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Re: combine SQL SELECT statements into one

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> -----Original Message-----
> From: Chris.Ellis@xxxxxxxxxxxxxxxxx 
> [mailto:Chris.Ellis@xxxxxxxxxxxxxxxxx] 
> Sent: Monday, February 01, 2010 4:08 AM
> To: neilstylz@xxxxxxxxx
> Cc: pgsql-general@xxxxxxxxxxxxxx
> Subject: Re: combine SQL SELECT statements into one
> 
> 
> Hi 
> 
> pgsql-general-owner@xxxxxxxxxxxxxx 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

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