
3130 |
**
|
3131 |
** <li>
|
3132 |
** ^When an error occurs, [sqlite3_step()] will return one of the detailed
|
3133 |
** [error codes] or [extended error codes]. ^The legacy behavior was that
|
3134 |
** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
|
3135 |
** and the application would have to make a second call to [sqlite3_reset()]
|
3136 |
** in order to find the underlying cause of the problem. With the "v2" prepare
|
3137 |
** interfaces, the underlying reason for the error is returned immediately.
|
3138 |
** </li>
|
3139 |
**
|
3140 |
** <li>
|
3141 |
** ^If the specific value bound to [parameter | host parameter] in the
|
3142 |
** WHERE clause might influence the choice of query plan for a statement,
|
3143 |
** then the statement will be automatically recompiled, as if there had been
|
3144 |
** a schema change, on the first [sqlite3_step()] call following any change
|
3145 |
** to the [sqlite3_bind_text | bindings] of that [parameter].
|
3146 |
** ^The specific value of WHERE-clause [parameter] might influence the
|
3147 |
** choice of query plan if the parameter is the left-hand side of a [LIKE]
|
3148 |
** or [GLOB] operator or if the parameter is compared to an indexed column
|
3149 |
** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
|
3150 |
** </li>
|
3151 |
** </ol>
|
3152 |
*/
|
3153 |
SQLITE_API int sqlite3_prepare(
|
3154 |
sqlite3 *db, /* Database handle */
|
3155 |
const char *zSql, /* SQL statement, UTF-8 encoded */ |
3156 |
int nByte, /* Maximum length of zSql in bytes. */ |
3157 |
sqlite3_stmt **ppStmt, /* OUT: Statement handle */
|
3158 |
const char **pzTail /* OUT: Pointer to unused portion of zSql */ |
3159 |
); |
3160 |
SQLITE_API int sqlite3_prepare_v2(
|
3161 |
sqlite3 *db, /* Database handle */
|
3162 |
const char *zSql, /* SQL statement, UTF-8 encoded */ |
3163 |
int nByte, /* Maximum length of zSql in bytes. */ |
3164 |
sqlite3_stmt **ppStmt, /* OUT: Statement handle */
|
3165 |
const char **pzTail /* OUT: Pointer to unused portion of zSql */ |
3166 |
); |
3167 |
SQLITE_API int sqlite3_prepare16(
|
3168 |
sqlite3 *db, /* Database handle */
|
3169 |
const void *zSql, /* SQL statement, UTF-16 encoded */ |
3170 |
int nByte, /* Maximum length of zSql in bytes. */ |
3171 |
sqlite3_stmt **ppStmt, /* OUT: Statement handle */
|
3172 |
const void **pzTail /* OUT: Pointer to unused portion of zSql */ |
3173 |
); |
3174 |
SQLITE_API int sqlite3_prepare16_v2(
|
3175 |
sqlite3 *db, /* Database handle */
|
3176 |
const void *zSql, /* SQL statement, UTF-16 encoded */ |
3177 |
int nByte, /* Maximum length of zSql in bytes. */ |
3178 |
sqlite3_stmt **ppStmt, /* OUT: Statement handle */
|
3179 |
const void **pzTail /* OUT: Pointer to unused portion of zSql */ |
3180 |
); |
3181 |
|
3182 |
/*
|
3183 |
** CAPI3REF: Retrieving Statement SQL
|
3184 |
**
|
3185 |
** ^This interface can be used to retrieve a saved copy of the original
|
3186 |
** SQL text used to create a [prepared statement] if that statement was
|
3187 |
** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
|
3188 |
*/
|
3189 |
SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); |
3190 |
|
3191 |
/*
|
3192 |
** CAPI3REF: Determine If An SQL Statement Writes The Database
|
3193 |
**
|
3194 |
** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
|
3195 |
** and only if the [prepared statement] X makes no direct changes to
|
3196 |
** the content of the database file.
|
3197 |
**
|
3198 |
** Note that [application-defined SQL functions] or
|
3199 |
** [virtual tables] might change the database indirectly as a side effect.
|
3200 |
** ^(For example, if an application defines a function "eval()" that
|
3201 |
** calls [sqlite3_exec()], then the following SQL statement would
|
3202 |
** change the database file through side-effects:
|
3203 |
**
|
3204 |
** <blockquote><pre>
|
3205 |
** SELECT eval('DELETE FROM t1') FROM t2;
|
3206 |
** </pre></blockquote>
|
3207 |
**
|
3208 |
** But because the [SELECT] statement does not change the database file
|
3209 |
** directly, sqlite3_stmt_readonly() would still return true.)^
|
3210 |
**
|
3211 |
** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
|
3212 |
** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
|
3213 |
** since the statements themselves do not actually modify the database but
|
3214 |
** rather they control the timing of when other statements modify the
|
3215 |
** database. ^The [ATTACH] and [DETACH] statements also cause
|
3216 |
** sqlite3_stmt_readonly() to return true since, while those statements
|
3217 |
** change the configuration of a database connection, they do not make
|
3218 |
** changes to the content of the database files on disk.
|
3219 |
*/
|
3220 |
SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
|
3221 |
|
3222 |
/*
|
3223 |
** CAPI3REF: Determine If A Prepared Statement Has Been Reset
|
3224 |
**
|
3225 |
** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
|
3226 |
** [prepared statement] S has been stepped at least once using
|
3227 |
** [sqlite3_step(S)] but has not run to completion and/or has not
|
3228 |
** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
|
3229 |
** interface returns false if S is a NULL pointer. If S is not a
|
3230 |
** NULL pointer and is not a pointer to a valid [prepared statement]
|
3231 |
** object, then the behavior is undefined and probably undesirable.
|
3232 |
**
|
3233 |
** This interface can be used in combination [sqlite3_next_stmt()]
|
3234 |
** to locate all prepared statements associated with a database
|
3235 |
** connection that are in need of being reset. This can be used,
|
3236 |
** for example, in diagnostic routines to search for prepared
|
3237 |
** statements that are holding a transaction open.
|
3238 |
*/
|
3239 |
SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
|
3240 |
|
3241 |
/*
|
3242 |
** CAPI3REF: Dynamically Typed Value Object
|
3243 |
** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
|
3244 |
**
|
3245 |
** SQLite uses the sqlite3_value object to represent all values
|
3246 |
** that can be stored in a database table. SQLite uses dynamic typing
|
3247 |
** for the values it stores. ^Values stored in sqlite3_value objects
|
3248 |
** can be integers, floating point values, strings, BLOBs, or NULL.
|
3249 |
**
|
3250 |
** An sqlite3_value object may be either "protected" or "unprotected".
|
3251 |
** Some interfaces require a protected sqlite3_value. Other interfaces
|
3252 |
** will accept either a protected or an unprotected sqlite3_value.
|
3253 |
** Every interface that accepts sqlite3_value arguments specifies
|
3254 |
** whether or not it requires a protected sqlite3_value.
|
3255 |
**
|
3256 |
** The terms "protected" and "unprotected" refer to whether or not
|
3257 |
** a mutex is held. An internal mutex is held for a protected
|
3258 |
** sqlite3_value object but no mutex is held for an unprotected
|
3259 |
** sqlite3_value object. If SQLite is compiled to be single-threaded
|
3260 |
** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
|
3261 |
** or if SQLite is run in one of reduced mutex modes
|
3262 |
** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
|
3263 |
** then there is no distinction between protected and unprotected
|
3264 |
** sqlite3_value objects and they can be used interchangeably. However,
|
3265 |
** for maximum code portability it is recommended that applications
|
3266 |
** still make the distinction between protected and unprotected
|
3267 |
** sqlite3_value objects even when not strictly required.
|
3268 |
**
|
3269 |
** ^The sqlite3_value objects that are passed as parameters into the
|
3270 |
** implementation of [application-defined SQL functions] are protected.
|
3271 |
** ^The sqlite3_value object returned by
|
3272 |
** [sqlite3_column_value()] is unprotected.
|
3273 |
** Unprotected sqlite3_value objects may only be used with
|
3274 |
** [sqlite3_result_value()] and [sqlite3_bind_value()].
|
3275 |
** The [sqlite3_value_blob | sqlite3_value_type()] family of
|
3276 |
** interfaces require protected sqlite3_value objects.
|
3277 |
*/
|
3278 |
typedef struct Mem sqlite3_value; |
3279 |
|
3280 |
/*
|
3281 |
** CAPI3REF: SQL Function Context Object
|
3282 |
**
|
3283 |
** The context in which an SQL function executes is stored in an
|
3284 |
** sqlite3_context object. ^A pointer to an sqlite3_context object
|
3285 |
** is always first parameter to [application-defined SQL functions].
|
3286 |
** The application-defined SQL function implementation will pass this
|
3287 |
** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
|
3288 |
** [sqlite3_aggregate_context()], [sqlite3_user_data()],
|
3289 |
** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
|
3290 |
** and/or [sqlite3_set_auxdata()].
|
3291 |
*/
|
3292 |
typedef struct sqlite3_context sqlite3_context; |
3293 |
|
3294 |
/*
|
3295 |
** CAPI3REF: Binding Values To Prepared Statements
|
3296 |
** KEYWORDS: {host parameter} {host parameters} {host parameter name}
|
3297 |
** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
|
3298 |
**
|
3299 |
** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
|
3300 |
** literals may be replaced by a [parameter] that matches one of following
|
3301 |
** templates:
|
3302 |
**
|
3303 |
** <ul>
|
3304 |
** <li> ?
|
3305 |
** <li> ?NNN
|
3306 |
** <li> :VVV
|
3307 |
** <li> @VVV
|
3308 |
** <li> $VVV
|
3309 |
** </ul>
|
3310 |
**
|
3311 |
** In the templates above, NNN represents an integer literal,
|
3312 |
** and VVV represents an alphanumeric identifier.)^ ^The values of these
|
3313 |
** parameters (also called "host parameter names" or "SQL parameters")
|
3314 |
** can be set using the sqlite3_bind_*() routines defined here.
|
3315 |
**
|
3316 |
** ^The first argument to the sqlite3_bind_*() routines is always
|
3317 |
** a pointer to the [sqlite3_stmt] object returned from
|
3318 |
** [sqlite3_prepare_v2()] or its variants.
|
3319 |
**
|
3320 |
** ^The second argument is the index of the SQL parameter to be set.
|
3321 |
** ^The leftmost SQL parameter has an index of 1. ^When the same named
|
3322 |
** SQL parameter is used more than once, second and subsequent
|
3323 |
** occurrences have the same index as the first occurrence.
|
3324 |
** ^The index for named parameters can be looked up using the
|
3325 |
** [sqlite3_bind_parameter_index()] API if desired. ^The index
|
3326 |
** for "?NNN" parameters is the value of NNN.
|
3327 |
** ^The NNN value must be between 1 and the [sqlite3_limit()]
|
3328 |
** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
|
3329 |
**
|
3330 |
** ^The third argument is the value to bind to the parameter.
|
3331 |
** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
|
3332 |
** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
|
3333 |
** is ignored and the end result is the same as sqlite3_bind_null().
|
3334 |
**
|
3335 |
** ^(In those routines that have a fourth argument, its value is the
|
3336 |
** number of bytes in the parameter. To be clear: the value is the
|
3337 |
** number of <u>bytes</u> in the value, not the number of characters.)^
|
3338 |
** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
|
3339 |
** is negative, then the length of the string is
|
3340 |
** the number of bytes up to the first zero terminator.
|
3341 |
** If the fourth parameter to sqlite3_bind_blob() is negative, then
|
3342 |
** the behavior is undefined.
|
3343 |
** If a non-negative fourth parameter is provided to sqlite3_bind_text()
|
3344 |
** or sqlite3_bind_text16() then that parameter must be the byte offset
|
3345 |
** where the NUL terminator would occur assuming the string were NUL
|
3346 |
** terminated. If any NUL characters occur at byte offsets less than
|
3347 |
** the value of the fourth parameter then the resulting string value will
|
3348 |
** contain embedded NULs. The result of expressions involving strings
|
3349 |
** with embedded NULs is undefined.
|
3350 |
**
|
3351 |
** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
|
3352 |
** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
|
3353 |
** string after SQLite has finished with it. ^The destructor is called
|
3354 |
** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(),
|
3355 |
** sqlite3_bind_text(), or sqlite3_bind_text16() fails.
|
3356 |
** ^If the fifth argument is
|
3357 |
** the special value [SQLITE_STATIC], then SQLite assumes that the
|
3358 |
** information is in static, unmanaged space and does not need to be freed.
|
3359 |
** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
|
3360 |
** SQLite makes its own private copy of the data immediately, before
|
3361 |
** the sqlite3_bind_*() routine returns.
|
3362 |
**
|
3363 |
** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
|
3364 |
** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
|
3365 |
** (just an integer to hold its size) while it is being processed.
|
3366 |
** Zeroblobs are intended to serve as placeholders for BLOBs whose
|
3367 |
** content is later written using
|
3368 |
** [sqlite3_blob_open | incremental BLOB I/O] routines.
|
3369 |
** ^A negative value for the zeroblob results in a zero-length BLOB.
|
3370 |
**
|
3371 |
** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
|
3372 |
** for the [prepared statement] or with a prepared statement for which
|
3373 |
** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
|
3374 |
** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
|
3375 |
** routine is passed a [prepared statement] that has been finalized, the
|
3376 |
** result is undefined and probably harmful.
|
3377 |
**
|
3378 |
** ^Bindings are not cleared by the [sqlite3_reset()] routine.
|
3379 |
** ^Unbound parameters are interpreted as NULL.
|
3380 |
**
|
3381 |
** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
|
3382 |
** [error code] if anything goes wrong.
|
3383 |
** ^[SQLITE_RANGE] is returned if the parameter
|
3384 |
** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
|
3385 |
**
|
3386 |
** See also: [sqlite3_bind_parameter_count()],
|
3387 |
** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
|
3388 |
*/
|
3389 |
SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); |
3390 |
SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); |
3391 |
SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); |
3392 |
SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); |
3393 |
SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); |
3394 |
SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); |
3395 |
SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); |
3396 |
SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); |
3397 |
SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); |
3398 |
|
3399 |
/*
|
3400 |
** CAPI3REF: Number Of SQL Parameters
|
3401 |
**
|
3402 |
** ^This routine can be used to find the number of [SQL parameters]
|
3403 |
** in a [prepared statement]. SQL parameters are tokens of the
|
3404 |
** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
|
3405 |
** placeholders for values that are [sqlite3_bind_blob | bound]
|
3406 |
** to the parameters at a later time.
|
3407 |
**
|
3408 |
** ^(This routine actually returns the index of the largest (rightmost)
|
3409 |
** parameter. For all forms except ?NNN, this will correspond to the
|
3410 |
** number of unique parameters. If parameters of the ?NNN form are used,
|
3411 |
** there may be gaps in the list.)^
|
3412 |
**
|
3413 |
** See also: [sqlite3_bind_blob|sqlite3_bind()],
|
3414 |
** [sqlite3_bind_parameter_name()], and
|
3415 |
** [sqlite3_bind_parameter_index()].
|
3416 |
*/
|
3417 |
SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
|
3418 |
|
3419 |
/*
|
3420 |
** CAPI3REF: Name Of A Host Parameter
|
3421 |
**
|
3422 |
** ^The sqlite3_bind_parameter_name(P,N) interface returns
|
3423 |
** the name of the N-th [SQL parameter] in the [prepared statement] P.
|
3424 |
** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
|
3425 |
** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
|
3426 |
** respectively.
|
3427 |
** In other words, the initial ":" or "$" or "@" or "?"
|
3428 |
** is included as part of the name.)^
|
3429 |
** ^Parameters of the form "?" without a following integer have no name
|
3430 |
** and are referred to as "nameless" or "anonymous parameters".
|
3431 |
**
|
3432 |
** ^The first host parameter has an index of 1, not 0.
|
3433 |
**
|
3434 |
** ^If the value N is out of range or if the N-th parameter is
|
3435 |
** nameless, then NULL is returned. ^The returned string is
|
3436 |
** always in UTF-8 encoding even if the named parameter was
|
3437 |
** originally specified as UTF-16 in [sqlite3_prepare16()] or
|
3438 |
** [sqlite3_prepare16_v2()].
|
3439 |
**
|
3440 |
** See also: [sqlite3_bind_blob|sqlite3_bind()],
|
3441 |
** [sqlite3_bind_parameter_count()], and
|
3442 |
** [sqlite3_bind_parameter_index()].
|
3443 |
*/
|
3444 |
SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); |
3445 |
|
3446 |
/*
|
3447 |
** CAPI3REF: Index Of A Parameter With A Given Name
|
3448 |
**
|
3449 |
** ^Return the index of an SQL parameter given its name. ^The
|
3450 |
** index value returned is suitable for use as the second
|
3451 |
** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
|
3452 |
** is returned if no matching parameter is found. ^The parameter
|
3453 |
** name must be given in UTF-8 even if the original statement
|
3454 |
** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].
|
3455 |
**
|
3456 |
** See also: [sqlite3_bind_blob|sqlite3_bind()],
|
3457 |
** [sqlite3_bind_parameter_count()], and
|
3458 |
** [sqlite3_bind_parameter_index()].
|
3459 |
*/
|
3460 |
SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); |
3461 |
|
3462 |
/*
|
3463 |
** CAPI3REF: Reset All Bindings On A Prepared Statement
|
3464 |
**
|
3465 |
** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
|
3466 |
** the [sqlite3_bind_blob | bindings] on a [prepared statement].
|
3467 |
** ^Use this routine to reset all host parameters to NULL.
|
3468 |
*/
|
3469 |
SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
|
3470 |
|
3471 |
/*
|
3472 |
** CAPI3REF: Number Of Columns In A Result Set
|
3473 |
**
|
3474 |
** ^Return the number of columns in the result set returned by the
|
3475 |
** [prepared statement]. ^This routine returns 0 if pStmt is an SQL
|
3476 |
** statement that does not return data (for example an [UPDATE]).
|
3477 |
**
|
3478 |
** See also: [sqlite3_data_count()]
|
3479 |
*/
|
3480 |
SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
|
3481 |
|
3482 |
/*
|
3483 |
** CAPI3REF: Column Names In A Result Set
|
3484 |
**
|
3485 |
** ^These routines return the name assigned to a particular column
|
3486 |
** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
|
3487 |
** interface returns a pointer to a zero-terminated UTF-8 string
|
3488 |
** and sqlite3_column_name16() returns a pointer to a zero-terminated
|
3489 |
** UTF-16 string. ^The first parameter is the [prepared statement]
|
3490 |
** that implements the [SELECT] statement. ^The second parameter is the
|
3491 |
** column number. ^The leftmost column is number 0.
|
3492 |
**
|
3493 |
** ^The returned string pointer is valid until either the [prepared statement]
|
3494 |
** is destroyed by [sqlite3_finalize()] or until the statement is automatically
|
3495 |
** reprepared by the first call to [sqlite3_step()] for a particular run
|
3496 |
** or until the next call to
|
3497 |
** sqlite3_column_name() or sqlite3_column_name16() on the same column.
|
3498 |
**
|
3499 |
** ^If sqlite3_malloc() fails during the processing of either routine
|
3500 |
** (for example during a conversion from UTF-8 to UTF-16) then a
|
3501 |
** NULL pointer is returned.
|
3502 |
**
|
3503 |
** ^The name of a result column is the value of the "AS" clause for
|
3504 |
** that column, if there is an AS clause. If there is no AS clause
|
3505 |
** then the name of the column is unspecified and may change from
|
3506 |
** one release of SQLite to the next.
|
3507 |
*/
|
3508 |
SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); |
3509 |
SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); |
3510 |
|
3511 |
/*
|
3512 |
** CAPI3REF: Source Of Data In A Query Result
|
3513 |
**
|
3514 |
** ^These routines provide a means to determine the database, table, and
|
3515 |
** table column that is the origin of a particular result column in
|
3516 |
** [SELECT] statement.
|
3517 |
** ^The name of the database or table or column can be returned as
|
3518 |
** either a UTF-8 or UTF-16 string. ^The _database_ routines return
|
3519 |
** the database name, the _table_ routines return the table name, and
|
3520 |
** the origin_ routines return the column name.
|
3521 |
** ^The returned string is valid until the [prepared statement] is destroyed
|
3522 |
** using [sqlite3_finalize()] or until the statement is automatically
|
3523 |
** reprepared by the first call to [sqlite3_step()] for a particular run
|
3524 |
** or until the same information is requested
|
3525 |
** again in a different encoding.
|
3526 |
**
|
3527 |
** ^The names returned are the original un-aliased names of the
|
3528 |
** database, table, and column.
|
3529 |
**
|
3530 |
** ^The first argument to these interfaces is a [prepared statement].
|
3531 |
** ^These functions return information about the Nth result column returned by
|
3532 |
** the statement, where N is the second function argument.
|
3533 |
** ^The left-most column is column 0 for these routines.
|
3534 |
**
|
3535 |
** ^If the Nth column returned by the statement is an expression or
|
3536 |
** subquery and is not a column value, then all of these functions return
|
3537 |
** NULL. ^These routine might also return NULL if a memory allocation error
|
3538 |
** occurs. ^Otherwise, they return the name of the attached database, table,
|
3539 |
** or column that query result column was extracted from.
|
3540 |
**
|
3541 |
** ^As with all other SQLite APIs, those whose names end with "16" return
|
3542 |
** UTF-16 encoded strings and the other functions return UTF-8.
|
3543 |
**
|
3544 |
** ^These APIs are only available if the library was compiled with the
|
3545 |
** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
|
3546 |
**
|
3547 |
** If two or more threads call one or more of these routines against the same
|
3548 |
** prepared statement and column at the same time then the results are
|
3549 |
** undefined.
|
3550 |
**
|
3551 |
** If two or more threads call one or more
|
3552 |
** [sqlite3_column_database_name | column metadata interfaces]
|
3553 |
** for the same [prepared statement] and result column
|
3554 |
** at the same time then the results are undefined.
|
3555 |
*/
|
3556 |
SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); |
3557 |
SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); |
3558 |
SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); |
3559 |
SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); |
3560 |
SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); |
3561 |
SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); |
3562 |
|
3563 |
/*
|
3564 |
** CAPI3REF: Declared Datatype Of A Query Result
|
3565 |
**
|
3566 |
** ^(The first parameter is a [prepared statement].
|
3567 |
** If this statement is a [SELECT] statement and the Nth column of the
|
3568 |
** returned result set of that [SELECT] is a table column (not an
|
3569 |
** expression or subquery) then the declared type of the table
|
3570 |
** column is returned.)^ ^If the Nth column of the result set is an
|
3571 |
** expression or subquery, then a NULL pointer is returned.
|
3572 |
** ^The returned string is always UTF-8 encoded.
|
3573 |
**
|
3574 |
** ^(For example, given the database schema:
|
3575 |
**
|
3576 |
** CREATE TABLE t1(c1 VARIANT);
|
3577 |
**
|
3578 |
** and the following statement to be compiled:
|
3579 |
**
|
3580 |
** SELECT c1 + 1, c1 FROM t1;
|
3581 |
**
|
3582 |
** this routine would return the string "VARIANT" for the second result
|
3583 |
** column (i==1), and a NULL pointer for the first result column (i==0).)^
|
3584 |
**
|
3585 |
** ^SQLite uses dynamic run-time typing. ^So just because a column
|
3586 |
** is declared to contain a particular type does not mean that the
|
3587 |
** data stored in that column is of the declared type. SQLite is
|
3588 |
** strongly typed, but the typing is dynamic not static. ^Type
|
3589 |
** is associated with individual values, not with the containers
|
3590 |
** used to hold those values.
|
3591 |
*/
|
3592 |
SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); |
3593 |
SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); |
3594 |
|
3595 |
/*
|
3596 |
** CAPI3REF: Evaluate An SQL Statement
|
3597 |
**
|
3598 |
** After a [prepared statement] has been prepared using either
|
3599 |
** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy
|
3600 |
** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
|
3601 |
** must be called one or more times to evaluate the statement.
|
3602 |
**
|
3603 |
** The details of the behavior of the sqlite3_step() interface depend
|
3604 |
** on whether the statement was prepared using the newer "v2" interface
|
3605 |
** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
|
3606 |
** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
|
3607 |
** new "v2" interface is recommended for new applications but the legacy
|
3608 |
** interface will continue to be supported.
|
3609 |
**
|
3610 |
** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
|
3611 |
** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
|
3612 |
** ^With the "v2" interface, any of the other [result codes] or
|
3613 |
** [extended result codes] might be returned as well.
|
3614 |
**
|
3615 |
** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
|
3616 |
** database locks it needs to do its job. ^If the statement is a [COMMIT]
|
3617 |
** or occurs outside of an explicit transaction, then you can retry the
|
3618 |
** statement. If the statement is not a [COMMIT] and occurs within an
|
3619 |
** explicit transaction then you should rollback the transaction before
|
3620 |
** continuing.
|
3621 |
**
|
3622 |
** ^[SQLITE_DONE] means that the statement has finished executing
|
3623 |
** successfully. sqlite3_step() should not be called again on this virtual
|
3624 |
** machine without first calling [sqlite3_reset()] to reset the virtual
|
3625 |
** machine back to its initial state.
|
3626 |
**
|
3627 |
** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
|
3628 |
** is returned each time a new row of data is ready for processing by the
|
3629 |
** caller. The values may be accessed using the [column access functions].
|
3630 |
** sqlite3_step() is called again to retrieve the next row of data.
|
3631 |
**
|
3632 |
** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
|
3633 |
** violation) has occurred. sqlite3_step() should not be called again on
|
3634 |
** the VM. More information may be found by calling [sqlite3_errmsg()].
|
3635 |
** ^With the legacy interface, a more specific error code (for example,
|
3636 |
** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
|
3637 |
** can be obtained by calling [sqlite3_reset()] on the
|
3638 |
** [prepared statement]. ^In the "v2" interface,
|
3639 |
** the more specific error code is returned directly by sqlite3_step().
|
3640 |
**
|
3641 |
** [SQLITE_MISUSE] means that the this routine was called inappropriately.
|
3642 |
** Perhaps it was called on a [prepared statement] that has
|
3643 |
** already been [sqlite3_finalize | finalized] or on one that had
|
3644 |
** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
|
3645 |
** be the case that the same database connection is being used by two or
|
3646 |
** more threads at the same moment in time.
|
3647 |
**
|
3648 |
** For all versions of SQLite up to and including 3.6.23.1, a call to
|
3649 |
** [sqlite3_reset()] was required after sqlite3_step() returned anything
|
3650 |
** other than [SQLITE_ROW] before any subsequent invocation of
|
3651 |
** sqlite3_step(). Failure to reset the prepared statement using
|
3652 |
** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
|
3653 |
** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began
|
3654 |
** calling [sqlite3_reset()] automatically in this circumstance rather
|
3655 |
** than returning [SQLITE_MISUSE]. This is not considered a compatibility
|
3656 |
** break because any application that ever receives an SQLITE_MISUSE error
|
3657 |
** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
|
3658 |
** can be used to restore the legacy behavior.
|
3659 |
**
|
3660 |
** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
|
3661 |
** API always returns a generic error code, [SQLITE_ERROR], following any
|
3662 |
** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
|
3663 |
** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
|
3664 |
** specific [error codes] that better describes the error.
|
3665 |
** We admit that this is a goofy design. The problem has been fixed
|
3666 |
** with the "v2" interface. If you prepare all of your SQL statements
|
3667 |
** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
|
3668 |
** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
|
3669 |
** then the more specific [error codes] are returned directly
|
3670 |
** by sqlite3_step(). The use of the "v2" interface is recommended.
|
3671 |
*/
|
3672 |
SQLITE_API int sqlite3_step(sqlite3_stmt*);
|
3673 |
|
3674 |
/*
|
3675 |
** CAPI3REF: Number of columns in a result set
|
3676 |
**
|
3677 |
** ^The sqlite3_data_count(P) interface returns the number of columns in the
|
3678 |
** current row of the result set of [prepared statement] P.
|
3679 |
** ^If prepared statement P does not have results ready to return
|
3680 |
** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of
|
3681 |
** interfaces) then sqlite3_data_count(P) returns 0.
|
3682 |
** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
|
3683 |
** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
|
3684 |
** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
|
3685 |
** will return non-zero if previous call to [sqlite3_step](P) returned
|
3686 |
** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
|
3687 |
** where it always returns zero since each step of that multi-step
|
3688 |
** pragma returns 0 columns of data.
|
3689 |
**
|
3690 |
** See also: [sqlite3_column_count()]
|
3691 |
*/
|
3692 |
SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
|
3693 |
|
3694 |
/*
|
3695 |
** CAPI3REF: Fundamental Datatypes
|
3696 |
** KEYWORDS: SQLITE_TEXT
|
3697 |
**
|
3698 |
** ^(Every value in SQLite has one of five fundamental datatypes:
|
3699 |
**
|
3700 |
** <ul>
|
3701 |
** <li> 64-bit signed integer
|
3702 |
** <li> 64-bit IEEE floating point number
|
3703 |
** <li> string
|
3704 |
** <li> BLOB
|
3705 |
** <li> NULL
|
3706 |
** </ul>)^
|
3707 |
**
|
3708 |
** These constants are codes for each of those types.
|
3709 |
**
|
3710 |
** Note that the SQLITE_TEXT constant was also used in SQLite version 2
|
3711 |
** for a completely different meaning. Software that links against both
|
3712 |
** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
|
3713 |
** SQLITE_TEXT.
|
3714 |
*/
|
3715 |
#define SQLITE_INTEGER 1 |
3716 |
#define SQLITE_FLOAT 2 |
3717 |
#define SQLITE_BLOB 4 |
3718 |
#define SQLITE_NULL 5 |
3719 |
#ifdef SQLITE_TEXT
|
3720 |
# undef SQLITE_TEXT
|
3721 |
#else
|
3722 |
# define SQLITE_TEXT 3 |
3723 |
#endif
|
3724 |
#define SQLITE3_TEXT 3 |
3725 |
|
3726 |
/*
|
3727 |
** CAPI3REF: Result Values From A Query
|
3728 |
** KEYWORDS: {column access functions}
|
3729 |
**
|
3730 |
** These routines form the "result set" interface.
|
3731 |
**
|
3732 |
** ^These routines return information about a single column of the current
|
3733 |
** result row of a query. ^In every case the first argument is a pointer
|
3734 |
** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
|
3735 |
** that was returned from [sqlite3_prepare_v2()] or one of its variants)
|
3736 |
** and the second argument is the index of the column for which information
|
3737 |
** should be returned. ^The leftmost column of the result set has the index 0.
|
3738 |
** ^The number of columns in the result can be determined using
|
3739 |
** [sqlite3_column_count()].
|
3740 |
**
|
3741 |
** If the SQL statement does not currently point to a valid row, or if the
|
3742 |
** column index is out of range, the result is undefined.
|
3743 |
** These routines may only be called when the most recent call to
|
3744 |
** [sqlite3_step()] has returned [SQLITE_ROW] and neither
|
3745 |
** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
|
3746 |
** If any of these routines are called after [sqlite3_reset()] or
|
3747 |
** [sqlite3_finalize()] or after [sqlite3_step()] has returned
|
3748 |
** something other than [SQLITE_ROW], the results are undefined.
|
3749 |
** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
|
3750 |
** are called from a different thread while any of these routines
|
3751 |
** are pending, then the results are undefined.
|
3752 |
**
|
3753 |
** ^The sqlite3_column_type() routine returns the
|
3754 |
** [SQLITE_INTEGER | datatype code] for the initial data type
|
3755 |
** of the result column. ^The returned value is one of [SQLITE_INTEGER],
|
3756 |
** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value
|
3757 |
** returned by sqlite3_column_type() is only meaningful if no type
|
3758 |
** conversions have occurred as described below. After a type conversion,
|
3759 |
** the value returned by sqlite3_column_type() is undefined. Future
|
3760 |
** versions of SQLite may change the behavior of sqlite3_column_type()
|
3761 |
** following a type conversion.
|
3762 |
**
|
3763 |
** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
|
3764 |
** routine returns the number of bytes in that BLOB or string.
|
3765 |
** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
|
3766 |
** the string to UTF-8 and then returns the number of bytes.
|
3767 |
** ^If the result is a numeric value then sqlite3_column_bytes() uses
|
3768 |
** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
|
3769 |
** the number of bytes in that string.
|
3770 |
** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
|
3771 |
**
|
3772 |
** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
|
3773 |
** routine returns the number of bytes in that BLOB or string.
|
3774 |
** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
|
3775 |
** the string to UTF-16 and then returns the number of bytes.
|
3776 |
** ^If the result is a numeric value then sqlite3_column_bytes16() uses
|
3777 |
** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
|
3778 |
** the number of bytes in that string.
|
3779 |
** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
|
3780 |
**
|
3781 |
** ^The values returned by [sqlite3_column_bytes()] and
|
3782 |
** [sqlite3_column_bytes16()] do not include the zero terminators at the end
|
3783 |
** of the string. ^For clarity: the values returned by
|
3784 |
** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
|
3785 |
** bytes in the string, not the number of characters.
|
3786 |
**
|
3787 |
** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
|
3788 |
** even empty strings, are always zero-terminated. ^The return
|
3789 |
** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
|
3790 |
**
|
3791 |
** ^The object returned by [sqlite3_column_value()] is an
|
3792 |
** [unprotected sqlite3_value] object. An unprotected sqlite3_value object
|
3793 |
** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()].
|
3794 |
** If the [unprotected sqlite3_value] object returned by
|
3795 |
** [sqlite3_column_value()] is used in any other way, including calls
|
3796 |
** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
|
3797 |
** or [sqlite3_value_bytes()], then the behavior is undefined.
|
3798 |
**
|
3799 |
** These routines attempt to convert the value where appropriate. ^For
|
3800 |
** example, if the internal representation is FLOAT and a text result
|
3801 |
** is requested, [sqlite3_snprintf()] is used internally to perform the
|
3802 |
** conversion automatically. ^(The following table details the conversions
|
3803 |
** that are applied:
|
3804 |
**
|
3805 |
** <blockquote>
|
3806 |
** <table border="1">
|
3807 |
** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
|
3808 |
**
|
3809 |
** <tr><td> NULL <td> INTEGER <td> Result is 0
|
3810 |
** <tr><td> NULL <td> FLOAT <td> Result is 0.0
|
3811 |
** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
|
3812 |
** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
|
3813 |
** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
|
3814 |
** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
|
3815 |
** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
|
3816 |
** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
|
3817 |
** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
|
3818 |
** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
|
3819 |
** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
|
3820 |
** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
|
3821 |
** <tr><td> TEXT <td> BLOB <td> No change
|
3822 |
** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
|
3823 |
** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
|
3824 |
** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed
|
3825 |
** </table>
|
3826 |
** </blockquote>)^
|
3827 |
**
|
3828 |
** The table above makes reference to standard C library functions atoi()
|
3829 |
** and atof(). SQLite does not really use these functions. It has its
|
3830 |
** own equivalent internal routines. The atoi() and atof() names are
|
3831 |
** used in the table for brevity and because they are familiar to most
|
3832 |
** C programmers.
|
3833 |
**
|
3834 |
** Note that when type conversions occur, pointers returned by prior
|
3835 |
** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
|
3836 |
** sqlite3_column_text16() may be invalidated.
|
3837 |
** Type conversions and pointer invalidations might occur
|
3838 |
** in the following cases:
|
3839 |
**
|
3840 |
** <ul>
|
3841 |
** <li> The initial content is a BLOB and sqlite3_column_text() or
|
3842 |
** sqlite3_column_text16() is called. A zero-terminator might
|
3843 |
** need to be added to the string.</li>
|
3844 |
** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
|
3845 |
** sqlite3_column_text16() is called. The content must be converted
|
3846 |
** to UTF-16.</li>
|
3847 |
** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
|
3848 |
** sqlite3_column_text() is called. The content must be converted
|
3849 |
** to UTF-8.</li>
|
3850 |
** </ul>
|
3851 |
**
|
3852 |
** ^Conversions between UTF-16be and UTF-16le are always done in place and do
|
3853 |
** not invalidate a prior pointer, though of course the content of the buffer
|
3854 |
** that the prior pointer references will have been modified. Other kinds
|
3855 |
** of conversion are done in place when it is possible, but sometimes they
|
3856 |
** are not possible and in those cases prior pointers are invalidated.
|
3857 |
**
|
3858 |
** The safest and easiest to remember policy is to invoke these routines
|
3859 |
** in one of the following ways:
|
3860 |
**
|
3861 |
** <ul>
|
3862 |
** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
|
3863 |
** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
|
3864 |
** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
|
3865 |
** </ul>
|
3866 |
**
|
3867 |
** In other words, you should call sqlite3_column_text(),
|
3868 |
** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
|
3869 |
** into the desired format, then invoke sqlite3_column_bytes() or
|
3870 |
** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
|
3871 |
** to sqlite3_column_text() or sqlite3_column_blob() with calls to
|
3872 |
** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
|
3873 |
** with calls to sqlite3_column_bytes().
|
3874 |
**
|
3875 |
** ^The pointers returned are valid until a type conversion occurs as
|
3876 |
** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
|
3877 |
** [sqlite3_finalize()] is called. ^The memory space used to hold strings
|
3878 |
** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned
|
3879 |
** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
|
3880 |
** [sqlite3_free()].
|
3881 |
**
|
3882 |
** ^(If a memory allocation error occurs during the evaluation of any
|
3883 |
** of these routines, a default value is returned. The default value
|
3884 |
** is either the integer 0, the floating point number 0.0, or a NULL
|
3885 |
** pointer. Subsequent calls to [sqlite3_errcode()] will return
|
3886 |
** [SQLITE_NOMEM].)^
|
3887 |
*/
|
3888 |
SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); |
3889 |
SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); |
3890 |
SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); |
3891 |
SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); |
3892 |
SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); |
3893 |
SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
|
3894 |
SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); |
3895 |
SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); |
3896 |
SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); |
3897 |
SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
|
3898 |
|
3899 |
/*
|
3900 |
** CAPI3REF: Destroy A Prepared Statement Object
|
3901 |
**
|
3902 |
** ^The sqlite3_finalize() function is called to delete a [prepared statement].
|
3903 |
** ^If the most recent evaluation of the statement encountered no errors
|
3904 |
** or if the statement is never been evaluated, then sqlite3_finalize() returns
|
3905 |
** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
|
3906 |
** sqlite3_finalize(S) returns the appropriate [error code] or
|
3907 |
** [extended error code].
|
3908 |
**
|
3909 |
** ^The sqlite3_finalize(S) routine can be called at any point during
|
3910 |
** the life cycle of [prepared statement] S:
|
3911 |
** before statement S is ever evaluated, after
|
3912 |
** one or more calls to [sqlite3_reset()], or after any call
|
3913 |
** to [sqlite3_step()] regardless of whether or not the statement has
|
3914 |
** completed execution.
|
3915 |
**
|
3916 |
** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
|
3917 |
**
|
3918 |
** The application must finalize every [prepared statement] in order to avoid
|
3919 |
** resource leaks. It is a grievous error for the application to try to use
|
3920 |
** a prepared statement after it has been finalized. Any use of a prepared
|
3921 |
** statement after it has been finalized can result in undefined and
|
3922 |
** undesirable behavior such as segfaults and heap corruption.
|
3923 |
*/
|
3924 |
SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
|
3925 |
|
3926 |
/*
|
3927 |
** CAPI3REF: Reset A Prepared Statement Object
|
3928 |
**
|
3929 |
** The sqlite3_reset() function is called to reset a [prepared statement]
|
3930 |
** object back to its initial state, ready to be re-executed.
|
3931 |
** ^Any SQL statement variables that had values bound to them using
|
3932 |
** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
|
3933 |
** Use [sqlite3_clear_bindings()] to reset the bindings.
|
3934 |
**
|
3935 |
** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
|
3936 |
** back to the beginning of its program.
|
3937 |
**
|
3938 |
** ^If the most recent call to [sqlite3_step(S)] for the
|
3939 |
** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
|
3940 |
** or if [sqlite3_step(S)] has never before been called on S,
|
3941 |
** then [sqlite3_reset(S)] returns [SQLITE_OK].
|
3942 |
**
|
3943 |
** ^If the most recent call to [sqlite3_step(S)] for the
|
3944 |
** [prepared statement] S indicated an error, then
|
3945 |
** [sqlite3_reset(S)] returns an appropriate [error code].
|
3946 |
**
|
3947 |
** ^The [sqlite3_reset(S)] interface does not change the values
|
3948 |
** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
|
3949 |
*/
|
3950 |
SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
|
3951 |
|
3952 |
/*
|
3953 |
** CAPI3REF: Create Or Redefine SQL Functions
|
3954 |
** KEYWORDS: {function creation routines}
|
3955 |
** KEYWORDS: {application-defined SQL function}
|
3956 |
** KEYWORDS: {application-defined SQL functions}
|
3957 |
**
|
3958 |
** ^These functions (collectively known as "function creation routines")
|
3959 |
** are used to add SQL functions or aggregates or to redefine the behavior
|
3960 |
** of existing SQL functions or aggregates. The only differences between
|
3961 |
** these routines are the text encoding expected for
|
3962 |
** the second parameter (the name of the function being created)
|
3963 |
** and the presence or absence of a destructor callback for
|
3964 |
** the application data pointer.
|
3965 |
**
|
3966 |
** ^The first parameter is the [database connection] to which the SQL
|
3967 |
** function is to be added. ^If an application uses more than one database
|
3968 |
** connection then application-defined SQL functions must be added
|
3969 |
** to each database connection separately.
|
3970 |
**
|
3971 |
** ^The second parameter is the name of the SQL function to be created or
|
3972 |
** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
|
3973 |
** representation, exclusive of the zero-terminator. ^Note that the name
|
3974 |
** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
|
3975 |
** ^Any attempt to create a function with a longer name
|
3976 |
** will result in [SQLITE_MISUSE] being returned.
|
3977 |
**
|
3978 |
** ^The third parameter (nArg)
|
3979 |
** is the number of arguments that the SQL function or
|
3980 |
** aggregate takes. ^If this parameter is -1, then the SQL function or
|
3981 |
** aggregate may take any number of arguments between 0 and the limit
|
3982 |
** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
|
3983 |
** parameter is less than -1 or greater than 127 then the behavior is
|
3984 |
** undefined.
|
3985 |
**
|
3986 |
** ^The fourth parameter, eTextRep, specifies what
|
3987 |
** [SQLITE_UTF8 | text encoding] this SQL function prefers for
|
3988 |
** its parameters. The application should set this parameter to
|
3989 |
** [SQLITE_UTF16LE] if the function implementation invokes
|
3990 |
** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
|
3991 |
** implementation invokes [sqlite3_value_text16be()] on an input, or
|
3992 |
** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
|
3993 |
** otherwise. ^The same SQL function may be registered multiple times using
|
3994 |
** different preferred text encodings, with different implementations for
|
3995 |
** each encoding.
|
3996 |
** ^When multiple implementations of the same function are available, SQLite
|
3997 |
** will pick the one that involves the least amount of data conversion.
|
3998 |
**
|
3999 |
** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
|
4000 |
** to signal that the function will always return the same result given
|
4001 |
** the same inputs within a single SQL statement. Most SQL functions are
|
4002 |
** deterministic. The built-in [random()] SQL function is an example of a
|
4003 |
** function that is not deterministic. The SQLite query planner is able to
|
4004 |
** perform additional optimizations on deterministic functions, so use
|
4005 |
** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
|
4006 |
**
|
4007 |
** ^(The fifth parameter is an arbitrary pointer. The implementation of the
|
4008 |
** function can gain access to this pointer using [sqlite3_user_data()].)^
|
4009 |
**
|
4010 |
** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are
|
4011 |
** pointers to C-language functions that implement the SQL function or
|
4012 |
** aggregate. ^A scalar SQL function requires an implementation of the xFunc
|
4013 |
** callback only; NULL pointers must be passed as the xStep and xFinal
|
4014 |
** parameters. ^An aggregate SQL function requires an implementation of xStep
|
4015 |
** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
|
4016 |
** SQL function or aggregate, pass NULL pointers for all three function
|
4017 |
** callbacks.
|
4018 |
**
|
4019 |
** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL,
|
4020 |
** then it is destructor for the application data pointer.
|
4021 |
** The destructor is invoked when the function is deleted, either by being
|
4022 |
** overloaded or when the database connection closes.)^
|
4023 |
** ^The destructor is also invoked if the call to
|
4024 |
** sqlite3_create_function_v2() fails.
|
4025 |
** ^When the destructor callback of the tenth parameter is invoked, it
|
4026 |
** is passed a single argument which is a copy of the application data
|
4027 |
** pointer which was the fifth parameter to sqlite3_create_function_v2().
|
4028 |
**
|
4029 |
** ^It is permitted to register multiple implementations of the same
|
4030 |
** functions with the same name but with either differing numbers of
|
4031 |
** arguments or differing preferred text encodings. ^SQLite will use
|
4032 |
** the implementation that most closely matches the way in which the
|
4033 |
** SQL function is used. ^A function implementation with a non-negative
|
4034 |
** nArg parameter is a better match than a function implementation with
|
4035 |
** a negative nArg. ^A function where the preferred text encoding
|
4036 |
** matches the database encoding is a better
|
4037 |
** match than a function where the encoding is different.
|
4038 |
** ^A function where the encoding difference is between UTF16le and UTF16be
|
4039 |
** is a closer match than a function where the encoding difference is
|
4040 |
** between UTF8 and UTF16.
|
4041 |
**
|
4042 |
** ^Built-in functions may be overloaded by new application-defined functions.
|
4043 |
**
|
4044 |
** ^An application-defined function is permitted to call other
|
4045 |
** SQLite interfaces. However, such calls must not
|
4046 |
** close the database connection nor finalize or reset the prepared
|
4047 |
** statement in which the function is running.
|
4048 |
*/
|
4049 |
SQLITE_API int sqlite3_create_function(
|
4050 |
sqlite3 *db, |
4051 |
const char *zFunctionName, |
4052 |
int nArg,
|
4053 |
int eTextRep,
|
4054 |
void *pApp,
|
4055 |
void (*xFunc)(sqlite3_context*,int,sqlite3_value**), |
4056 |
void (*xStep)(sqlite3_context*,int,sqlite3_value**), |
4057 |
void (*xFinal)(sqlite3_context*)
|
4058 |
); |
4059 |
SQLITE_API int sqlite3_create_function16(
|
4060 |
sqlite3 *db, |
4061 |
const void *zFunctionName, |
4062 |
int nArg,
|
4063 |
int eTextRep,
|
4064 |
void *pApp,
|
4065 |
void (*xFunc)(sqlite3_context*,int,sqlite3_value**), |
4066 |
void (*xStep)(sqlite3_context*,int,sqlite3_value**), |
4067 |
void (*xFinal)(sqlite3_context*)
|
4068 |
); |
4069 |
SQLITE_API int sqlite3_create_function_v2(
|
4070 |
sqlite3 *db, |
4071 |
const char *zFunctionName, |
4072 |
int nArg,
|
4073 |
int eTextRep,
|
4074 |
void *pApp,
|
4075 |
void (*xFunc)(sqlite3_context*,int,sqlite3_value**), |
4076 |
void (*xStep)(sqlite3_context*,int,sqlite3_value**), |
4077 |
void (*xFinal)(sqlite3_context*),
|
4078 |
void(*xDestroy)(void*) |
4079 |
); |
4080 |
|
4081 |
/*
|
4082 |
** CAPI3REF: Text Encodings
|
4083 |
**
|
4084 |
** These constant define integer codes that represent the various
|
4085 |
** text encodings supported by SQLite.
|
4086 |
*/
|
4087 |
#define SQLITE_UTF8 1 |
4088 |
#define SQLITE_UTF16LE 2 |
4089 |
#define SQLITE_UTF16BE 3 |
4090 |
#define SQLITE_UTF16 4 /* Use native byte order */ |
4091 |
#define SQLITE_ANY 5 /* Deprecated */ |
4092 |
#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ |
4093 |
|
4094 |
/*
|
4095 |
** CAPI3REF: Function Flags
|
4096 |
**
|
4097 |
** These constants may be ORed together with the
|
4098 |
** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
|
4099 |
** to [sqlite3_create_function()], [sqlite3_create_function16()], or
|
4100 |
** [sqlite3_create_function_v2()].
|
4101 |
*/
|
4102 |
#define SQLITE_DETERMINISTIC 0x800 |
4103 |
|
4104 |
/*
|
4105 |
** CAPI3REF: Deprecated Functions
|
4106 |
** DEPRECATED
|
4107 |
**
|
4108 |
** These functions are [deprecated]. In order to maintain
|
4109 |
** backwards compatibility with older code, these functions continue
|
4110 |
** to be supported. However, new applications should avoid
|
4111 |
** the use of these functions. To help encourage people to avoid
|
4112 |
** using these functions, we are not going to tell you what they do.
|
4113 |
*/
|
4114 |
#ifndef SQLITE_OMIT_DEPRECATED
|
4115 |
SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
|
4116 |
SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
|
4117 |
SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
|
4118 |
SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); |
4119 |
SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); |
4120 |
SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), |
4121 |
void*,sqlite3_int64);
|
4122 |
#endif
|
4123 |
|
4124 |
/*
|
4125 |
** CAPI3REF: Obtaining SQL Function Parameter Values
|
4126 |
**
|
4127 |
** The C-language implementation of SQL functions and aggregates uses
|
4128 |
** this set of interface routines to access the parameter values on
|
4129 |
** the function or aggregate.
|
4130 |
**
|
4131 |
** The xFunc (for scalar functions) or xStep (for aggregates) parameters
|
4132 |
** to [sqlite3_create_function()] and [sqlite3_create_function16()]
|
4133 |
** define callbacks that implement the SQL functions and aggregates.
|
4134 |
** The 3rd parameter to these callbacks is an array of pointers to
|
4135 |
** [protected sqlite3_value] objects. There is one [sqlite3_value] object for
|
4136 |
** each parameter to the SQL function. These routines are used to
|
4137 |
** extract values from the [sqlite3_value] objects.
|
4138 |
**
|
4139 |
** These routines work only with [protected sqlite3_value] objects.
|
4140 |
** Any attempt to use these routines on an [unprotected sqlite3_value]
|
4141 |
** object results in undefined behavior.
|
4142 |
**
|
4143 |
** ^These routines work just like the corresponding [column access functions]
|
4144 |
** except that these routines take a single [protected sqlite3_value] object
|
4145 |
** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
|
4146 |
**
|
4147 |
** ^The sqlite3_value_text16() interface extracts a UTF-16 string
|
4148 |
** in the native byte-order of the host machine. ^The
|
4149 |
** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
|
4150 |
** extract UTF-16 strings as big-endian and little-endian respectively.
|
4151 |
**
|
4152 |
** ^(The sqlite3_value_numeric_type() interface attempts to apply
|
4153 |
** numeric affinity to the value. This means that an attempt is
|
4154 |
** made to convert the value to an integer or floating point. If
|
4155 |
** such a conversion is possible without loss of information (in other
|
4156 |
** words, if the value is a string that looks like a number)
|
4157 |
** then the conversion is performed. Otherwise no conversion occurs.
|
4158 |
** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
|
4159 |
**
|
4160 |
** Please pay particular attention to the fact that the pointer returned
|
4161 |
** from [sqlite3_value_blob()], [sqlite3_value_text()], or
|
4162 |
** [sqlite3_value_text16()] can be invalidated by a subsequent call to
|
4163 |
** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
|
4164 |
** or [sqlite3_value_text16()].
|
4165 |
**
|
4166 |
** These routines must be called from the same thread as
|
4167 |
** the SQL function that supplied the [sqlite3_value*] parameters.
|
4168 |
*/
|
4169 |
SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); |
4170 |
SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
|
4171 |
SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
|
4172 |
SQLITE_API double sqlite3_value_double(sqlite3_value*);
|
4173 |
SQLITE_API int sqlite3_value_int(sqlite3_value*);
|
4174 |
SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); |
4175 |
SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); |
4176 |
SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); |
4177 |
SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); |
4178 |
SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); |
4179 |
SQLITE_API int sqlite3_value_type(sqlite3_value*);
