1155 lines
34 KiB
C
1155 lines
34 KiB
C
/*
|
|
** 2002 February 23
|
|
**
|
|
** The author disclaims copyright to this source code. In place of
|
|
** a legal notice, here is a blessing:
|
|
**
|
|
** May you do good and not evil.
|
|
** May you find forgiveness for yourself and forgive others.
|
|
** May you share freely, never taking more than you give.
|
|
**
|
|
*************************************************************************
|
|
** This file contains the C functions that implement various SQL
|
|
** functions of SQLite.
|
|
**
|
|
** There is only one exported symbol in this file - the function
|
|
** sqliteRegisterBuildinFunctions() found at the bottom of the file.
|
|
** All other code has file scope.
|
|
**
|
|
** $Id$
|
|
*/
|
|
#include "sqliteInt.h"
|
|
#include <ctype.h>
|
|
/* #include <math.h> */
|
|
#include <stdlib.h>
|
|
#include <assert.h>
|
|
#include "vdbeInt.h"
|
|
#include "os.h"
|
|
|
|
/*
|
|
** Return the collating function associated with a function.
|
|
*/
|
|
static CollSeq *sqlite3GetFuncCollSeq(sqlite3_context *context){
|
|
return context->pColl;
|
|
}
|
|
|
|
/*
|
|
** Implementation of the non-aggregate min() and max() functions
|
|
*/
|
|
static void minmaxFunc(
|
|
sqlite3_context *context,
|
|
int argc,
|
|
sqlite3_value **argv
|
|
){
|
|
int i;
|
|
int mask; /* 0 for min() or 0xffffffff for max() */
|
|
int iBest;
|
|
CollSeq *pColl;
|
|
|
|
if( argc==0 ) return;
|
|
mask = sqlite3_user_data(context)==0 ? 0 : -1;
|
|
pColl = sqlite3GetFuncCollSeq(context);
|
|
assert( pColl );
|
|
assert( mask==-1 || mask==0 );
|
|
iBest = 0;
|
|
if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
|
|
for(i=1; i<argc; i++){
|
|
if( sqlite3_value_type(argv[i])==SQLITE_NULL ) return;
|
|
if( (sqlite3MemCompare(argv[iBest], argv[i], pColl)^mask)>=0 ){
|
|
iBest = i;
|
|
}
|
|
}
|
|
sqlite3_result_value(context, argv[iBest]);
|
|
}
|
|
|
|
/*
|
|
** Return the type of the argument.
|
|
*/
|
|
static void typeofFunc(
|
|
sqlite3_context *context,
|
|
int argc,
|
|
sqlite3_value **argv
|
|
){
|
|
const char *z = 0;
|
|
switch( sqlite3_value_type(argv[0]) ){
|
|
case SQLITE_NULL: z = "null"; break;
|
|
case SQLITE_INTEGER: z = "integer"; break;
|
|
case SQLITE_TEXT: z = "text"; break;
|
|
case SQLITE_FLOAT: z = "real"; break;
|
|
case SQLITE_BLOB: z = "blob"; break;
|
|
}
|
|
sqlite3_result_text(context, z, -1, SQLITE_STATIC);
|
|
}
|
|
|
|
|
|
/*
|
|
** Implementation of the length() function
|
|
*/
|
|
static void lengthFunc(
|
|
sqlite3_context *context,
|
|
int argc,
|
|
sqlite3_value **argv
|
|
){
|
|
int len;
|
|
|
|
assert( argc==1 );
|
|
switch( sqlite3_value_type(argv[0]) ){
|
|
case SQLITE_BLOB:
|
|
case SQLITE_INTEGER:
|
|
case SQLITE_FLOAT: {
|
|
sqlite3_result_int(context, sqlite3_value_bytes(argv[0]));
|
|
break;
|
|
}
|
|
case SQLITE_TEXT: {
|
|
const unsigned char *z = sqlite3_value_text(argv[0]);
|
|
for(len=0; *z; z++){ if( (0xc0&*z)!=0x80 ) len++; }
|
|
sqlite3_result_int(context, len);
|
|
break;
|
|
}
|
|
default: {
|
|
sqlite3_result_null(context);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Implementation of the abs() function
|
|
*/
|
|
static void absFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
|
|
assert( argc==1 );
|
|
switch( sqlite3_value_type(argv[0]) ){
|
|
case SQLITE_INTEGER: {
|
|
i64 iVal = sqlite3_value_int64(argv[0]);
|
|
if( iVal<0 ){
|
|
if( (iVal<<1)==0 ){
|
|
sqlite3_result_error(context, "integer overflow", -1);
|
|
return;
|
|
}
|
|
iVal = -iVal;
|
|
}
|
|
sqlite3_result_int64(context, iVal);
|
|
break;
|
|
}
|
|
case SQLITE_NULL: {
|
|
sqlite3_result_null(context);
|
|
break;
|
|
}
|
|
default: {
|
|
double rVal = sqlite3_value_double(argv[0]);
|
|
if( rVal<0 ) rVal = -rVal;
|
|
sqlite3_result_double(context, rVal);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Implementation of the substr() function
|
|
*/
|
|
static void substrFunc(
|
|
sqlite3_context *context,
|
|
int argc,
|
|
sqlite3_value **argv
|
|
){
|
|
const unsigned char *z;
|
|
const unsigned char *z2;
|
|
int i;
|
|
int p1, p2, len;
|
|
|
|
assert( argc==3 );
|
|
z = sqlite3_value_text(argv[0]);
|
|
if( z==0 ) return;
|
|
p1 = sqlite3_value_int(argv[1]);
|
|
p2 = sqlite3_value_int(argv[2]);
|
|
for(len=0, z2=z; *z2; z2++){ if( (0xc0&*z2)!=0x80 ) len++; }
|
|
if( p1<0 ){
|
|
p1 += len;
|
|
if( p1<0 ){
|
|
p2 += p1;
|
|
p1 = 0;
|
|
}
|
|
}else if( p1>0 ){
|
|
p1--;
|
|
}
|
|
if( p1+p2>len ){
|
|
p2 = len-p1;
|
|
}
|
|
for(i=0; i<p1 && z[i]; i++){
|
|
if( (z[i]&0xc0)==0x80 ) p1++;
|
|
}
|
|
while( z[i] && (z[i]&0xc0)==0x80 ){ i++; p1++; }
|
|
for(; i<p1+p2 && z[i]; i++){
|
|
if( (z[i]&0xc0)==0x80 ) p2++;
|
|
}
|
|
while( z[i] && (z[i]&0xc0)==0x80 ){ i++; p2++; }
|
|
if( p2<0 ) p2 = 0;
|
|
sqlite3_result_text(context, (char*)&z[p1], p2, SQLITE_TRANSIENT);
|
|
}
|
|
|
|
/*
|
|
** Implementation of the round() function
|
|
*/
|
|
static void roundFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
|
|
int n = 0;
|
|
double r;
|
|
char zBuf[500]; /* larger than the %f representation of the largest double */
|
|
assert( argc==1 || argc==2 );
|
|
if( argc==2 ){
|
|
if( SQLITE_NULL==sqlite3_value_type(argv[1]) ) return;
|
|
n = sqlite3_value_int(argv[1]);
|
|
if( n>30 ) n = 30;
|
|
if( n<0 ) n = 0;
|
|
}
|
|
if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
|
|
r = sqlite3_value_double(argv[0]);
|
|
sqlite3_snprintf(sizeof(zBuf),zBuf,"%.*f",n,r);
|
|
sqlite3_result_double(context, atof(zBuf));
