How can I define a polymorphic relation between models in Django?

Question

I am working on a Django application which contains an Offer model. An Offer instance contains the pricing conditions and points to a product definition. The product model is actually a hierarchy (I have a Television model, a Camcorder model, etc.). So I would like the Offer model to contain a polymorphic (or "generic") association to point to any product.

For now, all I have found is this to use the generic associations in the ContentTypes application. This might do, but I am looking for alternatives, if any.

Thanks for your help.

(one solution per answer please)

Answer 1

ContentTypes is the right approach. This is because the ForignKey can only point to one type of table so you need to pass through the an intermediate table and do your split depending on the different type.

So model inheritance for the class hierarchy, but ContentType for the foreign keys.

Answer 2

If you only need to point to "any product," not any model, then the solution is to have a Product model that all products inherit from (i.e. Television and Camcorder are both subclasses of Product), and give your Offer model a ForeignKey to Product.