Re: [SQL] 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 a better way.

<<< Greg Stark <gsstark(at)mit(dot)edu> 9/24 1:42p >>>
Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:

> Karsten Hilbert <Karsten(dot)Hilbert(at)gmx(dot)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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