|
|
}
|
|
|
|
/*
|
|
** Implementation of the upper() and lower() SQL functions.
|
|
*/
|
|
static void upperFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
|
|
unsigned char *z;
|
|
int i;
|
|
if( argc<1 || SQLITE_NULL==sqlite3_value_type(argv[0]) ) return;
|
|
z = sqliteMalloc(sqlite3_value_bytes(argv[0])+1);
|
|
if( z==0 ) return;
|
|
strcpy((char*)z, (char*)sqlite3_value_text(argv[0]));
|
|
for(i=0; z[i]; i++){
|
|
z[i] = toupper(z[i]);
|
|
}
|
|
sqlite3_result_text(context, (char*)z, -1, SQLITE_TRANSIENT);
|
|
sqliteFree(z);
|
|
}
|
|
static void lowerFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
|
|
unsigned char *z;
|
|
int i;
|
|
if( argc<1 || SQLITE_NULL==sqlite3_value_type(argv[0]) ) return;
|
|
z = sqliteMalloc(sqlite3_value_bytes(argv[0])+1);
|
|
if( z==0 ) return;
|
|
strcpy((char*)z, (char*)sqlite3_value_text(argv[0]));
|
|
for(i=0; z[i]; i++){
|
|
z[i] = tolower(z[i]);
|
|
}
|
|
sqlite3_result_text(context, (char*)z, -1, SQLITE_TRANSIENT);
|
|
sqliteFree(z);
|
|
}
|
|
|
|
/*
|
|
** Implementation of the IFNULL(), NVL(), and COALESCE() functions.
|
|
** All three do the same thing. They return the first non-NULL
|
|
** argument.
|
|
*/
|
|
static void ifnullFunc(
|
|
sqlite3_context *context,
|
|
int argc,
|
|
sqlite3_value **argv
|
|
){
|
|
int i;
|
|
for(i=0; i<argc; i++){
|
|
if( SQLITE_NULL!=sqlite3_value_type(argv[i]) ){
|
|
sqlite3_result_value(context, argv[i]);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Implementation of random(). Return a random integer.
|
|
*/
|
|
static void randomFunc(
|
|
sqlite3_context *context,
|
|
int argc,
|
|
sqlite3_value **argv
|
|
){
|
|
sqlite_int64 r;
|
|
sqlite3Randomness(sizeof(r), &r);
|
|
if( (r<<1)==0 ) r = 0; /* Prevent 0x8000.... as the result so that we */
|
|
/* can always do abs() of the result */
|
|
sqlite3_result_int64(context, r);
|
|
}
|
|
|
|
/*
|
|
** Implementation of the last_insert_rowid() SQL function. The return
|
|
** value is the same as the sqlite3_last_insert_rowid() API function.
|
|
*/
|
|
static void last_insert_rowid(
|
|
sqlite3_context *context,
|
|
int arg,
|
|
sqlite3_value **argv
|
|
){
|
|
sqlite3 *db = sqlite3_user_data(context);
|
|
sqlite3_result_int64(context, sqlite3_last_insert_rowid(db));
|
|
}
|
|
|
|
/*
|
|
** Implementation of the changes() SQL function. The return value is the
|
|
** same as the sqlite3_changes() API function.
|
|
*/
|
|
static void changes(
|
|
sqlite3_context *context,
|
|
int arg,
|
|
sqlite3_value **argv
|
|
){
|
|
sqlite3 *db = sqlite3_user_data(context);
|
|
sqlite3_result_int(context, sqlite3_changes(db));
|
|
}
|
|
|
|
/*
|
|
** Implementation of the total_changes() SQL function. The return value is
|
|
** the same as the sqlite3_total_changes() API function.
|
|
*/
|
|
static void total_changes(
|
|
sqlite3_context *context,
|
|
int arg,
|
|
sqlite3_value **argv
|
|
){
|
|
sqlite3 *db = sqlite3_user_data(context);
|
|
sqlite3_result_int(context, sqlite3_total_changes(db));
|
|
}
|
|
|
|
/*
|
|
** A structure defining how to do GLOB-style comparisons.
|
|
*/
|
|
struct compareInfo {
|
|
u8 matchAll;
|
|
u8 matchOne;
|
|
u8 matchSet;
|
|
u8 noCase;
|
|
};
|
|
|
|
static const struct compareInfo globInfo = { '*', '?', '[', 0 };
|
|
/* The correct SQL-92 behavior is for the LIKE operator to ignore
|
|
** case. Thus 'a' LIKE 'A' would be true. */
|
|
static const struct compareInfo likeInfoNorm = { '%', '_', 0, 1 };
|
|
/* If SQLITE_CASE_SENSITIVE_LIKE is defined, then the LIKE operator
|
|
** is case sensitive causing 'a' LIKE 'A' to be false */
|
|
static const struct compareInfo likeInfoAlt = { '%', '_', 0, 0 };
