title: Laravel decrement column value but not negative
body: <p>I know i can reduce the column value in laravel using this query</p>
  
  <pre><code>DB::table('users')-&gt;decrement('votes', 5);
  </code></pre>
  
  <p>But i want to restrict the value from being become negative value. </p>
  
  <p>Is there anyway to do this with laravel?</p>