From: Bruno Wolff III <bruno@wolff.to>
To: A. R. Van Hook <hook@lake-lotawana.mo.us>
Cc: pgsql-sql@postgresql.org
Subject: Re: max question
Date: Wed, 13 Apr 2005 08:20:19 -0500
Message-ID: <20050413132019.GB4594@wolff.to> (raw)
In-Reply-To: <425C0445.8020603@lake-lotawana.mo.us>
References: <425C0445.8020603@lake-lotawana.mo.us>
On Tue, Apr 12, 2005 at 12:24:21 -0500,
"A. R. Van Hook" <hook@lake-lotawana.mo.us> wrote:
> I have the following in a table:
> oid | citkey | contby | contdate | abcontinue | ccdate
> ---------+------------+----------+------------+------------+------------
> 5774835 | 04-0594703 | | | |
> 5775325 | 04-0594703 | Attorney | 04/06/2005 | 6 | 03/07/2005
> 5776060 | 04-0594703 | Attorney | 05/04/2005 | 6 | 04/05/2005
> 5776067 | 04-0594703 | Attorney | 05/04/2005 | 6 | 04/05/2005
>
> I am trying to pull rows that have the max. contdate. Why does the
> following give more than 2 rows?
> ql "select oid,* from ccontinue where citkey ='04-0594703' group by
> oid,citkey,contby,contdate,abcontinue,ccdate having max(contdate) =
> contdate"
If you group by oid you are going to get a separate group for each row.
You haven't told us what you actually expect for output, so I don't
have specific advise for a query. However, you might find the Postgres
extension DISTINCT ON useful, depending on exactly what you want.
> oid | citkey | contby | contdate | abcontinue | ccdate
> ---------+------------+----------+------------+------------+------------
> 5776067 | 04-0594703 | Attorney | 05/04/2005 | 6 | 04/05/2005
> 5775325 | 04-0594703 | Attorney | 04/06/2005 | 6 | 03/07/2005
> 5776060 | 04-0594703 | Attorney | 05/04/2005 | 6 | 04/05/2005
> (3 rows)
>
> thanks
>
>
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To: pgsql-sql@postgresql.org
Cc: bruno@wolff.to, hook@lake-lotawana.mo.us
Subject: Re: max question
In-Reply-To: <20050413132019.GB4594@wolff.to>
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