|
|
|
|
/*
|
|
** X is a pointer to the first byte of a UTF-8 character. Increment
|
|
** X so that it points to the next character. This only works right
|
|
** if X points to a well-formed UTF-8 string.
|
|
*/
|
|
#define sqliteNextChar(X) while( (0xc0&*++(X))==0x80 ){}
|
|
#define sqliteCharVal(X) sqlite3ReadUtf8(X)
|
|
|
|
|
|
/*
|
|
** Compare two UTF-8 strings for equality where the first string can
|
|
** potentially be a "glob" expression. Return true (1) if they
|
|
** are the same and false (0) if they are different.
|
|
**
|
|
** Globbing rules:
|
|
**
|
|
** '*' Matches any sequence of zero or more characters.
|
|
**
|
|
** '?' Matches exactly one character.
|
|
**
|
|
** [...] Matches one character from the enclosed list of
|
|
** characters.
|
|
**
|
|
** [^...] Matches one character not in the enclosed list.
|
|
**
|
|
** With the [...] and [^...] matching, a ']' character can be included
|
|
** in the list by making it the first character after '[' or '^'. A
|
|
** range of characters can be specified using '-'. Example:
|
|
** "[a-z]" matches any single lower-case letter. To match a '-', make
|
|
** it the last character in the list.
|
|
**
|
|
** This routine is usually quick, but can be N**2 in the worst case.
|
|
**
|
|
** Hints: to match '*' or '?', put them in "[]". Like this:
|
|
**
|
|
** abc[*]xyz Matches "abc*xyz" only
|
|
*/
|
|
static int patternCompare(
|
|
const u8 *zPattern, /* The glob pattern */
|
|
const u8 *zString, /* The string to compare against the glob */
|
|
const struct compareInfo *pInfo, /* Information about how to do the compare */
|
|
const int esc /* The escape character */
|
|
){
|
|
register int c;
|
|
int invert;
|
|
int seen;
|
|
int c2;
|
|
u8 matchOne = pInfo->matchOne;
|
|
u8 matchAll = pInfo->matchAll;
|
|
u8 matchSet = pInfo->matchSet;
|
|
u8 noCase = pInfo->noCase;
|
|
int prevEscape = 0; /* True if the previous character was 'escape' */
|
|
|
|
while( (c = *zPattern)!=0 ){
|
|
if( !prevEscape && c==matchAll ){
|
|
while( (c=zPattern[1]) == matchAll || c == matchOne ){
|
|
if( c==matchOne ){
|
|
if( *zString==0 ) return 0;
|
|
sqliteNextChar(zString);
|
|
}
|
|
zPattern++;
|
|
}
|
|
if( c && esc && sqlite3ReadUtf8(&zPattern[1])==esc ){
|
|
u8 const *zTemp = &zPattern[1];
|
|
sqliteNextChar(zTemp);
|
|
c = *zTemp;
|
|
}
|
|
if( c==0 ) return 1;
|
|
if( c==matchSet ){
|
|
assert( esc==0 ); /* This is GLOB, not LIKE */
|
|
while( *zString && patternCompare(&zPattern[1],zString,pInfo,esc)==0 ){
|
|
sqliteNextChar(zString);
|
|
}
|
|
return *zString!=0;
|
|
}else{
|
|
while( (c2 = *zString)!=0 ){
|
|
if( noCase ){
|
|
c2 = sqlite3UpperToLower[c2];
|
|
c = sqlite3UpperToLower[c];
|
|
while( c2 != 0 && c2 != c ){ c2 = sqlite3UpperToLower[*++zString]; }
|
|
}else{
|
|
while( c2 != 0 && c2 != c ){ c2 = *++zString; }
|
|
}
|
|
if( c2==0 ) return 0;
|
|
if( patternCompare(&zPattern[1],zString,pInfo,esc) ) return 1;
|
|
sqliteNextChar(zString);
|
|
}
|
|
return 0;
|
|
}
|
|
}else if( !prevEscape && c==matchOne ){
|
|
if( *zString==0 ) return 0;
|
|
sqliteNextChar(zString);
|
|
zPattern++;
|
|
}else if( c==matchSet ){
|
|
int prior_c = 0;
|
|
assert( esc==0 ); /* This only occurs for GLOB, not LIKE */
|
|
seen = 0;
|
|
invert = 0;
|
|
c = sqliteCharVal(zString);
|
|
if( c==0 ) return 0;
|
|
c2 = *++zPattern;
|
|
if( c2=='^' ){ invert = 1; c2 = *++zPattern; }
|
|
if( c2==']' ){
|
|
if( c==']' ) seen = 1;
|
|
c2 = *++zPattern;
|
|
}
|
|
while( (c2 = sqliteCharVal(zPattern))!=0 && c2!=']' ){
|
|
if( c2=='-' && zPattern[1]!=']' && zPattern[1]!=0 && prior_c>0 ){
|
|
zPattern++;
|
|
c2 = sqliteCharVal(zPattern);
|
|
if( c>=prior_c && c<=c2 ) seen = 1;
|
|
prior_c = 0;
|
|
}else if( c==c2 ){
|
|
seen = 1;
|
|
prior_c = c2;
|
|
}else{
|
|
prior_c = c2;
|
|
}
|
|
sqliteNextChar(zPattern);
|
|
}
|
|
if( c2==0 || (seen ^ invert)==0 ) return 0;
|
|
sqliteNextChar(zString);
|
|
zPattern++;
|
|
}else if( esc && !prevEscape && sqlite3ReadUtf8(zPattern)==esc){
|
|
prevEscape = 1;
|
|
sqliteNextChar(zPattern);
|
|
}else{
|
|
if( noCase ){
|
|
if( sqlite3UpperToLower[c] != sqlite3UpperToLower[*zString] ) return 0;
|
|
}else{
|
|
if( c != *zString ) return 0;
|
|
}
|
|
zPattern++;
|
|
zString++;
|
|
prevEscape = 0;
|
|
}
|
|
}
|
|
return *zString==0;
