Date: Mon, 25 Oct 2004 05:44:06 -0600
From: "Andrew J. Kopciuch" <akopciuch@bddf.ca>
Subject: Re: sql
In-reply-to: <b918cf3d041025042021ca123e@mail.gmail.com>
To: Mike Rylander <mrylander@gmail.com>
Cc: pgsql-sql@postgresql.org
Reply-To: akopciuch@bddf.ca
Message-id: <200410250544.06403.akopciuch@bddf.ca>
Organization: BDDF Developments Inc.
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On Monday 25 October 2004 05:20, Mike Rylander wrote:
> SELECT * FROM temp50 GROUP BY gc ORDER BY ora DESC;

You can not have have expressions (columns etc.) in the SELECT list that are 
either not in a GROUP BY clause, or used in an aggregate function when you 
use GROUP BY in the statement.  By saying SELECT *, means you would have to 
GROUP BY gc, co, data, ora ...

That isn't going to do what he wants.  And the SQL you stated should give you 
an error:

ERROR:  column "temp50.co" must appear in the GROUP BY clause or be used in an 
aggregate function


What he wants to do is use DISTINCT ON:

SELECT DISTINCT ON (gc) gc, co, data, ora FROM temp50 ORDER BY gc, ora DESC;


Andy