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Add IS UNKNOWN, IS NOT UNKNOWN boolean tests, fix the existing boolean

tests to return the correct results per SQL9x when given NULL inputs.
Reimplement these tests as well as IS [NOT] NULL to have their own
expression node types, instead of depending on special functions.
From Joe Conway, with a little help from Tom Lane.
This commit is contained in:
Tom Lane
2001-06-19 22:39:12 +00:00
parent 8c30aca2ba
commit 116d2bba7e
18 changed files with 666 additions and 153 deletions

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.85 2001/05/20 20:28:19 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.86 2001/06/19 22:39:11 tgl Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
@ -1580,6 +1580,10 @@ expression_tree_walker(Node *node,
return true;
}
break;
case T_NullTest:
return walker(((NullTest *) node)->arg, context);
case T_BooleanTest:
return walker(((BooleanTest *) node)->arg, context);
case T_SubLink:
{
SubLink *sublink = (SubLink *) node;
@ -1933,6 +1937,26 @@ expression_tree_mutator(Node *node,
return (Node *) newnode;
}
break;
case T_NullTest:
{
NullTest *ntest = (NullTest *) node;
NullTest *newnode;
FLATCOPY(newnode, ntest, NullTest);
MUTATE(newnode->arg, ntest->arg, Node *);
return (Node *) newnode;
}
break;
case T_BooleanTest:
{
BooleanTest *btest = (BooleanTest *) node;
BooleanTest *newnode;
FLATCOPY(newnode, btest, BooleanTest);
MUTATE(newnode->arg, btest->arg, Node *);
return (Node *) newnode;
}
break;
case T_SubLink:
{