Should primary key be used on a table that has only 2 columns, both are unique

Question

If I have a table like the Following

CustomerAddress(CustomerId, AddressId)

Would I still need an additional primary key, e.g., int auto increment? Or would setting both the columns as primary keys be sufficient?

ASSUMPTION: When deleting, I will only delete by customerId, never by both customerId and AddressId

Answer 1

I suggest you to keep a primary key. Though it is not useful for now, it might be useful in future. May be the combination customerid and addressid could have new field like current_address_flag. And its just about creating a field that is almost manipulated by the DB system.

Answer 2

It seems this is a join table. In this case, I'd have a cascading delete between the dependent objects, e.g. when a customer is deleted, all customerAddresses belonging to said customer are also deleted.