|
|
}
|
|
|
|
/*
|
|
** Count the number of times that the LIKE operator (or GLOB which is
|
|
** just a variation of LIKE) gets called. This is used for testing
|
|
** only.
|
|
*/
|
|
#ifdef SQLITE_TEST
|
|
int sqlite3_like_count = 0;
|
|
#endif
|
|
|
|
|
|
/*
|
|
** 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));
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Implementation of the NULLIF(x,y) function. The result is the first
|
|
** argument if the arguments are different. The result is NULL if the
|
|
** arguments are equal to each other.
|
|
*/
|
|
static void nullifFunc(
|
|
sqlite3_context *context,
|
|
int argc,
|
|
sqlite3_value **argv
|
|
){
|
|
CollSeq *pColl = sqlite3GetFuncCollSeq(context);
|
|
if( sqlite3MemCompare(argv[0], argv[1], pColl)!=0 ){
|
|
sqlite3_result_value(context, argv[0]);
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Implementation of the VERSION(*) function. The result is the version
|
|
** of the SQLite library that is running.
|
|
*/
|
|
static void versionFunc(
|
|
sqlite3_context *context,
|
|
int argc,
|
|
sqlite3_value **argv
|
|
){
|
|
sqlite3_result_text(context, sqlite3_version, -1, SQLITE_STATIC);
|
|
}
|
|
|
|
|
|
/*
|
|
** EXPERIMENTAL - This is not an official function. The interface may
|
|
** change. This function may disappear. Do not write code that depends
|
|
** on this function.
|
|
**
|
|
** Implementation of the QUOTE() function. This function takes a single
|
|
** argument. If the argument is numeric, the return value is the same as
|
|
** the argument. If the argument is NULL, the return value is the string
|
|
** "NULL". Otherwise, the argument is enclosed in single quotes with
|
|
** single-quote escapes.
|
|
*/
|
|
static void quoteFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
|
|
if( argc<1 ) return;
|
|
switch( sqlite3_value_type(argv[0]) ){
|
|
case SQLITE_NULL: {
|
|
sqlite3_result_text(context, "NULL", 4, SQLITE_STATIC);
|
|
break;
|
|
}
|
|
case SQLITE_INTEGER:
|
|
case SQLITE_FLOAT: {
|
|
sqlite3_result_value(context, argv[0]);
|
|
break;
|
|
}
|
|
case SQLITE_BLOB: {
|
|
static const char hexdigits[] = {
|
|
'0', '1', '2', '3', '4', '5', '6', '7',
|
|
'8', '9', 'A', 'B', 'C', 'D', 'E', 'F'
|
|
};
|
|
char *zText = 0;
|
|
int nBlob = sqlite3_value_bytes(argv[0]);
|
|
char const *zBlob = sqlite3_value_blob(argv[0]);
|
|
|
|
zText = (char *)sqliteMalloc((2*nBlob)+4);
|
|
if( !zText ){
|
|
sqlite3_result_error(context, "out of memory", -1);
|
|
}else{
|
|
int i;
|
|
for(i=0; i<nBlob; i++){
|
|
zText[(i*2)+2] = hexdigits[(zBlob[i]>>4)&0x0F];
|
|
zText[(i*2)+3] = hexdigits[(zBlob[i])&0x0F];
|
|
}
|
|
zText[(nBlob*2)+2] = '\'';
|
|
zText[(nBlob*2)+3] = '\0';
|
|
zText[0] = 'X';
|
|
zText[1] = '\'';
|
|
sqlite3_result_text(context, zText, -1, SQLITE_TRANSIENT);
|
|
sqliteFree(zText);
|
|
}
|
|
break;
|
|
}
|
|
case SQLITE_TEXT: {
|
|
int i,j,n;
|
|
const unsigned char *zArg = sqlite3_value_text(argv[0]);
|
|
char *z;
|
|
|
|
for(i=n=0; zArg[i]; i++){ if( zArg[i]=='\'' ) n++; }
|
|
z = sqliteMalloc( i+n+3 );
|
|
if( z==0 ) return;
|
|
z[0] = '\'';
|
|
for(i=0, j=1; zArg[i]; i++){
|
|
z[j++] = zArg[i];
|
|
if( zArg[i]=='\'' ){
|
|
z[j++] = '\'';
|
|
}
|
|
}
|
|
z[j++] = '\'';
|
|
z[j] = 0;
|
|
sqlite3_result_text(context, z, j, SQLITE_TRANSIENT);
|
|
sqliteFree(z);
|
|
}
|
|
}
|
|
}
|
|
|
|
#ifdef SQLITE_SOUNDEX
|
|
/*
|
|
** Compute the soundex encoding of a word.
|
|
*/
|
|
static void soundexFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
|
|
char zResult[8];
|
|
const u8 *zIn;
|
|
int i, j;
|
|
static const unsigned char iCode[] = {
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
|
0, 0, 1, 2, 3, 0, 1, 2, 0, 0, 2, 2, 4, 5, 5, 0,
|
|
1, 2, 6, 2, 3, 0, 1, 0, 2, 0, 2, 0, 0, 0, 0, 0,
|
|
0, 0, 1, 2, 3, 0, 1, 2, 0, 0, 2, 2, 4, 5, 5, 0,
|
|
1, 2, 6, 2, 3, 0, 1, 0, 2, 0, 2, 0, 0, 0, 0, 0,
|
|
};
|
|
assert( argc==1 );
|
|
zIn = (u8*)sqlite3_value_text(argv[0]);
|
|
for(i=0; zIn[i] && !isalpha(zIn[i]); i++){}
|
|
if( zIn[i] ){
|
|
zResult[0] = toupper(zIn[i]);
|
|
for(j=1; j<4 && zIn[i]; i++){
|
|
int code = iCode[zIn[i]&0x7f];
|
|
if( code>0 ){
|
|
zResult[j++] = code + '0';
|
|
}
|
|
}
|
|
while( j<4 ){
|
|
zResult[j++] = '0';
|
|
}
|
|
zResult[j] = 0;
|
|
sqlite3_result_text(context, zResult, 4, SQLITE_TRANSIENT);
|
|
}else{
|
|
sqlite3_result_text(context, "?000", 4, SQLITE_STATIC);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#ifdef SQLITE_TEST
