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Allow the IN operator to take a list of arbitrary expressions on its

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right-hand side.  The expressions no longer need to be constant.  The
current implementation seems to work but needs more testing and optimization. (CVS 2542)

FossilOrigin-Name: ba56478dd8bc2135749966ff55831fd497883781
This commit is contained in:
drh
2005-07-08 18:25:26 +00:00
parent 9170dd7e1c
commit 57dbd7b324
4 changed files with 50 additions and 38 deletions
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50
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 1.210 2005/07/08 17:13:47 drh Exp $
** $Id: expr.c,v 1.211 2005/07/08 18:25:26 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
@@ -1238,19 +1238,25 @@ struct QueryCoder {
*/
#ifndef SQLITE_OMIT_SUBQUERY
void sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){
int label = 0; /* Address after sub-select code */
int testAddr = 0; /* One-time test address */
Vdbe *v = sqlite3GetVdbe(pParse);
if( v==0 ) return;
/* If this is not a variable (correlated) select, then execute
** it only once. Unless this is part of a trigger program. In
** that case re-execute every time (this could be optimized).
/* This code must be run in its entirety every time it is encountered
** if any of the following is true:
**
** * The right-hand side is a correlated subquery
** * The right-hand side is an expression list containing variables
** * We are inside a trigger
**
** If all of the above are false, then we can run this code just once
** save the results, and reuse the same result on subsequent invocations.
*/
if( !ExprHasAnyProperty(pExpr, EP_VarSelect) && !pParse->trigStack ){
int mem = pParse->nMem++;
sqlite3VdbeAddOp(v, OP_MemLoad, mem, 0);
label = sqlite3VdbeMakeLabel(v);
sqlite3VdbeAddOp(v, OP_If, 0, label);
testAddr = sqlite3VdbeAddOp(v, OP_If, 0, 0);
assert( testAddr>0 );
sqlite3VdbeAddOp(v, OP_Integer, 1, 0);
sqlite3VdbeAddOp(v, OP_MemStore, mem, 1);
}
@@ -1268,7 +1274,7 @@ void sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){
affinity = sqlite3ExprAffinity(pExpr->pLeft);
/* Whether this is an 'x IN(SELECT...)' or an 'x IN(<exprlist>)'
** expression it is handled the same way. A temporary table is
** expression it is handled the same way. A virtual table is
** filled with single-field index keys representing the results
** from the SELECT or the <exprlist>.
**
@@ -1310,20 +1316,30 @@ void sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){
** a column, use numeric affinity.
*/
int i;
ExprList *pList = pExpr->pList;
struct ExprList_item *pItem;
if( !affinity ){
affinity = SQLITE_AFF_NUMERIC;
}
keyInfo.aColl[0] = pExpr->pLeft->pColl;
/* Loop through each expression in <exprlist>. */
for(i=0; i<pExpr->pList->nExpr; i++){
Expr *pE2 = pExpr->pList->a[i].pExpr;
for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){
Expr *pE2 = pItem->pExpr;
/* Check that the expression is constant and valid. */
if( !sqlite3ExprIsConstant(pE2) ){
sqlite3ErrorMsg(pParse,
"right-hand side of IN operator must be constant");
return;
/* If the expression is not constant then we will need to
** disable the test that was generated above that makes sure
** this code only executes once. Because for a non-constant
** expression we need to rerun this code each time.
*/
if( testAddr>=0 && !sqlite3ExprIsConstant(pE2) ){
VdbeOp *aOp = sqlite3VdbeGetOp(v, testAddr-1);
int i;
for(i=0; i<4; i++){
aOp[i].opcode = OP_Noop;
}
testAddr = 0;
}
/* Evaluate the expression and insert it into the temp table */
@@ -1364,8 +1380,8 @@ void sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){
if( pExpr->pSelect ){
sqlite3VdbeAddOp(v, OP_AggContextPop, 0, 0);
}
if( label<0 ){
sqlite3VdbeResolveLabel(v, label);
if( testAddr ){
sqlite3VdbeChangeP2(v, testAddr, sqlite3VdbeCurrentAddr(v));
}
return;
}