title: Sorting UNION queries with Laravel 4.1
body: <p>I think there is something changed in the <code>union</code> between Laravel 4 and Laravel 4.1. I have 2 models.</p>
  
  <pre class="lang-php prettyprint-override"><code>$photos = DB::table('photos')-&gt;select('id', 'name', 'created_at');
  $videos = DB::table('videos')-&gt;select('id', 'name', 'created_at');
  </code></pre>
  
  <p>I want to union the 2 querys and order the 2 querys with the <code>created_at</code> field.</p>
  
  <pre class="lang-php prettyprint-override"><code>$photos = $photos-&gt;orderBy('created_at', 'desc');
  $combined = $photos-&gt;union($videos);
  </code></pre>
  
  <p>With Laravel 4 it gives me this query:</p>
  
  <pre class="lang-sql prettyprint-override"><code>select `id`, `name`, `created_at` from `videos`
  union
  select `id`, `name`, `created_at` from `photos`
  order by `created_at` desc
  </code></pre>
  
  <p>This works ok, it sorts the results for both querys together. In Laravel 4.1 it gives me this query:</p>
  
  <pre class="lang-sql prettyprint-override"><code>(select `id`, `name`, `created_at` from `videos`)
  union
  (select `id`, `name`, `created_at` from `photos` order by `created_at` desc)
  </code></pre>
  
  <p>This results in a list of videos and after that an ordered list of photos. I need to have a list where the to combined querys are sorted. I want Laravel to give me this query:</p>
  
  <pre class="lang-sql prettyprint-override"><code>(select `id`, `name`, `created_at` from `videos`)
  union
  (select `id`, `name`, `created_at` from `photos`)
  order by `created_at` desc
  </code></pre>
  
  <p>How do get this working in Laravel?</p>