Alban Hertroys <dal...@solfertje.student.utwente.nl> wrote: > [...] > Now the intent here is to restrict foreign keys referencing the base class to > unitclass records that describe a baseclass and to restrict foreign keys > referencing a derived class to unitclass records that do NOT describe a > baseclass. > Basically I'm trying to disallow derived classes to be derived of other > derived classes.
> I can of course add a few triggers to force that constraint, but I think it > would be nice if the above syntax could be made to work. Or is this already > in 8.4 or 8.5 or is this a can of worms? Does the SQL spec disallow it? If you want to avoid triggers, another, simpler approach is to have a otherwise superfluous column "is_baseclass" with a default "TRUE" and constraints "NOT NULL" and "CHECK(is_baseclass)" and then use a "normal" foreign key constraint. I usually find that easier to read as it's more familiar. Tim -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
