From: esquel@sommarskog.se   
      
   Tony Johansson (johansson.andersson@telia.com) writes:   
   > Yes a customer without order sounds ok   
   > But order without customer is incorrect.   
      
   I would say that it depends on the business rules. :-) But, yes, it   
   would be a bit peculiar.   
      
   In Northwind CustomerID is nullable, although there is no such order   
   in the data. Unfortunately, Northwind leaves a whole lot desired when it   
   comes to nullability, indexes etc.   
      
   --   
   Erland Sommarskog, Stockholm, esquel@sommarskog.se   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)