|
|
/*
|
|
** This function generates a string of random characters. Used for
|
|
** generating test data.
|
|
*/
|
|
static void randStr(sqlite3_context *context, int argc, sqlite3_value **argv){
|
|
static const unsigned char zSrc[] =
|
|
"abcdefghijklmnopqrstuvwxyz"
|
|
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
|
|
"0123456789"
|
|
".-!,:*^+=_|?/<> ";
|
|
int iMin, iMax, n, r, i;
|
|
unsigned char zBuf[1000];
|
|
if( argc>=1 ){
|
|
iMin = sqlite3_value_int(argv[0]);
|
|
if( iMin<0 ) iMin = 0;
|
|
if( iMin>=sizeof(zBuf) ) iMin = sizeof(zBuf)-1;
|
|
}else{
|
|
iMin = 1;
|
|
}
|
|
if( argc>=2 ){
|
|
iMax = sqlite3_value_int(argv[1]);
|
|
if( iMax<iMin ) iMax = iMin;
|
|
if( iMax>=sizeof(zBuf) ) iMax = sizeof(zBuf)-1;
|
|
}else{
|
|
iMax = 50;
|
|
}
|
|
n = iMin;
|
|
if( iMax>iMin ){
|
|
sqlite3Randomness(sizeof(r), &r);
|
|
r &= 0x7fffffff;
|
|
n += r%(iMax + 1 - iMin);
|
|
}
|
|
assert( n<sizeof(zBuf) );
|
|
sqlite3Randomness(n, zBuf);
|
|
for(i=0; i<n; i++){
|
|
zBuf[i] = zSrc[zBuf[i]%(sizeof(zSrc)-1)];
|
|
}
|
|
zBuf[n] = 0;
|
|
sqlite3_result_text(context, (char*)zBuf, n, SQLITE_TRANSIENT);
|
|
}
|
|
#endif /* SQLITE_TEST */
|
|
|
|
#ifdef SQLITE_TEST
|
|
/*
|
|
** The following two SQL functions are used to test returning a text
|
|
** result with a destructor. Function 'test_destructor' takes one argument
|
|
** and returns the same argument interpreted as TEXT. A destructor is
|
|
** passed with the sqlite3_result_text() call.
|
|
**
|
|
** SQL function 'test_destructor_count' returns the number of outstanding
|
|
** allocations made by 'test_destructor';
|
|
**
|
|
** WARNING: Not threadsafe.
|
|
*/
|
|
static int test_destructor_count_var = 0;
|
|
static void destructor(void *p){
|
|
char *zVal = (char *)p;
|
|
assert(zVal);
|
|
zVal--;
|
|
sqliteFree(zVal);
|
|
test_destructor_count_var--;
|
|
}
|
|
static void test_destructor(
|
|
sqlite3_context *pCtx,
|
|
int nArg,
|
|
sqlite3_value **argv
|
|
){
|
|
char *zVal;
|
|
int len;
|
|
sqlite3 *db = sqlite3_user_data(pCtx);
|
|
|
|
test_destructor_count_var++;
|
|
assert( nArg==1 );
|
|
if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
|
|
len = sqlite3ValueBytes(argv[0], ENC(db));
|
|
zVal = sqliteMalloc(len+3);
|
|
zVal[len] = 0;
|
|
zVal[len-1] = 0;
|
|
assert( zVal );
|
|
zVal++;
|
|
memcpy(zVal, sqlite3ValueText(argv[0], ENC(db)), len);
|
|
if( ENC(db)==SQLITE_UTF8 ){
|
|
sqlite3_result_text(pCtx, zVal, -1, destructor);
|
|
#ifndef SQLITE_OMIT_UTF16
|
|
}else if( ENC(db)==SQLITE_UTF16LE ){
|
|
sqlite3_result_text16le(pCtx, zVal, -1, destructor);
|
|
}else{
|
|
sqlite3_result_text16be(pCtx, zVal, -1, destructor);
|
|
#endif /* SQLITE_OMIT_UTF16 */
|
|
}
|
|
}
|
|
static void test_destructor_count(
|
|
sqlite3_context *pCtx,
|
|
int nArg,
|
|
sqlite3_value **argv
|
|
){
|
|
sqlite3_result_int(pCtx, test_destructor_count_var);
|
|
}
|
|
#endif /* SQLITE_TEST */
|
|
|
|
#ifdef SQLITE_TEST
|
|
/*
|
|
** Routines for testing the sqlite3_get_auxdata() and sqlite3_set_auxdata()
|
|
** interface.
|
|
**
|
|
** The test_auxdata() SQL function attempts to register each of its arguments
|
|
** as auxiliary data. If there are no prior registrations of aux data for
|
|
** that argument (meaning the argument is not a constant or this is its first
|
|
** call) then the result for that argument is 0. If there is a prior
|
|
** registration, the result for that argument is 1. The overall result
|
|
** is the individual argument results separated by spaces.
|
|
*/
|
|
static void free_test_auxdata(void *p) {sqliteFree(p);}
|
|
static void test_auxdata(
|
|
sqlite3_context *pCtx,
|
|
int nArg,
|
|
sqlite3_value **argv
|
|
){
|
|
int i;
|
|
char *zRet = sqliteMalloc(nArg*2);
|
|
if( !zRet ) return;
|
|
for(i=0; i<nArg; i++){
|
|
char const *z = (char*)sqlite3_value_text(argv[i]);
|
|
if( z ){
|
|
char *zAux = sqlite3_get_auxdata(pCtx, i);
|
|
if( zAux ){
|
|
zRet[i*2] = '1';
|
|
if( strcmp(zAux, z) ){
|
|
sqlite3_result_error(pCtx, "Auxilary data corruption", -1);
|
|
return;
|
|
}
|
|
}else{
|
|
zRet[i*2] = '0';
|
|
zAux = sqliteStrDup(z);
|
|
sqlite3_set_auxdata(pCtx, i, zAux, free_test_auxdata);
|
|
}
|
|
zRet[i*2+1] = ' ';
|
|
}
|
|
}
|
|
sqlite3_result_text(pCtx, zRet, 2*nArg-1, free_test_auxdata);
