function database_connection_with_pdo($host, $database, $user, $password, $port=3306, $charset='utf8mb4') {
    try {
		$dns = "mysql:host=$host;";
		if ($port) {
			$dns .= "port=$port;";
		}
		$dns .= "dbname=$database";
		if ($charset) {
			$dns .= ";charset=$charset";
		}
		$pdo = new PDO($dns, $user, $password);
        $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); // 设置错误模式为异常
    } catch (PDOException $e) {
		throw new PDOException($e->getMessage(), (int)$e->getCode());
    }
    return $pdo;
}

用法：$conn = database_connection_with_pdo($MySQLServer, $MySQLDBName, $MySQLUserName, $MySQLPassword, $MySQLPort, $charset='utf8mb4');