More fixes and comment updates.
FossilOrigin-Name: 38a9327bad1a01e3d7a47fad44ece2f6c7e88643
diff --git a/src/expr.c b/src/expr.c
index c50a2c0..08c22ff 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -1398,7 +1398,6 @@
if( iCol<0 ){
int iMem = ++pParse->nMem;
int iAddr;
- sqlite3VdbeUsesBtree(v, iDb);
iAddr = sqlite3VdbeAddOp1(v, OP_If, iMem);
sqlite3VdbeAddOp2(v, OP_Integer, 1, iMem);
@@ -1432,9 +1431,6 @@
char *pKey;
pKey = (char *)sqlite3IndexKeyinfo(pParse, pIdx);
- iDb = sqlite3SchemaToIndex(db, pIdx->pSchema);
- sqlite3VdbeUsesBtree(v, iDb);
-
iAddr = sqlite3VdbeAddOp1(v, OP_If, iMem);
sqlite3VdbeAddOp2(v, OP_Integer, 1, iMem);
@@ -2559,14 +2555,48 @@
}
case TK_TRIGGER: {
+ /* If the opcode is TK_TRIGGER, then the expression is a reference
+ ** to a column in the new.* or old.* pseudo-tables available to
+ ** trigger programs. In this case Expr.iTable is set to 1 for the
+ ** new.* pseudo-table, or 0 for the old.* pseudo-table. Expr.iColumn
+ ** is set to the column of the pseudo-table to read, or to -1 to
+ ** read the rowid field.
+ **
+ ** The expression is implemented using an OP_Param opcode. The p1
+ ** parameter is set to 0 for an old.rowid reference, or to (i+1)
+ ** to reference another column of the old.* pseudo-table, where
+ ** i is the index of the column. For a new.rowid reference, p1 is
+ ** set to (n+1), where n is the number of columns in each pseudo-table.
+ ** For a reference to any other column in the new.* pseudo-table, p1
+ ** is set to (n+2+i), where n and i are as defined previously. For
+ ** example, if the table on which triggers are being fired is
+ ** declared as:
+ **
+ ** CREATE TABLE t1(a, b);
+ **
+ ** Then p1 is interpreted as follows:
+ **
+ ** p1==0 -> old.rowid p1==3 -> new.rowid
+ ** p1==1 -> old.a p1==4 -> new.a
+ ** p1==2 -> old.b p1==5 -> new.b
+ */
Table *pTab = pExpr->pTab;
- int iVal = pExpr->iTable * (pTab->nCol+1) + 1 + pExpr->iColumn;
- sqlite3VdbeAddOp2(v, OP_Param, iVal, target);
+ int p1 = pExpr->iTable * (pTab->nCol+1) + 1 + pExpr->iColumn;
+
+ assert( pExpr->iTable==0 || pExpr->iTable==1 );
+ assert( pExpr->iColumn>=-1 && pExpr->iColumn<pTab->nCol );
+ assert( pTab->iPKey<0 || pExpr->iColumn!=pTab->iPKey );
+ assert( p1>=0 && p1<(pTab->nCol*2+2) );
+
+ sqlite3VdbeAddOp2(v, OP_Param, p1, target);
VdbeComment((v, "%s.%s -> $%d",
(pExpr->iTable ? "new" : "old"),
(pExpr->iColumn<0 ? "rowid" : pExpr->pTab->aCol[pExpr->iColumn].zName),
target
));
+
+ /* If the column has REAL affinity, it may currently be stored as an
+ ** integer. Use OP_RealAffinity to make sure it is really real. */
if( pExpr->iColumn>=0
&& pTab->aCol[pExpr->iColumn].affinity==SQLITE_AFF_REAL
){