From: Tom Lane <tgl@sss.pgh.pa.us>
To: oheinz@stud.fbi.fh-darmstadt.de
Cc: pgsql-sql@postgresql.org <pgsql-sql@postgresql.org>
Subject: Re: Problem using Subselect results
Date: Tue, 29 Jul 2003 11:00:56 -0400
Message-ID: <22142.1059490856@sss.pgh.pa.us> (raw)
In-Reply-To: <1059478450.3f265bb210e14@stud.fbi.fh-darmstadt.de>
References: <1058964708.3f1e84e407a8d@stud.fbi.fh-darmstadt.de>
<200307280947.21658.josh@agliodbs.com>
<1059478450.3f265bb210e14@stud.fbi.fh-darmstadt.de>
oheinz@stud.fbi.fh-darmstadt.de writes:
> But as this data is time sensitive, we introduce some kind of time stamp - a
> serial which is global to all tables. Now, for each record in table 'one' i
> want to see only the corresponding records in tables two, three, etc... that
> were created before 'one.updatenr'
> SELECT * FROM one, two WHERE (one.two_id=two.two_id AND one.updatenr >
> two.updatenr);
> This might match multiple records in tables two (two_id is not a pk, we have
> historic records in this table). Now I want only the most current version
> before one.updatenr. - And that's where I run into trouble.
You might be able to make this work by using SELECT DISTINCT ON. See
the "weather reports" example in the SELECT reference page.
regards, tom lane
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To: pgsql-sql@postgresql.org
Cc: tgl@sss.pgh.pa.us, oheinz@stud.fbi.fh-darmstadt.de
Subject: Re: Problem using Subselect results
In-Reply-To: <22142.1059490856@sss.pgh.pa.us>
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