|
|
}
|
|
#endif /* SQLITE_TEST */
|
|
|
|
#ifdef SQLITE_TEST
|
|
/*
|
|
** A function to test error reporting from user functions. This function
|
|
** returns a copy of it's first argument as an error.
|
|
*/
|
|
static void test_error(
|
|
sqlite3_context *pCtx,
|
|
int nArg,
|
|
sqlite3_value **argv
|
|
){
|
|
sqlite3_result_error(pCtx, (char*)sqlite3_value_text(argv[0]), 0);
|
|
}
|
|
#endif /* SQLITE_TEST */
|
|
|
|
/*
|
|
** An instance of the following structure holds the context of a
|
|
** sum() or avg() aggregate computation.
|
|
*/
|
|
typedef struct SumCtx SumCtx;
|
|
struct SumCtx {
|
|
double rSum; /* Floating point sum */
|
|
i64 iSum; /* Integer sum */
|
|
i64 cnt; /* Number of elements summed */
|
|
u8 overflow; /* True if integer overflow seen */
|
|
u8 approx; /* True if non-integer value was input to the sum */
|
|
};
|
|
|
|
/*
|
|
** Routines used to compute the sum, average, and total.
|
|
**
|
|
** The SUM() function follows the (broken) SQL standard which means
|
|
** that it returns NULL if it sums over no inputs. TOTAL returns
|
|
** 0.0 in that case. In addition, TOTAL always returns a float where
|
|
** SUM might return an integer if it never encounters a floating point
|
|
** value.
|
|
**
|
|
** I am told that SUM() should raise an exception if it encounters
|
|
** a integer overflow. But after pondering this, I decided that
|
|
** behavior leads to brittle programs. So instead, I have coded
|
|
** SUM() to revert to using floating point if it encounters an
|
|
** integer overflow. The answer may not be exact, but it will be
|
|
** close. If the SUM() function returns an integer, the value is
|
|
** exact. If SUM() returns a floating point value, it means the
|
|
** value might be approximated.
|
|
*/
|
|
static void sumStep(sqlite3_context *context, int argc, sqlite3_value **argv){
|
|
SumCtx *p;
|
|
int type;
|
|
assert( argc==1 );
|
|
p = sqlite3_aggregate_context(context, sizeof(*p));
|
|
type = sqlite3_value_numeric_type(argv[0]);
|
|
if( p && type!=SQLITE_NULL ){
|
|
p->cnt++;
|
|
if( type==SQLITE_INTEGER ){
|
|
i64 v = sqlite3_value_int64(argv[0]);
|
|
p->rSum += v;
|
|
if( (p->approx|p->overflow)==0 ){
|
|
i64 iNewSum = p->iSum + v;
|
|
int s1 = (int)(p->iSum >> (sizeof(i64)*8-1));
|
|
int s2 = (int)(v >> (sizeof(i64)*8-1));
|
|
int s3 = (int)(iNewSum >> (sizeof(i64)*8-1));
|
|
p->overflow = (s1&s2&~s3) | (~s1&~s2&s3);
|
|
p->iSum = iNewSum;
|
|
}
|
|
}else{
|
|
p->rSum += sqlite3_value_double(argv[0]);
|
|
p->approx = 1;
|
|
}
|
|
}
|
|
}
|
|
static void sumFinalize(sqlite3_context *context){
|
|
SumCtx *p;
|
|
p = sqlite3_aggregate_context(context, 0);
|
|
if( p && p->cnt>0 ){
|
|
if( p->overflow ){
|
|
sqlite3_result_error(context,"integer overflow",-1);
|
|
}else if( p->approx ){
|
|
sqlite3_result_double(context, p->rSum);
|
|
}else{
|
|
sqlite3_result_int64(context, p->iSum);
|
|
}
|
|
}
|
|
}
|
|
static void avgFinalize(sqlite3_context *context){
|
|
SumCtx *p;
|
|
p = sqlite3_aggregate_context(context, 0);
|
|
if( p && p->cnt>0 ){
|
|
sqlite3_result_double(context, p->rSum/(double)p->cnt);
|
|
}
|
|
}
|
|
static void totalFinalize(sqlite3_context *context){
|
|
SumCtx *p;
|
|
p = sqlite3_aggregate_context(context, 0);
|
|
sqlite3_result_double(context, p ? p->rSum : 0.0);
|
|
}
|
|
|
|
/*
|
|
** The following structure keeps track of state information for the
|
|
** count() aggregate function.
|
|
*/
|
|
typedef struct CountCtx CountCtx;
|
|
struct CountCtx {
|
|
i64 n;
|
|
};
|
|
|
|
/*
|
|
** Routines to implement the count() aggregate function.
|
|
*/
|
|
static void countStep(sqlite3_context *context, int argc, sqlite3_value **argv){
|
|
CountCtx *p;
|
|
p = sqlite3_aggregate_context(context, sizeof(*p));
|
|
if( (argc==0 || SQLITE_NULL!=sqlite3_value_type(argv[0])) && p ){
|
|
p->n++;
|
|
}
|
|
}
|
|
static void countFinalize(sqlite3_context *context){
|
|
CountCtx *p;
|
|
p = sqlite3_aggregate_context(context, 0);
|
|
sqlite3_result_int64(context, p ? p->n : 0);
