From: Loyd Goodbar <loyd@blackrobes.net>
To: pgsql-sql@postgresql.org
Subject: Re: SQL problem with aggregate functions.
Date: Thu, 11 Jul 2002 17:08:52 -0500
Message-ID: <q60siuo880dl7qflpur9tdoel98qvk31oi@4ax.com> (raw)
In-Reply-To: <200207110837.KAA07881@rodos>
References: <200207091036.17913.david.bouriaud@ac-rouen.fr>
<200207110837.KAA07881@rodos>
I would suggest something like
select sum(case when f1 = 'D' then 1 else 0 end) as D_COUNT,
sum(case when f1 = 'R' then 1 else 0 end) as R_COUNT,
sum(case when f1 = 'X' then 1 else 0 end) as X_COUNT
from tab
where f1 in ('D','R','X')
Not sure what the "field group" represents.
HTH,
Loyd
On Thu, 11 Jul 2002 10:37:40 METDST, Christoph Haller <ch@rodos.fzk.de> wrote:
>>
>> I've got a table in which there is a field that can have one amongst 3
>> possible values : D, R, X. Is it possible to get in one query the count of
>> this different values.Please, note that I don't want to have a querry like
>> this :
>> "select count (*) from tab group by f1;", cause i want to get all the possible
>> count values in one row (these data are already grouped on another field).
>> To give a more accurate example, here is what I want to retrieve :
>>
>> Field group | count of D | count of R | count of X.
>>
>> Any clues ?
>> --
>What about something like
>
>
>SELECT SUM(f1_d) AS count_d,
> SUM(f1_r) AS count_r,
> SUM(f1_x) AS count_x
>FROM (
> SELECT CASE WHEN f1 = 'D' THEN 1 ELSE 0 END AS f1_d,
> CASE WHEN f1 = 'R' THEN 1 ELSE 0 END AS f1_r,
> CASE WHEN f1 = 'X' THEN 1 ELSE 0 END AS f1_x
> FROM tab ) AS foo ;
>
>Regards, Christoph
>
>---------------------------(end of broadcast)---------------------------
>TIP 6: Have you searched our list archives?
>
>http://archives.postgresql.org
--
"Why, you can even hear yourself think." --Hobbes
"This is making me nervous. Let's go in." --Calvin
loyd@blackrobes.net ICQ#504581 http://www.blackrobes.net/
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-sql@postgresql.org
Cc: loyd@blackrobes.net
Subject: Re: SQL problem with aggregate functions.
In-Reply-To: <q60siuo880dl7qflpur9tdoel98qvk31oi@4ax.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox