title: PDO rowCount() or exec()?
body: <p>It seems to me that both <a href="http://php.chinaunix.net/manual/zh/function.PDOStatement-rowCount.php" rel="nofollow"><code>rowCount()</code></a> and <code>exec()</code> <em>Returns the number of rows affected by the last SQL statement</em>  .</p>
  
  <p>Why keep the duplicate stuff there?</p>