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Binding Values To Prepared Statements

代码语言:javascript
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int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
                        void(*)(void*));
int sqlite3_bind_double(sqlite3_stmt*, int, double);
int sqlite3_bind_int(sqlite3_stmt*, int, int);
int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
int sqlite3_bind_null(sqlite3_stmt*, int);
int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
                         void(*)(void*), unsigned char encoding);
int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);

In the SQL statement text input to sqlite3_prepare_v2() and its variants, literals may be replaced by a parameter that matches one of following templates:

  • ?
  • ?NNN
  • :VVV
  • @VVV
  • $VVV

In the templates above, NNN represents an integer literal, and VVV represents an alphanumeric identifier. The values of these parameters (also called "host parameter names" or "SQL parameters") can be set using the sqlite3_bind_*() routines defined here.

The first argument to the sqlite3_bind_*() routines is always a pointer to the sqlite3_stmt object returned from sqlite3_prepare_v2() or its variants.

The second argument is the index of the SQL parameter to be set. The leftmost SQL parameter has an index of 1. When the same named SQL parameter is used more than once, second and subsequent occurrences have the same index as the first occurrence. The index for named parameters can be looked up using the sqlite3_bind_parameter_index() API if desired. The index for "?NNN" parameters is the value of NNN. The NNN value must be between 1 and the sqlite3_limit() parameter SQLITE_LIMIT_VARIABLE_NUMBER (default value: 999).

The third argument is the value to bind to the parameter. If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() or sqlite3_bind_blob() is a NULL pointer then the fourth parameter is ignored and the end result is the same as sqlite3_bind_null().

In those routines that have a fourth argument, its value is the number of bytes in the parameter. To be clear: the value is the number of bytes in the value, not the number of characters. If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() is negative, then the length of the string is the number of bytes up to the first zero terminator. If the fourth parameter to sqlite3_bind_blob() is negative, then the behavior is undefined. If a non-negative fourth parameter is provided to sqlite3_bind_text() or sqlite3_bind_text16() or sqlite3_bind_text64() then that parameter must be the byte offset where the NUL terminator would occur assuming the string were NUL terminated. If any NUL characters occur at byte offsets less than the value of the fourth parameter then the resulting string value will contain embedded NULs. The result of expressions involving strings with embedded NULs is undefined.

The fifth argument to the BLOB and string binding interfaces is a destructor used to dispose of the BLOB or string after SQLite has finished with it. The destructor is called to dispose of the BLOB or string even if the call to bind API fails. If the fifth argument is the special value SQLITE_STATIC, then SQLite assumes that the information is in static, unmanaged space and does not need to be freed. If the fifth argument has the value SQLITE_TRANSIENT, then SQLite makes its own private copy of the data immediately, before the sqlite3_bind_*() routine returns.

The sixth argument to sqlite3_bind_text64() must be one of SQLITE_UTF8, SQLITE_UTF16, SQLITE_UTF16BE, or SQLITE_UTF16LE to specify the encoding of the text in the third parameter. If the sixth argument to sqlite3_bind_text64() is not one of the allowed values shown above, or if the text encoding is different from the encoding specified by the sixth parameter, then the behavior is undefined.

The sqlite3_bind_zeroblob() routine binds a BLOB of length N that is filled with zeroes. A zeroblob uses a fixed amount of memory (just an integer to hold its size) while it is being processed. Zeroblobs are intended to serve as placeholders for BLOBs whose content is later written using incremental BLOB I/O routines. A negative value for the zeroblob results in a zero-length BLOB.

The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in prepared statement S to have an SQL value of NULL, but to also be associated with the pointer P of type T. D is either a NULL pointer or a pointer to a destructor function for P. SQLite will invoke the destructor D with a single argument of P when it is finished using P. The T parameter should be a static string, preferably a string literal. The sqlite3_bind_pointer() routine is part of the pointer passing interface added for SQLite 3.20.0.

If any of the sqlite3_bind_*() routines are called with a NULL pointer for the prepared statement or with a prepared statement for which sqlite3_step() has been called more recently than sqlite3_reset(), then the call will return SQLITE_MISUSE. If any sqlite3_bind_() routine is passed a prepared statement that has been finalized, the result is undefined and probably harmful.

Bindings are not cleared by the sqlite3_reset() routine. Unbound parameters are interpreted as NULL.

The sqlite3_bind_* routines return SQLITE_OK on success or an error code if anything goes wrong. SQLITE_TOOBIG might be returned if the size of a string or BLOB exceeds limits imposed by sqlite3_limit(SQLITE_LIMIT_LENGTH) or SQLITE_MAX_LENGTH. SQLITE_RANGE is returned if the parameter index is out of range. SQLITE_NOMEM is returned if malloc() fails.

参见:sqlite3_bind_parameter_count(), sqlite3_bind_parameter_name()和sqlite3_bind_parameter_index()

参见对象、常量和函数列表

代码语言:txt
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