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Wildcards with the same name map into the same variable number. New

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api sqlite3_bind_parameter_index() added to map wildcard names into
wildcard index numbers.  Support for "?nnn" wildcards. (CVS 1945)

FossilOrigin-Name: 435b3f301fbb6953adc974c7f03589b06e9114c3
This commit is contained in:
drh
2004-09-07 16:19:52 +00:00
parent 1807ce37b8
commit fa6bc0000f
11 changed files with 299 additions and 48 deletions
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71
src/expr.c
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@@ -12,7 +12,7 @@
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.160 2004/09/06 17:24:13 drh Exp $
** $Id: expr.c,v 1.161 2004/09/07 16:19:53 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
@@ -273,6 +273,75 @@ Expr *sqlite3ExprFunction(ExprList *pList, Token *pToken){
return pNew;
}
/*
** Assign a variable number to an expression that encodes a wildcard
** in the original SQL statement.
**
** Wildcards consisting of a single "?" are assigned the next sequential
** variable number.
**
** Wildcards of the form "?nnn" are assigned the number "nnn". We make
** sure "nnn" is not too be to avoid a denial of service attack when
** the SQL statement comes from an external source.
**
** Wildcards of the form ":aaa" or "$aaa" are assigned the same number
** as the previous instance of the same wildcard. Or if this is the first
** instance of the wildcard, the next sequenial variable number is
** assigned.
*/
void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
Token *pToken;
if( pExpr==0 ) return;
pToken = &pExpr->token;
assert( pToken->n>=1 );
assert( pToken->z!=0 );
assert( pToken->z[0]!=0 );
if( pToken->n==1 ){
/* Wildcard of the form "?". Assign the next variable number */
pExpr->iTable = ++pParse->nVar;
}else if( pToken->z[0]=='?' ){
/* Wildcard of the form "?nnn". Convert "nnn" to an integer and
** use it as the variable number */
int i;
pExpr->iTable = i = atoi(&pToken->z[1]);
if( i<1 || i>SQLITE_MAX_VARIABLE_NUMBER ){
sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d",
SQLITE_MAX_VARIABLE_NUMBER);
}
if( i>pParse->nVar ){
pParse->nVar = i;
}
}else{
/* Wildcards of the form ":aaa" or "$aaa". Reuse the same variable
** number as the prior appearance of the same name, or if the name
** has never appeared before, reuse the same variable number
*/
int i, n;
n = pToken->n;
for(i=0; i<pParse->nVarExpr; i++){
Expr *pE;
if( (pE = pParse->apVarExpr[i])!=0
&& pE->token.n==n
&& memcmp(pE->token.z, pToken->z, n)==0 ){
pExpr->iTable = pE->iTable;
break;
}
}
if( i>=pParse->nVarExpr ){
pExpr->iTable = ++pParse->nVar;
if( pParse->nVarExpr>=pParse->nVarExprAlloc-1 ){
pParse->nVarExprAlloc += pParse->nVarExprAlloc + 10;
pParse->apVarExpr = sqliteRealloc(pParse->apVarExpr,
pParse->nVarExprAlloc*sizeof(pParse->apVarExpr[0]) );
}
if( !sqlite3_malloc_failed ){
assert( pParse->apVarExpr!=0 );
pParse->apVarExpr[pParse->nVarExpr++] = pExpr;
}
}
}
}
/*
** Recursively delete an expression tree.
*/