On 14 Jul 2010, at 18:13, David Kerr wrote: > Howdy, > > I'm trying to think of the best way to handle this situation. > > I've got 2 tables, X and Y > > Table X has a field foo varchar(20) > Table Y has a field bar varchar(20) > > I want to enforce, that if table X.foo = 'dave' then you can't insert (or update) Y.bar = 'dave' You could add a table Z ( baz varchar(20) PRIMARY KEY, foo varchar(20) REFERENCES X (foo), bar varchar(20) REFERENCES Y (bar), CHECK ((foo IS NULL AND bar IS NOT NULL) OR (foo IS NOT NULL AND bar IS NULL)) ) You can populate this table from a rule or trigger. OTOH, if you have a trigger anyway, you can move the checks in there as well. Alban Hertroys -- If you can't see the forest for the trees, cut the trees and you'll see there is no forest. !DSPAM:737,4c3dff91286211140418644! -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
