Question

I have two models ObjectA and ObjectB. ObjectB has two columns, a_1_id and a_2_id, which are both foreign keys to ObjectA. ObjectB belongs to each of these foreign ObjectA objects.

class ObjectA < ActiveRecord::Base
  attr_accessible :player_1, :player_2, :subject, :turn

  belongs_to :player_1, :class_name => "User"
  belongs_to :player_2, :class_name => "User"
  has_many :object_b, dependent: :destroy, :finder_sql => "SELECT * FROM object_bs where (a_1_id = #{id} or a_2_id = #{id})" 
end

class ObjectB < ActiveRecord::Base
  attr_accessible :a_1_id, :a_2_id

  belongs_to :a_1_id, :class_name => "ObjectA"
  belongs_to :a_2_id, :class_name => "ObjectA"
end

Is this the best way to setup the association?

Answer 1

Use the :foreign_key option:

belongs_to :player_1, :class_name => "User", :foreign_key => 'player1_id'
belongs_to :player_2, :class_name => "User", :foreign_key => 'player2_id'
#...
belongs_to :a_1_id, :class_name => "ObjectA", :foreign_key => 'a_1_id'
belongs_to :a_2_id, :class_name => "ObjectA", :foreign_key => 'a_2_id'