Re: foreign key question

On Wednesday 05 January 2011 09:53:43 Gary Stainburn wrote:
> Now I want to set up a new access level table specific to the itinerary,
> along the lines of
>
> u_id int4 not null references users(u_id)
> fl_level int4 not null references facility_levels(16, fl_level)
>
> Firstly, is this possible, and secondly how would I do it?

I've managed a work-around by creating a column that defaults to 16 and then
used ALTER TABLE ADD CONSTRAINT to add a foreign key with two pairs of keys.

This feels wrong though as my table now has a column that is ultimately
redundant, and worse can be changed to a wrong value.

Ok, I've sorted the last bit by adding a check constraint to make sure it
always contains 16, but it still feels wrong.

--
Gary Stainburn
I.T. Manager
Ringways Garages
http://www.ringways.co.uk