|
4180 |
SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
|
4181 |
|
4182 |
/*
|
4183 |
** CAPI3REF: Obtain Aggregate Function Context
|
4184 |
**
|
4185 |
** Implementations of aggregate SQL functions use this
|
4186 |
** routine to allocate memory for storing their state.
|
4187 |
**
|
4188 |
** ^The first time the sqlite3_aggregate_context(C,N) routine is called
|
4189 |
** for a particular aggregate function, SQLite
|
4190 |
** allocates N of memory, zeroes out that memory, and returns a pointer
|
4191 |
** to the new memory. ^On second and subsequent calls to
|
4192 |
** sqlite3_aggregate_context() for the same aggregate function instance,
|
4193 |
** the same buffer is returned. Sqlite3_aggregate_context() is normally
|
4194 |
** called once for each invocation of the xStep callback and then one
|
4195 |
** last time when the xFinal callback is invoked. ^(When no rows match
|
4196 |
** an aggregate query, the xStep() callback of the aggregate function
|
4197 |
** implementation is never called and xFinal() is called exactly once.
|
4198 |
** In those cases, sqlite3_aggregate_context() might be called for the
|
4199 |
** first time from within xFinal().)^
|
4200 |
**
|
4201 |
** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
|
4202 |
** when first called if N is less than or equal to zero or if a memory
|
4203 |
** allocate error occurs.
|
4204 |
**
|
4205 |
** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
|
4206 |
** determined by the N parameter on first successful call. Changing the
|
4207 |
** value of N in subsequent call to sqlite3_aggregate_context() within
|
4208 |
** the same aggregate function instance will not resize the memory
|
4209 |
** allocation.)^ Within the xFinal callback, it is customary to set
|
4210 |
** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
|
4211 |
** pointless memory allocations occur.
|
4212 |
**
|
4213 |
** ^SQLite automatically frees the memory allocated by
|
4214 |
** sqlite3_aggregate_context() when the aggregate query concludes.
|
4215 |
**
|
4216 |
** The first parameter must be a copy of the
|
4217 |
** [sqlite3_context | SQL function context] that is the first parameter
|
4218 |
** to the xStep or xFinal callback routine that implements the aggregate
|
4219 |
** function.
|
4220 |
**
|
4221 |
** This routine must be called from the same thread in which
|
4222 |
** the aggregate SQL function is running.
|
4223 |
*/
|
4224 |
SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); |
4225 |
|
4226 |
/*
|
4227 |
** CAPI3REF: User Data For Functions
|
4228 |
**
|
4229 |
** ^The sqlite3_user_data() interface returns a copy of
|
4230 |
** the pointer that was the pUserData parameter (the 5th parameter)
|
4231 |
** of the [sqlite3_create_function()]
|
4232 |
** and [sqlite3_create_function16()] routines that originally
|
4233 |
** registered the application defined function.
|
4234 |
**
|
4235 |
** This routine must be called from the same thread in which
|
4236 |
** the application-defined function is running.
|
4237 |
*/
|
4238 |
SQLITE_API void *sqlite3_user_data(sqlite3_context*);
|
4239 |
|
4240 |
/*
|
4241 |
** CAPI3REF: Database Connection For Functions
|
4242 |
**
|
4243 |
** ^The sqlite3_context_db_handle() interface returns a copy of
|
4244 |
** the pointer to the [database connection] (the 1st parameter)
|
4245 |
** of the [sqlite3_create_function()]
|
4246 |
** and [sqlite3_create_function16()] routines that originally
|
4247 |
** registered the application defined function.
|
4248 |
*/
|
4249 |
SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); |
4250 |
|
4251 |
/*
|
4252 |
** CAPI3REF: Function Auxiliary Data
|
4253 |
**
|
4254 |
** These functions may be used by (non-aggregate) SQL functions to
|
4255 |
** associate metadata with argument values. If the same value is passed to
|
4256 |
** multiple invocations of the same SQL function during query execution, under
|
4257 |
** some circumstances the associated metadata may be preserved. An example
|
4258 |
** of where this might be useful is in a regular-expression matching
|
4259 |
** function. The compiled version of the regular expression can be stored as
|
4260 |
** metadata associated with the pattern string.
|
4261 |
** Then as long as the pattern string remains the same,
|
4262 |
** the compiled regular expression can be reused on multiple
|
4263 |
** invocations of the same function.
|
4264 |
**
|
4265 |
** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata
|
4266 |
** associated by the sqlite3_set_auxdata() function with the Nth argument
|
4267 |
** value to the application-defined function. ^If there is no metadata
|
4268 |
** associated with the function argument, this sqlite3_get_auxdata() interface
|
4269 |
** returns a NULL pointer.
|
4270 |
**
|
4271 |
** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
|
4272 |
** argument of the application-defined function. ^Subsequent
|
4273 |
** calls to sqlite3_get_auxdata(C,N) return P from the most recent
|
4274 |
** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
|
4275 |
** NULL if the metadata has been discarded.
|
4276 |
** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
|
4277 |
** SQLite will invoke the destructor function X with parameter P exactly
|
4278 |
** once, when the metadata is discarded.
|
4279 |
** SQLite is free to discard the metadata at any time, including: <ul>
|
4280 |
** <li> when the corresponding function parameter changes, or
|
4281 |
** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
|
4282 |
** SQL statement, or
|
4283 |
** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or
|
4284 |
** <li> during the original sqlite3_set_auxdata() call when a memory
|
4285 |
** allocation error occurs. </ul>)^
|
4286 |
**
|
4287 |
** Note the last bullet in particular. The destructor X in
|
4288 |
** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
|
4289 |
** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
|
4290 |
** should be called near the end of the function implementation and the
|
4291 |
** function implementation should not make any use of P after
|
4292 |
** sqlite3_set_auxdata() has been called.
|
4293 |
**
|
4294 |
** ^(In practice, metadata is preserved between function calls for
|
4295 |
** function parameters that are compile-time constants, including literal
|
4296 |
** values and [parameters] and expressions composed from the same.)^
|
4297 |
**
|
4298 |
** These routines must be called from the same thread in which
|
4299 |
** the SQL function is running.
|
4300 |
*/
|
4301 |
SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); |
4302 |
SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); |
4303 |
|
4304 |
|
4305 |
/*
|
4306 |
** CAPI3REF: Constants Defining Special Destructor Behavior
|
4307 |
**
|
4308 |
** These are special values for the destructor that is passed in as the
|
4309 |
** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
|
4310 |
** argument is SQLITE_STATIC, it means that the content pointer is constant
|
4311 |
** and will never change. It does not need to be destroyed. ^The
|
4312 |
** SQLITE_TRANSIENT value means that the content will likely change in
|
4313 |
** the near future and that SQLite should make its own private copy of
|
4314 |
** the content before returning.
|
4315 |
**
|
4316 |
** The typedef is necessary to work around problems in certain
|
4317 |
** C++ compilers.
|
4318 |
*/
|
4319 |
typedef void (*sqlite3_destructor_type)(void*); |
4320 |
#define SQLITE_STATIC ((sqlite3_destructor_type)0) |
4321 |
#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) |
4322 |
|
4323 |
/*
|
4324 |
** CAPI3REF: Setting The Result Of An SQL Function
|
4325 |
**
|
4326 |
** These routines are used by the xFunc or xFinal callbacks that
|
4327 |
** implement SQL functions and aggregates. See
|
4328 |
** [sqlite3_create_function()] and [sqlite3_create_function16()]
|
4329 |
** for additional information.
|
4330 |
**
|
4331 |
** These functions work very much like the [parameter binding] family of
|
4332 |
** functions used to bind values to host parameters in prepared statements.
|
4333 |
** Refer to the [SQL parameter] documentation for additional information.
|
4334 |
**
|
4335 |
** ^The sqlite3_result_blob() interface sets the result from
|
4336 |
** an application-defined function to be the BLOB whose content is pointed
|
4337 |
** to by the second parameter and which is N bytes long where N is the
|
4338 |
** third parameter.
|
4339 |
**
|
4340 |
** ^The sqlite3_result_zeroblob() interfaces set the result of
|
4341 |
** the application-defined function to be a BLOB containing all zero
|
4342 |
** bytes and N bytes in size, where N is the value of the 2nd parameter.
|
4343 |
**
|
4344 |
** ^The sqlite3_result_double() interface sets the result from
|
4345 |
** an application-defined function to be a floating point value specified
|
4346 |
** by its 2nd argument.
|
4347 |
**
|
4348 |
** ^The sqlite3_result_error() and sqlite3_result_error16() functions
|
4349 |
** cause the implemented SQL function to throw an exception.
|
4350 |
** ^SQLite uses the string pointed to by the
|
4351 |
** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
|
4352 |
** as the text of an error message. ^SQLite interprets the error
|
4353 |
** message string from sqlite3_result_error() as UTF-8. ^SQLite
|
4354 |
** interprets the string from sqlite3_result_error16() as UTF-16 in native
|
4355 |
** byte order. ^If the third parameter to sqlite3_result_error()
|
4356 |
** or sqlite3_result_error16() is negative then SQLite takes as the error
|
4357 |
** message all text up through the first zero character.
|
4358 |
** ^If the third parameter to sqlite3_result_error() or
|
4359 |
** sqlite3_result_error16() is non-negative then SQLite takes that many
|
4360 |
** bytes (not characters) from the 2nd parameter as the error message.
|
4361 |
** ^The sqlite3_result_error() and sqlite3_result_error16()
|
4362 |
** routines make a private copy of the error message text before
|
4363 |
** they return. Hence, the calling function can deallocate or
|
4364 |
** modify the text after they return without harm.
|
4365 |
** ^The sqlite3_result_error_code() function changes the error code
|
4366 |
** returned by SQLite as a result of an error in a function. ^By default,
|
4367 |
** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
|
4368 |
** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
|
4369 |
**
|
4370 |
** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
|
4371 |
** error indicating that a string or BLOB is too long to represent.
|
4372 |
**
|
4373 |
** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
|
4374 |
** error indicating that a memory allocation failed.
|
4375 |
**
|
4376 |
** ^The sqlite3_result_int() interface sets the return value
|
4377 |
** of the application-defined function to be the 32-bit signed integer
|
4378 |
** value given in the 2nd argument.
|
4379 |
** ^The sqlite3_result_int64() interface sets the return value
|
4380 |
** of the application-defined function to be the 64-bit signed integer
|
4381 |
** value given in the 2nd argument.
|
4382 |
**
|
4383 |
** ^The sqlite3_result_null() interface sets the return value
|
4384 |
** of the application-defined function to be NULL.
|
4385 |
**
|
4386 |
** ^The sqlite3_result_text(), sqlite3_result_text16(),
|
4387 |
** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
|
4388 |
** set the return value of the application-defined function to be
|
4389 |
** a text string which is represented as UTF-8, UTF-16 native byte order,
|
4390 |
** UTF-16 little endian, or UTF-16 big endian, respectively.
|
4391 |
** ^SQLite takes the text result from the application from
|
4392 |
** the 2nd parameter of the sqlite3_result_text* interfaces.
|
4393 |
** ^If the 3rd parameter to the sqlite3_result_text* interfaces
|
4394 |
** is negative, then SQLite takes result text from the 2nd parameter
|
4395 |
** through the first zero character.
|
4396 |
** ^If the 3rd parameter to the sqlite3_result_text* interfaces
|
4397 |
** is non-negative, then as many bytes (not characters) of the text
|
4398 |
** pointed to by the 2nd parameter are taken as the application-defined
|
4399 |
** function result. If the 3rd parameter is non-negative, then it
|
4400 |
** must be the byte offset into the string where the NUL terminator would
|
4401 |
** appear if the string where NUL terminated. If any NUL characters occur
|
4402 |
** in the string at a byte offset that is less than the value of the 3rd
|
4403 |
** parameter, then the resulting string will contain embedded NULs and the
|
4404 |
** result of expressions operating on strings with embedded NULs is undefined.
|
4405 |
** ^If the 4th parameter to the sqlite3_result_text* interfaces
|
4406 |
** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
|
4407 |
** function as the destructor on the text or BLOB result when it has
|
4408 |
** finished using that result.
|
4409 |
** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
|
4410 |
** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
|
4411 |
** assumes that the text or BLOB result is in constant space and does not
|
4412 |
** copy the content of the parameter nor call a destructor on the content
|
4413 |
** when it has finished using that result.
|
4414 |
** ^If the 4th parameter to the sqlite3_result_text* interfaces
|
4415 |
** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
|
4416 |
** then SQLite makes a copy of the result into space obtained from
|
4417 |
** from [sqlite3_malloc()] before it returns.
|
4418 |
**
|
4419 |
** ^The sqlite3_result_value() interface sets the result of
|
4420 |
** the application-defined function to be a copy the
|
4421 |
** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
|
4422 |
** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
|
4423 |
** so that the [sqlite3_value] specified in the parameter may change or
|
4424 |
** be deallocated after sqlite3_result_value() returns without harm.
|
4425 |
** ^A [protected sqlite3_value] object may always be used where an
|
4426 |
** [unprotected sqlite3_value] object is required, so either
|
4427 |
** kind of [sqlite3_value] object can be used with this interface.
|
4428 |
**
|
4429 |
** If these routines are called from within the different thread
|
4430 |
** than the one containing the application-defined function that received
|
4431 |
** the [sqlite3_context] pointer, the results are undefined.
|
4432 |
*/
|
4433 |
SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); |
4434 |
SQLITE_API void sqlite3_result_double(sqlite3_context*, double); |
4435 |
SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); |
4436 |
SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); |
4437 |
SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
|
4438 |
SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
|
4439 |
SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); |
4440 |
SQLITE_API void sqlite3_result_int(sqlite3_context*, int); |
4441 |
SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
|
4442 |
SQLITE_API void sqlite3_result_null(sqlite3_context*);
|
4443 |
SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); |
4444 |
SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); |
4445 |
SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); |
4446 |
SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); |
4447 |
SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
|
4448 |
SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); |
4449 |
|
4450 |
/*
|
4451 |
** CAPI3REF: Define New Collating Sequences
|
4452 |
**
|
4453 |
** ^These functions add, remove, or modify a [collation] associated
|
4454 |
** with the [database connection] specified as the first argument.
|
4455 |
**
|
4456 |
** ^The name of the collation is a UTF-8 string
|
4457 |
** for sqlite3_create_collation() and sqlite3_create_collation_v2()
|
4458 |
** and a UTF-16 string in native byte order for sqlite3_create_collation16().
|
4459 |
** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
|
4460 |
** considered to be the same name.
|
4461 |
**
|
4462 |
** ^(The third argument (eTextRep) must be one of the constants:
|
4463 |
** <ul>
|
4464 |
** <li> [SQLITE_UTF8],
|
4465 |
** <li> [SQLITE_UTF16LE],
|
4466 |
** <li> [SQLITE_UTF16BE],
|
4467 |
** <li> [SQLITE_UTF16], or
|
4468 |
** <li> [SQLITE_UTF16_ALIGNED].
|
4469 |
** </ul>)^
|
4470 |
** ^The eTextRep argument determines the encoding of strings passed
|
4471 |
** to the collating function callback, xCallback.
|
4472 |
** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
|
4473 |
** force strings to be UTF16 with native byte order.
|
4474 |
** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
|
4475 |
** on an even byte address.
|
4476 |
**
|
4477 |
** ^The fourth argument, pArg, is an application data pointer that is passed
|
4478 |
** through as the first argument to the collating function callback.
|
4479 |
**
|
4480 |
** ^The fifth argument, xCallback, is a pointer to the collating function.
|
4481 |
** ^Multiple collating functions can be registered using the same name but
|
4482 |
** with different eTextRep parameters and SQLite will use whichever
|
4483 |
** function requires the least amount of data transformation.
|
4484 |
** ^If the xCallback argument is NULL then the collating function is
|
4485 |
** deleted. ^When all collating functions having the same name are deleted,
|
4486 |
** that collation is no longer usable.
|
4487 |
**
|
4488 |
** ^The collating function callback is invoked with a copy of the pArg
|
4489 |
** application data pointer and with two strings in the encoding specified
|
4490 |
** by the eTextRep argument. The collating function must return an
|
4491 |
** integer that is negative, zero, or positive
|
4492 |
** if the first string is less than, equal to, or greater than the second,
|
4493 |
** respectively. A collating function must always return the same answer
|
4494 |
** given the same inputs. If two or more collating functions are registered
|
4495 |
** to the same collation name (using different eTextRep values) then all
|
4496 |
** must give an equivalent answer when invoked with equivalent strings.
|
4497 |
** The collating function must obey the following properties for all
|
4498 |
** strings A, B, and C:
|
4499 |
**
|
4500 |
** <ol>
|
4501 |
** <li> If A==B then B==A.
|
4502 |
** <li> If A==B and B==C then A==C.
|
4503 |
** <li> If A<B THEN B>A.
|
4504 |
** <li> If A<B and B<C then A<C.
|
4505 |
** </ol>
|
4506 |
**
|
4507 |
** If a collating function fails any of the above constraints and that
|
4508 |
** collating function is registered and used, then the behavior of SQLite
|
4509 |
** is undefined.
|
4510 |
**
|
4511 |
** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
|
4512 |
** with the addition that the xDestroy callback is invoked on pArg when
|
4513 |
** the collating function is deleted.
|
4514 |
** ^Collating functions are deleted when they are overridden by later
|
4515 |
** calls to the collation creation functions or when the
|
4516 |
** [database connection] is closed using [sqlite3_close()].
|
4517 |
**
|
4518 |
** ^The xDestroy callback is <u>not</u> called if the
|
4519 |
** sqlite3_create_collation_v2() function fails. Applications that invoke
|
4520 |
** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
|
4521 |
** check the return code and dispose of the application data pointer
|
4522 |
** themselves rather than expecting SQLite to deal with it for them.
|
4523 |
** This is different from every other SQLite interface. The inconsistency
|
4524 |
** is unfortunate but cannot be changed without breaking backwards
|
4525 |
** compatibility.
|
4526 |
**
|
4527 |
** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
|
4528 |
*/
|
4529 |
SQLITE_API int sqlite3_create_collation(
|
4530 |
sqlite3*, |
4531 |
const char *zName, |
4532 |
int eTextRep,
|
4533 |
void *pArg,
|
4534 |
int(*xCompare)(void*,int,const void*,int,const void*) |
4535 |
); |
4536 |
SQLITE_API int sqlite3_create_collation_v2(
|
4537 |
sqlite3*, |
4538 |
const char *zName, |
4539 |
int eTextRep,
|
4540 |
void *pArg,
|
4541 |
int(*xCompare)(void*,int,const void*,int,const void*), |
4542 |
void(*xDestroy)(void*) |
4543 |
); |
4544 |
SQLITE_API int sqlite3_create_collation16(
|
4545 |
sqlite3*, |
4546 |
const void *zName, |
4547 |
int eTextRep,
|
4548 |
void *pArg,
|
4549 |
int(*xCompare)(void*,int,const void*,int,const void*) |
4550 |
); |
4551 |
|
4552 |
/*
|
4553 |
** CAPI3REF: Collation Needed Callbacks
|
4554 |
**
|
4555 |
** ^To avoid having to register all collation sequences before a database
|
4556 |
** can be used, a single callback function may be registered with the
|
4557 |
** [database connection] to be invoked whenever an undefined collation
|
4558 |
** sequence is required.
|
4559 |
**
|
4560 |
** ^If the function is registered using the sqlite3_collation_needed() API,
|
4561 |
** then it is passed the names of undefined collation sequences as strings
|
4562 |
** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
|
4563 |
** the names are passed as UTF-16 in machine native byte order.
|
4564 |
** ^A call to either function replaces the existing collation-needed callback.
|
4565 |
**
|
4566 |
** ^(When the callback is invoked, the first argument passed is a copy
|
4567 |
** of the second argument to sqlite3_collation_needed() or
|
4568 |
** sqlite3_collation_needed16(). The second argument is the database
|
4569 |
** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
|
4570 |
** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
|
4571 |
** sequence function required. The fourth parameter is the name of the
|
4572 |
** required collation sequence.)^
|
4573 |
**
|
4574 |
** The callback function should register the desired collation using
|
4575 |
** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
|
4576 |
** [sqlite3_create_collation_v2()].
|
4577 |
*/
|
4578 |
SQLITE_API int sqlite3_collation_needed(
|
4579 |
sqlite3*, |
4580 |
void*,
|
4581 |
void(*)(void*,sqlite3*,int eTextRep,const char*) |
4582 |
); |
4583 |
SQLITE_API int sqlite3_collation_needed16(
|
4584 |
sqlite3*, |
4585 |
void*,
|
4586 |
void(*)(void*,sqlite3*,int eTextRep,const void*) |
4587 |
); |
4588 |
|
4589 |
#ifdef SQLITE_HAS_CODEC
|
4590 |
/*
|
4591 |
** Specify the key for an encrypted database. This routine should be
|
4592 |
** called right after sqlite3_open().
|
4593 |
**
|
4594 |
** The code to implement this API is not available in the public release
|
4595 |
** of SQLite.
|
4596 |
*/
|
4597 |
SQLITE_API int sqlite3_key(
|
4598 |
sqlite3 *db, /* Database to be rekeyed */
|
4599 |
const void *pKey, int nKey /* The key */ |
4600 |
); |
4601 |
SQLITE_API int sqlite3_key_v2(
|
4602 |
sqlite3 *db, /* Database to be rekeyed */
|
4603 |
const char *zDbName, /* Name of the database */ |
4604 |
const void *pKey, int nKey /* The key */ |
4605 |
); |
4606 |
|
4607 |
/*
|
4608 |
** Change the key on an open database. If the current database is not
|
4609 |
** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the
|
4610 |
** database is decrypted.
|
4611 |
**
|
4612 |
** The code to implement this API is not available in the public release
|
4613 |
** of SQLite.
|
4614 |
*/
|
4615 |
SQLITE_API int sqlite3_rekey(
|
4616 |
sqlite3 *db, /* Database to be rekeyed */
|
4617 |
const void *pKey, int nKey /* The new key */ |
4618 |
); |
4619 |
SQLITE_API int sqlite3_rekey_v2(
|
4620 |
sqlite3 *db, /* Database to be rekeyed */
|
4621 |
const char *zDbName, /* Name of the database */ |
4622 |
const void *pKey, int nKey /* The new key */ |
4623 |
); |
4624 |
|
4625 |
/*
|
4626 |
** Specify the activation key for a SEE database. Unless
|
4627 |
** activated, none of the SEE routines will work.
|
4628 |
*/
|
4629 |
SQLITE_API void sqlite3_activate_see(
|
4630 |
const char *zPassPhrase /* Activation phrase */ |
4631 |
); |
4632 |
#endif
|
4633 |
|
4634 |
#ifdef SQLITE_ENABLE_CEROD
|
4635 |
/*
|
4636 |
** Specify the activation key for a CEROD database. Unless
|
4637 |
** activated, none of the CEROD routines will work.
|
4638 |
*/
|
4639 |
SQLITE_API void sqlite3_activate_cerod(
|
4640 |
const char *zPassPhrase /* Activation phrase */ |
4641 |
); |
4642 |
#endif
|
4643 |
|
4644 |
/*
|
4645 |
** CAPI3REF: Suspend Execution For A Short Time
|
4646 |
**
|
4647 |
** The sqlite3_sleep() function causes the current thread to suspend execution
|
4648 |
** for at least a number of milliseconds specified in its parameter.
|
4649 |
**
|
4650 |
** If the operating system does not support sleep requests with
|
4651 |
** millisecond time resolution, then the time will be rounded up to
|
4652 |
** the nearest second. The number of milliseconds of sleep actually
|
4653 |
** requested from the operating system is returned.
|
4654 |
**
|
4655 |
** ^SQLite implements this interface by calling the xSleep()
|
4656 |
** method of the default [sqlite3_vfs] object. If the xSleep() method
|
4657 |
** of the default VFS is not implemented correctly, or not implemented at
|
4658 |
** all, then the behavior of sqlite3_sleep() may deviate from the description
|
4659 |
** in the previous paragraphs.
|
4660 |
*/
|
4661 |
SQLITE_API int sqlite3_sleep(int); |
4662 |
|
4663 |
/*
|
4664 |
** CAPI3REF: Name Of The Folder Holding Temporary Files
|
4665 |
**
|
4666 |
** ^(If this global variable is made to point to a string which is
|
4667 |
** the name of a folder (a.k.a. directory), then all temporary files
|
4668 |
** created by SQLite when using a built-in [sqlite3_vfs | VFS]
|
4669 |
** will be placed in that directory.)^ ^If this variable
|
4670 |
** is a NULL pointer, then SQLite performs a search for an appropriate
|
4671 |
** temporary file directory.
|
4672 |
**
|
4673 |
** It is not safe to read or modify this variable in more than one
|
4674 |
** thread at a time. It is not safe to read or modify this variable
|
4675 |
** if a [database connection] is being used at the same time in a separate
|
4676 |
** thread.
|
4677 |
** It is intended that this variable be set once
|
4678 |
** as part of process initialization and before any SQLite interface
|
4679 |
** routines have been called and that this variable remain unchanged
|
4680 |
** thereafter.
|
4681 |
**
|
4682 |
** ^The [temp_store_directory pragma] may modify this variable and cause
|
4683 |
** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
|
4684 |
** the [temp_store_directory pragma] always assumes that any string
|
4685 |
** that this variable points to is held in memory obtained from
|
4686 |
** [sqlite3_malloc] and the pragma may attempt to free that memory
|
4687 |
** using [sqlite3_free].
|
4688 |
** Hence, if this variable is modified directly, either it should be
|
4689 |
** made NULL or made to point to memory obtained from [sqlite3_malloc]
|
4690 |
** or else the use of the [temp_store_directory pragma] should be avoided.
|
4691 |
**
|
4692 |
** <b>Note to Windows Runtime users:</b> The temporary directory must be set
|
4693 |
** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
|
4694 |
** features that require the use of temporary files may fail. Here is an
|
4695 |
** example of how to do this using C++ with the Windows Runtime:
|
4696 |
**
|
4697 |
** <blockquote><pre>
|
4698 |
** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
|
4699 |
** TemporaryFolder->Path->Data();
|
4700 |
** char zPathBuf[MAX_PATH + 1];
|
4701 |
** memset(zPathBuf, 0, sizeof(zPathBuf));
|
4702 |
** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
|
4703 |
** NULL, NULL);
|
4704 |
** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
|
4705 |
** </pre></blockquote>
|
4706 |
*/
|
4707 |
SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
|
4708 |
|
4709 |
/*
|
4710 |
** CAPI3REF: Name Of The Folder Holding Database Files
|
4711 |
**
|
4712 |
** ^(If this global variable is made to point to a string which is
|
4713 |
** the name of a folder (a.k.a. directory), then all database files
|
4714 |
** specified with a relative pathname and created or accessed by
|
4715 |
** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
|
4716 |
** to be relative to that directory.)^ ^If this variable is a NULL
|
4717 |
** pointer, then SQLite assumes that all database files specified
|
4718 |
** with a relative pathname are relative to the current directory
|
4719 |
** for the process. Only the windows VFS makes use of this global
|
4720 |
** variable; it is ignored by the unix VFS.
|
4721 |
**
|
4722 |
** Changing the value of this variable while a database connection is
|
4723 |
** open can result in a corrupt database.
|
4724 |
**
|
4725 |
** It is not safe to read or modify this variable in more than one
|
4726 |
** thread at a time. It is not safe to read or modify this variable
|
4727 |
** if a [database connection] is being used at the same time in a separate
|
4728 |
** thread.
|
4729 |
** It is intended that this variable be set once
|
4730 |
** as part of process initialization and before any SQLite interface
|
4731 |
** routines have been called and that this variable remain unchanged
|
4732 |
** thereafter.
|
4733 |
**
|
4734 |
** ^The [data_store_directory pragma] may modify this variable and cause
|
4735 |
** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
|
4736 |
** the [data_store_directory pragma] always assumes that any string
|
4737 |
** that this variable points to is held in memory obtained from
|
4738 |
** [sqlite3_malloc] and the pragma may attempt to free that memory
|
4739 |
** using [sqlite3_free].
|
4740 |
** Hence, if this variable is modified directly, either it should be
|
4741 |
** made NULL or made to point to memory obtained from [sqlite3_malloc]
|
4742 |
** or else the use of the [data_store_directory pragma] should be avoided.
|
4743 |
*/
|
4744 |
SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
|
4745 |
|
4746 |
/*
|
4747 |
** CAPI3REF: Test For Auto-Commit Mode
|
4748 |
** KEYWORDS: {autocommit mode}
|
4749 |
**
|
4750 |
** ^The sqlite3_get_autocommit() interface returns non-zero or
|
4751 |
** zero if the given database connection is or is not in autocommit mode,
|
4752 |
** respectively. ^Autocommit mode is on by default.
|
4753 |
** ^Autocommit mode is disabled by a [BEGIN] statement.
|
4754 |
** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
|
4755 |
**
|
4756 |
** If certain kinds of errors occur on a statement within a multi-statement
|
4757 |
** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
|
4758 |
** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
|
4759 |
** transaction might be rolled back automatically. The only way to
|
4760 |
** find out whether SQLite automatically rolled back the transaction after
|
4761 |
** an error is to use this function.
|
4762 |
**
|
4763 |
** If another thread changes the autocommit status of the database
|
4764 |
** connection while this routine is running, then the return value
|
4765 |
** is undefined.
|
4766 |
*/
|
4767 |
SQLITE_API int sqlite3_get_autocommit(sqlite3*);
|
4768 |
|
4769 |
/*
|
4770 |
** CAPI3REF: Find The Database Handle Of A Prepared Statement
|
4771 |
**
|
4772 |
** ^The sqlite3_db_handle interface returns the [database connection] handle
|
4773 |
** to which a [prepared statement] belongs. ^The [database connection]
|
4774 |
** returned by sqlite3_db_handle is the same [database connection]
|
4775 |
** that was the first argument
|
4776 |
** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
|
4777 |
** create the statement in the first place.
|
4778 |
*/
|
4779 |
SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); |
4780 |
|
4781 |
/*
|
4782 |
** CAPI3REF: Return The Filename For A Database Connection
|
4783 |
**
|
4784 |
** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename
|
4785 |
** associated with database N of connection D. ^The main database file
|
4786 |
** has the name "main". If there is no attached database N on the database
|
4787 |
** connection D, or if database N is a temporary or in-memory database, then
|
4788 |
** a NULL pointer is returned.
|
4789 |
**
|
4790 |
** ^The filename returned by this function is the output of the
|
4791 |
** xFullPathname method of the [VFS]. ^In other words, the filename
|
4792 |
** will be an absolute pathname, even if the filename used
|
4793 |
** to open the database originally was a URI or relative pathname.
|
4794 |
*/
|
4795 |
SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); |
4796 |
|
4797 |
/*
|
4798 |
** CAPI3REF: Determine if a database is read-only
|
4799 |
**
|
4800 |
** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
|
4801 |
** of connection D is read-only, 0 if it is read/write, or -1 if N is not
|
4802 |
** the name of a database on connection D.
|
4803 |
*/
|
4804 |
SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); |
4805 |
|
4806 |
/*
|
4807 |
** CAPI3REF: Find the next prepared statement
|
4808 |
**
|
4809 |
** ^This interface returns a pointer to the next [prepared statement] after
|
4810 |
** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
|
4811 |
** then this interface returns a pointer to the first prepared statement
|
4812 |
** associated with the database connection pDb. ^If no prepared statement
|
4813 |
** satisfies the conditions of this routine, it returns NULL.
|
4814 |
**
|
4815 |
** The [database connection] pointer D in a call to
|
4816 |
** [sqlite3_next_stmt(D,S)] must refer to an open database
|
4817 |
** connection and in particular must not be a NULL pointer.
|
4818 |
*/
|
4819 |
SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); |
4820 |
|
4821 |
/*
|
4822 |
** CAPI3REF: Commit And Rollback Notification Callbacks
|
4823 |
**
|
4824 |
** ^The sqlite3_commit_hook() interface registers a callback
|
4825 |
** function to be invoked whenever a transaction is [COMMIT | committed].
|
4826 |
** ^Any callback set by a previous call to sqlite3_commit_hook()
|
4827 |
** for the same database connection is overridden.
|
4828 |
** ^The sqlite3_rollback_hook() interface registers a callback
|
4829 |
** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
|
4830 |
** ^Any callback set by a previous call to sqlite3_rollback_hook()
|
4831 |
** for the same database connection is overridden.
|
4832 |
** ^The pArg argument is passed through to the callback.
|
4833 |
** ^If the callback on a commit hook function returns non-zero,
|
4834 |
** then the commit is converted into a rollback.
|
4835 |
**
|
4836 |
** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
|
4837 |
** return the P argument from the previous call of the same function
|
4838 |
** on the same [database connection] D, or NULL for
|
4839 |
** the first call for each function on D.
|
4840 |
**
|
4841 |
** The commit and rollback hook callbacks are not reentrant.
|
4842 |
** The callback implementation must not do anything that will modify
|
4843 |
** the database connection that invoked the callback. Any actions
|
4844 |
** to modify the database connection must be deferred until after the
|
4845 |
** completion of the [sqlite3_step()] call that triggered the commit
|
4846 |
** or rollback hook in the first place.
|
4847 |
** Note that running any other SQL statements, including SELECT statements,
|
4848 |
** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
|
4849 |
** the database connections for the meaning of "modify" in this paragraph.
|
4850 |
**
|
4851 |
** ^Registering a NULL function disables the callback.
|
4852 |
**
|
4853 |
** ^When the commit hook callback routine returns zero, the [COMMIT]
|
4854 |
** operation is allowed to continue normally. ^If the commit hook
|
4855 |
** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
|
4856 |
** ^The rollback hook is invoked on a rollback that results from a commit
|
4857 |
** hook returning non-zero, just as it would be with any other rollback.
|
4858 |
**
|
4859 |
** ^For the purposes of this API, a transaction is said to have been
|
4860 |
** rolled back if an explicit "ROLLBACK" statement is executed, or
|
4861 |
** an error or constraint causes an implicit rollback to occur.
|
4862 |
** ^The rollback callback is not invoked if a transaction is
|
4863 |
** automatically rolled back because the database connection is closed.
|
4864 |
**
|
4865 |
** See also the [sqlite3_update_hook()] interface.
|
4866 |
*/
|
4867 |
SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); |
4868 |
SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); |
4869 |
|
4870 |
/*
|
4871 |
** CAPI3REF: Data Change Notification Callbacks
|
4872 |
**
|
4873 |
** ^The sqlite3_update_hook() interface registers a callback function
|
4874 |
** with the [database connection] identified by the first argument
|
4875 |
** to be invoked whenever a row is updated, inserted or deleted in
|
4876 |
** a rowid table.
|
4877 |
** ^Any callback set by a previous call to this function
|
4878 |
** for the same database connection is overridden.
|
4879 |
**
|
4880 |
** ^The second argument is a pointer to the function to invoke when a
|
4881 |
** row is updated, inserted or deleted in a rowid table.
|
4882 |
** ^The first argument to the callback is a copy of the third argument
|
4883 |
** to sqlite3_update_hook().
|
4884 |
** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
|
4885 |
** or [SQLITE_UPDATE], depending on the operation that caused the callback
|
4886 |
** to be invoked.
|
4887 |
** ^The third and fourth arguments to the callback contain pointers to the
|
4888 |
** database and table name containing the affected row.
|
4889 |
** ^The final callback parameter is the [rowid] of the row.
|
4890 |
** ^In the case of an update, this is the [rowid] after the update takes place.
|
4891 |
**
|
4892 |
** ^(The update hook is not invoked when internal system tables are
|
4893 |
** modified (i.e. sqlite_master and sqlite_sequence).)^
|
4894 |
** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
|
4895 |
**
|
4896 |
** ^In the current implementation, the update hook
|
4897 |
** is not invoked when duplication rows are deleted because of an
|
4898 |
** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
|
4899 |
** invoked when rows are deleted using the [truncate optimization].
|
4900 |
** The exceptions defined in this paragraph might change in a future
|
4901 |
** release of SQLite.
|
4902 |
**
|
4903 |
** The update hook implementation must not do anything that will modify
|
4904 |
** the database connection that invoked the update hook. Any actions
|
4905 |
** to modify the database connection must be deferred until after the
|
4906 |
** completion of the [sqlite3_step()] call that triggered the update hook.
|
4907 |
** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
|
4908 |
** database connections for the meaning of "modify" in this paragraph.
|
4909 |
**
|
4910 |
** ^The sqlite3_update_hook(D,C,P) function
|
4911 |
** returns the P argument from the previous call
|
4912 |
** on the same [database connection] D, or NULL for
|
4913 |
** the first call on D.
|
4914 |
**
|
4915 |
** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()]
|
4916 |
** interfaces.
|
4917 |
*/
|
4918 |
SQLITE_API void *sqlite3_update_hook(
|
4919 |
sqlite3*, |
4920 |
void(*)(void *,int ,char const *,char const *,sqlite3_int64), |
4921 |
void*
|
4922 |
); |
4923 |
|
4924 |
/*
|
4925 |
** CAPI3REF: Enable Or Disable Shared Pager Cache
|
4926 |
**
|
4927 |
** ^(This routine enables or disables the sharing of the database cache
|
4928 |
** and schema data structures between [database connection | connections]
|
4929 |
** to the same database. Sharing is enabled if the argument is true
|
4930 |
** and disabled if the argument is false.)^
|
4931 |
**
|
4932 |
** ^Cache sharing is enabled and disabled for an entire process.
|
4933 |
** This is a change as of SQLite version 3.5.0. In prior versions of SQLite,
|
4934 |
** sharing was enabled or disabled for each thread separately.
|
4935 |
**
|
4936 |
** ^(The cache sharing mode set by this interface effects all subsequent
|
4937 |
** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
|
4938 |
** Existing database connections continue use the sharing mode
|
4939 |
** that was in effect at the time they were opened.)^
|
4940 |
**
|
4941 |
** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
|
4942 |
** successfully. An [error code] is returned otherwise.)^
|
4943 |
**
|
4944 |
** ^Shared cache is disabled by default. But this might change in
|
4945 |
** future releases of SQLite. Applications that care about shared
|
4946 |
** cache setting should set it explicitly.
|
4947 |
**
|
4948 |
** This interface is threadsafe on processors where writing a
|
4949 |
** 32-bit integer is atomic.
|
4950 |
**
|
4951 |
** See Also: [SQLite Shared-Cache Mode]
|
4952 |
*/
|
4953 |
SQLITE_API int sqlite3_enable_shared_cache(int); |
4954 |
|
4955 |
/*
|
4956 |
** CAPI3REF: Attempt To Free Heap Memory
|
4957 |
**
|
4958 |
** ^The sqlite3_release_memory() interface attempts to free N bytes
|
4959 |
** of heap memory by deallocating non-essential memory allocations
|
4960 |
** held by the database library. Memory used to cache database
|
4961 |
** pages to improve performance is an example of non-essential memory.
|
4962 |
** ^sqlite3_release_memory() returns the number of bytes actually freed,
|
4963 |
** which might be more or less than the amount requested.
|
4964 |
** ^The sqlite3_release_memory() routine is a no-op returning zero
|
4965 |
** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
|
4966 |
**
|
4967 |
** See also: [sqlite3_db_release_memory()]
|
4968 |
*/
|
4969 |
SQLITE_API int sqlite3_release_memory(int); |
4970 |
|
4971 |
/*
|
4972 |
** CAPI3REF: Free Memory Used By A Database Connection
|
4973 |
**
|
4974 |
** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
|
4975 |
** memory as possible from database connection D. Unlike the
|
4976 |
** [sqlite3_release_memory()] interface, this interface is in effect even
|
4977 |
** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
|
4978 |
** omitted.
|
4979 |
**
|
4980 |
** See also: [sqlite3_release_memory()]
|
4981 |
*/
|
4982 |
SQLITE_API int sqlite3_db_release_memory(sqlite3*);
