Best way to model Customer <--> Address

Question

Every Customer has a physical address and an optional mailing address. What is your preferred way to model this?

Option 1. Customer has fo

Answer 1

Like in many cases: It depends.

If your customers deal with multiple addresses then a to-many relationship would be appropriate. You could introduce a flag on address that signals if an address is for shipment or bill, etc. Or you store the different address types in different tables and have multiple to-one relationships on a customer.

In cases where you only need to know one address of a customer why would you model that to-many? A to-one relationship would satisfy your needs here.

Important: Denormalize only if you encounter performance issues.