title: Returning multiple models with includes in Active Record
body: <p>I have two models, Invitation and RSVP. An invitation has many rsvps and rsvp belongs to an invitation. I want to run a query that will return all invitations and the rsvps that belong to each invitation. I want to have all the attributes that belong to both invitation and rsvp. I'm aware of includes and have been trying things like</p>
  
  <pre><code>@results = RSVP.where(user_id: 3).includes(:invitation)
  </code></pre>
  
  <p>but I'm only getting the attributes of RSVP returned. I ideally want to have the attributes of the Invitation that RSVP belongs to added to the results. What concept am I missing or should I think of this a different way?</p>