Re: union with count?

--- Gerardo Herzig <gherzig(at)fmed(dot)uba(dot)ar> wrote:

> Hi dudes, i have the following question
> i have 2 tables with the same format, and i want to know if is there a
> possibility of using some sort of count(*) for achieving this result:
> select a from table1 where (condition) union select a from table2 where
> (condition), count(a) group by a

I think you are showing count(a) in the wrong spot in your example. But if I understand you
correctly the following should do what you want:

SELECT count(a)
FROM
(
SELECT a
FROM table1
WHERE (your_condition = true)

UNION -- you can use UNION ALL if you
-- want rows that are duplicates from each table.

SELECT a
FROM table2
WHERE (your_condition = true)
)
GROUP BY a;