> I have this tables > > > Table: Contact > IdContact > First Name > Second Name > … other columns > > Table: Employee > IdEmployee > IdContact, related to Contact table > … other columns > > Table: Salesman > IdSaleman > IdEmployee, if salesman is employee, related to Employee table > IdContact, if salesman is not an employee, related to Contact table > > > I need a query > > Id Salesman - Second name - First name > > But I can't figure how to do it, can someone can give advise? > > Thanks Needless to say, this is bit of an odd table layout. You always end up at the contact table, but the layout makes it harder to query. Personally I'd have a foreign key from the contact table to the employee table, rather than the employee table to the contact table - that would also eliminate the employee foreign key in the salesman table. It would also allow you to just join the salesman table to the contact table and then figure out if the contact is an employee. well, that said. Here's a quick one without a lot of deep thought... select a.idsalesman, b.firstname, b.secondname from salesman a join contact b on b.idcontact=a.idcontact union select c.idsalesman, d.firstname, d.secondname from salesman c join employee e on e.idemployee=c.idemployee join contact d on d.idcontact=e.idcontact No guarantees though. It's midnight here and I had a long day... -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
