/**
  * show table listing
  *
  * @throws DatabaseException
  *
  * @return array:
  */
 public function showTableList()
 {
     try {
         if (!$this->db) {
             throw new DatabaseException(__METHOD__ . 'No Database Object has been given', MySQL::ERR_NO_CREDENTIALS, MySQL::SEVERITY_LOG, __FILE__, __LINE__);
         }
         $sql = (string) "SELECT * FROM `information_schema`.`tables`";
         $res = $this->db->query($sql);
         if (empty($res)) {
             return [];
         }
         return $this->db->fetchObjectList($res);
     } catch (DatabaseException $e) {
         throw $e;
     }
 }