Re: count & distinct - Mailing list pgsql-general

From Vashenko Maxim
Subject Re: count & distinct
Date
Msg-id 3948BD24.12C66D59@nino.ru
Whole thread Raw
In response to count & distinct  ("Andrea Aime" <aaime@comune.modena.it>)
List pgsql-general
Andrea Aime wrote:
>
> Hi people. I would like to make a query that
> tells me how many distinct values there are
> in a column. Standard count doesn't seems
> to support a count distinct option.
> select distint count(*) of course doens't
> work (distinti clause is applied after the
> result are calculated). I've tried to define
> a view, but it didn't worked (
> create view distValues as select distinct ...
> but views doesn't support distinct clause)...
>
> Well, maybe I should create a new aggregate
> function, but before spending time on PGSQL
> guide I would like to know if someone can
> give me a fast tip... ;-)
> Thanks in advance
> Andrea
>
> PS: well, of course I can open a cursor on
> a "select distinct column from table" and then
> loop over the cursor couting how many values
> there are, but it seem a bit ugly...


SELECT field, count(*) FROM table GROUP BY field



With best regards, Max Vaschenko,
Nizhny Novgorod Information Networks.

pgsql-general by date:

Previous
From: Vashenko Maxim
Date:
Subject: Re: group by problem
Next
From: Vipin Samtani
Date:
Subject: Access Permission Denied