title: Laravel modifying multiple rows at once
body: <p>I have an array of <code>$ids</code>.</p>
  
  <p>I'd like to essentially say:</p>
  
  <pre><code>foreach($ids as $id):
  
    $user = User::find(1);
    $user-&gt;life_expectancy -= 1;
    $user-&gt;save();
  
  endforeach;
  </code></pre>
  
  <p>Except I have thousands of ids in the array, and I'd much rather do something like:</p>
  
  <pre><code>$users = User::whereIn('id', $ids)-&gt;update(array('life_expectancy' =&gt; --1));
  </code></pre>
  
  <p>To just get it done in a single query. But that isn't going to work... is there another method?</p>
  
  <p>I know I can update multiple users to all have the same <code>life_expectancy</code>, but I'd like it to be a modification of the previous value.</p>