|
|
}
|
|
|
|
/*
|
|
** Routines to implement min() and max() aggregate functions.
|
|
*/
|
|
static void minmaxStep(sqlite3_context *context, int argc, sqlite3_value **argv){
|
|
Mem *pArg = (Mem *)argv[0];
|
|
Mem *pBest;
|
|
|
|
if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
|
|
pBest = (Mem *)sqlite3_aggregate_context(context, sizeof(*pBest));
|
|
if( !pBest ) return;
|
|
|
|
if( pBest->flags ){
|
|
int max;
|
|
int cmp;
|
|
CollSeq *pColl = sqlite3GetFuncCollSeq(context);
|
|
/* This step function is used for both the min() and max() aggregates,
|
|
** the only difference between the two being that the sense of the
|
|
** comparison is inverted. For the max() aggregate, the
|
|
** sqlite3_user_data() function returns (void *)-1. For min() it
|
|
** returns (void *)db, where db is the sqlite3* database pointer.
|
|
** Therefore the next statement sets variable 'max' to 1 for the max()
|
|
** aggregate, or 0 for min().
|
|
*/
|
|
max = ((sqlite3_user_data(context)==(void *)-1)?1:0);
|
|
cmp = sqlite3MemCompare(pBest, pArg, pColl);
|
|
if( (max && cmp<0) || (!max && cmp>0) ){
|
|
sqlite3VdbeMemCopy(pBest, pArg);
|
|
}
|
|
}else{
|
|
sqlite3VdbeMemCopy(pBest, pArg);
|
|
}
|
|
}
|
|
static void minMaxFinalize(sqlite3_context *context){
|
|
sqlite3_value *pRes;
|
|
pRes = (sqlite3_value *)sqlite3_aggregate_context(context, 0);
|
|
if( pRes ){
|
|
if( pRes->flags ){
|
|
sqlite3_result_value(context, pRes);
|
|
}
|
|
sqlite3VdbeMemRelease(pRes);
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
** This function registered all of the above C functions as SQL
|
|
** functions. This should be the only routine in this file with
|
|
** external linkage.
|
|
*/
|
|
void sqlite3RegisterBuiltinFunctions(sqlite3 *db){
|
|
static const struct {
|
|
char *zName;
|
|
signed char nArg;
|
|
u8 argType; /* 0: none. 1: db 2: (-1) */
|
|
u8 eTextRep; /* 1: UTF-16. 0: UTF-8 */
|
|
u8 needCollSeq;
|
|
void (*xFunc)(sqlite3_context*,int,sqlite3_value **);
|
|
} aFuncs[] = {
|
|
{ "min", -1, 0, SQLITE_UTF8, 1, minmaxFunc },
|
|
{ "min", 0, 0, SQLITE_UTF8, 1, 0 },
|
|
{ "max", -1, 2, SQLITE_UTF8, 1, minmaxFunc },
|
|
{ "max", 0, 2, SQLITE_UTF8, 1, 0 },
|
|
{ "typeof", 1, 0, SQLITE_UTF8, 0, typeofFunc },
|
|
{ "length", 1, 0, SQLITE_UTF8, 0, lengthFunc },
|
|
{ "substr", 3, 0, SQLITE_UTF8, 0, substrFunc },
|
|
#ifndef SQLITE_OMIT_UTF16
|
|
{ "substr", 3, 0, SQLITE_UTF16LE, 0, sqlite3utf16Substr },
|
|
#endif
|
|
{ "abs", 1, 0, SQLITE_UTF8, 0, absFunc },
|
|
{ "round", 1, 0, SQLITE_UTF8, 0, roundFunc },
|
|
{ "round", 2, 0, SQLITE_UTF8, 0, roundFunc },
|
|
{ "upper", 1, 0, SQLITE_UTF8, 0, upperFunc },
|
|
{ "lower", 1, 0, SQLITE_UTF8, 0, lowerFunc },
|
|
{ "coalesce", -1, 0, SQLITE_UTF8, 0, ifnullFunc },
|
|
{ "coalesce", 0, 0, SQLITE_UTF8, 0, 0 },
|
|
{ "coalesce", 1, 0, SQLITE_UTF8, 0, 0 },
|
|
{ "ifnull", 2, 0, SQLITE_UTF8, 1, ifnullFunc },
|
|
{ "random", -1, 0, SQLITE_UTF8, 0, randomFunc },
|
|
{ "nullif", 2, 0, SQLITE_UTF8, 1, nullifFunc },
|
|
{ "sqlite_version", 0, 0, SQLITE_UTF8, 0, versionFunc},
|
|
{ "quote", 1, 0, SQLITE_UTF8, 0, quoteFunc },
|
|
{ "last_insert_rowid", 0, 1, SQLITE_UTF8, 0, last_insert_rowid },
|
|
{ "changes", 0, 1, SQLITE_UTF8, 0, changes },
|
|
{ "total_changes", 0, 1, SQLITE_UTF8, 0, total_changes },
|
|
#ifdef SQLITE_SOUNDEX
|
|
{ "soundex", 1, 0, SQLITE_UTF8, 0, soundexFunc},
|
|
#endif
|
|
#ifdef SQLITE_TEST
|
|
{ "randstr", 2, 0, SQLITE_UTF8, 0, randStr },
|
|
{ "test_destructor", 1, 1, SQLITE_UTF8, 0, test_destructor},
|
|
{ "test_destructor_count", 0, 0, SQLITE_UTF8, 0, test_destructor_count},
|
|
{ "test_auxdata", -1, 0, SQLITE_UTF8, 0, test_auxdata},
|
|
{ "test_error", 1, 0, SQLITE_UTF8, 0, test_error},
|
|
#endif
|
|
};
|
|
static const struct {
|
|
char *zName;
|
|
signed char nArg;
|
|
u8 argType;
|
|
u8 needCollSeq;
|
|
void (*xStep)(sqlite3_context*,int,sqlite3_value**);
|
|
void (*xFinalize)(sqlite3_context*);
|
|
} aAggs[] = {
|
|
{ "min", 1, 0, 1, minmaxStep, minMaxFinalize },
|
|
{ "max", 1, 2, 1, minmaxStep, minMaxFinalize },
|
|
{ "sum", 1, 0, 0, sumStep, sumFinalize },
|
|
{ "total", 1, 0, 0, sumStep, totalFinalize },
|
|
