I have three tables that I want to link for a many to many relationship: sales: Type, int, PK Cust, int, PK Order, int, PK .... Order: Order, int, PK, identity Rep, int, PK Rep Rep, int, PK, identity .... I can link Rep and Order via the Rep field with no problem, but when I try to establish an FK relationship between Sales.Order and Order.Order I get an error message. If I add a Sales.Rep field I can create an FK using Order AND Rep but that defeats my purpose. There are no rows in any table. Is there a way to link the two tables with composite PK's? Thanks.