Re: combine SQL SELECT statements into one

Hi

pgsql-general-owner(at)postgresql(dot)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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