Re: SQL problem with aggregate functions.

>
> 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