title: Django ORM filter in multiple columns
body: <p>I'm new to Django and Web frameworks. 
  I have a question regarding Django ORM Filter querying </p>
  
  <p>Order is a Table which references to another table named Show. Show has 3 managers say manager, manager_2, manager_3.</p>
  
  <p>Now I want to pick the Orders, whose users are either of these 3 managers. 
  How do i do that. 
  I'm looking for some thing like this:</p>
  
  <pre><code>Order.objects.filter(    
      order_cancelled__isnull = True,
      (show__manager = user || show_manager_2 = user || show_manager_3 = user))
  </code></pre>