|
4983 |
|
4984 |
/*
|
4985 |
** CAPI3REF: Impose A Limit On Heap Size
|
4986 |
**
|
4987 |
** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
|
4988 |
** soft limit on the amount of heap memory that may be allocated by SQLite.
|
4989 |
** ^SQLite strives to keep heap memory utilization below the soft heap
|
4990 |
** limit by reducing the number of pages held in the page cache
|
4991 |
** as heap memory usages approaches the limit.
|
4992 |
** ^The soft heap limit is "soft" because even though SQLite strives to stay
|
4993 |
** below the limit, it will exceed the limit rather than generate
|
4994 |
** an [SQLITE_NOMEM] error. In other words, the soft heap limit
|
4995 |
** is advisory only.
|
4996 |
**
|
4997 |
** ^The return value from sqlite3_soft_heap_limit64() is the size of
|
4998 |
** the soft heap limit prior to the call, or negative in the case of an
|
4999 |
** error. ^If the argument N is negative
|
5000 |
** then no change is made to the soft heap limit. Hence, the current
|
5001 |
** size of the soft heap limit can be determined by invoking
|
5002 |
** sqlite3_soft_heap_limit64() with a negative argument.
|
5003 |
**
|
5004 |
** ^If the argument N is zero then the soft heap limit is disabled.
|
5005 |
**
|
5006 |
** ^(The soft heap limit is not enforced in the current implementation
|
5007 |
** if one or more of following conditions are true:
|
5008 |
**
|
5009 |
** <ul>
|
5010 |
** <li> The soft heap limit is set to zero.
|
5011 |
** <li> Memory accounting is disabled using a combination of the
|
5012 |
** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
|
5013 |
** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
|
5014 |
** <li> An alternative page cache implementation is specified using
|
5015 |
** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
|
5016 |
** <li> The page cache allocates from its own memory pool supplied
|
5017 |
** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
|
5018 |
** from the heap.
|
5019 |
** </ul>)^
|
5020 |
**
|
5021 |
** Beginning with SQLite version 3.7.3, the soft heap limit is enforced
|
5022 |
** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT]
|
5023 |
** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT],
|
5024 |
** the soft heap limit is enforced on every memory allocation. Without
|
5025 |
** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced
|
5026 |
** when memory is allocated by the page cache. Testing suggests that because
|
5027 |
** the page cache is the predominate memory user in SQLite, most
|
5028 |
** applications will achieve adequate soft heap limit enforcement without
|
5029 |
** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT].
|
5030 |
**
|
5031 |
** The circumstances under which SQLite will enforce the soft heap limit may
|
5032 |
** changes in future releases of SQLite.
|
5033 |
*/
|
5034 |
SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); |
5035 |
|
5036 |
/*
|
5037 |
** CAPI3REF: Deprecated Soft Heap Limit Interface
|
5038 |
** DEPRECATED
|
5039 |
**
|
5040 |
** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
|
5041 |
** interface. This routine is provided for historical compatibility
|
5042 |
** only. All new applications should use the
|
5043 |
** [sqlite3_soft_heap_limit64()] interface rather than this one.
|
5044 |
*/
|
5045 |
SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); |
5046 |
|
5047 |
|
5048 |
/*
|
5049 |
** CAPI3REF: Extract Metadata About A Column Of A Table
|
5050 |
**
|
5051 |
** ^This routine returns metadata about a specific column of a specific
|
5052 |
** database table accessible using the [database connection] handle
|
5053 |
** passed as the first function argument.
|
5054 |
**
|
5055 |
** ^The column is identified by the second, third and fourth parameters to
|
5056 |
** this function. ^The second parameter is either the name of the database
|
5057 |
** (i.e. "main", "temp", or an attached database) containing the specified
|
5058 |
** table or NULL. ^If it is NULL, then all attached databases are searched
|
5059 |
** for the table using the same algorithm used by the database engine to
|
5060 |
** resolve unqualified table references.
|
5061 |
**
|
5062 |
** ^The third and fourth parameters to this function are the table and column
|
5063 |
** name of the desired column, respectively. Neither of these parameters
|
5064 |
** may be NULL.
|
5065 |
**
|
5066 |
** ^Metadata is returned by writing to the memory locations passed as the 5th
|
5067 |
** and subsequent parameters to this function. ^Any of these arguments may be
|
5068 |
** NULL, in which case the corresponding element of metadata is omitted.
|
5069 |
**
|
5070 |
** ^(<blockquote>
|
5071 |
** <table border="1">
|
5072 |
** <tr><th> Parameter <th> Output<br>Type <th> Description
|
5073 |
**
|
5074 |
** <tr><td> 5th <td> const char* <td> Data type
|
5075 |
** <tr><td> 6th <td> const char* <td> Name of default collation sequence
|
5076 |
** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
|
5077 |
** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
|
5078 |
** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
|
5079 |
** </table>
|
5080 |
** </blockquote>)^
|
5081 |
**
|
5082 |
** ^The memory pointed to by the character pointers returned for the
|
5083 |
** declaration type and collation sequence is valid only until the next
|
5084 |
** call to any SQLite API function.
|
5085 |
**
|
5086 |
** ^If the specified table is actually a view, an [error code] is returned.
|
5087 |
**
|
5088 |
** ^If the specified column is "rowid", "oid" or "_rowid_" and an
|
5089 |
** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
|
5090 |
** parameters are set for the explicitly declared column. ^(If there is no
|
5091 |
** explicitly declared [INTEGER PRIMARY KEY] column, then the output
|
5092 |
** parameters are set as follows:
|
5093 |
**
|
5094 |
** <pre>
|
5095 |
** data type: "INTEGER"
|
5096 |
** collation sequence: "BINARY"
|
5097 |
** not null: 0
|
5098 |
** primary key: 1
|
5099 |
** auto increment: 0
|
5100 |
** </pre>)^
|
5101 |
**
|
5102 |
** ^(This function may load one or more schemas from database files. If an
|
5103 |
** error occurs during this process, or if the requested table or column
|
5104 |
** cannot be found, an [error code] is returned and an error message left
|
5105 |
** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^
|
5106 |
**
|
5107 |
** ^This API is only available if the library was compiled with the
|
5108 |
** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined.
|
5109 |
*/
|
5110 |
SQLITE_API int sqlite3_table_column_metadata(
|
5111 |
sqlite3 *db, /* Connection handle */
|
5112 |
const char *zDbName, /* Database name or NULL */ |
5113 |
const char *zTableName, /* Table name */ |
5114 |
const char *zColumnName, /* Column name */ |
5115 |
char const **pzDataType, /* OUTPUT: Declared data type */ |
5116 |
char const **pzCollSeq, /* OUTPUT: Collation sequence name */ |
5117 |
int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ |
5118 |
int *pPrimaryKey, /* OUTPUT: True if column part of PK */ |
5119 |
int *pAutoinc /* OUTPUT: True if column is auto-increment */ |
5120 |
); |
5121 |
|
5122 |
/*
|
5123 |
** CAPI3REF: Load An Extension
|
5124 |
**
|
5125 |
** ^This interface loads an SQLite extension library from the named file.
|
5126 |
**
|
5127 |
** ^The sqlite3_load_extension() interface attempts to load an
|
5128 |
** [SQLite extension] library contained in the file zFile. If
|
5129 |
** the file cannot be loaded directly, attempts are made to load
|
5130 |
** with various operating-system specific extensions added.
|
5131 |
** So for example, if "samplelib" cannot be loaded, then names like
|
5132 |
** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
|
5133 |
** be tried also.
|
5134 |
**
|
5135 |
** ^The entry point is zProc.
|
5136 |
** ^(zProc may be 0, in which case SQLite will try to come up with an
|
5137 |
** entry point name on its own. It first tries "sqlite3_extension_init".
|
5138 |
** If that does not work, it constructs a name "sqlite3_X_init" where the
|
5139 |
** X is consists of the lower-case equivalent of all ASCII alphabetic
|
5140 |
** characters in the filename from the last "/" to the first following
|
5141 |
** "." and omitting any initial "lib".)^
|
5142 |
** ^The sqlite3_load_extension() interface returns
|
5143 |
** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
|
5144 |
** ^If an error occurs and pzErrMsg is not 0, then the
|
5145 |
** [sqlite3_load_extension()] interface shall attempt to
|
5146 |
** fill *pzErrMsg with error message text stored in memory
|
5147 |
** obtained from [sqlite3_malloc()]. The calling function
|
5148 |
** should free this memory by calling [sqlite3_free()].
|
5149 |
**
|
5150 |
** ^Extension loading must be enabled using
|
5151 |
** [sqlite3_enable_load_extension()] prior to calling this API,
|
5152 |
** otherwise an error will be returned.
|
5153 |
**
|
5154 |
** See also the [load_extension() SQL function].
|
5155 |
*/
|
5156 |
SQLITE_API int sqlite3_load_extension(
|
5157 |
sqlite3 *db, /* Load the extension into this database connection */
|
5158 |
const char *zFile, /* Name of the shared library containing extension */ |
5159 |
const char *zProc, /* Entry point. Derived from zFile if 0 */ |
5160 |
char **pzErrMsg /* Put error message here if not 0 */ |
5161 |
); |
5162 |
|
5163 |
/*
|
5164 |
** CAPI3REF: Enable Or Disable Extension Loading
|
5165 |
**
|
5166 |
** ^So as not to open security holes in older applications that are
|
5167 |
** unprepared to deal with [extension loading], and as a means of disabling
|
5168 |
** [extension loading] while evaluating user-entered SQL, the following API
|
5169 |
** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
|
5170 |
**
|
5171 |
** ^Extension loading is off by default.
|
5172 |
** ^Call the sqlite3_enable_load_extension() routine with onoff==1
|
5173 |
** to turn extension loading on and call it with onoff==0 to turn
|
5174 |
** it back off again.
|
5175 |
*/
|
5176 |
SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); |
5177 |
|
5178 |
/*
|
5179 |
** CAPI3REF: Automatically Load Statically Linked Extensions
|
5180 |
**
|
5181 |
** ^This interface causes the xEntryPoint() function to be invoked for
|
5182 |
** each new [database connection] that is created. The idea here is that
|
5183 |
** xEntryPoint() is the entry point for a statically linked [SQLite extension]
|
5184 |
** that is to be automatically loaded into all new database connections.
|
5185 |
**
|
5186 |
** ^(Even though the function prototype shows that xEntryPoint() takes
|
5187 |
** no arguments and returns void, SQLite invokes xEntryPoint() with three
|
5188 |
** arguments and expects and integer result as if the signature of the
|
5189 |
** entry point where as follows:
|
5190 |
**
|
5191 |
** <blockquote><pre>
|
5192 |
** int xEntryPoint(
|
5193 |
** sqlite3 *db,
|
5194 |
** const char **pzErrMsg,
|
5195 |
** const struct sqlite3_api_routines *pThunk
|
5196 |
** );
|
5197 |
** </pre></blockquote>)^
|
5198 |
**
|
5199 |
** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
|
5200 |
** point to an appropriate error message (obtained from [sqlite3_mprintf()])
|
5201 |
** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
|
5202 |
** is NULL before calling the xEntryPoint(). ^SQLite will invoke
|
5203 |
** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
|
5204 |
** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
|
5205 |
** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
|
5206 |
**
|
5207 |
** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
|
5208 |
** on the list of automatic extensions is a harmless no-op. ^No entry point
|
5209 |
** will be called more than once for each database connection that is opened.
|
5210 |
**
|
5211 |
** See also: [sqlite3_reset_auto_extension()]
|
5212 |
** and [sqlite3_cancel_auto_extension()]
|
5213 |
*/
|
5214 |
SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void)); |
5215 |
|
5216 |
/*
|
5217 |
** CAPI3REF: Cancel Automatic Extension Loading
|
5218 |
**
|
5219 |
** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
|
5220 |
** initialization routine X that was registered using a prior call to
|
5221 |
** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
|
5222 |
** routine returns 1 if initialization routine X was successfully
|
5223 |
** unregistered and it returns 0 if X was not on the list of initialization
|
5224 |
** routines.
|
5225 |
*/
|
5226 |
SQLITE_API int sqlite3_cancel_auto_extension(void (*xEntryPoint)(void)); |
5227 |
|
5228 |
/*
|
5229 |
** CAPI3REF: Reset Automatic Extension Loading
|
5230 |
**
|
5231 |
** ^This interface disables all automatic extensions previously
|
5232 |
** registered using [sqlite3_auto_extension()].
|
5233 |
*/
|
5234 |
SQLITE_API void sqlite3_reset_auto_extension(void); |
5235 |
|
5236 |
/*
|
5237 |
** The interface to the virtual-table mechanism is currently considered
|
5238 |
** to be experimental. The interface might change in incompatible ways.
|
5239 |
** If this is a problem for you, do not use the interface at this time.
|
5240 |
**
|
5241 |
** When the virtual-table mechanism stabilizes, we will declare the
|
5242 |
** interface fixed, support it indefinitely, and remove this comment.
|
5243 |
*/
|
5244 |
|
5245 |
/*
|
5246 |
** Structures used by the virtual table interface
|
5247 |
*/
|
5248 |
typedef struct sqlite3_vtab sqlite3_vtab; |
5249 |
typedef struct sqlite3_index_info sqlite3_index_info; |
5250 |
typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; |
5251 |
typedef struct sqlite3_module sqlite3_module; |
5252 |
|
5253 |
/*
|
5254 |
** CAPI3REF: Virtual Table Object
|
5255 |
** KEYWORDS: sqlite3_module {virtual table module}
|
5256 |
**
|
5257 |
** This structure, sometimes called a "virtual table module",
|
5258 |
** defines the implementation of a [virtual tables].
|
5259 |
** This structure consists mostly of methods for the module.
|
5260 |
**
|
5261 |
** ^A virtual table module is created by filling in a persistent
|
5262 |
** instance of this structure and passing a pointer to that instance
|
5263 |
** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
|
5264 |
** ^The registration remains valid until it is replaced by a different
|
5265 |
** module or until the [database connection] closes. The content
|
5266 |
** of this structure must not change while it is registered with
|
5267 |
** any database connection.
|
5268 |
*/
|
5269 |
struct sqlite3_module {
|
5270 |
int iVersion;
|
5271 |
int (*xCreate)(sqlite3*, void *pAux, |
5272 |
int argc, const char *const*argv, |
5273 |
sqlite3_vtab **ppVTab, char**);
|
5274 |
int (*xConnect)(sqlite3*, void *pAux, |
5275 |
int argc, const char *const*argv, |
5276 |
sqlite3_vtab **ppVTab, char**);
|
5277 |
int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
|
5278 |
int (*xDisconnect)(sqlite3_vtab *pVTab);
|
5279 |
int (*xDestroy)(sqlite3_vtab *pVTab);
|
5280 |
int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
|
5281 |
int (*xClose)(sqlite3_vtab_cursor*);
|
5282 |
int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, |
5283 |
int argc, sqlite3_value **argv);
|
5284 |
int (*xNext)(sqlite3_vtab_cursor*);
|
5285 |
int (*xEof)(sqlite3_vtab_cursor*);
|
5286 |
int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); |
5287 |
int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
|
5288 |
int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); |
5289 |
int (*xBegin)(sqlite3_vtab *pVTab);
|
5290 |
int (*xSync)(sqlite3_vtab *pVTab);
|
5291 |
int (*xCommit)(sqlite3_vtab *pVTab);
|
5292 |
int (*xRollback)(sqlite3_vtab *pVTab);
|
5293 |
int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, |
5294 |
void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), |
5295 |
void **ppArg);
