Hi,

> I´ve installed firebird 1.0 and when i execute the following command my
> client crash.

Are you sure it crashed ? or was it taking to long berfore you saw results ?

> select r.cod_hermes, r.nom_rev from revendedora r
> where
> r.cod_hermes in
> ( select r1.cod_hermes from revendedora r1
> group by r1.cod_hermes
> having count(*)>1 )

Use EXISTS() instead :

SELECT
r.cod_hermes,
r.nom_rev
FROM
revendedora r
WHERE
EXISTS(SELECT * FROM revendedora r1
WHERE r1.cod_hermes = r.cod_hermes
HAVING count(*) > 1)

Regards,
Arno Brinkman