Best practice for adding a bidirectional relation in OO model

Question

I\'m struggling to come up with a good way of adding a bidirectional relation in OO model. Let\'s say there is a Customer who can place many Orders, that is to say there is a on

Answer 1

first, unless you plan on moving orders between customers, I think you shouldn't provide a setCustomer() method, the customer should be a parameter for the constructor and leave it unchanged.

then, the constructor shouldn't be accessible for the user, only use the factory method of Owner.