/*
** Implementation of the like() SQL function. This function implements
** the build-in LIKE operator. The first argument to the function is the
** pattern and the second argument is the string. So, the SQL statements:
**
** A LIKE B
**
** is implemented as like(B,A).
**
** This same function (with a different compareInfo structure) computes
** the GLOB operator.
*/
static void likeFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
const unsigned char *zA = sqlite3_value_text(argv[0]);
const unsigned char *zB = sqlite3_value_text(argv[1]);
int escape = 0;
if( argc==3 ){
/* The escape character string must consist of a single UTF-8 character.
** Otherwise, return an error.
*/
const unsigned char *zEsc = sqlite3_value_text(argv[2]);
if( sqlite3utf8CharLen((char*)zEsc, -1)!=1 ){
sqlite3_result_error(context,
"ESCAPE expression must be a single character", -1);
return;
}
escape = sqlite3ReadUtf8(zEsc);
}
if( zA && zB ){
struct compareInfo *pInfo = sqlite3_user_data(context);
#ifdef SQLITE_TEST
sqlite3_like_count++;
#endif
sqlite3_result_int(context, patternCompare(zA, zB, pInfo, escape));
}
}
/*
** Compile the UTF-16 encoded SQL statement zSql into a statement handle.
*/
int sqlite3_prepare16(
sqlite3 *db, /* Database handle. */
const void *zSql, /* UTF-8 encoded SQL statement. */
int nBytes, /* Length of zSql in bytes. */
sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */
const void **pzTail /* OUT: End of parsed string */
){
/* This function currently works by first transforming the UTF-16
** encoded string to UTF-8, then invoking sqlite3_prepare(). The
** tricky bit is figuring out the pointer to return in *pzTail.
*/
char *zSql8;
const char *zTail8 = 0;
int rc = SQLITE_OK;
if( sqlite3SafetyCheck(db) ){
return SQLITE_MISUSE;
}
zSql8 = sqlite3utf16to8(zSql, nBytes);
if( zSql8 ){
rc = sqlite3_prepare(db, zSql8, -1, ppStmt, &zTail8);
}
if( zTail8 && pzTail ){
/* If sqlite3_prepare returns a tail pointer, we calculate the
** equivalent pointer into the UTF-16 string by counting the unicode
** characters between zSql8 and zTail8, and then returning a pointer
** the same number of characters into the UTF-16 string.
*/
int chars_parsed = sqlite3utf8CharLen(zSql8, zTail8-zSql8);
*pzTail = (u8 *)zSql + sqlite3utf16ByteLen(zSql, chars_parsed);
}
sqliteFree(zSql8);
return sqlite3ApiExit(db, rc);
}
/*
** Compile the UTF-16 encoded SQL statement zSql into a statement handle.
*/
int sqlite3_prepare16(
sqlite3 *db, /* Database handle. */
const void *zSql, /* UTF-8 encoded SQL statement. */
int nBytes, /* Length of zSql in bytes. */
sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */
const void **pzTail /* OUT: End of parsed string */
){
/* This function currently works by first transforming the UTF-16
** encoded string to UTF-8, then invoking sqlite3_prepare(). The
** tricky bit is figuring out the pointer to return in *pzTail.
*/
char const *zSql8 = 0;
char const *zTail8 = 0;
int rc;
sqlite3_value *pTmp;
if( sqlite3SafetyCheck(db) ){
return SQLITE_MISUSE;
}
pTmp = sqlite3GetTransientValue(db);
sqlite3ValueSetStr(pTmp, -1, zSql, SQLITE_UTF16NATIVE, SQLITE_STATIC);
zSql8 = sqlite3ValueText(pTmp, SQLITE_UTF8);
if( !zSql8 ){
sqlite3Error(db, SQLITE_NOMEM, 0);
return SQLITE_NOMEM;
}
rc = sqlite3_prepare(db, zSql8, -1, ppStmt, &zTail8);
if( zTail8 && pzTail ){
/* If sqlite3_prepare returns a tail pointer, we calculate the
** equivalent pointer into the UTF-16 string by counting the unicode
** characters between zSql8 and zTail8, and then returning a pointer
** the same number of characters into the UTF-16 string.
*/
int chars_parsed = sqlite3utf8CharLen(zSql8, zTail8-zSql8);
*pzTail = (u8 *)zSql + sqlite3utf16ByteLen(zSql, chars_parsed);
}
return rc;
}
