On Monday 01 March 2004 22:59, Curt Sampson wrote: > On Mon, 1 Mar 2004, Tom Lane wrote: > > Curt Sampson <[EMAIL PROTECTED]> writes: > > > Can you explain how to do this? There is no reference to a plan in the > > > contract table; the constraint just checks to see that, if a contract > > > exists, there is at least one plan referencing that contract. > > > There is of course a foreign key constraint used in the plan table to > > > make sure that the contract exists. > > > > If so, how would it be possible to create a plan before creating the > > contract? I don't think the OP's requirements are clearly thought out. > > You create the contract and its first plan at the same time, inserting > the plan first. It works fine. > <snip> > > In the meantime, if what's wanted is a one-time check at row insertion, > > the right way to express that behavior is with an ON INSERT trigger. > > That's not an adequate check; it would allow you later to delete the > plan without deleting the contract. >
Wouldn't a FK on both tables be the appropriate schema? With the FK on contract being deffered? Robert Treat -- Build A Brighter Lamp :: Linux Apache {middleware} PostgreSQL ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster