@ -11,7 +11,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.230 2001/06/09 23:21:54 petere Exp $
* $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.231 2001/06/19 22:39:11 tgl Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
@ -315,7 +315,7 @@ static void doNegateFloat(Value *v);
SCHEMA, SCROLL, SECOND_P, SELECT, SESSION, SESSION_USER, SET, SOME, SUBSTRING,
TABLE, TEMPORARY, THEN, TIME, TIMESTAMP, TIMEZONE_HOUR,
TIMEZONE_MINUTE, TO, TRAILING, TRANSACTION, TRIM, TRUE_P,
UNION, UNIQUE, UPDATE, USER, USING,
UNION, UNIQUE, UNKNOWN, U PDATE, USER, USING,
VALUES, VARCHAR, VARYING, VIEW,
WHEN, WHERE, WITH, WORK, YEAR_P, ZONE
@ -386,7 +386,7 @@ static void doNegateFloat(Value *v);
%left Op /* multi-character ops and user-defined operators */
%nonassoc NOTNULL
%nonassoc ISNULL
%nonassoc IS NULL_P TRUE_P FALSE_P /* sets precedence for IS NULL, etc */
%nonassoc IS NULL_P TRUE_P FALSE_P UNKNOWN /* sets precedence for IS NULL, etc */
%left '+' '-'
%left '*' '/' '%'
%left '^'
@ -4434,9 +4434,19 @@ a_expr: c_expr
* (like Microsoft's). Turn these into IS NULL exprs.
*/
if (exprIsNullConstant($3))
$$ = makeA_Expr(ISNULL, NULL, $1, NULL);
{
NullTest *n = makeNode(NullTest);
n->arg = $1;
n->nulltesttype = IS_NULL;
$$ = (Node *)n;
}
else if (exprIsNullConstant($1))
$$ = makeA_Expr(ISNULL, NULL, $3, NULL);
{
NullTest *n = makeNode(NullTest);
n->arg = $3;
n->nulltesttype = IS_NULL;
$$ = (Node *)n;
}
else
$$ = makeA_Expr(OP, "=", $1, $3);
}
@ -4499,59 +4509,95 @@ a_expr: c_expr
n->agg_distinct = FALSE;
$$ = makeA_Expr(OP, "!~~*", $1, (Node *) n);
}
/* NullTest clause
* Define SQL92-style Null test clause.
* Allow two forms described in the standard:
* a IS NULL
* a IS NOT NULL
* Allow two SQL extensions
* a ISNULL
* a NOTNULL
* NOTE: this is not yet fully SQL-compatible, since SQL92
* allows a row constructor as argument, not just a scalar.
*/
| a_expr ISNULL
{ $$ = makeA_Expr(ISNULL, NULL, $1, NULL); }
{
NullTest *n = makeNode(NullTest);
n->arg = $1;
n->nulltesttype = IS_NULL;
$$ = (Node *)n;
}
| a_expr IS NULL_P
{ $$ = makeA_Expr(ISNULL, NULL, $1, NULL); }
{
NullTest *n = makeNode(NullTest);
n->arg = $1;
n->nulltesttype = IS_NULL;
$$ = (Node *)n;
}
| a_expr NOTNULL
{ $$ = makeA_Expr(NOTNULL, NULL, $1, NULL); }
{
NullTest *n = makeNode(NullTest);
n->arg = $1;
n->nulltesttype = IS_NOT_NULL;
$$ = (Node *)n;
}
| a_expr IS NOT NULL_P
{ $$ = makeA_Expr(NOTNULL, NULL, $1, NULL); }
{
NullTest *n = makeNode(NullTest);
n->arg = $1;
n->nulltesttype = IS_NOT_NULL;
$$ = (Node *)n;
}
/* IS TRUE, IS FALSE, etc used to be function calls
* but let's make them expressions to allow the optimizer
* a chance to eliminate them if a_expr is a constant string.
