title: execute() SQLSTATE[HY093]: Invalid parameter number
body: <p>I have a problem in my code and I don't understand that!
  here is the part of my code that has problem</p>
  
  <pre class="lang-sql prettyprint-override"><code>$conn = new PDO(DB_DSN, DB_USERNAME, DB_PASSWORD);
  $sql = "SELECT SQL_CALC_FOUND_ROWS *, UNIX_TIMESTAMP(publicationDate) AS publicationDate FROM NEWS order by " . mysql_real_escape_string($order) . " LIMIT :numROws";
  $st = $conn -&gt; prepare($sql);
  $st -&gt; bindValue(":numRows", $numRows, PDO::PARAM_INT);
  $st -&gt; execute();
  </code></pre>
  
  <p>if it is not clear please tell.</p>