From: | "Adam Rich" <adam(dot)r(at)sbcglobal(dot)net> |
---|---|
To: | "'David Rowley'" <dgrowley(at)gmail(dot)com>, "'David Fetter'" <david(at)fetter(dot)org> |
Cc: | "'Madison Kelly'" <linux(at)alteeve(dot)com>, <pgsql-general(at)postgresql(dot)org> |
Subject: | Re: SELECT DISTINCT ... ORDER BY problem |
Date: | 2008-12-09 01:30:35 |
Message-ID: | 121c01c9599d$bcb97ca0$362c75e0$@r@sbcglobal.net |
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Thread: | |
Lists: | pgsql-general |
> >
> > When we get windowing functions, a lot of this pain will go away :)
> >
>
> Yes! Hope it won't be too long now. The patch seems to behave like it
> should
> now :)
> Hopefully we'll see it commited for 8.4.
>
> Though this does not look too much cleaner at least it's standard SQL:
>
> A preview for Madi:
>
> SELECT foo,bar
> FROM (SELECT foo,bar,
> ROW_NUMBER() OVER (PARTITION BY foo ORDER BY bar) AS pos
> FROM table
> ) AS t
> WHERE pos = 1
> ORDER BY bar;
>
> Probably easier to understand what's going on in this one.
>
> David.
>
Is Oracle's FIRST_VALUE function not a SQL standard? The way I would
do this in Oracle looks like:
SELECT foo, FIRST_VALUE(bar) OVER (PARTITION BY foo ORDER BY bar) as bar
FROM table
http://download.oracle.com/docs/cd/B28359_01/server.111/b28286/functions059.
htm
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