title: Is the has_may relationship on rails necessary or the belong_to is enough?
body: <p>I have a model with a var reference to another one. </p>
  
  <pre><code>User -&gt; Profile
  </code></pre>
  
  <p>When I have generated the Profile model I used the references
  feature so it has generated the corresponding migration</p>
  
  <pre><code>....
  t.references :user
  ....
  </code></pre>
  
  <p>My question is do I have to add a relationship on the User model too?</p>
  
  <pre><code>has_one :Profile
  </code></pre>