title: PDO fetchAll() returns empty array
body: <p>I'm executing a simple query, without bound parameters, using PDO. I have tested it directly against my database and it executes cleanly, returning the expected results. However, when I plug it in to my PDO object and call <code>fetchAll()</code>, it returns an empty array.</p>
  
  <pre><code>$query = 'SELECT count(*) as mycount FROM mytable';
  $mysql = $connection-&gt;prepare($query);
  $result = $mysql-&gt;fetchAll();
  
  print_r($result);
  </code></pre>
  
  <p>Expected result:</p>
  
  <pre><code>array
  (
      [mycount] =&gt; 8
  )
  </code></pre>
  
  <p>Actual result:</p>
  
  <pre><code>array
  (
  )
  </code></pre>
  
  <p>Any ideas what might be causing this, or how to go about troubleshooting this?</p>