ruby on rails - Multiple foreign keys referencing the same table in RoR

Question

I want a Customer to reference two Address models, one for the billing address and one for the shipping address. As I understand it, the foreign key is determined by its name, as _id. Obviously I can't name two rows address_id (to reference the Address table). How would I do this?

create_table :customers do |t|
  t.integer :address_id
  t.integer :address_id_1 # how do i make this reference addresses table?
  # other attributes not shown
end

question from:https://stackoverflow.com/questions/2166613/multiple-foreign-keys-referencing-the-same-table-in-ror

Answer 1

This sounds like a has_many relationship to me - put the customer_id in the Address table instead.

Customer
  has_many :addresses

Address
  belongs_to :customer

You can also provide a foreign key and class in the assoc declaration

Customer
   has_one :address
   has_one :other_address, foreign_key => "address_id_2", class_name => "Address"