killerion wrote:

> I have this query:
> SELECT clients.id_client, clients.fname, clients.lname, (SELECT total
> FROM prcdr_due(clients.id_client) AS due, clients.due_date FROM clients
>
> the due column returns as null instead of having a value, when I
> execute the procedure in ibexpert I get the correct results, so any
> suggestions would be greatly appreciated

Try this :
select c.id_client, c.fname, c.lname, p.total as due, c.due_date
from clients c
left join prcdr_due(c.id_client) p on (1=1);

regards,
ts.