From: Rajesh Kumar Mallah <mallah@trade-india.com>
Organization: Infocom Network Limited
To: Tomasz Myrta <jasiek@klaster.net>
Subject: Re: sql question regarding count(*)
Date: Fri, 7 Mar 2003 10:53:06 +0530
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References: <200303061702.26339.mallah@trade-india.com>
	<3E673874.5030606@klaster.net>
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Tomasz did you notice the two queries are totally differet on different
tables?


On Thursday 06 March 2003 05:30 pm, Tomasz Myrta wrote:
> Rajesh Kumar Mallah wrote:
> > When does count(*) returns "o rows" ?
> > and when does it return 1 row value being 0.
> >
> > tradein_clients=# SELECT count(*)   from public.eyp_listing  where sno> 0
> > and amount> 0  group by sno,branch,edition having count(distinct userid)
> > > 1 ; count
> > -------
> > (0 rows)
> >
> > tradein_clients=#
> > tradein_clients=#
> > tradein_clients=# SELECT count(*) from public.users where userid=-1;
> >  count
> > -------
> >      0
> > (1 row)
> >
> > tradein_clients=#
>
> It's because of your having clause.
> If count(*)=0 then having count(*)>1 results in no rows.
>
> Regards,
> Tomasz Myrta

-- 

Regds
Mallah

----------------------------------------
Rajesh Kumar Mallah,
Project Manager (Development)
Infocom Network Limited, New Delhi
phone: +91(11)6152172 (221) (L) ,9811255597 (M)

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