* - thomas 1997-12-22
*
* Created BooleanTest Node type, and changed handling
* for NULL inputs
* - jec 2001-06-18
*/
| a_expr IS TRUE_P
{
A_Const *n = makeNode(A_Const);
n->val.type = T_String;
n->val.val.str = "t";
n->typename = makeNode(TypeName);
n->typename->name = xlateSqlType("bool");
n->typename->typmod = -1;
$$ = makeA_Expr(OP, "=", $1,(Node *)n);
BooleanTest *b = makeNode(BooleanTest);
b->arg = $1;
b->booltesttype = IS_TRUE;
$$ = (Node *)b;
}
| a_expr IS NOT FALS E_P
| a_expr IS NOT TRUE_P
{
A_Const *n = makeNode(A_Const);
n->val.type = T_String;
n->val.val.str = "t";
n->typename = makeNode(TypeName);
n->typename->name = xlateSqlType("bool");
n->typename->typmod = -1;
$$ = makeA_Expr(OP, "=", $1,(Node *)n);
BooleanTest *b = makeNode(BooleanTest);
b->arg = $1;
b->booltesttype = IS_NOT_TRUE;
$$ = (Node *)b;
}
| a_expr IS FALSE_P
{
A_Const *n = makeNode(A_Const);
n->val.type = T_String;
n->val.val.str = "f";
n->typename = makeNode(TypeName);
n->typename->name = xlateSqlType("bool");
n->typename->typmod = -1;
$$ = makeA_Expr(OP, "=", $1,(Node *)n);
BooleanTest *b = makeNode(BooleanTest);
b->arg = $1;
b->booltesttype = IS_FALSE;
$$ = (Node *)b;
}
| a_expr IS NOT TRU E_P
| a_expr IS NOT FALSE_P
{
A_Const *n = makeNode(A_Const);
n->val.type = T_String;
n->val.val.str = "f";
n->typename = makeNode(TypeName);
n->typename->name = xlateSqlType("bool");
n->typename->typmod = -1;
$$ = makeA_Expr(OP, "=", $1,(Node *)n);
BooleanTest *b = makeNode(BooleanTest);
b->arg = $1;
b->booltesttype = IS_NOT_FALSE;
$$ = (Node *)b;
}
| a_expr IS UNKNOWN
{
BooleanTest *b = makeNode(BooleanTest);
b->arg = $1;
b->booltesttype = IS_UNKNOWN;
$$ = (Node *)b;
}
| a_expr IS NOT UNKNOWN
{
BooleanTest *b = makeNode(BooleanTest);
b->arg = $1;
b->booltesttype = IS_NOT_UNKNOWN;
$$ = (Node *)b;
}
| a_expr BETWEEN b_expr AND b_expr %prec BETWEEN
{
@ -5206,12 +5252,14 @@ case_expr: CASE case_arg when_clause_list case_default END_TRANS
| COALESCE '(' expr_list ')'
{
CaseExpr *c = makeNode(CaseExpr);
CaseWhen *w;
List *l;
foreach (l,$3)
{
w = makeNode(CaseWhen);
w->expr = makeA_Expr(NOTNULL, NULL, lfirst(l), NULL);
CaseWhen *w = makeNode(CaseWhen);
NullTest *n = makeNode(NullTest);
n->arg = lfirst(l);
n->nulltesttype = IS_NOT_NULL;
w->expr = (Node *) n;
w->result = lfirst(l);
c->args = lappend(c->args, w);
}
@ -5765,6 +5813,7 @@ ColLabel: ColId { $$ = $1; }
| TRUE_P { $$ = "true"; }
| UNION { $$ = "union"; }
| UNIQUE { $$ = "unique"; }
| UNKNOWN { $$ = "unknown"; }
| USER { $$ = "user"; }
| USING { $$ = "using"; }
| VACUUM { $$ = "vacuum"; }
Tom Lane
25 years ago