Re: [HACKERS] Foreign keys: unexpected result from ALTER TABLE... ADD CONSTRAINT...

Peter Eisentraut wrote: >On Mon, 17 Jan 2000, Oliver Elphick wrote: > >> I cannot do this pair of table creations
directly,because they are mutual     >ly >> dependent. >>  > >I don't think this will ever work. I can't really decode
yourintentions >here but I recall that translating proper relational schemas (you know, >the ones with the bubbles and
lines)into tables never creates this sort >of situation. Then again I could be wrong.
 
The idea is that suppliers of products can only supply products that are
purchased, rather than manufactured; and purchased products must have
suppliers.  However, it is possible for there to be more than one potential
supplier of a product; the one listed in purchased_jobs is the currently
favoured supplier.

I guess I will have to remove the restriction that products listed in
product_suppliers must be purchased; it may indeed become possible for the
to change status from time to time, so that is not too unsatisfactory.

-- 
Oliver Elphick                                Oliver.Elphick@lfix.co.uk
Isle of Wight                              http://www.lfix.co.uk/oliver              PGP key from public servers; key
ID32B8FAA1                ========================================    "And, behold, I come quickly; and my reward is
withme,     to give every man according as his work shall be."                                  Revelation 22:12