From: | John Taylor <postgres(at)jtresponse(dot)co(dot)uk> |
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To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, John Taylor <postgres(at)jtresponse(dot)co(dot)uk> |
Cc: | pgsql-novice(at)postgresql(dot)org |
Subject: | Re: problem query ... |
Date: | 2002-01-31 17:08:29 |
Message-ID: | 02013117082906.01674@splash.hq.jtresponse.co.uk |
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Thread: | |
Lists: | pgsql-novice |
On Thursday 31 January 2002 17:02, Tom Lane wrote:
> John Taylor <postgres(at)jtresponse(dot)co(dot)uk> writes:
> > I want to return 1 row for each id, that contains the maximum update
> > value for that id, and the values for name and desc.
>
> There's no simple way to do that in standard SQL. However you can do
> it easily with SELECT DISTINCT ON, if you don't mind using a nonstandard
> construct. See the "weather report" example on the SELECT reference
> page.
That was it!
I did try distinct on before, but was trying to be too complicated, with group or subselects.
What I wanted is:
select distinct on (id) id,name,descr from john order by id,update desc;
Thanks
JohnT
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