* Ken Tozier <kentozier@comcast.net> [2004-10-16 22:52:10 -0400]:
> Or is it one of those things that enforces data integrity behind the
> scenes?
That's exactly it -- one of the most attractive things about the
database is that if constraints are defined appropriately it can
defend itself from the programmer. ;)
xinu=> insert into grocery_items (grocery_types_id, name, price) values (100, 'Roast Beef', 5.50);
ERROR: insert or update on table "grocery_items" violates foreign key constraint "grocery_types_id_exists"
DETAIL: Key (grocery_types_id)=(100) is not present in table "grocery_types".
--
Steven Klassen - Lead Programmer
Command Prompt, Inc. - http://www.commandprompt.com/
PostgreSQL Replication & Support Services, (503) 667-4564