diff options
Diffstat (limited to 'src/backend')
| -rw-r--r-- | src/backend/parser/gram.y | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index 2b992fab4a7..4688bc79778 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -11,7 +11,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.606 2008/02/07 21:07:55 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.607 2008/02/15 22:17:06 tgl Exp $ * * HISTORY * AUTHOR DATE MAJOR EVENT @@ -477,6 +477,7 @@ static Node *makeXmlExpr(XmlExprOp op, char *name, List *named_args, List *args) %nonassoc BETWEEN %nonassoc IN_P %left POSTFIXOP /* dummy for postfix Op rules */ +%nonassoc IDENT /* to support target_el without AS */ %left Op OPERATOR /* multi-character ops and user-defined operators */ %nonassoc NOTNULL %nonassoc ISNULL @@ -8705,7 +8706,6 @@ target_list: | target_list ',' target_el { $$ = lappend($1, $3); } ; -/* AS is not optional because shift/red conflict with unary ops */ target_el: a_expr AS ColLabel { $$ = makeNode(ResTarget); @@ -8714,6 +8714,22 @@ target_el: a_expr AS ColLabel $$->val = (Node *)$1; $$->location = @1; } + /* + * We support omitting AS only for column labels that aren't + * any known keyword. There is an ambiguity against postfix + * operators: is "a ! b" an infix expression, or a postfix + * expression and a column label? We prefer to resolve this + * as an infix expression, which we accomplish by assigning + * IDENT a precedence higher than POSTFIXOP. + */ + | a_expr IDENT + { + $$ = makeNode(ResTarget); + $$->name = $2; + $$->indirection = NIL; + $$->val = (Node *)$1; + $$->location = @1; + } | a_expr { $$ = makeNode(ResTarget); |