2010/9/28 Tom Lane <t...@sss.pgh.pa.us>: > Pavel Stehule <pavel.steh...@gmail.com> writes: >> 2010/9/28 Tom Lane <t...@sss.pgh.pa.us>: >>> As an example, is this a for-in-query or a >>> for-in-array? >>> >>> FOR v IN (SELECT arraycol FROM tab) LOOP ... > >> This is a subquery - so it is a for-in-array - should return one row >> with one column. > > That's not obvious at all. It's legal right now to write that, and it > will be interpreted as for-in-query.
but it has not a sense. It's based on implementation and I am sure, so this isn't documented. Yes, we are able to write a := 10 FROM tab WHERE y = 10 but it is just more bug then required feature. FOR v IN (SELECT FROM) when select returns more than one row is big inconsistency - and this is bug, when this is allowed Regards Pavel Furthermore, there are cases where > it's essential to be able to write a left paren before SELECT, so that > you can control the precedence of UNION/INTERSECT/EXCEPT constructs. > So you're proposing to remove functionality and break existing code in > order to have a "simple" syntax for for-in-array. > > regards, tom lane > -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
