public static function connectDb() {
        if 
            (!isset(self::$dbLink)) {
            $dbParams = self::getDatabaseParameters();
            self::validateDbParameters($dbParams);
            $dbParamsSan = self::sanitizeDbParameters($dbParams);
            $config = new Configuration();
            self::$dbLink = DriverManager::getConnection($dbParamsSan, $config);
        }
        
        return self::$dbLink;
    }