protected function _setupDatabaseAdapter()
    {
        if (! $this->_db) {
            $this->_db = self::getDefaultAdapter();
            if (!$this->_db instanceof Zend_Db_Adapter_Abstract) {
                // require_once 'Zend/Db/Table/Exception.php';
                throw new Zend_Db_Table_Exception('No adapter found for ' . get_class($this));
            }
        }
    }