title: Avoid query to check if relation exists in Laravel
body: <p>In Laravel I've 2 models <code>Man</code> and <code>Car</code>, and the <code>Car</code> model has a foreign key <code>man_id</code>.</p>
  
  <p>Now I would like to check if a <code>Car</code> has an owner, so I can do<br>
  <code>if($car-&gt;man != null)</code></p>
  
  <p>I could also do:<br>
  <code>if($car-&gt;man_id != null)</code><br>
  but I don't like this solution...</p>
  
  <p>But in this way Laravel do a query to check if <code>Man</code> exists, is there a way to avoid this useless query?</p>