database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-11-10 17:42:29 +03:00
Code Activity

COALESCE() and NULLIF() are now first-class expressions, not macros

Browse Source 
that turn into CASE expressions.  They evaluate their arguments at most
once.  Patch by Kris Jurka, review and (very light) editorializing by me.
This commit is contained in:
Tom Lane
2003-02-16 02:30:39 +00:00
parent de25638d2f
commit 51972a9d5d
22 changed files with 644 additions and 107 deletions
Download Patch File Download Diff File Expand all files Collapse all files

39
src/backend/nodes/equalfuncs.c
View File

@@ -18,7 +18,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.186 2003/02/10 04:44:45 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.187 2003/02/16 02:30:37 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -378,6 +378,37 @@ _equalCaseWhen(CaseWhen *a, CaseWhen *b)
return true;
}
static bool
_equalCoalesceExpr(CoalesceExpr *a, CoalesceExpr *b)
{
COMPARE_SCALAR_FIELD(coalescetype);
COMPARE_NODE_FIELD(args);
return true;
}
static bool
_equalNullIfExpr(NullIfExpr *a, NullIfExpr *b)
{
COMPARE_SCALAR_FIELD(opno);
/*
* Special-case opfuncid: it is allowable for it to differ if one
* node contains zero and the other doesn't. This just means that the
* one node isn't as far along in the parse/plan pipeline and hasn't
* had the opfuncid cache filled yet.
*/
if (a->opfuncid != b->opfuncid &&
a->opfuncid != 0 &&
b->opfuncid != 0)
return false;
COMPARE_SCALAR_FIELD(opresulttype);
COMPARE_SCALAR_FIELD(opretset);
COMPARE_NODE_FIELD(args);
return true;
}
static bool
_equalNullTest(NullTest *a, NullTest *b)
{
@@ -1613,6 +1644,12 @@ equal(void *a, void *b)
case T_CaseWhen:
retval = _equalCaseWhen(a, b);
break;
case T_CoalesceExpr:
retval = _equalCoalesceExpr(a, b);
break;
case T_NullIfExpr:
retval = _equalNullIfExpr(a, b);
break;
case T_NullTest:
retval = _equalNullTest(a, b);
break;