/**
  * @param $html string
  * @return string
  */
 function getContentMessage($html)
 {
     if ($this->useMessageCache()) {
         if ($html) {
             $msg = 'dberrortext';
             $sql = htmlspecialchars($this->getSQL());
             $fname = htmlspecialchars($this->fname);
             $error = htmlspecialchars($this->error);
         } else {
             $msg = 'dberrortextcl';
             $sql = $this->getSQL();
             $fname = $this->fname;
             $error = $this->error;
         }
         return wfMessage($msg)->rawParams($sql, $fname, $this->errno, $error)->text();
     } else {
         return parent::getContentMessage($html);
     }
 }