Question

I’m a little rusty on my ActiveRecord, so forgive me if the answer is somehow obvious.

I have three model objects in a rails project: Student, Assignment, and Course. As you might imagine, a Course has_many assignments. Now I want to be able to assign to a Student an arbitrary number of Courses and individual Assignments.

I’ve tried to use a polymorphic association based on the notion of ‘assignable’, but can’t get it to work properly.

What’s the most natural way to model these relationships in rails?

Answer 1

One way to do it is to simply say that a Student has_many assignments and has_many courses. A Course also has_many assignments. Of course I don’t know what you’re trying to achieve in your application, but it seems that courses and assignments are completely different entities, so I’m not sure why you’d like a polymorphic association.