From: esquel@sommarskog.se   
      
   Tony Johansson (johansson.andersson@telia.com) writes:   
   > I have these relations one Rider can have many horses but one horse can   
   > only be owned by one rider.So here we have one to many counted from the   
   > Rider side.   
      
   From what I have understood, a horse can be co-owned by several people.   
   And the rider does not necessarily own the horse at all. But it might   
   be that a horse typically only has one rider.   
      
   > For example   
   > Nisse Hult owns the two horses Trisdan and Sylfid.   
   >   
   > In my current E-R design I can tell which horse the Rider is using in a   
   > special class I can only know that Nisse Hult is using any of the horses   
   > that he owns.   
      
   Not sure that I follow. If you tie the horse to the class, then you   
   also know the rider. As long as we can assume that the horse can   
   only have one rider. Since this is not my business domain, I am not   
   sure how safe this assumption is. Else you would need both horse, rider and   
   class to be the key in that table.   
      
   > The other solution is that I can create a new table with is the contents   
   > of Horse and Rider and then remove the  Horse and Rider.   
   > But if I do so I get a lot of double information as you can see here.   
      
   Right, as you have realised that is not the way should go.   
      
      
   --   
   Erland Sommarskog, Stockholm, esquel@sommarskog.se   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)