Topic: How to make sampling of several tables?
Good evening! As it is possible to implement request through select from several tables. Begins with the table subject, the beret idsubject searches in the table company for coincidence idsubject if is not present searches in the table person for coincidence idsubject? I.e. coincidence can be only in one table company or person. When coincidence is found then selects all appropriate fields. How to make such request?