From: Manfred Koizar <mkoi-pg@aon.at>
To: Albrecht Berger <berger1517@gmx.ch>
Cc: pgsql <pgsql-sql@postgresql.org>
Subject: Re: sql group by statement
Date: Fri, 13 Sep 2002 14:16:02 +0200
Message-ID: <g2l3ou44jver0jvic4477cd66d0k92c6li@4ax.com> (raw)
In-Reply-To: <002f01c25b10$6db4b940$a07ba8c0@wxp>
References: <002f01c25b10$6db4b940$a07ba8c0@wxp>
On Fri, 13 Sep 2002 12:29:21 +0200, "Albrecht Berger"
<berger1517@gmx.ch> wrote:
>Table :
>pk id val1 val2
> 1 1 2 3
> 2 1 2 4
> 3 2 1 1
> 4 1 0 5
> 5 2 1 8
>
>
>Needed Result :
>pk id val1 val2
> 4 1 0 5
> 5 2 1 8
Albrecht,
"DISTINCT ON eliminates rows that match on all the specified
expressions, keeping only the first row of each set of duplicates."
So the trick is to sort appropriately:
SELECT DISTINCT on (id) pk, id, val1, val2
FROM yourtable
ORDER BY id asc, val2 desc, pk desc;
Servus
Manfred
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To: pgsql-sql@postgresql.org
Cc: mkoi-pg@aon.at, berger1517@gmx.ch
Subject: Re: sql group by statement
In-Reply-To: <g2l3ou44jver0jvic4477cd66d0k92c6li@4ax.com>
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