Provides add_foreign_key and remove_foreign_key to migrations:

  class CreatePeople < ActiveRecord::Migration
    def self.up
      create_table :people do |t|
        t.string :name, :null => false
        t.references :address
      end

      add_foreign_key :people, :addresses
    end

    def self.down
      drop_table :people
    end
  end

If your foreign key isn’t named like <table_name>_id you can do:

  add_foreign_key :people, :addresses, :location_id