In my table i have the product id, the start_date and the end_date
as primary key.
So the problem is that if i rent a book from 10-10-2007 till 20-10-2007 That is a combination that can be fill only one time.
But the combination of the same book end the date between 10-10-2007 en 20-10-2007 can be storage.
So i have to save al the between data to my product, that way i can't rent a book twice in one period.
I have tride something like WHERE datum_begin ! BETWEEN datum_begin AND datum_end. That combination works fine, but it works for a query and not for the table.
Does some one knows a solution?