title: Scoping with two foreign keys
body: <p>I have the following schema:
  <img src="https://i.stack.imgur.com/cge1k.png" alt="enter image description here"></p>
  
  <p>I want to have the option to call <code>proposals</code> for both foreign_keys (<code>author_id</code> and <code>editor_id</code>) as well for separate ones (for example <code>author_proposals</code> and <code>editor_proposals</code>) and I need to have the option to lazy or eager load them (for example <code>User.includes(:proposals)</code> or without it with <code>joins</code>).</p>
  
  <p>Update: </p>
  
  <pre><code>#I have the scopes which is like this:
  class User &lt; ActiveRecord::Base
    has_many :author_proposals, class_name: 'Proposal', foreign_key: :author_id
    has_many :editor_proposals, class_name: 'Proposal', foreign_key: :editor_id
  end
  
  class Proposal &lt; ActiveRecord::Base
    belongs_to :author, class_name: 'User', foreign_key: :author_id
    belongs_to :editor, class_name: 'User', foreign_key: :editor_id
  end
  </code></pre>
  
  <p>But I need a universal one which it will give me all the proposals (both <code>author_proposals</code> and <code>editor_proposals</code>) which it will also eager load them. Should I use conditions on <code>has_many</code>?</p>