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Implement IS OF type predicate. Can now do queries of the form: 

select value IS OF (integer, float8);
This commit is contained in:
Thomas G. Lockhart 2002-08-04 06:46:12 +00:00
parent b71310d8e0
commit 7c1e67bd52
1 changed files with 44 additions and 9 deletions
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53
src/backend/parser/parse_expr.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/parser/parse_expr.c,v 1.123 2002/07/18 17:14:19 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/parser/parse_expr.c,v 1.124 2002/08/04 06:46:12 thomas Exp $
*
*-------------------------------------------------------------------------
*/
@ -282,6 +282,41 @@ transformExpr(ParseState *pstate, Node *expr)
rexpr);
((Expr *)result)->opType = DISTINCT_EXPR;
}
break;
case OF:
{
List *telem;
A_Const *n;
Oid ltype, rtype;
bool matched = FALSE;
/* Checking an expression for match to type.
* Will result in a boolean constant node.
*/
Node *lexpr = transformExpr(pstate,
a->lexpr);
ltype = exprType(lexpr);
foreach(telem, (List *) a->rexpr)
{
rtype = LookupTypeName(lfirst(telem));
matched = (rtype == ltype);
if (matched) break;
}
/* Expect two forms: equals or not equals.
* Flip the sense of the result for not equals.
*/
if (strcmp(strVal(lfirst(a->name)), "!=") == 0)
matched = (! matched);
n = makeNode(A_Const);
n->val.type = T_String;
n->val.val.str = (matched? "t": "f");
n->typename = SystemTypeName("bool");
result = transformExpr(pstate, (Node *) n);
}
break;
}
break;
}
@ -589,14 +624,14 @@ transformExpr(ParseState *pstate, Node *expr)
break;
}
/*
* Quietly accept node types that may be presented when we are
* called on an already-transformed tree.
*
* Do any other node types need to be accepted? For now we are
* taking a conservative approach, and only accepting node
* types that are demonstrably necessary to accept.
*/
/*********************************************
* Quietly accept node types that may be presented when we are
* called on an already-transformed tree.
*
* Do any other node types need to be accepted? For now we are
* taking a conservative approach, and only accepting node
* types that are demonstrably necessary to accept.
*********************************************/
case T_Expr:
case T_Var:
case T_Const: