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:-) (CVS 55)

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FossilOrigin-Name: bd8b2645cc16759571c8c622dce4752bd35c04cf
This commit is contained in:
drh
2000-06-06 01:50:43 +00:00
parent 600b1b2f01
commit fef5208c15
9 changed files with 530 additions and 163 deletions
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172
src/expr.c
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@@ -23,10 +23,35 @@
*************************************************************************
** This file contains C code routines used for processing expressions
**
** $Id: expr.c,v 1.6 2000/06/05 18:54:46 drh Exp $
** $Id: expr.c,v 1.7 2000/06/06 01:50:43 drh Exp $
*/
#include "sqliteInt.h"
/*
** Walk an expression tree. Return 1 if the expression is constant
** and 0 if it involves variables.
*/
static int isConstant(Expr *p){
switch( p->op ){
case TK_ID:
case TK_FIELD:
case TK_DOT:
return 0;
default: {
if( p->pLeft && !isConstant(p->pLeft) ) return 0;
if( p->pRight && !isConstant(p->pRight) ) return 0;
if( p->pList ){
int i;
for(i=0; i<p->pList->nExpr; i++){
if( !isConstant(p->pList->a[i].pExpr) ) return 0;
}
}
break;
}
}
return 1;
}
/*
** This routine walks an expression tree and resolves references to
** table fields. Nodes of the form ID.ID or ID resolve into an
@@ -36,7 +61,18 @@
** value. The iField value is changed to the index of the field of the
** referenced table.
**
** This routine also looks for SELECTs that are part of an expression.
** We also check for instances of the IN operator. IN comes in two
** forms:
**
** expr IN (exprlist)
** and
** expr IN (SELECT ...)
**
** The first form is handled by creating a set holding the list
** of allowed values. The second form causes the SELECT to generate
** a temporary table.
**
** This routine also looks for scalar SELECTs that are part of an expression.
** If it finds any, it generates code to write the value of that select
** into a memory cell.
**
@@ -137,9 +173,70 @@ int sqliteExprResolveIds(Parse *pParse, IdList *pTabList, Expr *pExpr){
break;
}
case TK_IN: {
Vdbe *v = pParse->pVdbe;
if( v==0 ){
v = pParse->pVdbe = sqliteVdbeCreate(pParse->db->pBe);
}
if( v==0 ) return 1;
if( pExpr->pSelect ){
/* Case 1: expr IN (SELECT ...)
**
** Generate code to write the results of the select into a temporary
** table. The cursor number of the temporary table is stored in
** iTable.
*/
pExpr->iTable = pParse->nTab++;
sqliteVdbeAddOp(v, OP_Open, pExpr->iTable, 0, 0, 0);
if( sqliteSelect(pParse, pExpr->pSelect, SRT_Set, pExpr->iTable) );
}else if( pExpr->pList ){
/* Case 2: expr IN (exprlist)
**
** Create a set to put the exprlist values in. The Set id is stored
** in iTable.
*/
int i, iSet;
for(i=0; i<pExpr->pList->nExpr; i++){
Expr *pE2 = pExpr->pList->a[i].pExpr;
if( sqliteExprCheck(pParse, pE2, 0, 0) ){
return 1;
}
if( !isConstant(pE2) ){
sqliteSetString(&pParse->zErrMsg,
"right-hand side of IN operator must be constant", 0);
pParse->nErr++;
return 1;
}
}
iSet = pExpr->iTable = pParse->nSet++;
for(i=0; i<pExpr->pList->nExpr; i++){
Expr *pE2 = pExpr->pList->a[i].pExpr;
switch( pE2->op ){
case TK_FLOAT:
case TK_INTEGER:
case TK_STRING: {
int addr = sqliteVdbeAddOp(v, OP_SetInsert, iSet, 0, 0, 0);
sqliteVdbeChangeP3(v, addr, pE2->token.z, pE2->token.n);
sqliteVdbeDequoteP3(v, addr);
break;
}
default: {
sqliteExprCode(pParse, pE2);
sqliteVdbeAddOp(v, OP_SetInsert, iSet, 0, 0, 0);
break;
}
}
}
}
}
case TK_SELECT: {
/* This has to be a scalar SELECT. Generate code to put the
** value of this select in a memory cell and record the number
** of the memory cell in iField.
*/
pExpr->iField = pParse->nMem++;
if( sqliteSelect(pParse, pExpr->pSelect, -1, pExpr->iField) ){
if( sqliteSelect(pParse, pExpr->pSelect, SRT_Mem, pExpr->iField) ){
return 1;
}
break;
@@ -281,6 +378,13 @@ int sqliteExprCheck(Parse *pParse, Expr *pExpr, int allowAgg, int *pIsAgg){
if( nErr==0 && pExpr->pRight ){
nErr = sqliteExprCheck(pParse, pExpr->pRight, 0, 0);
}
if( nErr==0 && pExpr->pList ){
int n = pExpr->pList->nExpr;
int i;
for(i=0; nErr==0 && i<n; i++){
nErr = sqliteExprCheck(pParse, pExpr->pList->a[i].pExpr, 0, 0);
}
}
break;
}
}
@@ -402,6 +506,27 @@ void sqliteExprCode(Parse *pParse, Expr *pExpr){
sqliteVdbeAddOp(v, OP_MemLoad, pExpr->iField, 0, 0, 0);
break;
}
case TK_IN: {
int addr;
sqliteVdbeAddOp(v, OP_Integer, 0, 0, 0, 0);
sqliteExprCode(pParse, pExpr->pLeft);
addr = sqliteVdbeCurrentAddr(v);
if( pExpr->pSelect ){
sqliteVdbeAddOp(v, OP_Found, pExpr->iTable, addr+2, 0, 0);
}else{
sqliteVdbeAddOp(v, OP_SetFound, pExpr->iTable, addr+2, 0, 0);
}
sqliteVdbeAddOp(v, OP_AddImm, 1, 0, 0, 0);
break;
}
case TK_BETWEEN: {
int lbl = sqliteVdbeMakeLabel(v);
sqliteVdbeAddOp(v, OP_Integer, 0, 0, 0, 0);
sqliteExprIfFalse(pParse, pExpr, lbl);
sqliteVdbeAddOp(v, OP_AddImm, 1, 0, 0, 0);
sqliteVdbeResolveLabel(v, lbl);
break;
}
}
return;
}
@@ -463,6 +588,26 @@ void sqliteExprIfTrue(Parse *pParse, Expr *pExpr, int dest){
sqliteVdbeAddOp(v, op, 0, dest, 0, 0);
break;
}
case TK_IN: {
if( pExpr->pSelect ){
sqliteVdbeAddOp(v, OP_Found, pExpr->iTable, dest, 0, 0);
}else{
sqliteVdbeAddOp(v, OP_SetFound, pExpr->iTable, dest, 0, 0);
}
break;
}
case TK_BETWEEN: {
int lbl = sqliteVdbeMakeLabel(v);
sqliteExprCode(pParse, pExpr->pLeft);
sqliteVdbeAddOp(v, OP_Dup, 0, 0, 0, 0);
sqliteExprCode(pParse, pExpr->pList->a[0].pExpr);
sqliteVdbeAddOp(v, OP_Lt, 0, lbl, 0, 0);
sqliteExprCode(pParse, pExpr->pList->a[1].pExpr);
sqliteVdbeAddOp(v, OP_Le, 0, dest, 0, 0);
sqliteVdbeAddOp(v, OP_Integer, 0, 0, 0, 0);
sqliteVdbeAddOp(v, OP_Pop, 1, 0, 0, lbl);
break;
}
default: {
sqliteExprCode(pParse, pExpr);
sqliteVdbeAddOp(v, OP_If, 0, dest, 0, 0);
@@ -533,6 +678,27 @@ void sqliteExprIfFalse(Parse *pParse, Expr *pExpr, int dest){
sqliteVdbeAddOp(v, op, 0, dest, 0, 0);
break;
}
case TK_IN: {
if( pExpr->pSelect ){
sqliteVdbeAddOp(v, OP_NotFound, pExpr->iTable, dest, 0, 0);
}else{
sqliteVdbeAddOp(v, OP_SetNotFound, pExpr->iTable, dest, 0, 0);
}
break;
}
case TK_BETWEEN: {
int addr;
sqliteExprCode(pParse, pExpr->pLeft);
sqliteVdbeAddOp(v, OP_Dup, 0, 0, 0, 0);
sqliteExprCode(pParse, pExpr->pList->a[0].pExpr);
addr = sqliteVdbeCurrentAddr(v);
sqliteVdbeAddOp(v, OP_Ge, 0, addr+3, 0, 0);
sqliteVdbeAddOp(v, OP_Pop, 1, 0, 0, 0);
sqliteVdbeAddOp(v, OP_Goto, 0, dest, 0, 0);
sqliteExprCode(pParse, pExpr->pList->a[1].pExpr);
sqliteVdbeAddOp(v, OP_Gt, 0, dest, 0, 0);
break;
}
default: {
sqliteExprCode(pParse, pExpr);
sqliteVdbeAddOp(v, OP_Not, 0, 0, 0, 0);