>But what is the logic... Would something like this work?
>
>

>CREATE TRIGGER CheckPK ON [Product]
>FOR UPDATE
>AS
>DECLARE @countFk int
>SELECT @countFk = SELECT count(fk_product) from Traveler where fk_product = insert.pk)
>
>IF @countFk > 0
>	AND (fk_engine != insert.fk_engine
>	OR fk_stage != insert.fk_stage
>	OR fk_part != insert.fk_part)
>BEGIN
>PRINT ‘Cannot change Products that have dependents’
>PRINT ‘Transaction has been cancelled’
>ROLLBACK
>END
>
>

Margaret,

I think you should check the previous value (e.g. from deleted) and then may be your logic against inserted table, though I'm not sure what exactly you're checking.

In other words, it should check

SELECT @countFk = SELECT count(fk_product) from Traveler where fk_product = deleted.pk)

and then act accordingly. Also do you want to check if you changed fk_engine, etc. fields? If yes, then join deleted with inserted tables based on the PK.