From: | Stephan Szabo <sszabo(at)megazone23(dot)bigpanda(dot)com> |
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To: | Patrik Kudo <kudo(at)partitur(dot)se> |
Cc: | Haller Christoph <ch(at)rodos(dot)fzk(dot)de>, pgsql-sql(at)postgresql(dot)org |
Subject: | Re: Selecting latest value |
Date: | 2001-09-20 14:49:08 |
Message-ID: | Pine.BSF.4.21.0109200746550.74020-100000@megazone23.bigpanda.com |
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Lists: | pgsql-sql |
On Thu, 20 Sep 2001, Patrik Kudo wrote:
> On Thu, 20 Sep 2001, Haller Christoph wrote:
>
> > Try
> > create NEWtable (userid text, val integer, ts timestamp);
> > insert into NEWtable
> > select userid, val, max(ts) from table group by userid, val;
>
> That won't work. That will give me multiple userid-val combinations. Sure,
> the userid-val combinations will be unique, but I want unique userids
> with only the latest val for each userid.
Maybe something like: (assuming that ts is unique within each userid,
otherwise what does latest mean? I haven't tried this, so it probably
doesn't parse, but...)
select userid, val from table where ts=(select max(ts) from table t where
t.userid=table.userid group by userid);
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