Unique keys in Entity Framework 4

Question

An existing DB schema has unique, non-primary, keys, and some foreign keys that rely on them.

Is it possible to define unique keys, which are not primary keys, in

Answer 1

I've tried defining the following tables:

• Orders [Id (primary, identity), ClientName, FriendlyOrderNum (unique)]
• OrderItems [Id (primary, identity), FriendlyOrderNum (unique), ItemName]

And a foreign key mapping from OrderItems.FriendlyOrderNum (Mant) to Orders.FriendlyOrderNum (one).

If unique non-primary keys are possible the following SSDL should work:

It doesn't. There's also no possibility for adding more elements in an .

My conclusion is that non-primary unique keys are not support in EF 4.