Add an experimental location(X) SQL function that attempt to return the
location of the payload within the database for the record that contains
column X. location(X) returns NULL if X is not an ordinary table column or
if SQLite cannot figure out the location because it is using a covering index.
FossilOrigin-Name: 51be9558164301c5dd4df23ab8b3e67de0b522f8d36f79f3d84d45d3dc2a83a4
diff --git a/src/expr.c b/src/expr.c
index 524e539..b7c64d3 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -3871,9 +3871,18 @@
if( !pColl ) pColl = db->pDfltColl;
sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
}
- sqlite3VdbeAddOp4(v, pParse->iSelfTab ? OP_PureFunc0 : OP_Function0,
- constMask, r1, target, (char*)pDef, P4_FUNCDEF);
- sqlite3VdbeChangeP5(v, (u8)nFarg);
+ if( pDef->funcFlags & SQLITE_FUNC_LOCATION ){
+ Expr *pArg = pFarg->a[0].pExpr;
+ if( pArg->op==TK_COLUMN ){
+ sqlite3VdbeAddOp2(v, OP_Location, pArg->iTable, target);
+ }else{
+ sqlite3VdbeAddOp2(v, OP_Null, 0, target);
+ }
+ }else{
+ sqlite3VdbeAddOp4(v, pParse->iSelfTab ? OP_PureFunc0 : OP_Function0,
+ constMask, r1, target, (char*)pDef, P4_FUNCDEF);
+ sqlite3VdbeChangeP5(v, (u8)nFarg);
+ }
if( nFarg && constMask==0 ){
sqlite3ReleaseTempRange(pParse, r1, nFarg);
}