சிவகுமார் மா wrote: >> You want to have a "conditional" foreign key reference that checks >> against different tables depending on a "type" field, right? >> >> For complicated conditions like this, you could use a >> BEFORE INSERT trigger that throws an error when the condition >> is violated. > > That we do. My query is to put a check on select queries to avoid > programmers not using all the necessary conditions. You can create a view that does the join the correct way (maybe a UNION of two different joins) and give the programmers access to that view, but not to the underlying tables. Yours, Laurenz Albe ---------------------------(end of broadcast)---------------------------TIP 4: Have you searched our list archives? http://archives.postgresql.org/