{ "avg", 1, 0, 0, sumStep, avgFinalize },
|
|
{ "count", 0, 0, 0, countStep, countFinalize },
|
|
{ "count", 1, 0, 0, countStep, countFinalize },
|
|
};
|
|
int i;
|
|
|
|
for(i=0; i<sizeof(aFuncs)/sizeof(aFuncs[0]); i++){
|
|
void *pArg = 0;
|
|
switch( aFuncs[i].argType ){
|
|
case 1: pArg = db; break;
|
|
case 2: pArg = (void *)(-1); break;
|
|
}
|
|
sqlite3CreateFunc(db, aFuncs[i].zName, aFuncs[i].nArg,
|
|
aFuncs[i].eTextRep, pArg, aFuncs[i].xFunc, 0, 0);
|
|
if( aFuncs[i].needCollSeq ){
|
|
FuncDef *pFunc = sqlite3FindFunction(db, aFuncs[i].zName,
|
|
strlen(aFuncs[i].zName), aFuncs[i].nArg, aFuncs[i].eTextRep, 0);
|
|
if( pFunc && aFuncs[i].needCollSeq ){
|
|
pFunc->needCollSeq = 1;
|
|
}
|
|
}
|
|
}
|
|
#ifndef SQLITE_OMIT_ALTERTABLE
|
|
sqlite3AlterFunctions(db);
|
|
#endif
|
|
#ifndef SQLITE_OMIT_PARSER
|
|
sqlite3AttachFunctions(db);
|
|
#endif
|
|
for(i=0; i<sizeof(aAggs)/sizeof(aAggs[0]); i++){
|
|
void *pArg = 0;
|
|
switch( aAggs[i].argType ){
|
|
case 1: pArg = db; break;
|
|
case 2: pArg = (void *)(-1); break;
|
|
}
|
|
sqlite3CreateFunc(db, aAggs[i].zName, aAggs[i].nArg, SQLITE_UTF8,
|
|
pArg, 0, aAggs[i].xStep, aAggs[i].xFinalize);
|
|
if( aAggs[i].needCollSeq ){
|
|
FuncDef *pFunc = sqlite3FindFunction( db, aAggs[i].zName,
|
|
strlen(aAggs[i].zName), aAggs[i].nArg, SQLITE_UTF8, 0);
|
|
if( pFunc && aAggs[i].needCollSeq ){
|
|
pFunc->needCollSeq = 1;
|
|
}
|
|
}
|
|
}
|
|
sqlite3RegisterDateTimeFunctions(db);
|
|
#ifdef SQLITE_SSE
|
|
(void)sqlite3SseFunctions(db);
|
|
#endif
|
|
#ifdef SQLITE_CASE_SENSITIVE_LIKE
|
|
sqlite3RegisterLikeFunctions(db, 1);
|
|
#else
|
|
sqlite3RegisterLikeFunctions(db, 0);
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
** Set the LIKEOPT flag on the 2-argument function with the given name.
|
|
*/
|
|
static void setLikeOptFlag(sqlite3 *db, const char *zName, int flagVal){
|
|
FuncDef *pDef;
|
|
pDef = sqlite3FindFunction(db, zName, strlen(zName), 2, SQLITE_UTF8, 0);
|
|
if( pDef ){
|
|
pDef->flags = flagVal;
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Register the built-in LIKE and GLOB functions. The caseSensitive
|
|
** parameter determines whether or not the LIKE operator is case
|
|
** sensitive. GLOB is always case sensitive.
|
|
*/
|
|
void sqlite3RegisterLikeFunctions(sqlite3 *db, int caseSensitive){
|
|
struct compareInfo *pInfo;
|
|
if( caseSensitive ){
|
|
pInfo = (struct compareInfo*)&likeInfoAlt;
|
|
}else{
|
|
pInfo = (struct compareInfo*)&likeInfoNorm;
|
|
}
|
|
sqlite3CreateFunc(db, "like", 2, SQLITE_UTF8, pInfo, likeFunc, 0, 0);
|
|
sqlite3CreateFunc(db, "like", 3, SQLITE_UTF8, pInfo, likeFunc, 0, 0);
|
|
sqlite3CreateFunc(db, "glob", 2, SQLITE_UTF8,
|
|
(struct compareInfo*)&globInfo, likeFunc, 0,0);
|
|
setLikeOptFlag(db, "glob", SQLITE_FUNC_LIKE | SQLITE_FUNC_CASE);
|
|
setLikeOptFlag(db, "like",
|
|
caseSensitive ? (SQLITE_FUNC_LIKE | SQLITE_FUNC_CASE) : SQLITE_FUNC_LIKE);
|
|
}
|
|
|
|
/*
|
|
** pExpr points to an expression which implements a function. If
|
|
** it is appropriate to apply the LIKE optimization to that function
|
|
** then set aWc[0] through aWc[2] to the wildcard characters and
|
|
** return TRUE. If the function is not a LIKE-style function then
|
|
** return FALSE.
|
|
*/
|
|
int sqlite3IsLikeFunction(sqlite3 *db, Expr *pExpr, int *pIsNocase, char *aWc){
|
|
FuncDef *pDef;
|
|
if( pExpr->op!=TK_FUNCTION ){
|
|
return 0;
|
|
}
|
|
if( pExpr->pList->nExpr!=2 ){
|
|
return 0;
|
|
}
|
|
pDef = sqlite3FindFunction(db, (char*)pExpr->token.z, pExpr->token.n, 2,
|
|
SQLITE_UTF8, 0);
|
|
if( pDef==0 || (pDef->flags & SQLITE_FUNC_LIKE)==0 ){
|
|
return 0;
|
|
}
|
|
|
|
/* The memcpy() statement assumes that the wildcard characters are
|
|
** the first three statements in the compareInfo structure. The
|
|
** asserts() that follow verify that assumption
|
|
*/
|
|
memcpy(aWc, pDef->pUserData, 3);
|
|
assert( (char*)&likeInfoAlt == (char*)&likeInfoAlt.matchAll );
|
|
assert( &((char*)&likeInfoAlt)[1] == (char*)&likeInfoAlt.matchOne );
|
|
assert( &((char*)&likeInfoAlt)[2] == (char*)&likeInfoAlt.matchSet );
|
|
*pIsNocase = (pDef->flags & SQLITE_FUNC_CASE)==0;
|
|
return 1;
|
|
}
|