title: Simulating a right join in Eloquent
body: <p>I have a model <code>Person</code> that <code>belongsToMany</code> <code>Review</code> objects.</p>
  
  <p>This is all working great, and I can query thing successfully.</p>
  
  <p>What I'd like to do now is to query all <code>Person</code> where there isn't a <code>Review</code> associated with them.</p>
  
  <p>I've tried things like</p>
  
  <p><code>Person::with('reviews')-&gt;whereNull('reviews.id')-&gt;get();</code></p>
  
  <p>and</p>
  
  <pre><code>Person::whereHas('reviews', function($q)
      {
          $q-&gt;whereNull('id');
      })-&gt;get();
  </code></pre>
  
  <p>but with no success - what do I need to do to just get the <code>Person</code> objects where they have no <code>Review</code> objects?</p>
  
  <p>This would be very easy with normal SQL, but I have lots of other code that uses the Eloquent models, so I'd like to keep using Eloquent here.</p>