On Wed, Dec 10, 2008 at 3:58 PM, Jason Long <mailing.list@xxxxxxxxxxxxxxxxxxxxx> wrote: > I need to add some complex constraints at the DB. > These will involve several tables. > What is the best approach for this? Well ANSI-SQL provides the CREATE ASSERTION for this purpose. However, PostgreSQL doesn't support this feature. It can be mimiced by using the PostgreSQL CONSTRAINT TRIGGER extenstion. IIRC, it works very much like an ordinary trigger except that you must raise an error when an DML attempt possibly violates your condition. > Can someone point me to an example of doing something like this? http://www.postgresql.org/docs/8.3/interactive/sql-createconstraint.html http://www.postgresql.org/docs/8.3/interactive/triggers.html I hope this helps. -- Regards, Richard Broersma Jr. Visit the Los Angeles PostgreSQL Users Group (LAPUG) http://pugs.postgresql.org/lapug -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
