database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-06-14 18:42:34 +03:00
Code Activity

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

Browse Source 
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
Download Patch File Download Diff File Expand all files Collapse all files

138
src/backend/executor/execQual.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/executor/execQual.c,v 1.86 2001/04/19 04:29:02 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/executor/execQual.c,v 1.87 2001/06/19 22:39:11 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -62,6 +62,10 @@ static Datum ExecEvalAnd(Expr *andExpr, ExprContext *econtext, bool *isNull);
static Datum ExecEvalOr(Expr *orExpr, ExprContext *econtext, bool *isNull);
static Datum ExecEvalCase(CaseExpr *caseExpr, ExprContext *econtext,
bool *isNull, ExprDoneCond *isDone);
static Datum ExecEvalNullTest(NullTest *ntest, ExprContext *econtext,
bool *isNull, ExprDoneCond *isDone);
static Datum ExecEvalBooleanTest(BooleanTest *btest, ExprContext *econtext,
bool *isNull, ExprDoneCond *isDone);
/*----------
@ -1091,6 +1095,126 @@ ExecEvalCase(CaseExpr *caseExpr, ExprContext *econtext,
return (Datum) 0;
}
/* ----------------------------------------------------------------
* ExecEvalNullTest
*
* Evaluate a NullTest node.
* ----------------------------------------------------------------
*/
static Datum
ExecEvalNullTest(NullTest *ntest,
ExprContext *econtext,
bool *isNull,
ExprDoneCond *isDone)
{
Datum result;
result = ExecEvalExpr(ntest->arg, econtext, isNull, isDone);
switch (ntest->nulltesttype)
{
case IS_NULL:
if (*isNull)
{
*isNull = false;
return BoolGetDatum(true);
}
else
return BoolGetDatum(false);
case IS_NOT_NULL:
if (*isNull)
{
*isNull = false;
return BoolGetDatum(false);
}
else
return BoolGetDatum(true);
default:
elog(ERROR, "ExecEvalNullTest: unexpected nulltesttype %d",
(int) ntest->nulltesttype);
return (Datum) 0; /* keep compiler quiet */
}
}
/* ----------------------------------------------------------------
* ExecEvalBooleanTest
*
* Evaluate a BooleanTest node.
* ----------------------------------------------------------------
*/
static Datum
ExecEvalBooleanTest(BooleanTest *btest,
ExprContext *econtext,
bool *isNull,
ExprDoneCond *isDone)
{
Datum result;
result = ExecEvalExpr(btest->arg, econtext, isNull, isDone);
switch (btest->booltesttype)
{
case IS_TRUE:
if (*isNull)
{
*isNull = false;
return BoolGetDatum(false);
}
else if (DatumGetBool(result))
return BoolGetDatum(true);
else
return BoolGetDatum(false);
case IS_NOT_TRUE:
if (*isNull)
{
*isNull = false;
return BoolGetDatum(true);
}
else if (DatumGetBool(result))
return BoolGetDatum(false);
else
return BoolGetDatum(true);
case IS_FALSE:
if (*isNull)
{
*isNull = false;
return BoolGetDatum(false);
}
else if (DatumGetBool(result))
return BoolGetDatum(false);
else
return BoolGetDatum(true);
case IS_NOT_FALSE:
if (*isNull)
{
*isNull = false;
return BoolGetDatum(true);
}
else if (DatumGetBool(result))
return BoolGetDatum(true);
else
return BoolGetDatum(false);
case IS_UNKNOWN:
if (*isNull)
{
*isNull = false;
return BoolGetDatum(true);
}
else
return BoolGetDatum(false);
case IS_NOT_UNKNOWN:
if (*isNull)
{
*isNull = false;
return BoolGetDatum(false);
}
else
return BoolGetDatum(true);
default:
elog(ERROR, "ExecEvalBooleanTest: unexpected booltesttype %d",
(int) btest->booltesttype);
return (Datum) 0; /* keep compiler quiet */
}
}
/* ----------------------------------------------------------------
* ExecEvalFieldSelect
*
@ -1266,6 +1390,18 @@ ExecEvalExpr(Node *expression,
isNull,
isDone);
break;
case T_NullTest:
retDatum = ExecEvalNullTest((NullTest *) expression,
econtext,
isNull,
isDone);
break;
case T_BooleanTest:
retDatum = ExecEvalBooleanTest((BooleanTest *) expression,
econtext,
isNull,
isDone);
break;
default:
elog(ERROR, "ExecEvalExpr: unknown expression type %d",