|
5296 |
int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); |
5297 |
/* The methods above are in version 1 of the sqlite_module object. Those
|
5298 |
** below are for version 2 and greater. */
|
5299 |
int (*xSavepoint)(sqlite3_vtab *pVTab, int); |
5300 |
int (*xRelease)(sqlite3_vtab *pVTab, int); |
5301 |
int (*xRollbackTo)(sqlite3_vtab *pVTab, int); |
5302 |
}; |
5303 |
|
5304 |
/*
|
5305 |
** CAPI3REF: Virtual Table Indexing Information
|
5306 |
** KEYWORDS: sqlite3_index_info
|
5307 |
**
|
5308 |
** The sqlite3_index_info structure and its substructures is used as part
|
5309 |
** of the [virtual table] interface to
|
5310 |
** pass information into and receive the reply from the [xBestIndex]
|
5311 |
** method of a [virtual table module]. The fields under **Inputs** are the
|
5312 |
** inputs to xBestIndex and are read-only. xBestIndex inserts its
|
5313 |
** results into the **Outputs** fields.
|
5314 |
**
|
5315 |
** ^(The aConstraint[] array records WHERE clause constraints of the form:
|
5316 |
**
|
5317 |
** <blockquote>column OP expr</blockquote>
|
5318 |
**
|
5319 |
** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is
|
5320 |
** stored in aConstraint[].op using one of the
|
5321 |
** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
|
5322 |
** ^(The index of the column is stored in
|
5323 |
** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
|
5324 |
** expr on the right-hand side can be evaluated (and thus the constraint
|
5325 |
** is usable) and false if it cannot.)^
|
5326 |
**
|
5327 |
** ^The optimizer automatically inverts terms of the form "expr OP column"
|
5328 |
** and makes other simplifications to the WHERE clause in an attempt to
|
5329 |
** get as many WHERE clause terms into the form shown above as possible.
|
5330 |
** ^The aConstraint[] array only reports WHERE clause terms that are
|
5331 |
** relevant to the particular virtual table being queried.
|
5332 |
**
|
5333 |
** ^Information about the ORDER BY clause is stored in aOrderBy[].
|
5334 |
** ^Each term of aOrderBy records a column of the ORDER BY clause.
|
5335 |
**
|
5336 |
** The [xBestIndex] method must fill aConstraintUsage[] with information
|
5337 |
** about what parameters to pass to xFilter. ^If argvIndex>0 then
|
5338 |
** the right-hand side of the corresponding aConstraint[] is evaluated
|
5339 |
** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
|
5340 |
** is true, then the constraint is assumed to be fully handled by the
|
5341 |
** virtual table and is not checked again by SQLite.)^
|
5342 |
**
|
5343 |
** ^The idxNum and idxPtr values are recorded and passed into the
|
5344 |
** [xFilter] method.
|
5345 |
** ^[sqlite3_free()] is used to free idxPtr if and only if
|
5346 |
** needToFreeIdxPtr is true.
|
5347 |
**
|
5348 |
** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
|
5349 |
** the correct order to satisfy the ORDER BY clause so that no separate
|
5350 |
** sorting step is required.
|
5351 |
**
|
5352 |
** ^The estimatedCost value is an estimate of the cost of a particular
|
5353 |
** strategy. A cost of N indicates that the cost of the strategy is similar
|
5354 |
** to a linear scan of an SQLite table with N rows. A cost of log(N)
|
5355 |
** indicates that the expense of the operation is similar to that of a
|
5356 |
** binary search on a unique indexed field of an SQLite table with N rows.
|
5357 |
**
|
5358 |
** ^The estimatedRows value is an estimate of the number of rows that
|
5359 |
** will be returned by the strategy.
|
5360 |
**
|
5361 |
** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
|
5362 |
** structure for SQLite version 3.8.2. If a virtual table extension is
|
5363 |
** used with an SQLite version earlier than 3.8.2, the results of attempting
|
5364 |
** to read or write the estimatedRows field are undefined (but are likely
|
5365 |
** to included crashing the application). The estimatedRows field should
|
5366 |
** therefore only be used if [sqlite3_libversion_number()] returns a
|
5367 |
** value greater than or equal to 3008002.
|
5368 |
*/
|
5369 |
struct sqlite3_index_info {
|
5370 |
/* Inputs */
|
5371 |
int nConstraint; /* Number of entries in aConstraint */ |
5372 |
struct sqlite3_index_constraint {
|
5373 |
int iColumn; /* Column on left-hand side of constraint */ |
5374 |
unsigned char op; /* Constraint operator */ |
5375 |
unsigned char usable; /* True if this constraint is usable */ |
5376 |
int iTermOffset; /* Used internally - xBestIndex should ignore */ |
5377 |
} *aConstraint; /* Table of WHERE clause constraints */
|
5378 |
int nOrderBy; /* Number of terms in the ORDER BY clause */ |
5379 |
struct sqlite3_index_orderby {
|
5380 |
int iColumn; /* Column number */ |
5381 |
unsigned char desc; /* True for DESC. False for ASC. */ |
5382 |
} *aOrderBy; /* The ORDER BY clause */
|
5383 |
/* Outputs */
|
5384 |
struct sqlite3_index_constraint_usage {
|
5385 |
int argvIndex; /* if >0, constraint is part of argv to xFilter */ |
5386 |
unsigned char omit; /* Do not code a test for this constraint */ |
5387 |
} *aConstraintUsage; |
5388 |
int idxNum; /* Number used to identify the index */ |
5389 |
char *idxStr; /* String, possibly obtained from sqlite3_malloc */ |
5390 |
int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ |
5391 |
int orderByConsumed; /* True if output is already ordered */ |
5392 |
double estimatedCost; /* Estimated cost of using this index */ |
5393 |
/* Fields below are only available in SQLite 3.8.2 and later */
|
5394 |
sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
|
5395 |
}; |
5396 |
|
5397 |
/*
|
5398 |
** CAPI3REF: Virtual Table Constraint Operator Codes
|
5399 |
**
|
5400 |
** These macros defined the allowed values for the
|
5401 |
** [sqlite3_index_info].aConstraint[].op field. Each value represents
|
5402 |
** an operator that is part of a constraint term in the wHERE clause of
|
5403 |
** a query that uses a [virtual table].
|
5404 |
*/
|
5405 |
#define SQLITE_INDEX_CONSTRAINT_EQ 2 |
5406 |
#define SQLITE_INDEX_CONSTRAINT_GT 4 |
5407 |
#define SQLITE_INDEX_CONSTRAINT_LE 8 |
5408 |
#define SQLITE_INDEX_CONSTRAINT_LT 16 |
5409 |
#define SQLITE_INDEX_CONSTRAINT_GE 32 |
5410 |
#define SQLITE_INDEX_CONSTRAINT_MATCH 64 |
5411 |
|
5412 |
/*
|
5413 |
** CAPI3REF: Register A Virtual Table Implementation
|
5414 |
**
|
5415 |
** ^These routines are used to register a new [virtual table module] name.
|
5416 |
** ^Module names must be registered before
|
5417 |
** creating a new [virtual table] using the module and before using a
|
5418 |
** preexisting [virtual table] for the module.
|
5419 |
**
|
5420 |
** ^The module name is registered on the [database connection] specified
|
5421 |
** by the first parameter. ^The name of the module is given by the
|
5422 |
** second parameter. ^The third parameter is a pointer to
|
5423 |
** the implementation of the [virtual table module]. ^The fourth
|
5424 |
** parameter is an arbitrary client data pointer that is passed through
|
5425 |
** into the [xCreate] and [xConnect] methods of the virtual table module
|
5426 |
** when a new virtual table is be being created or reinitialized.
|
5427 |
**
|
5428 |
** ^The sqlite3_create_module_v2() interface has a fifth parameter which
|
5429 |
** is a pointer to a destructor for the pClientData. ^SQLite will
|
5430 |
** invoke the destructor function (if it is not NULL) when SQLite
|
5431 |
** no longer needs the pClientData pointer. ^The destructor will also
|
5432 |
** be invoked if the call to sqlite3_create_module_v2() fails.
|
5433 |
** ^The sqlite3_create_module()
|
5434 |
** interface is equivalent to sqlite3_create_module_v2() with a NULL
|
5435 |
** destructor.
|
5436 |
*/
|
5437 |
SQLITE_API int sqlite3_create_module(
|
5438 |
sqlite3 *db, /* SQLite connection to register module with */
|
5439 |
const char *zName, /* Name of the module */ |
5440 |
const sqlite3_module *p, /* Methods for the module */ |
5441 |
void *pClientData /* Client data for xCreate/xConnect */ |
5442 |
); |
5443 |
SQLITE_API int sqlite3_create_module_v2(
|
5444 |
sqlite3 *db, /* SQLite connection to register module with */
|
5445 |
const char *zName, /* Name of the module */ |
5446 |
const sqlite3_module *p, /* Methods for the module */ |
5447 |
void *pClientData, /* Client data for xCreate/xConnect */ |
5448 |
void(*xDestroy)(void*) /* Module destructor function */ |
5449 |
); |
5450 |
|
5451 |
/*
|
5452 |
** CAPI3REF: Virtual Table Instance Object
|
5453 |
** KEYWORDS: sqlite3_vtab
|
5454 |
**
|
5455 |
** Every [virtual table module] implementation uses a subclass
|
5456 |
** of this object to describe a particular instance
|
5457 |
** of the [virtual table]. Each subclass will
|
5458 |
** be tailored to the specific needs of the module implementation.
|
5459 |
** The purpose of this superclass is to define certain fields that are
|
5460 |
** common to all module implementations.
|
5461 |
**
|
5462 |
** ^Virtual tables methods can set an error message by assigning a
|
5463 |
** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
|
5464 |
** take care that any prior string is freed by a call to [sqlite3_free()]
|
5465 |
** prior to assigning a new string to zErrMsg. ^After the error message
|
5466 |
** is delivered up to the client application, the string will be automatically
|
5467 |
** freed by sqlite3_free() and the zErrMsg field will be zeroed.
|
5468 |
*/
|
5469 |
struct sqlite3_vtab {
|
5470 |
const sqlite3_module *pModule; /* The module for this virtual table */ |
5471 |
int nRef; /* NO LONGER USED */ |
5472 |
char *zErrMsg; /* Error message from sqlite3_mprintf() */ |
5473 |
/* Virtual table implementations will typically add additional fields */
|
5474 |
}; |
5475 |
|
5476 |
/*
|
5477 |
** CAPI3REF: Virtual Table Cursor Object
|
5478 |
** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
|
5479 |
**
|
5480 |
** Every [virtual table module] implementation uses a subclass of the
|
5481 |
** following structure to describe cursors that point into the
|
5482 |
** [virtual table] and are used
|
5483 |
** to loop through the virtual table. Cursors are created using the
|
5484 |
** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
|
5485 |
** by the [sqlite3_module.xClose | xClose] method. Cursors are used
|
5486 |
** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
|
5487 |
** of the module. Each module implementation will define
|
5488 |
** the content of a cursor structure to suit its own needs.
|
5489 |
**
|
5490 |
** This superclass exists in order to define fields of the cursor that
|
5491 |
** are common to all implementations.
|
5492 |
*/
|
5493 |
struct sqlite3_vtab_cursor {
|
5494 |
sqlite3_vtab *pVtab; /* Virtual table of this cursor */
|
5495 |
/* Virtual table implementations will typically add additional fields */
|
5496 |
}; |
5497 |
|
5498 |
/*
|
5499 |
** CAPI3REF: Declare The Schema Of A Virtual Table
|
5500 |
**
|
5501 |
** ^The [xCreate] and [xConnect] methods of a
|
5502 |
** [virtual table module] call this interface
|
5503 |
** to declare the format (the names and datatypes of the columns) of
|
5504 |
** the virtual tables they implement.
|
5505 |
*/
|
5506 |
SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); |
5507 |
|
5508 |
/*
|
5509 |
** CAPI3REF: Overload A Function For A Virtual Table
|
5510 |
**
|
5511 |
** ^(Virtual tables can provide alternative implementations of functions
|
5512 |
** using the [xFindFunction] method of the [virtual table module].
|
5513 |
** But global versions of those functions
|
5514 |
** must exist in order to be overloaded.)^
|
5515 |
**
|
5516 |
** ^(This API makes sure a global version of a function with a particular
|
5517 |
** name and number of parameters exists. If no such function exists
|
5518 |
** before this API is called, a new function is created.)^ ^The implementation
|
5519 |
** of the new function always causes an exception to be thrown. So
|
5520 |
** the new function is not good for anything by itself. Its only
|
5521 |
** purpose is to be a placeholder function that can be overloaded
|
5522 |
** by a [virtual table].
|
5523 |
*/
|
5524 |
SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); |
5525 |
|
5526 |
/*
|
5527 |
** The interface to the virtual-table mechanism defined above (back up
|
5528 |
** to a comment remarkably similar to this one) is currently considered
|
5529 |
** to be experimental. The interface might change in incompatible ways.
|
5530 |
** If this is a problem for you, do not use the interface at this time.
|
5531 |
**
|
5532 |
** When the virtual-table mechanism stabilizes, we will declare the
|
5533 |
** interface fixed, support it indefinitely, and remove this comment.
|
5534 |
*/
|
5535 |
|
5536 |
/*
|
5537 |
** CAPI3REF: A Handle To An Open BLOB
|
5538 |
** KEYWORDS: {BLOB handle} {BLOB handles}
|
5539 |
**
|
5540 |
** An instance of this object represents an open BLOB on which
|
5541 |
** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
|
5542 |
** ^Objects of this type are created by [sqlite3_blob_open()]
|
5543 |
** and destroyed by [sqlite3_blob_close()].
|
5544 |
** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
|
5545 |
** can be used to read or write small subsections of the BLOB.
|
5546 |
** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
|
5547 |
*/
|
5548 |
typedef struct sqlite3_blob sqlite3_blob; |
5549 |
|
5550 |
/*
|
5551 |
** CAPI3REF: Open A BLOB For Incremental I/O
|
5552 |
**
|
5553 |
** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
|
5554 |
** in row iRow, column zColumn, table zTable in database zDb;
|
5555 |
** in other words, the same BLOB that would be selected by:
|
5556 |
**
|
5557 |
** <pre>
|
5558 |
** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
|
5559 |
** </pre>)^
|
5560 |
**
|
5561 |
** ^If the flags parameter is non-zero, then the BLOB is opened for read
|
5562 |
** and write access. ^If it is zero, the BLOB is opened for read access.
|
5563 |
** ^It is not possible to open a column that is part of an index or primary
|
5564 |
** key for writing. ^If [foreign key constraints] are enabled, it is
|
5565 |
** not possible to open a column that is part of a [child key] for writing.
|
5566 |
**
|
5567 |
** ^Note that the database name is not the filename that contains
|
5568 |
** the database but rather the symbolic name of the database that
|
5569 |
** appears after the AS keyword when the database is connected using [ATTACH].
|
5570 |
** ^For the main database file, the database name is "main".
|
5571 |
** ^For TEMP tables, the database name is "temp".
|
5572 |
**
|
5573 |
** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written
|
5574 |
** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set
|
5575 |
** to be a null pointer.)^
|
5576 |
** ^This function sets the [database connection] error code and message
|
5577 |
** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related
|
5578 |
** functions. ^Note that the *ppBlob variable is always initialized in a
|
5579 |
** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob
|
5580 |
** regardless of the success or failure of this routine.
|
5581 |
**
|
5582 |
** ^(If the row that a BLOB handle points to is modified by an
|
5583 |
** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
|
5584 |
** then the BLOB handle is marked as "expired".
|
5585 |
** This is true if any column of the row is changed, even a column
|
5586 |
** other than the one the BLOB handle is open on.)^
|
5587 |
** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
|
5588 |
** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
|
5589 |
** ^(Changes written into a BLOB prior to the BLOB expiring are not
|
5590 |
** rolled back by the expiration of the BLOB. Such changes will eventually
|
5591 |
** commit if the transaction continues to completion.)^
|
5592 |
**
|
5593 |
** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
|
5594 |
** the opened blob. ^The size of a blob may not be changed by this
|
5595 |
** interface. Use the [UPDATE] SQL command to change the size of a
|
5596 |
** blob.
|
5597 |
**
|
5598 |
** ^The [sqlite3_blob_open()] interface will fail for a [WITHOUT ROWID]
|
5599 |
** table. Incremental BLOB I/O is not possible on [WITHOUT ROWID] tables.
|
5600 |
**
|
5601 |
** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
|
5602 |
** and the built-in [zeroblob] SQL function can be used, if desired,
|
5603 |
** to create an empty, zero-filled blob in which to read or write using
|
5604 |
** this interface.
|
5605 |
**
|
5606 |
** To avoid a resource leak, every open [BLOB handle] should eventually
|
5607 |
** be released by a call to [sqlite3_blob_close()].
|
5608 |
*/
|
5609 |
SQLITE_API int sqlite3_blob_open(
|
5610 |
sqlite3*, |
5611 |
const char *zDb, |
5612 |
const char *zTable, |
5613 |
const char *zColumn, |
5614 |
sqlite3_int64 iRow, |
5615 |
int flags,
|
5616 |
sqlite3_blob **ppBlob |
5617 |
); |
5618 |
|
5619 |
/*
|
5620 |
** CAPI3REF: Move a BLOB Handle to a New Row
|
5621 |
**
|
5622 |
** ^This function is used to move an existing blob handle so that it points
|
5623 |
** to a different row of the same database table. ^The new row is identified
|
5624 |
** by the rowid value passed as the second argument. Only the row can be
|
5625 |
** changed. ^The database, table and column on which the blob handle is open
|
5626 |
** remain the same. Moving an existing blob handle to a new row can be
|
5627 |
** faster than closing the existing handle and opening a new one.
|
5628 |
**
|
5629 |
** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
|
5630 |
** it must exist and there must be either a blob or text value stored in
|
5631 |
** the nominated column.)^ ^If the new row is not present in the table, or if
|
5632 |
** it does not contain a blob or text value, or if another error occurs, an
|
5633 |
** SQLite error code is returned and the blob handle is considered aborted.
|
5634 |
** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
|
5635 |
** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
|
5636 |
** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
|
5637 |
** always returns zero.
|
5638 |
**
|
5639 |
** ^This function sets the database handle error code and message.
|
5640 |
*/
|
5641 |
SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
|
5642 |
|
5643 |
/*
|
5644 |
** CAPI3REF: Close A BLOB Handle
|
5645 |
**
|
5646 |
** ^Closes an open [BLOB handle].
|
5647 |
**
|
5648 |
** ^Closing a BLOB shall cause the current transaction to commit
|
5649 |
** if there are no other BLOBs, no pending prepared statements, and the
|
5650 |
** database connection is in [autocommit mode].
|
5651 |
** ^If any writes were made to the BLOB, they might be held in cache
|
5652 |
** until the close operation if they will fit.
|
5653 |
**
|
5654 |
** ^(Closing the BLOB often forces the changes
|
5655 |
** out to disk and so if any I/O errors occur, they will likely occur
|
5656 |
** at the time when the BLOB is closed. Any errors that occur during
|
5657 |
** closing are reported as a non-zero return value.)^
|
5658 |
**
|
5659 |
** ^(The BLOB is closed unconditionally. Even if this routine returns
|
5660 |
** an error code, the BLOB is still closed.)^
|
5661 |
**
|
5662 |
** ^Calling this routine with a null pointer (such as would be returned
|
5663 |
** by a failed call to [sqlite3_blob_open()]) is a harmless no-op.
|
5664 |
*/
|
5665 |
SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
|
5666 |
|
5667 |
/*
|
5668 |
** CAPI3REF: Return The Size Of An Open BLOB
|
5669 |
**
|
5670 |
** ^Returns the size in bytes of the BLOB accessible via the
|
5671 |
** successfully opened [BLOB handle] in its only argument. ^The
|
5672 |
** incremental blob I/O routines can only read or overwriting existing
|
5673 |
** blob content; they cannot change the size of a blob.
|
5674 |
**
|
5675 |
** This routine only works on a [BLOB handle] which has been created
|
5676 |
** by a prior successful call to [sqlite3_blob_open()] and which has not
|
5677 |
** been closed by [sqlite3_blob_close()]. Passing any other pointer in
|
5678 |
** to this routine results in undefined and probably undesirable behavior.
|
5679 |
*/
|
5680 |
SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
|
5681 |
|
5682 |
/*
|
5683 |
** CAPI3REF: Read Data From A BLOB Incrementally
|
5684 |
**
|
5685 |
** ^(This function is used to read data from an open [BLOB handle] into a
|
5686 |
** caller-supplied buffer. N bytes of data are copied into buffer Z
|
5687 |
** from the open BLOB, starting at offset iOffset.)^
|
5688 |
**
|
5689 |
** ^If offset iOffset is less than N bytes from the end of the BLOB,
|
5690 |
** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
|
5691 |
** less than zero, [SQLITE_ERROR] is returned and no data is read.
|
5692 |
** ^The size of the blob (and hence the maximum value of N+iOffset)
|
5693 |
** can be determined using the [sqlite3_blob_bytes()] interface.
|
5694 |
**
|
5695 |
** ^An attempt to read from an expired [BLOB handle] fails with an
|
5696 |
** error code of [SQLITE_ABORT].
|
5697 |
**
|
5698 |
** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
|
5699 |
** Otherwise, an [error code] or an [extended error code] is returned.)^
|
5700 |
**
|
5701 |
** This routine only works on a [BLOB handle] which has been created
|
5702 |
** by a prior successful call to [sqlite3_blob_open()] and which has not
|
5703 |
** been closed by [sqlite3_blob_close()]. Passing any other pointer in
|
5704 |
** to this routine results in undefined and probably undesirable behavior.
|
5705 |
**
|
5706 |
** See also: [sqlite3_blob_write()].
|
5707 |
*/
|
5708 |
SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); |
5709 |
|
5710 |
/*
|
5711 |
** CAPI3REF: Write Data Into A BLOB Incrementally
|
5712 |
**
|
5713 |
** ^This function is used to write data into an open [BLOB handle] from a
|
5714 |
** caller-supplied buffer. ^N bytes of data are copied from the buffer Z
|
5715 |
** into the open BLOB, starting at offset iOffset.
|
5716 |
**
|
5717 |
** ^If the [BLOB handle] passed as the first argument was not opened for
|
5718 |
** writing (the flags parameter to [sqlite3_blob_open()] was zero),
|
5719 |
** this function returns [SQLITE_READONLY].
|
5720 |
**
|
5721 |
** ^This function may only modify the contents of the BLOB; it is
|
5722 |
** not possible to increase the size of a BLOB using this API.
|
5723 |
** ^If offset iOffset is less than N bytes from the end of the BLOB,
|
5724 |
** [SQLITE_ERROR] is returned and no data is written. ^If N is
|
5725 |
** less than zero [SQLITE_ERROR] is returned and no data is written.
|
5726 |
** The size of the BLOB (and hence the maximum value of N+iOffset)
|
5727 |
** can be determined using the [sqlite3_blob_bytes()] interface.
|
5728 |
**
|
5729 |
** ^An attempt to write to an expired [BLOB handle] fails with an
|
5730 |
** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
|
5731 |
** before the [BLOB handle] expired are not rolled back by the
|
5732 |
** expiration of the handle, though of course those changes might
|
5733 |
** have been overwritten by the statement that expired the BLOB handle
|
5734 |
** or by other independent statements.
|
5735 |
**
|
5736 |
** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
|
5737 |
** Otherwise, an [error code] or an [extended error code] is returned.)^
|
5738 |
**
|
5739 |
** This routine only works on a [BLOB handle] which has been created
|
5740 |
** by a prior successful call to [sqlite3_blob_open()] and which has not
|
5741 |
** been closed by [sqlite3_blob_close()]. Passing any other pointer in
|
5742 |
** to this routine results in undefined and probably undesirable behavior.
|
5743 |
**
|
5744 |
** See also: [sqlite3_blob_read()].
|
5745 |
*/
|
5746 |
SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); |
5747 |
|
5748 |
/*
|
5749 |
** CAPI3REF: Virtual File System Objects
|
5750 |
**
|
5751 |
** A virtual filesystem (VFS) is an [sqlite3_vfs] object
|
5752 |
** that SQLite uses to interact
|
5753 |
** with the underlying operating system. Most SQLite builds come with a
|
5754 |
** single default VFS that is appropriate for the host computer.
|
5755 |
** New VFSes can be registered and existing VFSes can be unregistered.
|
5756 |
** The following interfaces are provided.
|
5757 |
**
|
5758 |
** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
|
5759 |
** ^Names are case sensitive.
|
5760 |
** ^Names are zero-terminated UTF-8 strings.
|
5761 |
** ^If there is no match, a NULL pointer is returned.
|
5762 |
** ^If zVfsName is NULL then the default VFS is returned.
|
5763 |
**
|
5764 |
** ^New VFSes are registered with sqlite3_vfs_register().
|
5765 |
** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
|
5766 |
** ^The same VFS can be registered multiple times without injury.
|
5767 |
** ^To make an existing VFS into the default VFS, register it again
|
5768 |
** with the makeDflt flag set. If two different VFSes with the
|
5769 |
** same name are registered, the behavior is undefined. If a
|
5770 |
** VFS is registered with a name that is NULL or an empty string,
|
5771 |
** then the behavior is undefined.
|
5772 |
**
|
5773 |
** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
|
5774 |
** ^(If the default VFS is unregistered, another VFS is chosen as
|
5775 |
** the default. The choice for the new VFS is arbitrary.)^
|
5776 |
*/
|
5777 |
SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); |
5778 |
SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); |
5779 |
SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
|
5780 |
|
5781 |
/*
|
5782 |
** CAPI3REF: Mutexes
|
5783 |
**
|
5784 |
** The SQLite core uses these routines for thread
|
5785 |
** synchronization. Though they are intended for internal
|
5786 |
** use by SQLite, code that links against SQLite is
|
5787 |
** permitted to use any of these routines.
|
5788 |
**
|
5789 |
** The SQLite source code contains multiple implementations
|
5790 |
** of these mutex routines. An appropriate implementation
|
5791 |
** is selected automatically at compile-time. ^(The following
|
5792 |
** implementations are available in the SQLite core:
|
5793 |
**
|
5794 |
** <ul>
|
5795 |
** <li> SQLITE_MUTEX_PTHREADS
|
5796 |
** <li> SQLITE_MUTEX_W32
|
5797 |
** <li> SQLITE_MUTEX_NOOP
|
5798 |
** </ul>)^
|
5799 |
**
|
5800 |
** ^The SQLITE_MUTEX_NOOP implementation is a set of routines
|
5801 |
** that does no real locking and is appropriate for use in
|
5802 |
** a single-threaded application. ^The SQLITE_MUTEX_PTHREADS and
|
5803 |
** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
|
5804 |
** and Windows.
|
5805 |
**
|
5806 |
** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
|
5807 |
** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
|
5808 |
** implementation is included with the library. In this case the
|
5809 |
** application must supply a custom mutex implementation using the
|
5810 |
** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
|
5811 |
** before calling sqlite3_initialize() or any other public sqlite3_
|
5812 |
** function that calls sqlite3_initialize().)^
|
5813 |
**
|
5814 |
** ^The sqlite3_mutex_alloc() routine allocates a new
|
5815 |
** mutex and returns a pointer to it. ^If it returns NULL
|
5816 |
** that means that a mutex could not be allocated. ^SQLite
|
5817 |
** will unwind its stack and return an error. ^(The argument
|
5818 |
** to sqlite3_mutex_alloc() is one of these integer constants:
|
5819 |
**
|
5820 |
** <ul>
|
5821 |
** <li> SQLITE_MUTEX_FAST
|
5822 |
** <li> SQLITE_MUTEX_RECURSIVE
|
5823 |
** <li> SQLITE_MUTEX_STATIC_MASTER
|
5824 |
** <li> SQLITE_MUTEX_STATIC_MEM
|
5825 |
** <li> SQLITE_MUTEX_STATIC_MEM2
|
5826 |
** <li> SQLITE_MUTEX_STATIC_PRNG
|
5827 |
** <li> SQLITE_MUTEX_STATIC_LRU
|
5828 |
** <li> SQLITE_MUTEX_STATIC_LRU2
|
5829 |
** </ul>)^
|
5830 |
**
|
5831 |
** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
|
5832 |
** cause sqlite3_mutex_alloc() to create
|
5833 |
** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
|
5834 |
** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
|
5835 |
** The mutex implementation does not need to make a distinction
|
5836 |
** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
|
5837 |
** not want to. ^SQLite will only request a recursive mutex in
|
5838 |
** cases where it really needs one. ^If a faster non-recursive mutex
|
5839 |
** implementation is available on the host platform, the mutex subsystem
|
5840 |
** might return such a mutex in response to SQLITE_MUTEX_FAST.
|
5841 |
**
|
5842 |
** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
|
5843 |
** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
|
5844 |
** a pointer to a static preexisting mutex. ^Six static mutexes are
|
5845 |
** used by the current version of SQLite. Future versions of SQLite
|
5846 |
** may add additional static mutexes. Static mutexes are for internal
|
5847 |
** use by SQLite only. Applications that use SQLite mutexes should
|
5848 |
** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
|
5849 |
** SQLITE_MUTEX_RECURSIVE.
|
5850 |
**
|
5851 |
** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
|
5852 |
** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
|
5853 |
** returns a different mutex on every call. ^But for the static
|
5854 |
** mutex types, the same mutex is returned on every call that has
|
5855 |
** the same type number.
|
5856 |
**
|
5857 |
** ^The sqlite3_mutex_free() routine deallocates a previously
|
5858 |
** allocated dynamic mutex. ^SQLite is careful to deallocate every
|
5859 |
** dynamic mutex that it allocates. The dynamic mutexes must not be in
|
5860 |
** use when they are deallocated. Attempting to deallocate a static
|
5861 |
** mutex results in undefined behavior. ^SQLite never deallocates
|
5862 |
** a static mutex.
|
5863 |
**
|
5864 |
** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
|
5865 |
** to enter a mutex. ^If another thread is already within the mutex,
|
5866 |
** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
|
5867 |
** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
|
5868 |
** upon successful entry. ^(Mutexes created using
|
5869 |
** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
|
5870 |
** In such cases the,
|
5871 |
** mutex must be exited an equal number of times before another thread
|
5872 |
** can enter.)^ ^(If the same thread tries to enter any other
|
5873 |
** kind of mutex more than once, the behavior is undefined.
|
5874 |
** SQLite will never exhibit
|
5875 |
** such behavior in its own use of mutexes.)^
|
5876 |
**
|
5877 |
** ^(Some systems (for example, Windows 95) do not support the operation
|
5878 |
** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
|
5879 |
** will always return SQLITE_BUSY. The SQLite core only ever uses
|
5880 |
** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^
|
5881 |
**
|
5882 |
** ^The sqlite3_mutex_leave() routine exits a mutex that was
|
5883 |
** previously entered by the same thread. ^(The behavior
|
5884 |
** is undefined if the mutex is not currently entered by the
|
5885 |
** calling thread or is not currently allocated. SQLite will
|
5886 |
** never do either.)^
|
5887 |
**
|
5888 |
** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
|
5889 |
** sqlite3_mutex_leave() is a NULL pointer, then all three routines
|
5890 |
** behave as no-ops.
|
5891 |
**
|
5892 |
** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
|
5893 |
*/
|
5894 |
SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
|
5895 |
SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
|
5896 |
SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
|
5897 |
SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
|
5898 |
SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
|
5899 |
|
5900 |
/*
|
5901 |
** CAPI3REF: Mutex Methods Object
|
5902 |
**
|
5903 |
** An instance of this structure defines the low-level routines
|
5904 |
** used to allocate and use mutexes.
|
5905 |
**
|
5906 |
** Usually, the default mutex implementations provided by SQLite are
|
5907 |
** sufficient, however the user has the option of substituting a custom
|
5908 |
** implementation for specialized deployments or systems for which SQLite
|
5909 |
** does not provide a suitable implementation. In this case, the user
|
5910 |
** creates and populates an instance of this structure to pass
|
5911 |
** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
|
5912 |
** Additionally, an instance of this structure can be used as an
|
5913 |
** output variable when querying the system for the current mutex
|
5914 |
** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
|
5915 |
**
|
5916 |
** ^The xMutexInit method defined by this structure is invoked as
|
5917 |
** part of system initialization by the sqlite3_initialize() function.
|
5918 |
** ^The xMutexInit routine is called by SQLite exactly once for each
|
5919 |
** effective call to [sqlite3_initialize()].
|
5920 |
**
|
5921 |
** ^The xMutexEnd method defined by this structure is invoked as
|
5922 |
** part of system shutdown by the sqlite3_shutdown() function. The
|
5923 |
** implementation of this method is expected to release all outstanding
|
5924 |
** resources obtained by the mutex methods implementation, especially
|
5925 |
** those obtained by the xMutexInit method. ^The xMutexEnd()
|
5926 |
** interface is invoked exactly once for each call to [sqlite3_shutdown()].
|
5927 |
**
|
5928 |
** ^(The remaining seven methods defined by this structure (xMutexAlloc,
|
5929 |
** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
|
5930 |
** xMutexNotheld) implement the following interfaces (respectively):
|
5931 |
**
|
5932 |
** <ul>
|
5933 |
** <li> [sqlite3_mutex_alloc()] </li>
|
5934 |
** <li> [sqlite3_mutex_free()] </li>
|
5935 |
** <li> [sqlite3_mutex_enter()] </li>
|
5936 |
** <li> [sqlite3_mutex_try()] </li>
|
5937 |
** <li> [sqlite3_mutex_leave()] </li>
|
5938 |
** <li> [sqlite3_mutex_held()] </li>
|
5939 |
** <li> [sqlite3_mutex_notheld()] </li>
|
5940 |
** </ul>)^
|
5941 |
**
|
5942 |
** The only difference is that the public sqlite3_XXX functions enumerated
|
5943 |
** above silently ignore any invocations that pass a NULL pointer instead
|
5944 |
** of a valid mutex handle. The implementations of the methods defined
|
5945 |
** by this structure are not required to handle this case, the results
|
5946 |
** of passing a NULL pointer instead of a valid mutex handle are undefined
|
5947 |
** (i.e. it is acceptable to provide an implementation that segfaults if
|
5948 |
** it is passed a NULL pointer).
|
5949 |
**
|
5950 |
** The xMutexInit() method must be threadsafe. ^It must be harmless to
|
5951 |
** invoke xMutexInit() multiple times within the same process and without
|
5952 |
** intervening calls to xMutexEnd(). Second and subsequent calls to
|
5953 |
** xMutexInit() must be no-ops.
|
5954 |
**
|
5955 |
** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
|
5956 |
** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory
|
5957 |
** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
|
5958 |
** memory allocation for a fast or recursive mutex.
|
5959 |
**
|
5960 |
** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
|
5961 |
** called, but only if the prior call to xMutexInit returned SQLITE_OK.
|
5962 |
** If xMutexInit fails in any way, it is expected to clean up after itself
|
5963 |
** prior to returning.
|
5964 |
*/
|
5965 |
typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; |
5966 |
struct sqlite3_mutex_methods {
|
5967 |
int (*xMutexInit)(void); |
5968 |
int (*xMutexEnd)(void); |
5969 |
sqlite3_mutex *(*xMutexAlloc)(int);
|
5970 |
void (*xMutexFree)(sqlite3_mutex *);
|
5971 |
void (*xMutexEnter)(sqlite3_mutex *);
|
5972 |
int (*xMutexTry)(sqlite3_mutex *);
|
5973 |
void (*xMutexLeave)(sqlite3_mutex *);
|
5974 |
int (*xMutexHeld)(sqlite3_mutex *);
|
5975 |
int (*xMutexNotheld)(sqlite3_mutex *);
|
5976 |
}; |
5977 |
|
5978 |
/*
|
5979 |
** CAPI3REF: Mutex Verification Routines
|
5980 |
**
|
5981 |
** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
|
5982 |
** are intended for use inside assert() statements. ^The SQLite core
|
5983 |
** never uses these routines except inside an assert() and applications
|
5984 |
** are advised to follow the lead of the core. ^The SQLite core only
|
5985 |
** provides implementations for these routines when it is compiled
|
5986 |
** with the SQLITE_DEBUG flag. ^External mutex implementations
|
5987 |
** are only required to provide these routines if SQLITE_DEBUG is
|
5988 |
** defined and if NDEBUG is not defined.
|
5989 |
**
|
5990 |
** ^These routines should return true if the mutex in their argument
|
5991 |
** is held or not held, respectively, by the calling thread.
|
5992 |
**
|
5993 |
** ^The implementation is not required to provide versions of these
|
5994 |
** routines that actually work. If the implementation does not provide working
|
5995 |
** versions of these routines, it should at least provide stubs that always
|
5996 |
** return true so that one does not get spurious assertion failures.
|
5997 |
**
|
5998 |
** ^If the argument to sqlite3_mutex_held() is a NULL pointer then
|
5999 |
** the routine should return 1. This seems counter-intuitive since
|
6000 |
** clearly the mutex cannot be held if it does not exist. But
|
6001 |
** the reason the mutex does not exist is because the build is not
|
6002 |
** using mutexes. And we do not want the assert() containing the
|
6003 |
** call to sqlite3_mutex_held() to fail, so a non-zero return is
|
6004 |
** the appropriate thing to do. ^The sqlite3_mutex_notheld()
|
6005 |
** interface should also return 1 when given a NULL pointer.
|
6006 |
*/
|
6007 |
#ifndef NDEBUG
|
6008 |
SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
|
6009 |
SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
|
6010 |
#endif
|
6011 |
|
6012 |
/*
|
6013 |
** CAPI3REF: Mutex Types
|
6014 |
**
|
6015 |
** The [sqlite3_mutex_alloc()] interface takes a single argument
|
6016 |
** which is one of these integer constants.
|
6017 |
**
|
6018 |
** The set of static mutexes may change from one SQLite release to the
|
6019 |
** next. Applications that override the built-in mutex logic must be
|
6020 |
** prepared to accommodate additional static mutexes.
|
6021 |
*/
|
6022 |
#define SQLITE_MUTEX_FAST 0 |
6023 |
#define SQLITE_MUTEX_RECURSIVE 1 |
6024 |
#define SQLITE_MUTEX_STATIC_MASTER 2 |
6025 |
#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ |
6026 |
#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ |
6027 |
#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ |
6028 |
#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ |
6029 |
#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ |
6030 |
#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ |
6031 |
#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ |
6032 |
|
6033 |
/*
|
6034 |
** CAPI3REF: Retrieve the mutex for a database connection
|
6035 |
**
|
6036 |
** ^This interface returns a pointer the [sqlite3_mutex] object that
|
6037 |
** serializes access to the [database connection] given in the argument
|
6038 |
** when the [threading mode] is Serialized.
|
6039 |
** ^If the [threading mode] is Single-thread or Multi-thread then this
|
6040 |
** routine returns a NULL pointer.
|
6041 |
*/
|
6042 |
SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); |
6043 |
|
6044 |
/*
|
6045 |
** CAPI3REF: Low-Level Control Of Database Files
|
6046 |
**
|
6047 |
** ^The [sqlite3_file_control()] interface makes a direct call to the
|
6048 |
** xFileControl method for the [sqlite3_io_methods] object associated
|
6049 |
** with a particular database identified by the second argument. ^The
|
6050 |
** name of the database is "main" for the main database or "temp" for the
|
6051 |
** TEMP database, or the name that appears after the AS keyword for
|
6052 |
** databases that are added using the [ATTACH] SQL command.
|
6053 |
** ^A NULL pointer can be used in place of "main" to refer to the
|
6054 |
** main database file.
|
6055 |
** ^The third and fourth parameters to this routine
|
6056 |
** are passed directly through to the second and third parameters of
|
6057 |
** the xFileControl method. ^The return value of the xFileControl
|
6058 |
** method becomes the return value of this routine.
|
6059 |
**
|
6060 |
** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes
|
6061 |
** a pointer to the underlying [sqlite3_file] object to be written into
|
6062 |
** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER
|
6063 |
** case is a short-circuit path which does not actually invoke the
|
6064 |
** underlying sqlite3_io_methods.xFileControl method.
|
6065 |
**
|
6066 |
** ^If the second parameter (zDbName) does not match the name of any
|
6067 |
** open database file, then SQLITE_ERROR is returned. ^This error
|
6068 |
** code is not remembered and will not be recalled by [sqlite3_errcode()]
|
6069 |
** or [sqlite3_errmsg()]. The underlying xFileControl method might
|
6070 |
** also return SQLITE_ERROR. There is no way to distinguish between
|
6071 |
** an incorrect zDbName and an SQLITE_ERROR return from the underlying
|
6072 |
** xFileControl method.
|
6073 |
**
|
6074 |
** See also: [SQLITE_FCNTL_LOCKSTATE]
|
6075 |
*/
|
6076 |
SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); |
6077 |
|
6078 |
/*
|
6079 |
** CAPI3REF: Testing Interface
|
6080 |
**
|
6081 |
** ^The sqlite3_test_control() interface is used to read out internal
|
6082 |
** state of SQLite and to inject faults into SQLite for testing
|
6083 |
** purposes. ^The first parameter is an operation code that determines
|
6084 |
** the number, meaning, and operation of all subsequent parameters.
|
6085 |
**
|
6086 |
** This interface is not for use by applications. It exists solely
|
6087 |
** for verifying the correct operation of the SQLite library. Depending
|
6088 |
** on how the SQLite library is compiled, this interface might not exist.
|
6089 |
**
|
6090 |
** The details of the operation codes, their meanings, the parameters
|
6091 |
** they take, and what they do are all subject to change without notice.
|
6092 |
** Unlike most of the SQLite API, this function is not guaranteed to
|
6093 |
** operate consistently from one release to the next.
|
6094 |
*/
|
6095 |
SQLITE_API int sqlite3_test_control(int op, ...); |
6096 |
|
6097 |
/*
|
6098 |
** CAPI3REF: Testing Interface Operation Codes
|
6099 |
**
|
6100 |
** These constants are the valid operation code parameters used
|
6101 |
** as the first argument to [sqlite3_test_control()].
|
6102 |
**
|
6103 |
** These parameters and their meanings are subject to change
|
6104 |
** without notice. These values are for testing purposes only.
|
6105 |
** Applications should not use any of these parameters or the
|
6106 |
** [sqlite3_test_control()] interface.
|
6107 |
*/
|
6108 |
#define SQLITE_TESTCTRL_FIRST 5 |
6109 |
#define SQLITE_TESTCTRL_PRNG_SAVE 5 |
6110 |
#define SQLITE_TESTCTRL_PRNG_RESTORE 6 |
6111 |
#define SQLITE_TESTCTRL_PRNG_RESET 7 |
6112 |
#define SQLITE_TESTCTRL_BITVEC_TEST 8 |
6113 |
#define SQLITE_TESTCTRL_FAULT_INSTALL 9 |
6114 |
#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 |
6115 |
#define SQLITE_TESTCTRL_PENDING_BYTE 11 |
6116 |
#define SQLITE_TESTCTRL_ASSERT 12 |
6117 |
#define SQLITE_TESTCTRL_ALWAYS 13 |
6118 |
#define SQLITE_TESTCTRL_RESERVE 14 |
6119 |
#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 |
6120 |
#define SQLITE_TESTCTRL_ISKEYWORD 16 |
6121 |
#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 |
6122 |
#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 |
6123 |
#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 |
6124 |
#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 |
6125 |
#define SQLITE_TESTCTRL_LAST 20 |
6126 |
|
6127 |
/*
|
6128 |
** CAPI3REF: SQLite Runtime Status
|
6129 |
**
|
6130 |
** ^This interface is used to retrieve runtime status information
|
6131 |
** about the performance of SQLite, and optionally to reset various
|
6132 |
** highwater marks. ^The first argument is an integer code for
|
6133 |
** the specific parameter to measure. ^(Recognized integer codes
|
6134 |
** are of the form [status parameters | SQLITE_STATUS_...].)^
|
6135 |
** ^The current value of the parameter is returned into *pCurrent.
|
6136 |
** ^The highest recorded value is returned in *pHighwater. ^If the
|
6137 |
** resetFlag is true, then the highest record value is reset after
|
6138 |
** *pHighwater is written. ^(Some parameters do not record the highest
|
6139 |
** value. For those parameters
|
6140 |
** nothing is written into *pHighwater and the resetFlag is ignored.)^
|
6141 |
** ^(Other parameters record only the highwater mark and not the current
|
6142 |
** value. For these latter parameters nothing is written into *pCurrent.)^
|
6143 |
**
|
6144 |
** ^The sqlite3_status() routine returns SQLITE_OK on success and a
|
6145 |
** non-zero [error code] on failure.
|
6146 |
**
|
6147 |
** This routine is threadsafe but is not atomic. This routine can be
|
6148 |
** called while other threads are running the same or different SQLite
|
6149 |
** interfaces. However the values returned in *pCurrent and
|
6150 |
** *pHighwater reflect the status of SQLite at different points in time
|
6151 |
** and it is possible that another thread might change the parameter
|
6152 |
** in between the times when *pCurrent and *pHighwater are written.
|
6153 |
**
|
6154 |
** See also: [sqlite3_db_status()]
|
6155 |
*/
|
6156 |
SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); |
6157 |
|
6158 |
|
6159 |
/*
|
6160 |
** CAPI3REF: Status Parameters
|
6161 |
** KEYWORDS: {status parameters}
|
6162 |
**
|
6163 |
** These integer constants designate various run-time status parameters
|
6164 |
** that can be returned by [sqlite3_status()].
|
6165 |
**
|
6166 |
** <dl>
|
6167 |
** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
|
6168 |
** <dd>This parameter is the current amount of memory checked out
|
6169 |
** using [sqlite3_malloc()], either directly or indirectly. The
|
6170 |
** figure includes calls made to [sqlite3_malloc()] by the application
|
6171 |
** and internal memory usage by the SQLite library. Scratch memory
|
6172 |
** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache
|
6173 |
** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
|
6174 |
** this parameter. The amount returned is the sum of the allocation
|
6175 |
** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
|
6176 |
**
|
6177 |
** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
|
6178 |
** <dd>This parameter records the largest memory allocation request
|
6179 |
** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
|
6180 |
** internal equivalents). Only the value returned in the
|
6181 |
** *pHighwater parameter to [sqlite3_status()] is of interest.
|
6182 |
** The value written into the *pCurrent parameter is undefined.</dd>)^
|
6183 |
**
|
6184 |
** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
|
6185 |
** <dd>This parameter records the number of separate memory allocations
|
6186 |
** currently checked out.</dd>)^
|
6187 |
**
|
6188 |
** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
|
6189 |
** <dd>This parameter returns the number of pages used out of the
|
6190 |
** [pagecache memory allocator] that was configured using
|
6191 |
** [SQLITE_CONFIG_PAGECACHE]. The
|
6192 |
** value returned is in pages, not in bytes.</dd>)^
|
6193 |
**
|
6194 |
** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
|
6195 |
** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
|
6196 |
** <dd>This parameter returns the number of bytes of page cache
|
6197 |
** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
|
6198 |
** buffer and where forced to overflow to [sqlite3_malloc()]. The
|
6199 |
** returned value includes allocations that overflowed because they
|
6200 |
** where too large (they were larger than the "sz" parameter to
|
6201 |
** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
|
6202 |
** no space was left in the page cache.</dd>)^
|
6203 |
**
|
6204 |
** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
|
6205 |
** <dd>This parameter records the largest memory allocation request
|
6206 |
** handed to [pagecache memory allocator]. Only the value returned in the
|
6207 |
** *pHighwater parameter to [sqlite3_status()] is of interest.
|
6208 |
** The value written into the *pCurrent parameter is undefined.</dd>)^
|
6209 |
**
|
6210 |
** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt>
|
6211 |
** <dd>This parameter returns the number of allocations used out of the
|
6212 |
** [scratch memory allocator] configured using
|
6213 |
** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not
|
6214 |
** in bytes. Since a single thread may only have one scratch allocation
|
6215 |
** outstanding at time, this parameter also reports the number of threads
|
6216 |
** using scratch memory at the same time.</dd>)^
|
6217 |
**
|
6218 |
** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
|
6219 |
** <dd>This parameter returns the number of bytes of scratch memory
|
6220 |
** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH]
|
6221 |
** buffer and where forced to overflow to [sqlite3_malloc()]. The values
|
6222 |
** returned include overflows because the requested allocation was too
|
6223 |
** larger (that is, because the requested allocation was larger than the
|
6224 |
** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer
|
6225 |
** slots were available.
|
6226 |
** </dd>)^
|
6227 |
**
|
6228 |
** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
|
6229 |
** <dd>This parameter records the largest memory allocation request
|
6230 |
** handed to [scratch memory allocator]. Only the value returned in the
|
6231 |
** *pHighwater parameter to [sqlite3_status()] is of interest.
|
6232 |
** The value written into the *pCurrent parameter is undefined.</dd>)^
|
6233 |
**
|
6234 |
** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
|
6235 |
** <dd>This parameter records the deepest parser stack. It is only
|
6236 |
** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
|
6237 |
** </dl>
|
6238 |
**
|
6239 |
** New status parameters may be added from time to time.
|
6240 |
*/
|
6241 |
#define SQLITE_STATUS_MEMORY_USED 0 |
6242 |
#define SQLITE_STATUS_PAGECACHE_USED 1 |
6243 |
#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 |
6244 |
#define SQLITE_STATUS_SCRATCH_USED 3 |
6245 |
#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 |
6246 |
#define SQLITE_STATUS_MALLOC_SIZE 5 |
6247 |
#define SQLITE_STATUS_PARSER_STACK 6 |
6248 |
#define SQLITE_STATUS_PAGECACHE_SIZE 7 |
6249 |
#define SQLITE_STATUS_SCRATCH_SIZE 8 |
6250 |
#define SQLITE_STATUS_MALLOC_COUNT 9 |
6251 |
|
6252 |
/*
|
6253 |
** CAPI3REF: Database Connection Status
|
6254 |
**
|
6255 |
** ^This interface is used to retrieve runtime status information
|
6256 |
** about a single [database connection]. ^The first argument is the
|
6257 |
** database connection object to be interrogated. ^The second argument
|
6258 |
** is an integer constant, taken from the set of
|
6259 |
** [SQLITE_DBSTATUS options], that
|
6260 |
** determines the parameter to interrogate. The set of
|
6261 |
** [SQLITE_DBSTATUS options] is likely
|
6262 |
** to grow in future releases of SQLite.
|
6263 |
**
|
6264 |
** ^The current value of the requested parameter is written into *pCur
|
6265 |
** and the highest instantaneous value is written into *pHiwtr. ^If
|
6266 |
** the resetFlg is true, then the highest instantaneous value is
|
6267 |
** reset back down to the current value.
|
6268 |
**
|
6269 |
** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
|
6270 |
** non-zero [error code] on failure.
|
6271 |
**
|
6272 |
** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
|
6273 |
*/
|
6274 |
SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); |
6275 |
|
6276 |
/*
|
6277 |
** CAPI3REF: Status Parameters for database connections
|
6278 |
** KEYWORDS: {SQLITE_DBSTATUS options}
|
6279 |
**
|
6280 |
** These constants are the available integer "verbs" that can be passed as
|
6281 |
** the second argument to the [sqlite3_db_status()] interface.
|
6282 |
**
|
6283 |
** New verbs may be added in future releases of SQLite. Existing verbs
|
6284 |
** might be discontinued. Applications should check the return code from
|
6285 |
** [sqlite3_db_status()] to make sure that the call worked.
|
6286 |
** The [sqlite3_db_status()] interface will return a non-zero error code
|
6287 |
** if a discontinued or unsupported verb is invoked.
|
6288 |
**
|
6289 |
** <dl>
|
6290 |
** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
|
6291 |
** <dd>This parameter returns the number of lookaside memory slots currently
|
6292 |
** checked out.</dd>)^
|
6293 |
**
|
6294 |
** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
|
6295 |
** <dd>This parameter returns the number malloc attempts that were
|
6296 |
** satisfied using lookaside memory. Only the high-water value is meaningful;
|
6297 |
** the current value is always zero.)^
|
6298 |
**
|
6299 |
** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
|
6300 |
** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
|
6301 |
** <dd>This parameter returns the number malloc attempts that might have
|
6302 |
** been satisfied using lookaside memory but failed due to the amount of
|
6303 |
** memory requested being larger than the lookaside slot size.
|
6304 |
** Only the high-water value is meaningful;
|
6305 |
** the current value is always zero.)^
|
6306 |
**
|
6307 |
** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
|
6308 |
** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
|
6309 |
** <dd>This parameter returns the number malloc attempts that might have
|
6310 |
** been satisfied using lookaside memory but failed due to all lookaside
|
6311 |
** memory already being in use.
|
6312 |
** Only the high-water value is meaningful;
|
6313 |
** the current value is always zero.)^
|
6314 |
**
|
6315 |
** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
|
6316 |
** <dd>This parameter returns the approximate number of of bytes of heap
|
6317 |
** memory used by all pager caches associated with the database connection.)^
|
6318 |
** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
|
6319 |
**
|
6320 |
** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
|
6321 |
** <dd>This parameter returns the approximate number of of bytes of heap
|
6322 |
** memory used to store the schema for all databases associated
|
6323 |
** with the connection - main, temp, and any [ATTACH]-ed databases.)^
|
6324 |
** ^The full amount of memory used by the schemas is reported, even if the
|
6325 |
** schema memory is shared with other database connections due to
|
6326 |
** [shared cache mode] being enabled.
|
6327 |
** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
|
6328 |
**
|
6329 |
** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
|
6330 |
** <dd>This parameter returns the approximate number of of bytes of heap
|
6331 |
** and lookaside memory used by all prepared statements associated with
|
6332 |
** the database connection.)^
|
6333 |
** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
|
6334 |
** </dd>
|
6335 |
**
|
6336 |
** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
|
6337 |
** <dd>This parameter returns the number of pager cache hits that have
|
6338 |
** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
|
6339 |
** is always 0.
|
6340 |
** </dd>
|
6341 |
**
|
6342 |
** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
|
6343 |
** <dd>This parameter returns the number of pager cache misses that have
|
6344 |
** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
|
6345 |
** is always 0.
|
6346 |
** </dd>
|
6347 |
**
|
6348 |
** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
|
6349 |
** <dd>This parameter returns the number of dirty cache entries that have
|
6350 |
** been written to disk. Specifically, the number of pages written to the
|
6351 |
** wal file in wal mode databases, or the number of pages written to the
|
6352 |
** database file in rollback mode databases. Any pages written as part of
|
6353 |
** transaction rollback or database recovery operations are not included.
|
6354 |
** If an IO or other error occurs while writing a page to disk, the effect
|
6355 |
** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
|
6356 |
** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
|
6357 |
** </dd>
|
6358 |
**
|
6359 |
** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
|
6360 |
** <dd>This parameter returns zero for the current value if and only if
|
6361 |
** all foreign key constraints (deferred or immediate) have been
|
6362 |
** resolved.)^ ^The highwater mark is always 0.
|
6363 |
** </dd>
|
6364 |
** </dl>
|
6365 |
*/
|
6366 |
#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 |
6367 |
#define SQLITE_DBSTATUS_CACHE_USED 1 |
6368 |
#define SQLITE_DBSTATUS_SCHEMA_USED 2 |
6369 |
#define SQLITE_DBSTATUS_STMT_USED 3 |
6370 |
#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 |
6371 |
#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 |
6372 |
#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 |
6373 |
#define SQLITE_DBSTATUS_CACHE_HIT 7 |
6374 |
#define SQLITE_DBSTATUS_CACHE_MISS 8 |
6375 |
#define SQLITE_DBSTATUS_CACHE_WRITE 9 |
6376 |
#define SQLITE_DBSTATUS_DEFERRED_FKS 10 |
6377 |
#define SQLITE_DBSTATUS_MAX 10 /* Largest defined DBSTATUS */ |
6378 |
|
6379 |
|
6380 |
/*
|
6381 |
** CAPI3REF: Prepared Statement Status
|
6382 |
**
|
6383 |
** ^(Each prepared statement maintains various
|
6384 |
** [SQLITE_STMTSTATUS counters] that measure the number
|
6385 |
** of times it has performed specific operations.)^ These counters can
|
6386 |
** be used to monitor the performance characteristics of the prepared
|
6387 |
** statements. For example, if the number of table steps greatly exceeds
|
6388 |
** the number of table searches or result rows, that would tend to indicate
|
6389 |
** that the prepared statement is using a full table scan rather than
|
6390 |
** an index.
|
6391 |
**
|
6392 |
** ^(This interface is used to retrieve and reset counter values from
|
6393 |
** a [prepared statement]. The first argument is the prepared statement
|
6394 |
** object to be interrogated. The second argument
|
6395 |
** is an integer code for a specific [SQLITE_STMTSTATUS counter]
|
6396 |
** to be interrogated.)^
|
6397 |
** ^The current value of the requested counter is returned.
|
6398 |
** ^If the resetFlg is true, then the counter is reset to zero after this
|
6399 |
** interface call returns.
|
6400 |
**
|
6401 |
** See also: [sqlite3_status()] and [sqlite3_db_status()].
|
6402 |
*/
|
6403 |
SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); |
6404 |
|
6405 |
/*
|
6406 |
** CAPI3REF: Status Parameters for prepared statements
|
6407 |
** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
|
6408 |
**
|
6409 |
** These preprocessor macros define integer codes that name counter
|
6410 |
** values associated with the [sqlite3_stmt_status()] interface.
|
6411 |
** The meanings of the various counters are as follows:
|
6412 |
**
|
6413 |
** <dl>
|
6414 |
** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
|
6415 |
** <dd>^This is the number of times that SQLite has stepped forward in
|
6416 |
** a table as part of a full table scan. Large numbers for this counter
|
6417 |
** may indicate opportunities for performance improvement through
|
6418 |
** careful use of indices.</dd>
|
6419 |
**
|
6420 |
** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
|
6421 |
** <dd>^This is the number of sort operations that have occurred.
|
6422 |
** A non-zero value in this counter may indicate an opportunity to
|
6423 |
** improvement performance through careful use of indices.</dd>
|
6424 |
**
|
6425 |
** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
|
6426 |
** <dd>^This is the number of rows inserted into transient indices that
|
6427 |
** were created automatically in order to help joins run faster.
|
6428 |
** A non-zero value in this counter may indicate an opportunity to
|
6429 |
** improvement performance by adding permanent indices that do not
|
6430 |
** need to be reinitialized each time the statement is run.</dd>
|
6431 |
**
|
6432 |
** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
|
6433 |
** <dd>^This is the number of virtual machine operations executed
|
6434 |
** by the prepared statement if that number is less than or equal
|
6435 |
** to 2147483647. The number of virtual machine operations can be
|
6436 |
** used as a proxy for the total work done by the prepared statement.
|
6437 |
** If the number of virtual machine operations exceeds 2147483647
|
6438 |
** then the value returned by this statement status code is undefined.
|
6439 |
** </dd>
|
6440 |
** </dl>
|
6441 |
*/
|
6442 |
#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 |
6443 |
#define SQLITE_STMTSTATUS_SORT 2 |
6444 |
#define SQLITE_STMTSTATUS_AUTOINDEX 3 |
6445 |
#define SQLITE_STMTSTATUS_VM_STEP 4 |
6446 |
|
6447 |
/*
|
6448 |
** CAPI3REF: Custom Page Cache Object
|
6449 |
**
|
6450 |
** The sqlite3_pcache type is opaque. It is implemented by
|
6451 |
** the pluggable module. The SQLite core has no knowledge of
|
6452 |
** its size or internal structure and never deals with the
|
6453 |
** sqlite3_pcache object except by holding and passing pointers
|
6454 |
** to the object.
|
6455 |
**
|
6456 |
** See [sqlite3_pcache_methods2] for additional information.
|
6457 |
*/
|
6458 |
typedef struct sqlite3_pcache sqlite3_pcache; |
6459 |
|
6460 |
/*
|
6461 |
** CAPI3REF: Custom Page Cache Object
|
6462 |
**
|
6463 |
** The sqlite3_pcache_page object represents a single page in the
|
6464 |
** page cache. The page cache will allocate instances of this
|
6465 |
** object. Various methods of the page cache use pointers to instances
|
6466 |
** of this object as parameters or as their return value.
|
6467 |
**
|
6468 |
** See [sqlite3_pcache_methods2] for additional information.
|
6469 |
*/
|
6470 |
typedef struct sqlite3_pcache_page sqlite3_pcache_page; |
6471 |
struct sqlite3_pcache_page {
|
6472 |
void *pBuf; /* The content of the page */ |
6473 |
void *pExtra; /* Extra information associated with the page */ |
6474 |
}; |
6475 |
|
6476 |
/*
|
6477 |
** CAPI3REF: Application Defined Page Cache.
|
6478 |
** KEYWORDS: {page cache}
|
6479 |
**
|
6480 |
** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
|
6481 |
** register an alternative page cache implementation by passing in an
|
6482 |
** instance of the sqlite3_pcache_methods2 structure.)^
|
6483 |
** In many applications, most of the heap memory allocated by
|
6484 |
** SQLite is used for the page cache.
|
6485 |
** By implementing a
|
6486 |
** custom page cache using this API, an application can better control
|
6487 |
** the amount of memory consumed by SQLite, the way in which
|
6488 |
** that memory is allocated and released, and the policies used to
|
6489 |
** determine exactly which parts of a database file are cached and for
|
6490 |
** how long.
|
6491 |
**
|
6492 |
** The alternative page cache mechanism is an
|
6493 |
** extreme measure that is only needed by the most demanding applications.
|
6494 |
** The built-in page cache is recommended for most uses.
|
6495 |
**
|
6496 |
** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
|
6497 |
** internal buffer by SQLite within the call to [sqlite3_config]. Hence
|
6498 |
** the application may discard the parameter after the call to
|
6499 |
** [sqlite3_config()] returns.)^
|
6500 |
**
|
6501 |
** [[the xInit() page cache method]]
|
6502 |
** ^(The xInit() method is called once for each effective
|
6503 |
** call to [sqlite3_initialize()])^
|
6504 |
** (usually only once during the lifetime of the process). ^(The xInit()
|
6505 |
** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
|
6506 |
** The intent of the xInit() method is to set up global data structures
|
6507 |
** required by the custom page cache implementation.
|
6508 |
** ^(If the xInit() method is NULL, then the
|
6509 |
** built-in default page cache is used instead of the application defined
|
6510 |
** page cache.)^
|
6511 |
**
|
6512 |
** [[the xShutdown() page cache method]]
|
6513 |
** ^The xShutdown() method is called by [sqlite3_shutdown()].
|
6514 |
** It can be used to clean up
|
6515 |
** any outstanding resources before process shutdown, if required.
|
6516 |
** ^The xShutdown() method may be NULL.
|
6517 |
**
|
6518 |
** ^SQLite automatically serializes calls to the xInit method,
|
6519 |
** so the xInit method need not be threadsafe. ^The
|
6520 |
** xShutdown method is only called from [sqlite3_shutdown()] so it does
|
6521 |
** not need to be threadsafe either. All other methods must be threadsafe
|
6522 |
** in multithreaded applications.
|
6523 |
**
|
6524 |
** ^SQLite will never invoke xInit() more than once without an intervening
|
6525 |
** call to xShutdown().
|
6526 |
**
|
6527 |
** [[the xCreate() page cache methods]]
|
6528 |
** ^SQLite invokes the xCreate() method to construct a new cache instance.
|
6529 |
** SQLite will typically create one cache instance for each open database file,
|
6530 |
** though this is not guaranteed. ^The
|
6531 |
** first parameter, szPage, is the size in bytes of the pages that must
|
6532 |
** be allocated by the cache. ^szPage will always a power of two. ^The
|
6533 |
** second parameter szExtra is a number of bytes of extra storage
|
6534 |
** associated with each page cache entry. ^The szExtra parameter will
|
6535 |
** a number less than 250. SQLite will use the
|
6536 |
** extra szExtra bytes on each page to store metadata about the underlying
|
6537 |
** database page on disk. The value passed into szExtra depends
|
6538 |
** on the SQLite version, the target platform, and how SQLite was compiled.
|
6539 |
** ^The third argument to xCreate(), bPurgeable, is true if the cache being
|
6540 |
** created will be used to cache database pages of a file stored on disk, or
|
6541 |
** false if it is used for an in-memory database. The cache implementation
|
6542 |
** does not have to do anything special based with the value of bPurgeable;
|
6543 |
** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
|
6544 |
** never invoke xUnpin() except to deliberately delete a page.
|
6545 |
** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
|
6546 |
** false will always have the "discard" flag set to true.
|
6547 |
** ^Hence, a cache created with bPurgeable false will
|
6548 |
** never contain any unpinned pages.
|
6549 |
**
|
6550 |
** [[the xCachesize() page cache method]]
|
6551 |
** ^(The xCachesize() method may be called at any time by SQLite to set the
|
6552 |
** suggested maximum cache-size (number of pages stored by) the cache
|
6553 |
** instance passed as the first argument. This is the value configured using
|
6554 |
** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
|
6555 |
** parameter, the implementation is not required to do anything with this
|
6556 |
** value; it is advisory only.
|
6557 |
**
|
6558 |
** [[the xPagecount() page cache methods]]
|
6559 |
** The xPagecount() method must return the number of pages currently
|
6560 |
** stored in the cache, both pinned and unpinned.
|
6561 |
**
|
6562 |
** [[the xFetch() page cache methods]]
|
6563 |
** The xFetch() method locates a page in the cache and returns a pointer to
|
6564 |
** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
|
6565 |
** The pBuf element of the returned sqlite3_pcache_page object will be a
|
6566 |
** pointer to a buffer of szPage bytes used to store the content of a
|
6567 |
** single database page. The pExtra element of sqlite3_pcache_page will be
|
6568 |
** a pointer to the szExtra bytes of extra storage that SQLite has requested
|
6569 |
** for each entry in the page cache.
|
6570 |
**
|
6571 |
** The page to be fetched is determined by the key. ^The minimum key value
|
6572 |
** is 1. After it has been retrieved using xFetch, the page is considered
|
6573 |
** to be "pinned".
|
6574 |
**
|
6575 |
** If the requested page is already in the page cache, then the page cache
|
6576 |
** implementation must return a pointer to the page buffer with its content
|
6577 |
** intact. If the requested page is not already in the cache, then the
|
6578 |
** cache implementation should use the value of the createFlag
|
6579 |
** parameter to help it determined what action to take:
|
6580 |
**
|
6581 |
** <table border=1 width=85% align=center>
|
6582 |
** <tr><th> createFlag <th> Behavior when page is not already in cache
|
6583 |
** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
|
6584 |
** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
|
6585 |
** Otherwise return NULL.
|
6586 |
** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
|
6587 |
** NULL if allocating a new page is effectively impossible.
|
6588 |
** </table>
|
6589 |
**
|
6590 |
** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
|
6591 |
** will only use a createFlag of 2 after a prior call with a createFlag of 1
|
6592 |
** failed.)^ In between the to xFetch() calls, SQLite may
|
6593 |
** attempt to unpin one or more cache pages by spilling the content of
|
6594 |
** pinned pages to disk and synching the operating system disk cache.
|
6595 |
**
|
6596 |
** [[the xUnpin() page cache method]]
|
6597 |
** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
|
6598 |
** as its second argument. If the third parameter, discard, is non-zero,
|
6599 |
** then the page must be evicted from the cache.
|
6600 |
** ^If the discard parameter is
|
6601 |
** zero, then the page may be discarded or retained at the discretion of
|
6602 |
** page cache implementation. ^The page cache implementation
|
6603 |
** may choose to evict unpinned pages at any time.
|
6604 |
**
|
6605 |
** The cache must not perform any reference counting. A single
|
6606 |
** call to xUnpin() unpins the page regardless of the number of prior calls
|
6607 |
** to xFetch().
|
6608 |
**
|
6609 |
** [[the xRekey() page cache methods]]
|
6610 |
** The xRekey() method is used to change the key value associated with the
|
6611 |
** page passed as the second argument. If the cache
|
6612 |
** previously contains an entry associated with newKey, it must be
|
6613 |
** discarded. ^Any prior cache entry associated with newKey is guaranteed not
|
6614 |
** to be pinned.
|
6615 |
**
|
6616 |
** When SQLite calls the xTruncate() method, the cache must discard all
|
6617 |
** existing cache entries with page numbers (keys) greater than or equal
|
6618 |
** to the value of the iLimit parameter passed to xTruncate(). If any
|
6619 |
** of these pages are pinned, they are implicitly unpinned, meaning that
|
6620 |
** they can be safely discarded.
|
6621 |
**
|
6622 |
** [[the xDestroy() page cache method]]
|
6623 |
** ^The xDestroy() method is used to delete a cache allocated by xCreate().
|
6624 |
** All resources associated with the specified cache should be freed. ^After
|
6625 |
** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
|
6626 |
** handle invalid, and will not use it with any other sqlite3_pcache_methods2
|
6627 |
** functions.
|
6628 |
**
|
6629 |
** [[the xShrink() page cache method]]
|
6630 |
** ^SQLite invokes the xShrink() method when it wants the page cache to
|
6631 |
** free up as much of heap memory as possible. The page cache implementation
|
6632 |
** is not obligated to free any memory, but well-behaved implementations should
|
6633 |
** do their best.
|
6634 |
*/
|
6635 |
typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; |
6636 |
struct sqlite3_pcache_methods2 {
|
6637 |
int iVersion;
|
6638 |
void *pArg;
|
6639 |
int (*xInit)(void*); |
6640 |
void (*xShutdown)(void*); |
6641 |
sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); |
6642 |
void (*xCachesize)(sqlite3_pcache*, int nCachesize); |
6643 |
int (*xPagecount)(sqlite3_pcache*);
|
6644 |
sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); |
6645 |
void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); |
6646 |
void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
|
6647 |
unsigned oldKey, unsigned newKey); |
6648 |
void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); |
6649 |
void (*xDestroy)(sqlite3_pcache*);
|
6650 |
void (*xShrink)(sqlite3_pcache*);
|
6651 |
}; |
6652 |
|
6653 |
/*
|
6654 |
** This is the obsolete pcache_methods object that has now been replaced
|
6655 |
** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
|
6656 |
** retained in the header file for backwards compatibility only.
|
6657 |
*/
|
6658 |
typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; |
6659 |
struct sqlite3_pcache_methods {
|
6660 |
void *pArg;
|
6661 |
int (*xInit)(void*); |
6662 |
void (*xShutdown)(void*); |
6663 |
sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); |
6664 |
void (*xCachesize)(sqlite3_pcache*, int nCachesize); |
6665 |
int (*xPagecount)(sqlite3_pcache*);
|
6666 |
void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); |
6667 |
void (*xUnpin)(sqlite3_pcache*, void*, int discard); |
6668 |
void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); |
6669 |
void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); |
6670 |
void (*xDestroy)(sqlite3_pcache*);
