Posted by David Portas on 12/08/05 18:14

arzewski@hotmail.com wrote:

> I have a situation where attending a meeting could be either staff or
> coalition members. But don't know how to enforce a foreign key
> constraint. any ideas ?
>
> Table Meeting
> MeetingID int NOT NULL,
> AttendeeID int NOT NULL
> Primary Key (MeetingID, AttendeeID)
>
> Table Staff
> StaffID int IDENTITY not null PRIMARY KEY
>
> Table CoalitionMember
> MemberID int Identity not null PRIMARY KEY
>
> Since AttendeeID can either a value from Staff.StaffID or from
> CoalitionMember.MemberID, I cannot place both constraints as
>
> ADD CONSTRAINT [FK_Meeting_Staff] FOREIGN KEY
> (AttendeeID)
> REFERENCES [Staff] ([StaffID])
>
> ADD CONSTRAINT [FK_Meeting_CoalitionMember] FOREIGN KEY
> (AttendeeID)
> REFERENCES [CoalitionMember] ([MemberID])


Please do not multi-post!
This has been answer in microsoft.public.sqlserver.programming

--
David Portas
SQL Server MVP
--

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