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 na

Answer 1

In Rails 5.1 or greater you can do it like this:

Migration

create_table(:customers) do |t|
    t.references :address, foreign_key: true
    t.references :address1, foreign_key: { to_table: 'addresses' }
end

This will create the fields address_id, and address1_id and make the database level references to the addresses table

Models

class Customer < ActiveRecord::Base
  belongs_to :address
  belongs_to :address1, class_name: "Address"
end

class Address < ActiveRecord::Base
  has_many :customers,
  has_many :other_customers, class_name: "Customer", foreign_key: "address1_id"
end

FactoryBot

If you uses FactoryBot then your factory might look something like this:

FactoryBot.define do
  factory :customer do
    address
    association :address1, factory: :address
  end
end