How do you deal with polymorphism in a database?

Question

Example

I have Person, SpecialPerson, and User. Person and SpecialPerson are just people - they don\

Answer 1

In the past I've done it exactly as you suggest -- have a Person table for common stuff, then SpecialPerson linked for the derived class. However, I'm re-thinking that, as Linq2Sql wants to have a field in the same table indicate the difference. I haven't looked at the entity model too much, though -- pretty sure that allows the other method.