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To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Karsten Hilbert <Karsten.Hilbert@gmx.net>,
	pgsql-general@postgresql.org, pgsql-sql@postgresql.org
Subject: Re: [SQL] need ``row number``
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	<21339.1096035613@sss.pgh.pa.us>
In-Reply-To: <21339.1096035613@sss.pgh.pa.us>
From: Greg Stark <gsstark@mit.edu>
Organization: The Emacs Conspiracy; member since 1992
Date: 24 Sep 2004 16:34:47 -0400
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Tom Lane <tgl@sss.pgh.pa.us> writes:

> Karsten Hilbert <Karsten.Hilbert@gmx.net> writes:
> > I am not convinced I'll need a SRF. I am not trying to
> > calculate something that isn't there yet. I am just trying to
> > join two views appropriately. I might have to employ some
> > variant of Celko's integer helper table but I'm not sure how
> > to proceed.
> 
> A fairly common hack for this is to use a sequence:
> 
> 	create temp sequence tseq;
> 	select nextval('tseq'), * from (select .... order by ...) ss;

But I thought she wanted to get the row number within a group. Not the row
number for the entire result set. A sequence can't do that. Or at least, I
suppose it could but it would be mighty strange to see setval() in a SELECT
query. And I can't think of how to detect the level break in a select query
either.

-- 
greg