Re: combine SQL SELECT statements into one

> -----Original Message-----
> From: Chris.Ellis@shropshire.gov.uk
> [mailto:Chris.Ellis@shropshire.gov.uk]
> Sent: Monday, February 01, 2010 4:08 AM
> To: neilstylz@yahoo.com
> Cc: pgsql-general@postgresql.org
> Subject: Re: combine SQL SELECT statements into one
>
>
> Hi
>
> pgsql-general-owner@postgresql.org wrote on 02/01/2010 07:36:55 AM:
>
> > Good Evening, Good Morning Wherever you are whenever you
> may be reading this.
> >
> >
>         snip
> >
> > count1 |  count2  | count3
> > -------------------------------
> >  2              2              4
> >
> > Can this be done with ONE SQL STATEMENT? touching the
> database only ONE time?
>
> You can do the following:
>
> SELECT
>         (SELECT COUNT(distinct model) FROM inventory WHERE
> modified >= '2010-02-01') AS "COUNT_1",
>        (SELECT COUNT(distinct model) FROM inventory WHERE
> modified >= '2010-01-20') AS "COUNT_2",
>        (SELECT COUNT(distinct model) FROM inventory WHERE
> modified >= '2010-01-01') AS "COUNT_3"
> ;
>
> PostgreSQL allows sub-queries in the select list as long as
> the sub-query returns one column
>
> Job done
>
> > Please let me know.
> >
> > Thanx> :)
> > NEiL
> >
>
> Chris Ellis
>
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Original poster asked for the sql that will touch inventory table only
once.

Your statement (with 3 subqueries) will do it 3 times.

Igor Neyman