database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-07-24 22:22:08 +03:00
Code Activity

Change the way "(a, b) = (SELECT *)" expressions are handled in where.c if there is an index on one of the columns only.

Browse Source 
FossilOrigin-Name: 4dfebff2924f46284d5b9cda69175f79b29d6028
This commit is contained in:
dan
2016-07-29 18:12:12 +00:00
parent 7b35a77b1a
commit 145b4ea519
7 changed files with 45 additions and 31 deletions
Download Patch File Download Diff File Expand all files Collapse all files

32
src/wherecode.c
View File

@ -359,7 +359,31 @@ static int codeEqualityTerm(
assert( pLevel->pWLoop->aLTerm[iEq]==pTerm );
assert( iTarget>0 );
if( pX->op==TK_EQ || pX->op==TK_IS ){
iReg = sqlite3ExprCodeTarget(pParse, pX->pRight, iTarget);
Expr *pRight = pX->pRight;
if( pRight->op==TK_SELECT_COLUMN ){
/* This case occurs for expressions like "(a, b) == (SELECT ...)". */
WhereLoop *pLoop = pLevel->pWLoop;
int i;
Expr *pSub = pRight->pLeft;
assert( pSub->op==TK_SELECT );
for(i=pLoop->nSkip; i<iEq; i++){
Expr *pExpr = pLoop->aLTerm[i]->pExpr->pRight;
if( pExpr && pExpr->op==TK_SELECT_COLUMN && pExpr->pLeft==pSub ) break;
}
if( i==iEq ){
iReg = sqlite3CodeSubselect(pParse, pSub, 0, 0);
for(/*no-op*/; i<pLoop->nLTerm; i++){
Expr *pExpr = pLoop->aLTerm[i]->pExpr->pRight;
if( pExpr && pExpr->op==TK_SELECT_COLUMN && pExpr->pLeft==pSub ){
sqlite3VdbeAddOp2(v, OP_Copy, iReg+pExpr->iColumn, iTarget-iEq+i);
}
}
}
iReg = iTarget;
}else{
iReg = sqlite3ExprCodeTarget(pParse, pRight, iTarget);
}
}else if( pX->op==TK_ISNULL ){
iReg = iTarget;
sqlite3VdbeAddOp2(v, OP_Null, 0, iReg);
@ -1489,10 +1513,6 @@ Bitmask sqlite3WhereCodeOneLoopStart(
testcase( op==OP_IdxLE ); VdbeCoverageIf(v, op==OP_IdxLE );
}
/* Disable the start and end range terms if possible */
/* disableTerm(pLevel, pRangeStart); */
/* disableTerm(pLevel, pRangeEnd); */
/* Seek the table cursor, if required */
if( omitTable ){
/* pIdx is a covering index. No need to access the main table. */
@ -1594,7 +1614,7 @@ Bitmask sqlite3WhereCodeOneLoopStart(
u16 wctrlFlags; /* Flags for sub-WHERE clause */
Expr *pAndExpr = 0; /* An ".. AND (...)" expression */
Table *pTab = pTabItem->pTab;
pTerm = pLoop->aLTerm[0];
assert( pTerm!=0 );
assert( pTerm->eOperator & WO_OR );