On Wed, May 29, 2013 at 9:58 AM, Rodrigo Rosenfeld Rosas <rr.ro...@gmail.com > wrote:
> I know I could use a trigger, or some check constraint maybe, to ensure > the field exists upon insert (or update), but I can't ensure the database > will become inconsistent in case I remove a mapped field from the other > schema. > > Now I can finally explain my question: is it possible that I set some sort > of foreign key whose referenced table and column would depend on the value > of another column? > The FK tests are basically triggers, but highly optimized. That said, the way they enforce the integrity is by having a trigger on both tables. So for your custom need here, you would want to put a trigger on the referenced table to disallow deleting a value that is still referenced, or do whatever appropriate action upon delete/update your application needs.
