Re: [GENERAL] need ``row number``

Right.  Sequence within a group.  I did this in a SRF resetting the sequence after each subgroup.  I would love to see
abetter way. 

<<< Greg Stark <gsstark@mit.edu>  9/24  1:42p >>>
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


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