title: rails active record has_many custom query
body: <p>is it possible to have an active record has_many associations, but i have a specific condition.</p>
  
  <pre><code>class Team &lt; AR
    has_many :matches, query: 'team1 == ID or team2 == ID'
  end
  
  class Match &lt; AR
    attr_accessible :team1, :team2
  end
  </code></pre>