public function getDefault() {
        // timestamp default
        if ($this->default === Schema::DF_CURRENT_TIMESTAMP) {
            // check for right datatpye
            $stamp_type = $this->findQuery($this->schema->dataTypes['TIMESTAMP']);
            if ($this->type != 'TIMESTAMP' &&
                ($this->passThrough && strtoupper($this->type) != strtoupper($stamp_type))
            )
                trigger_error(self::TEXT_CurrentStampDataType,E_USER_ERROR);
            return $this->findQuery($this->schema->defaultTypes[strtoupper($this->default)]);
        } else {
            // static defaults
            $type_val = $this->getTypeVal();
            $pdo_type = preg_match('/int|bool/i', $type_val, $parts) ?
                constant('\PDO::PARAM_'.strtoupper($parts[0])) : \PDO::PARAM_STR;
            return ($this->default === NULL ? 'NULL' :
                $this->db->quote(htmlspecialchars($this->default, ENT_QUOTES,
                    \Base::instance()->get('ENCODING')), $pdo_type));
        }
    }