From: Achilleus Mantzios <achill@matrix.gatewaynet.com>
To: Joachim Trinkwitz <jtr@uni-bonn.de>
Cc: pgsql-sql@postgresql.org
Subject: Re: Aggregates not allowed in WHERE clause?
Date: Wed, 19 Jun 2002 11:18:13 +0300 (EEST)
Message-ID: <Pine.LNX.4.44.0206191115510.7173-100000@matrix.gatewaynet.com> (raw)
In-Reply-To: <874rfzr8xj.fsf@waffel.germanistik.uni-bonn.de>
On 19 Jun 2002, Joachim Trinkwitz wrote:
> Hi all,
>
> I have a table (lv) with a field "semester" and I'm trying to fish out all
> rows which have a value corresponding to a max() value of another
> table's (lf_sem) "semester" field. The intention is to keep a value
> with the current term in lf_sem so I can get all rows which concern
> this term.
>
> Example tables:
>
> lv
> ==
> semester | kvvnr
> ---------+------
> 2001ss | 4185
> 2001ss | 4203
> 2002ws | 4163
> 2002ws | 4190
>
> lf_sem
> ======
> semester
> --------
> 2001ws
> 2002ss
> 2002ws
>
> At first I tried this query:
>
> SELECT kvvnr
> FROM lv, lf_sem
> WHERE lv.semester = max(lf_sem.semester);
>
> This yields the message: 'Aggregates not allowed in WHERE clause'.
>
> Next I tried this one:
>
> SELECT kvvnr, max(lf_sem.semester) AS akt_semester
> FROM lv, lf_sem
> WHERE lv.semester = akt_semester;
>
> Now I got: 'Attribute 'akt_semester' not found'
>
> Is there another way to get what I want?
SELECT lv.kvvnr,lv.semester from lv where lv.semester = (select
max(semester) from lf_sem);
>
> Clueless,
> joachim
>
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--
Achilleus Mantzios
S/W Engineer
IT dept
Dynacom Tankers Mngmt
tel: +30-10-8981112
fax: +30-10-8981877
email: achill@matrix.gatewaynet.com
mantzios@softlab.ece.ntua.gr
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To: pgsql-sql@postgresql.org
Cc: achill@matrix.gatewaynet.com, jtr@uni-bonn.de
Subject: Re: Aggregates not allowed in WHERE clause?
In-Reply-To: <Pine.LNX.4.44.0206191115510.7173-100000@matrix.gatewaynet.com>
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