protected function _getPrimary($id, $type = null)
    {
        $this->_setupPrimaryKey();

        if ($type === null) {
            $type = self::PRIMARY_TYPE_NUM;
        }

        $primaryArray = array();

        foreach ($this->_primary as $index => $primary) {
            switch ($this->_primaryAssignment[$index]) {
                case self::PRIMARY_ASSIGNMENT_SESSION_SAVE_PATH:
                    $value = $this->_sessionSavePath;
                    break;
                case self::PRIMARY_ASSIGNMENT_SESSION_NAME:
                    $value = $this->_sessionName;
                    break;
                case self::PRIMARY_ASSIGNMENT_SESSION_ID:
                    $value = (string) $id;
                    break;
                default:
                    $value = (string) $this->_primaryAssignment[$index];
                    break;
            }

            switch ((string) $type) {
                case self::PRIMARY_TYPE_PRIMARYNUM:
                    $primaryArray[$index] = $value;
                    break;
                case self::PRIMARY_TYPE_ASSOC:
                    $primaryArray[$primary] = $value;
                    break;
                case self::PRIMARY_TYPE_WHERECLAUSE:
                    $primaryArray[] = $this->getAdapter()->quoteIdentifier($primary, true) . ' = '
                                    . $this->getAdapter()->quote($value);
                    break;
                case self::PRIMARY_TYPE_NUM:
                default:
                    $primaryArray[] = $value;
                    break;
            }
        }

        return $primaryArray;
    }