thanks fo the reply. i was misled by pgAdmin (1.6) giving both as "record" in the datatype (i thought "row" and "?column?" were just "best guess" column headers).
so, if they are indeed differently shaped is there any way to make them be the same shape? note that this one also fails with the same error (one would think these are the "same shape"): select (select (1,2)) is distinct from (select (1,2)) ; ERROR: operator does not exist: record = record SQL state: 42883 Hint: No operator matches the given name and argument type(s). You may need to add explicit type casts. > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Andrew Sullivan > Sent: Tuesday, October 31, 2006 1:23 PM > To: pgsql-sql@postgresql.org > Subject: Re: [SQL] record datatype comparisons > > On Tue, Oct 31, 2006 at 12:38:36PM -0800, George Pavlov wrote: > > Both (1::int,'a'::varchar) and (select (2::int,'a'::varchar)) are of > > type record, aren't they? > > I don't think so. Psql gives you a hint that not: > > testing=# SELECT (1::int, 'a'::varchar); > row > ------- > (1,a) > (1 row) > > testing=# SELECT (SELECT(1::int, 'a'::varchar)); > ?column? > ---------- > (1,a) > (1 row) > > Note the column headers. They're differently shaped. Because > pseudotype record doesn't have a shape, equality doesn't make sense, > so you need two shapes that are already identical, so they can use > the matching rules for that. > > A > > -- > Andrew Sullivan | [EMAIL PROTECTED] > Everything that happens in the world happens at some place. > --Jane Jacobs ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
