From: Andreas <maps.on@gmx.net>
To: pgsql-sql@postgresql.org
Subject: Select every first/last record of a partition?
Date: Mon, 21 May 2012 18:04:55 +0200
Message-ID: <4FBA67A7.4010302@gmx.net> (raw)
Hi,
suppose a table that has records with some ID and a timestamp.
id, ts
3, 2012/01/03
5, 2012/01/05
7, 2012/01/07
3, 2012/02/03
3, 2012/01/05
5, 2012/03/01
7, 2012/04/04
to fetch every last row of those IDs I do:
select id, ts
from ( select id, ts, row_number() over ( partition by id order
by ts desc ) as nr from mytab ) as x
where nr = 1
Is there a another way without a subselect?
There might be more columns so the window-functions first/last won't help.
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To: pgsql-sql@postgresql.org
Cc: maps.on@gmx.net
Subject: Re: Select every first/last record of a partition?
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