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,
CASEWHEN f1 = 'X' THEN 1 ELSE 0 END AS f1_xFROM tab ) AS foo ;
 

Regards, Christoph