database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-11-16 23:02:26 +03:00
Code Activity

Make LIMIT and OFFSET values available to sqlite3_vtab_rhs_value().

Browse Source 
FossilOrigin-Name: b2d37c086c87fe4aee013bba4eab26f642207cd2a797fe4888a6ef868884c191
This commit is contained in:
drh
2022-01-27 18:45:26 +00:00
parent 895bab3383
commit 233ba1b8eb
3 changed files with 40 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

41
src/whereexpr.c
View File

@@ -1527,18 +1527,40 @@ void sqlite3WhereSplit(WhereClause *pWC, Expr *pExpr, u8 op){
** OFFSET (if eMatchOp==SQLITE_INDEX_CONSTRAINT_OFFSET) term to the
** where-clause passed as the first argument. The value for the term
** is found in register iReg.
**
** In the common case where the value is a simple integer
** (example: "LIMIT 5 OFFSET 10") then the expression codes as a
** TK_INTEGER so that it will be available to sqlite3_vtab_rhs_value().
** If not, then it codes as a TK_REGISTER expression.
*/
void whereAddLimitExpr(WhereClause *pWC, int iReg, int iCsr, int eMatchOp){
void whereAddLimitExpr(
WhereClause *pWC, /* Add the constraint to this WHERE clause */
int iReg, /* Register that will hold value of the limit/offset */
Expr *pExpr, /* Expression that defines the limit/offset */
int iCsr, /* Cursor to which the constraint applies */
int eMatchOp /* SQLITE_INDEX_CONSTRAINT_LIMIT or _OFFSET */
){
Parse *pParse = pWC->pWInfo->pParse;
sqlite3 *db = pParse->db;
Expr *pExpr;
Expr *pNew;
int iVal = 0;
pExpr = sqlite3PExpr(pParse, TK_MATCH, 0, sqlite3Expr(db,TK_REGISTER,0));
if( pExpr ){
if( sqlite3ExprIsInteger(pExpr, &iVal) ){
Expr *pVal = sqlite3Expr(db, TK_INTEGER, 0);
if( pVal==0 ) return;
ExprSetProperty(pVal, EP_IntValue);
pVal->u.iValue = iVal;
pNew = sqlite3PExpr(pParse, TK_MATCH, 0, pVal);
}else{
Expr *pVal = sqlite3Expr(db, TK_REGISTER, 0);
if( pVal==0 ) return;
pVal->iTable = iReg;
pNew = sqlite3PExpr(pParse, TK_MATCH, 0, pVal);
}
if( pNew ){
WhereTerm *pTerm;
int idx;
pExpr->pRight->iTable = iReg;
idx = whereClauseInsert(pWC, pExpr, TERM_DYNAMIC|TERM_VIRTUAL);
idx = whereClauseInsert(pWC, pNew, TERM_DYNAMIC|TERM_VIRTUAL);
pTerm = &pWC->a[idx];
pTerm->leftCursor = iCsr;
pTerm->eOperator = WO_AUX;
@@ -1589,9 +1611,12 @@ void sqlite3WhereAddLimit(WhereClause *pWC, Select *p){
}
/* All conditions are met. Add the terms to the where-clause object. */
whereAddLimitExpr(pWC, p->iLimit, iCsr, SQLITE_INDEX_CONSTRAINT_LIMIT);
assert( p->pLimit->op==TK_LIMIT );
whereAddLimitExpr(pWC, p->iLimit, p->pLimit->pLeft,
iCsr, SQLITE_INDEX_CONSTRAINT_LIMIT);
if( p->iOffset>0 ){
whereAddLimitExpr(pWC, p->iOffset, iCsr, SQLITE_INDEX_CONSTRAINT_OFFSET);
whereAddLimitExpr(pWC, p->iOffset, p->pLimit->pRight,
iCsr, SQLITE_INDEX_CONSTRAINT_OFFSET);
}
}
}