|
6671 |
}; |
6672 |
|
6673 |
|
6674 |
/*
|
6675 |
** CAPI3REF: Online Backup Object
|
6676 |
**
|
6677 |
** The sqlite3_backup object records state information about an ongoing
|
6678 |
** online backup operation. ^The sqlite3_backup object is created by
|
6679 |
** a call to [sqlite3_backup_init()] and is destroyed by a call to
|
6680 |
** [sqlite3_backup_finish()].
|
6681 |
**
|
6682 |
** See Also: [Using the SQLite Online Backup API]
|
6683 |
*/
|
6684 |
typedef struct sqlite3_backup sqlite3_backup; |
6685 |
|
6686 |
/*
|
6687 |
** CAPI3REF: Online Backup API.
|
6688 |
**
|
6689 |
** The backup API copies the content of one database into another.
|
6690 |
** It is useful either for creating backups of databases or
|
6691 |
** for copying in-memory databases to or from persistent files.
|
6692 |
**
|
6693 |
** See Also: [Using the SQLite Online Backup API]
|
6694 |
**
|
6695 |
** ^SQLite holds a write transaction open on the destination database file
|
6696 |
** for the duration of the backup operation.
|
6697 |
** ^The source database is read-locked only while it is being read;
|
6698 |
** it is not locked continuously for the entire backup operation.
|
6699 |
** ^Thus, the backup may be performed on a live source database without
|
6700 |
** preventing other database connections from
|
6701 |
** reading or writing to the source database while the backup is underway.
|
6702 |
**
|
6703 |
** ^(To perform a backup operation:
|
6704 |
** <ol>
|
6705 |
** <li><b>sqlite3_backup_init()</b> is called once to initialize the
|
6706 |
** backup,
|
6707 |
** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
|
6708 |
** the data between the two databases, and finally
|
6709 |
** <li><b>sqlite3_backup_finish()</b> is called to release all resources
|
6710 |
** associated with the backup operation.
|
6711 |
** </ol>)^
|
6712 |
** There should be exactly one call to sqlite3_backup_finish() for each
|
6713 |
** successful call to sqlite3_backup_init().
|
6714 |
**
|
6715 |
** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
|
6716 |
**
|
6717 |
** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
|
6718 |
** [database connection] associated with the destination database
|
6719 |
** and the database name, respectively.
|
6720 |
** ^The database name is "main" for the main database, "temp" for the
|
6721 |
** temporary database, or the name specified after the AS keyword in
|
6722 |
** an [ATTACH] statement for an attached database.
|
6723 |
** ^The S and M arguments passed to
|
6724 |
** sqlite3_backup_init(D,N,S,M) identify the [database connection]
|
6725 |
** and database name of the source database, respectively.
|
6726 |
** ^The source and destination [database connections] (parameters S and D)
|
6727 |
** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
|
6728 |
** an error.
|
6729 |
**
|
6730 |
** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
|
6731 |
** returned and an error code and error message are stored in the
|
6732 |
** destination [database connection] D.
|
6733 |
** ^The error code and message for the failed call to sqlite3_backup_init()
|
6734 |
** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
|
6735 |
** [sqlite3_errmsg16()] functions.
|
6736 |
** ^A successful call to sqlite3_backup_init() returns a pointer to an
|
6737 |
** [sqlite3_backup] object.
|
6738 |
** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
|
6739 |
** sqlite3_backup_finish() functions to perform the specified backup
|
6740 |
** operation.
|
6741 |
**
|
6742 |
** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
|
6743 |
**
|
6744 |
** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
|
6745 |
** the source and destination databases specified by [sqlite3_backup] object B.
|
6746 |
** ^If N is negative, all remaining source pages are copied.
|
6747 |
** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
|
6748 |
** are still more pages to be copied, then the function returns [SQLITE_OK].
|
6749 |
** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
|
6750 |
** from source to destination, then it returns [SQLITE_DONE].
|
6751 |
** ^If an error occurs while running sqlite3_backup_step(B,N),
|
6752 |
** then an [error code] is returned. ^As well as [SQLITE_OK] and
|
6753 |
** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
|
6754 |
** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
|
6755 |
** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
|
6756 |
**
|
6757 |
** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
|
6758 |
** <ol>
|
6759 |
** <li> the destination database was opened read-only, or
|
6760 |
** <li> the destination database is using write-ahead-log journaling
|
6761 |
** and the destination and source page sizes differ, or
|
6762 |
** <li> the destination database is an in-memory database and the
|
6763 |
** destination and source page sizes differ.
|
6764 |
** </ol>)^
|
6765 |
**
|
6766 |
** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
|
6767 |
** the [sqlite3_busy_handler | busy-handler function]
|
6768 |
** is invoked (if one is specified). ^If the
|
6769 |
** busy-handler returns non-zero before the lock is available, then
|
6770 |
** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
|
6771 |
** sqlite3_backup_step() can be retried later. ^If the source
|
6772 |
** [database connection]
|
6773 |
** is being used to write to the source database when sqlite3_backup_step()
|
6774 |
** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
|
6775 |
** case the call to sqlite3_backup_step() can be retried later on. ^(If
|
6776 |
** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
|
6777 |
** [SQLITE_READONLY] is returned, then
|
6778 |
** there is no point in retrying the call to sqlite3_backup_step(). These
|
6779 |
** errors are considered fatal.)^ The application must accept
|
6780 |
** that the backup operation has failed and pass the backup operation handle
|
6781 |
** to the sqlite3_backup_finish() to release associated resources.
|
6782 |
**
|
6783 |
** ^The first call to sqlite3_backup_step() obtains an exclusive lock
|
6784 |
** on the destination file. ^The exclusive lock is not released until either
|
6785 |
** sqlite3_backup_finish() is called or the backup operation is complete
|
6786 |
** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
|
6787 |
** sqlite3_backup_step() obtains a [shared lock] on the source database that
|
6788 |
** lasts for the duration of the sqlite3_backup_step() call.
|
6789 |
** ^Because the source database is not locked between calls to
|
6790 |
** sqlite3_backup_step(), the source database may be modified mid-way
|
6791 |
** through the backup process. ^If the source database is modified by an
|
6792 |
** external process or via a database connection other than the one being
|
6793 |
** used by the backup operation, then the backup will be automatically
|
6794 |
** restarted by the next call to sqlite3_backup_step(). ^If the source
|
6795 |
** database is modified by the using the same database connection as is used
|
6796 |
** by the backup operation, then the backup database is automatically
|
6797 |
** updated at the same time.
|
6798 |
**
|
6799 |
** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
|
6800 |
**
|
6801 |
** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
|
6802 |
** application wishes to abandon the backup operation, the application
|
6803 |
** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
|
6804 |
** ^The sqlite3_backup_finish() interfaces releases all
|
6805 |
** resources associated with the [sqlite3_backup] object.
|
6806 |
** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
|
6807 |
** active write-transaction on the destination database is rolled back.
|
6808 |
** The [sqlite3_backup] object is invalid
|
6809 |
** and may not be used following a call to sqlite3_backup_finish().
|
6810 |
**
|
6811 |
** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
|
6812 |
** sqlite3_backup_step() errors occurred, regardless or whether or not
|
6813 |
** sqlite3_backup_step() completed.
|
6814 |
** ^If an out-of-memory condition or IO error occurred during any prior
|
6815 |
** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
|
6816 |
** sqlite3_backup_finish() returns the corresponding [error code].
|
6817 |
**
|
6818 |
** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
|
6819 |
** is not a permanent error and does not affect the return value of
|
6820 |
** sqlite3_backup_finish().
|
6821 |
**
|
6822 |
** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]]
|
6823 |
** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
|
6824 |
**
|
6825 |
** ^Each call to sqlite3_backup_step() sets two values inside
|
6826 |
** the [sqlite3_backup] object: the number of pages still to be backed
|
6827 |
** up and the total number of pages in the source database file.
|
6828 |
** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces
|
6829 |
** retrieve these two values, respectively.
|
6830 |
**
|
6831 |
** ^The values returned by these functions are only updated by
|
6832 |
** sqlite3_backup_step(). ^If the source database is modified during a backup
|
6833 |
** operation, then the values are not updated to account for any extra
|
6834 |
** pages that need to be updated or the size of the source database file
|
6835 |
** changing.
|
6836 |
**
|
6837 |
** <b>Concurrent Usage of Database Handles</b>
|
6838 |
**
|
6839 |
** ^The source [database connection] may be used by the application for other
|
6840 |
** purposes while a backup operation is underway or being initialized.
|
6841 |
** ^If SQLite is compiled and configured to support threadsafe database
|
6842 |
** connections, then the source database connection may be used concurrently
|
6843 |
** from within other threads.
|
6844 |
**
|
6845 |
** However, the application must guarantee that the destination
|
6846 |
** [database connection] is not passed to any other API (by any thread) after
|
6847 |
** sqlite3_backup_init() is called and before the corresponding call to
|
6848 |
** sqlite3_backup_finish(). SQLite does not currently check to see
|
6849 |
** if the application incorrectly accesses the destination [database connection]
|
6850 |
** and so no error code is reported, but the operations may malfunction
|
6851 |
** nevertheless. Use of the destination database connection while a
|
6852 |
** backup is in progress might also also cause a mutex deadlock.
|
6853 |
**
|
6854 |
** If running in [shared cache mode], the application must
|
6855 |
** guarantee that the shared cache used by the destination database
|
6856 |
** is not accessed while the backup is running. In practice this means
|
6857 |
** that the application must guarantee that the disk file being
|
6858 |
** backed up to is not accessed by any connection within the process,
|
6859 |
** not just the specific connection that was passed to sqlite3_backup_init().
|
6860 |
**
|
6861 |
** The [sqlite3_backup] object itself is partially threadsafe. Multiple
|
6862 |
** threads may safely make multiple concurrent calls to sqlite3_backup_step().
|
6863 |
** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
|
6864 |
** APIs are not strictly speaking threadsafe. If they are invoked at the
|
6865 |
** same time as another thread is invoking sqlite3_backup_step() it is
|
6866 |
** possible that they return invalid values.
|
6867 |
*/
|
6868 |
SQLITE_API sqlite3_backup *sqlite3_backup_init( |
6869 |
sqlite3 *pDest, /* Destination database handle */
|
6870 |
const char *zDestName, /* Destination database name */ |
6871 |
sqlite3 *pSource, /* Source database handle */
|
6872 |
const char *zSourceName /* Source database name */ |
6873 |
); |
6874 |
SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); |
6875 |
SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
|
6876 |
SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
|
6877 |
SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
|
6878 |
|
6879 |
/*
|
6880 |
** CAPI3REF: Unlock Notification
|
6881 |
**
|
6882 |
** ^When running in shared-cache mode, a database operation may fail with
|
6883 |
** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
|
6884 |
** individual tables within the shared-cache cannot be obtained. See
|
6885 |
** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
|
6886 |
** ^This API may be used to register a callback that SQLite will invoke
|
6887 |
** when the connection currently holding the required lock relinquishes it.
|
6888 |
** ^This API is only available if the library was compiled with the
|
6889 |
** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
|
6890 |
**
|
6891 |
** See Also: [Using the SQLite Unlock Notification Feature].
|
6892 |
**
|
6893 |
** ^Shared-cache locks are released when a database connection concludes
|
6894 |
** its current transaction, either by committing it or rolling it back.
|
6895 |
**
|
6896 |
** ^When a connection (known as the blocked connection) fails to obtain a
|
6897 |
** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
|
6898 |
** identity of the database connection (the blocking connection) that
|
6899 |
** has locked the required resource is stored internally. ^After an
|
6900 |
** application receives an SQLITE_LOCKED error, it may call the
|
6901 |
** sqlite3_unlock_notify() method with the blocked connection handle as
|
6902 |
** the first argument to register for a callback that will be invoked
|
6903 |
** when the blocking connections current transaction is concluded. ^The
|
6904 |
** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
|
6905 |
** call that concludes the blocking connections transaction.
|
6906 |
**
|
6907 |
** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
|
6908 |
** there is a chance that the blocking connection will have already
|
6909 |
** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
|
6910 |
** If this happens, then the specified callback is invoked immediately,
|
6911 |
** from within the call to sqlite3_unlock_notify().)^
|
6912 |
**
|
6913 |
** ^If the blocked connection is attempting to obtain a write-lock on a
|
6914 |
** shared-cache table, and more than one other connection currently holds
|
6915 |
** a read-lock on the same table, then SQLite arbitrarily selects one of
|
6916 |
** the other connections to use as the blocking connection.
|
6917 |
**
|
6918 |
** ^(There may be at most one unlock-notify callback registered by a
|
6919 |
** blocked connection. If sqlite3_unlock_notify() is called when the
|
6920 |
** blocked connection already has a registered unlock-notify callback,
|
6921 |
** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
|
6922 |
** called with a NULL pointer as its second argument, then any existing
|
6923 |
** unlock-notify callback is canceled. ^The blocked connections
|
6924 |
** unlock-notify callback may also be canceled by closing the blocked
|
6925 |
** connection using [sqlite3_close()].
|
6926 |
**
|
6927 |
** The unlock-notify callback is not reentrant. If an application invokes
|
6928 |
** any sqlite3_xxx API functions from within an unlock-notify callback, a
|
6929 |
** crash or deadlock may be the result.
|
6930 |
**
|
6931 |
** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
|
6932 |
** returns SQLITE_OK.
|
6933 |
**
|
6934 |
** <b>Callback Invocation Details</b>
|
6935 |
**
|
6936 |
** When an unlock-notify callback is registered, the application provides a
|
6937 |
** single void* pointer that is passed to the callback when it is invoked.
|
6938 |
** However, the signature of the callback function allows SQLite to pass
|
6939 |
** it an array of void* context pointers. The first argument passed to
|
6940 |
** an unlock-notify callback is a pointer to an array of void* pointers,
|
6941 |
** and the second is the number of entries in the array.
|
6942 |
**
|
6943 |
** When a blocking connections transaction is concluded, there may be
|
6944 |
** more than one blocked connection that has registered for an unlock-notify
|
6945 |
** callback. ^If two or more such blocked connections have specified the
|
6946 |
** same callback function, then instead of invoking the callback function
|
6947 |
** multiple times, it is invoked once with the set of void* context pointers
|
6948 |
** specified by the blocked connections bundled together into an array.
|
6949 |
** This gives the application an opportunity to prioritize any actions
|
6950 |
** related to the set of unblocked database connections.
|
6951 |
**
|
6952 |
** <b>Deadlock Detection</b>
|
6953 |
**
|
6954 |
** Assuming that after registering for an unlock-notify callback a
|
6955 |
** database waits for the callback to be issued before taking any further
|
6956 |
** action (a reasonable assumption), then using this API may cause the
|
6957 |
** application to deadlock. For example, if connection X is waiting for
|
6958 |
** connection Y's transaction to be concluded, and similarly connection
|
6959 |
** Y is waiting on connection X's transaction, then neither connection
|
6960 |
** will proceed and the system may remain deadlocked indefinitely.
|
6961 |
**
|
6962 |
** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
|
6963 |
** detection. ^If a given call to sqlite3_unlock_notify() would put the
|
6964 |
** system in a deadlocked state, then SQLITE_LOCKED is returned and no
|
6965 |
** unlock-notify callback is registered. The system is said to be in
|
6966 |
** a deadlocked state if connection A has registered for an unlock-notify
|
6967 |
** callback on the conclusion of connection B's transaction, and connection
|
6968 |
** B has itself registered for an unlock-notify callback when connection
|
6969 |
** A's transaction is concluded. ^Indirect deadlock is also detected, so
|
6970 |
** the system is also considered to be deadlocked if connection B has
|
6971 |
** registered for an unlock-notify callback on the conclusion of connection
|
6972 |
** C's transaction, where connection C is waiting on connection A. ^Any
|
6973 |
** number of levels of indirection are allowed.
|
6974 |
**
|
6975 |
** <b>The "DROP TABLE" Exception</b>
|
6976 |
**
|
6977 |
** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
|
6978 |
** always appropriate to call sqlite3_unlock_notify(). There is however,
|
6979 |
** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
|
6980 |
** SQLite checks if there are any currently executing SELECT statements
|
6981 |
** that belong to the same connection. If there are, SQLITE_LOCKED is
|
6982 |
** returned. In this case there is no "blocking connection", so invoking
|
6983 |
** sqlite3_unlock_notify() results in the unlock-notify callback being
|
6984 |
** invoked immediately. If the application then re-attempts the "DROP TABLE"
|
6985 |
** or "DROP INDEX" query, an infinite loop might be the result.
|
6986 |
**
|
6987 |
** One way around this problem is to check the extended error code returned
|
6988 |
** by an sqlite3_step() call. ^(If there is a blocking connection, then the
|
6989 |
** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
|
6990 |
** the special "DROP TABLE/INDEX" case, the extended error code is just
|
6991 |
** SQLITE_LOCKED.)^
|
6992 |
*/
|
6993 |
SQLITE_API int sqlite3_unlock_notify(
|
6994 |
sqlite3 *pBlocked, /* Waiting connection */
|
6995 |
void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ |
6996 |
void *pNotifyArg /* Argument to pass to xNotify */ |
6997 |
); |
6998 |
|
6999 |
|
7000 |
/*
|
7001 |
** CAPI3REF: String Comparison
|
7002 |
**
|
7003 |
** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
|
7004 |
** and extensions to compare the contents of two buffers containing UTF-8
|
7005 |
** strings in a case-independent fashion, using the same definition of "case
|
7006 |
** independence" that SQLite uses internally when comparing identifiers.
|
7007 |
*/
|
7008 |
SQLITE_API int sqlite3_stricmp(const char *, const char *); |
7009 |
SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); |
7010 |
|
7011 |
/*
|
7012 |
** CAPI3REF: String Globbing
|
7013 |
*
|
7014 |
** ^The [sqlite3_strglob(P,X)] interface returns zero if string X matches
|
7015 |
** the glob pattern P, and it returns non-zero if string X does not match
|
7016 |
** the glob pattern P. ^The definition of glob pattern matching used in
|
7017 |
** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
|
7018 |
** SQL dialect used by SQLite. ^The sqlite3_strglob(P,X) function is case
|
7019 |
** sensitive.
|
7020 |
**
|
7021 |
** Note that this routine returns zero on a match and non-zero if the strings
|
7022 |
** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
|
7023 |
*/
|
7024 |
SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); |
7025 |
|
7026 |
/*
|
7027 |
** CAPI3REF: Error Logging Interface
|
7028 |
**
|
7029 |
** ^The [sqlite3_log()] interface writes a message into the [error log]
|
7030 |
** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
|
7031 |
** ^If logging is enabled, the zFormat string and subsequent arguments are
|
7032 |
** used with [sqlite3_snprintf()] to generate the final output string.
|
7033 |
**
|
7034 |
** The sqlite3_log() interface is intended for use by extensions such as
|
7035 |
** virtual tables, collating functions, and SQL functions. While there is
|
7036 |
** nothing to prevent an application from calling sqlite3_log(), doing so
|
7037 |
** is considered bad form.
|
7038 |
**
|
7039 |
** The zFormat string must not be NULL.
|
7040 |
**
|
7041 |
** To avoid deadlocks and other threading problems, the sqlite3_log() routine
|
7042 |
** will not use dynamically allocated memory. The log message is stored in
|
7043 |
** a fixed-length buffer on the stack. If the log message is longer than
|
7044 |
** a few hundred characters, it will be truncated to the length of the
|
7045 |
** buffer.
|
7046 |
*/
|
7047 |
SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); |
7048 |
|
7049 |
/*
|
7050 |
** CAPI3REF: Write-Ahead Log Commit Hook
|
7051 |
**
|
7052 |
** ^The [sqlite3_wal_hook()] function is used to register a callback that
|
7053 |
** will be invoked each time a database connection commits data to a
|
7054 |
** [write-ahead log] (i.e. whenever a transaction is committed in
|
7055 |
** [journal_mode | journal_mode=WAL mode]).
|
7056 |
**
|
7057 |
** ^The callback is invoked by SQLite after the commit has taken place and
|
7058 |
** the associated write-lock on the database released, so the implementation
|
7059 |
** may read, write or [checkpoint] the database as required.
|
7060 |
**
|
7061 |
** ^The first parameter passed to the callback function when it is invoked
|
7062 |
** is a copy of the third parameter passed to sqlite3_wal_hook() when
|
7063 |
** registering the callback. ^The second is a copy of the database handle.
|
7064 |
** ^The third parameter is the name of the database that was written to -
|
7065 |
** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
|
7066 |
** is the number of pages currently in the write-ahead log file,
|
7067 |
** including those that were just committed.
|
7068 |
**
|
7069 |
** The callback function should normally return [SQLITE_OK]. ^If an error
|
7070 |
** code is returned, that error will propagate back up through the
|
7071 |
** SQLite code base to cause the statement that provoked the callback
|
7072 |
** to report an error, though the commit will have still occurred. If the
|
7073 |
** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
|
7074 |
** that does not correspond to any valid SQLite error code, the results
|
7075 |
** are undefined.
|
7076 |
**
|
7077 |
** A single database handle may have at most a single write-ahead log callback
|
7078 |
** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
|
7079 |
** previously registered write-ahead log callback. ^Note that the
|
7080 |
** [sqlite3_wal_autocheckpoint()] interface and the
|
7081 |
** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
|
7082 |
** those overwrite any prior [sqlite3_wal_hook()] settings.
|
7083 |
*/
|
7084 |
SQLITE_API void *sqlite3_wal_hook(
|
7085 |
sqlite3*, |
7086 |
int(*)(void *,sqlite3*,const char*,int), |
7087 |
void*
|
7088 |
); |
7089 |
|
7090 |
/*
|
7091 |
** CAPI3REF: Configure an auto-checkpoint
|
7092 |
**
|
7093 |
** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
|
7094 |
** [sqlite3_wal_hook()] that causes any database on [database connection] D
|
7095 |
** to automatically [checkpoint]
|
7096 |
** after committing a transaction if there are N or
|
7097 |
** more frames in the [write-ahead log] file. ^Passing zero or
|
7098 |
** a negative value as the nFrame parameter disables automatic
|
7099 |
** checkpoints entirely.
|
7100 |
**
|
7101 |
** ^The callback registered by this function replaces any existing callback
|
7102 |
** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
|
7103 |
** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
|
7104 |
** configured by this function.
|
7105 |
**
|
7106 |
** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
|
7107 |
** from SQL.
|
7108 |
**
|
7109 |
** ^Every new [database connection] defaults to having the auto-checkpoint
|
7110 |
** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
|
7111 |
** pages. The use of this interface
|
7112 |
** is only necessary if the default setting is found to be suboptimal
|
7113 |
** for a particular application.
|
7114 |
*/
|
7115 |
SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); |
7116 |
|
7117 |
/*
|
7118 |
** CAPI3REF: Checkpoint a database
|
7119 |
**
|
7120 |
** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X
|
7121 |
** on [database connection] D to be [checkpointed]. ^If X is NULL or an
|
7122 |
** empty string, then a checkpoint is run on all databases of
|
7123 |
** connection D. ^If the database connection D is not in
|
7124 |
** [WAL | write-ahead log mode] then this interface is a harmless no-op.
|
7125 |
**
|
7126 |
** ^The [wal_checkpoint pragma] can be used to invoke this interface
|
7127 |
** from SQL. ^The [sqlite3_wal_autocheckpoint()] interface and the
|
7128 |
** [wal_autocheckpoint pragma] can be used to cause this interface to be
|
7129 |
** run whenever the WAL reaches a certain size threshold.
|
7130 |
**
|
7131 |
** See also: [sqlite3_wal_checkpoint_v2()]
|
7132 |
*/
|
7133 |
SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); |
7134 |
|
7135 |
/*
|
7136 |
** CAPI3REF: Checkpoint a database
|
7137 |
**
|
7138 |
** Run a checkpoint operation on WAL database zDb attached to database
|
7139 |
** handle db. The specific operation is determined by the value of the
|
7140 |
** eMode parameter:
|
7141 |
**
|
7142 |
** <dl>
|
7143 |
** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
|
7144 |
** Checkpoint as many frames as possible without waiting for any database
|
7145 |
** readers or writers to finish. Sync the db file if all frames in the log
|
7146 |
** are checkpointed. This mode is the same as calling
|
7147 |
** sqlite3_wal_checkpoint(). The busy-handler callback is never invoked.
|
7148 |
**
|
7149 |
** <dt>SQLITE_CHECKPOINT_FULL<dd>
|
7150 |
** This mode blocks (calls the busy-handler callback) until there is no
|
7151 |
** database writer and all readers are reading from the most recent database
|
7152 |
** snapshot. It then checkpoints all frames in the log file and syncs the
|
7153 |
** database file. This call blocks database writers while it is running,
|
7154 |
** but not database readers.
|
7155 |
**
|
7156 |
** <dt>SQLITE_CHECKPOINT_RESTART<dd>
|
7157 |
** This mode works the same way as SQLITE_CHECKPOINT_FULL, except after
|
7158 |
** checkpointing the log file it blocks (calls the busy-handler callback)
|
7159 |
** until all readers are reading from the database file only. This ensures
|
7160 |
** that the next client to write to the database file restarts the log file
|
7161 |
** from the beginning. This call blocks database writers while it is running,
|
7162 |
** but not database readers.
|
7163 |
** </dl>
|
7164 |
**
|
7165 |
** If pnLog is not NULL, then *pnLog is set to the total number of frames in
|
7166 |
** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to
|
7167 |
** the total number of checkpointed frames (including any that were already
|
7168 |
** checkpointed when this function is called). *pnLog and *pnCkpt may be
|
7169 |
** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK.
|
7170 |
** If no values are available because of an error, they are both set to -1
|
7171 |
** before returning to communicate this to the caller.
|
7172 |
**
|
7173 |
** All calls obtain an exclusive "checkpoint" lock on the database file. If
|
7174 |
** any other process is running a checkpoint operation at the same time, the
|
7175 |
** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a
|
7176 |
** busy-handler configured, it will not be invoked in this case.
|
7177 |
**
|
7178 |
** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive
|
7179 |
** "writer" lock on the database file. If the writer lock cannot be obtained
|
7180 |
** immediately, and a busy-handler is configured, it is invoked and the writer
|
7181 |
** lock retried until either the busy-handler returns 0 or the lock is
|
7182 |
** successfully obtained. The busy-handler is also invoked while waiting for
|
7183 |
** database readers as described above. If the busy-handler returns 0 before
|
7184 |
** the writer lock is obtained or while waiting for database readers, the
|
7185 |
** checkpoint operation proceeds from that point in the same way as
|
7186 |
** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
|
7187 |
** without blocking any further. SQLITE_BUSY is returned in this case.
|
7188 |
**
|
7189 |
** If parameter zDb is NULL or points to a zero length string, then the
|
7190 |
** specified operation is attempted on all WAL databases. In this case the
|
7191 |
** values written to output parameters *pnLog and *pnCkpt are undefined. If
|
7192 |
** an SQLITE_BUSY error is encountered when processing one or more of the
|
7193 |
** attached WAL databases, the operation is still attempted on any remaining
|
7194 |
** attached databases and SQLITE_BUSY is returned to the caller. If any other
|
7195 |
** error occurs while processing an attached database, processing is abandoned
|
7196 |
** and the error code returned to the caller immediately. If no error
|
7197 |
** (SQLITE_BUSY or otherwise) is encountered while processing the attached
|
7198 |
** databases, SQLITE_OK is returned.
|
7199 |
**
|
7200 |
** If database zDb is the name of an attached database that is not in WAL
|
7201 |
** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If
|
7202 |
** zDb is not NULL (or a zero length string) and is not the name of any
|
7203 |
** attached database, SQLITE_ERROR is returned to the caller.
|
7204 |
*/
|
7205 |
SQLITE_API int sqlite3_wal_checkpoint_v2(
|
7206 |
sqlite3 *db, /* Database handle */
|
7207 |
const char *zDb, /* Name of attached database (or NULL) */ |
7208 |
int eMode, /* SQLITE_CHECKPOINT_* value */ |
7209 |
int *pnLog, /* OUT: Size of WAL log in frames */ |
7210 |
int *pnCkpt /* OUT: Total number of frames checkpointed */ |
7211 |
); |
7212 |
|
7213 |
/*
|
7214 |
** CAPI3REF: Checkpoint operation parameters
|
7215 |
**
|
7216 |
** These constants can be used as the 3rd parameter to
|
7217 |
** [sqlite3_wal_checkpoint_v2()]. See the [sqlite3_wal_checkpoint_v2()]
|
7218 |
** documentation for additional information about the meaning and use of
|
7219 |
** each of these values.
|
7220 |
*/
|
7221 |
#define SQLITE_CHECKPOINT_PASSIVE 0 |
7222 |
#define SQLITE_CHECKPOINT_FULL 1 |
7223 |
#define SQLITE_CHECKPOINT_RESTART 2 |
7224 |
|
7225 |
/*
|
7226 |
** CAPI3REF: Virtual Table Interface Configuration
|
7227 |
**
|
7228 |
** This function may be called by either the [xConnect] or [xCreate] method
|
7229 |
** of a [virtual table] implementation to configure
|
7230 |
** various facets of the virtual table interface.
|
7231 |
**
|
7232 |
** If this interface is invoked outside the context of an xConnect or
|
7233 |
** xCreate virtual table method then the behavior is undefined.
|
7234 |
**
|
7235 |
** At present, there is only one option that may be configured using
|
7236 |
** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options
|
7237 |
** may be added in the future.
|
7238 |
*/
|
7239 |
SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); |
7240 |
|
7241 |
/*
|
7242 |
** CAPI3REF: Virtual Table Configuration Options
|
7243 |
**
|
7244 |
** These macros define the various options to the
|
7245 |
** [sqlite3_vtab_config()] interface that [virtual table] implementations
|
7246 |
** can use to customize and optimize their behavior.
|
7247 |
**
|
7248 |
** <dl>
|
7249 |
** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT
|
7250 |
** <dd>Calls of the form
|
7251 |
** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
|
7252 |
** where X is an integer. If X is zero, then the [virtual table] whose
|
7253 |
** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
|
7254 |
** support constraints. In this configuration (which is the default) if
|
7255 |
** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
|
7256 |
** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
|
7257 |
** specified as part of the users SQL statement, regardless of the actual
|
7258 |
** ON CONFLICT mode specified.
|
7259 |
**
|
7260 |
** If X is non-zero, then the virtual table implementation guarantees
|
7261 |
** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
|
7262 |
** any modifications to internal or persistent data structures have been made.
|
7263 |
** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
|
7264 |
** is able to roll back a statement or database transaction, and abandon
|
7265 |
** or continue processing the current SQL statement as appropriate.
|
7266 |
** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
|
7267 |
** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
|
7268 |
** had been ABORT.
|
7269 |
**
|
7270 |
** Virtual table implementations that are required to handle OR REPLACE
|
7271 |
** must do so within the [xUpdate] method. If a call to the
|
7272 |
** [sqlite3_vtab_on_conflict()] function indicates that the current ON
|
7273 |
** CONFLICT policy is REPLACE, the virtual table implementation should
|
7274 |
** silently replace the appropriate rows within the xUpdate callback and
|
7275 |
** return SQLITE_OK. Or, if this is not possible, it may return
|
7276 |
** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
|
7277 |
** constraint handling.
|
7278 |
** </dl>
|
7279 |
*/
|
7280 |
#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 |
7281 |
|
7282 |
/*
|
7283 |
** CAPI3REF: Determine The Virtual Table Conflict Policy
|
7284 |
**
|
7285 |
** This function may only be called from within a call to the [xUpdate] method
|
7286 |
** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
|
7287 |
** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
|
7288 |
** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
|
7289 |
** of the SQL statement that triggered the call to the [xUpdate] method of the
|
7290 |
** [virtual table].
|
7291 |
*/
|
7292 |
SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
|
7293 |
|
7294 |
/*
|
7295 |
** CAPI3REF: Conflict resolution modes
|
7296 |
**
|
7297 |
** These constants are returned by [sqlite3_vtab_on_conflict()] to
|
7298 |
** inform a [virtual table] implementation what the [ON CONFLICT] mode
|
7299 |
** is for the SQL statement being evaluated.
|
7300 |
**
|
7301 |
** Note that the [SQLITE_IGNORE] constant is also used as a potential
|
7302 |
** return value from the [sqlite3_set_authorizer()] callback and that
|
7303 |
** [SQLITE_ABORT] is also a [result code].
|
7304 |
*/
|
7305 |
#define SQLITE_ROLLBACK 1 |
7306 |
/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
|
7307 |
#define SQLITE_FAIL 3 |
7308 |
/* #define SQLITE_ABORT 4 // Also an error code */
|
7309 |
#define SQLITE_REPLACE 5 |
7310 |
|
7311 |
|
7312 |
|
7313 |
/*
|
7314 |
** Undo the hack that converts floating point types to integer for
|
7315 |
** builds on processors without floating point support.
|
7316 |
*/
|
7317 |
#ifdef SQLITE_OMIT_FLOATING_POINT
|
7318 |
# undef double |
7319 |
#endif
|
7320 |
|
7321 |
#ifdef __cplusplus
|
7322 |
} /* End of the 'extern "C"' block */
|
7323 |
#endif
|
7324 |
#endif /* _SQLITE3_H_ */ |
7325 |
|
7326 |
/*
|
7327 |
** 2010 August 30
|
7328 |
**
|
7329 |
** The author disclaims copyright to this source code. In place of
|
7330 |
** a legal notice, here is a blessing:
|
7331 |
**
|
7332 |
** May you do good and not evil.
|
7333 |
** May you find forgiveness for yourself and forgive others.
|
7334 |
** May you share freely, never taking more than you give.
|
7335 |
**
|
7336 |
*************************************************************************
|
7337 |
*/
|
7338 |
|
7339 |
#ifndef _SQLITE3RTREE_H_
|
7340 |
#define _SQLITE3RTREE_H_
|
7341 |
|
7342 |
|
7343 |
#ifdef __cplusplus
|
7344 |
extern "C" { |
7345 |
#endif
|
7346 |
|
7347 |
typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; |
7348 |
|
7349 |
/*
|
7350 |
** Register a geometry callback named zGeom that can be used as part of an
|
7351 |
** R-Tree geometry query as follows:
|
7352 |
**
|
7353 |
** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
|
7354 |
*/
|
7355 |
SQLITE_API int sqlite3_rtree_geometry_callback(
|
7356 |
sqlite3 *db, |
7357 |
const char *zGeom, |
7358 |
#ifdef SQLITE_RTREE_INT_ONLY
|
7359 |
int (*xGeom)(sqlite3_rtree_geometry*, int n, sqlite3_int64 *a, int *pRes), |
7360 |
#else
|
7361 |
int (*xGeom)(sqlite3_rtree_geometry*, int n, double *a, int *pRes), |
7362 |
#endif
|
7363 |
void *pContext
|
7364 |
); |
7365 |
|
7366 |
|
7367 |
/*
|
7368 |
** A pointer to a structure of the following type is passed as the first
|
7369 |
** argument to callbacks registered using rtree_geometry_callback().
|
7370 |
*/
|
7371 |
struct sqlite3_rtree_geometry {
|
7372 |
void *pContext; /* Copy of pContext passed to s_r_g_c() */ |
7373 |
int nParam; /* Size of array aParam[] */ |
7374 |
double *aParam; /* Parameters passed to SQL geom function */ |
7375 |
void *pUser; /* Callback implementation user data */ |
7376 |
void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ |
7377 |
}; |
7378 |
|
7379 |
|
7380 |
#ifdef __cplusplus
|
7381 |
} /* end of the 'extern "C"' block */
|
7382 |
#endif
|
7383 |
|
7384 |
#endif /* ifndef _SQLITE3RTREE_H_ */ |
7385 |
|