Received: from davinci.ethosmedia.com (davinci.ethosmedia.com [209.10.40.250])
	by mail.postgresql.org (8.11.1/8.11.1) with ESMTP id f0I44n095201
	for <pgsql-sql@postgresql.org>; Wed, 17 Jan 2001 23:04:50 -0500 (EST)
	(envelope-from josh@agliodbs.com)
Received: from [209.10.40.250] (account <josh@agliodbs.com>)
	by davinci.ethosmedia.com (CommuniGate Pro WebUser 3.3)
	with HTTP id 1178595 for <pgsql-sql@postgresql.org>;
	Wed, 17 Jan 2001 20:04:45 -0800
From: "Josh Berkus" <josh@agliodbs.com>
Subject: Re: update help 
To: pgsql-sql@postgresql.org
X-Mailer: CommuniGate Pro Web Mailer v.3.3
Date: Wed, 17 Jan 2001 20:04:45 -0800
Message-ID: <web-1178595@davinci.ethosmedia.com>
In-Reply-To: <22930.979787939@sss.pgh.pa.us>
MIME-Version: 1.0
Content-Type: text/plain; charset="ISO-8859-1"
Content-Transfer-Encoding: 8bit
X-Archive-Number: 200101/207
X-Sequence-Number: 872

Tom,

> UPDATE t1 SET amount = (select sum(b.amount) from t2 b
> WHERE t1.id = b.id);

Interesting.  I'm used to (not necessarily in PGSQL):

UPDATE t1 SET amount = t2ttl.totalamount
FROM (SELECT sum(amount) as totalamount,
		id FROM t2 GROUP BY id) t2ttl
WHERE t1.id = t2.id

Although this is a subselect in the FROM clause, something
we've had trouble with as I recall.

-Josh Berkus