Qt three ways to connect to MySQL database remotely (ODBC way, DSN way, direct connection way)

1. ODBC remote connection to MySQL database

void createMySQLConnByODBC() {
    qDebug() << "Qt 6支持的数据库驱动有:" << QSqlDatabase::drivers();
    QSqlDatabase db = QSqlDatabase::addDatabase("QODBC");
    db.setDatabaseName("mysql_on_alicloud");//是你在ODBC中创建的DSN-Data Source Name
    
    if (!db.open()) {
        QMessageBox::warning(0, QObject::tr("提示"), QObject::tr("连接失败！\r\n") +                         db.lastError().driverText());
    } else {
        QMessageBox::information(0, QObject::tr("提示"), QObject::tr("连接成功！"));
        QSqlQuery result = db.exec("select user from user;");
        
        while (result.next())
            qDebug() << result.value("user").toString();
        }
    }
}

Note: When creating a user DSN or system DSN through the ODBC data source (64-bit) of the Windows operating system, please select "MySQL ODBC 8.0 Unicode Driver".

2. Remote connection to MySQL database in DSN mode (creating ODBC in program mode)

void createMySQLConnByDSN() {
    qDebug() << "Qt 6支持的数据库驱动有：" << QSqlDatabase::drivers();
    QString dsn = "Driver={MySQL ODBC 8.0 UniCode Driver};"; // Driver is now {MySQL}
    dsn.append("Server=远程服务器IP,3306;"); // IP,Port
    dsn.append("Database=mysql;"); // Schema
    dsn.append("Uid=root;"); // User
    dsn.append("Pwd=数据库密码;"); // Password
    dsn.append("MULTI_HOST=1;");

    QSqlDatabase db = QSqlDatabase::addDatabase("QODBC");   
    db.setDatabaseName(dsn);

    bool success = db.open();
    if (!success)
        qDebug() << "未能连接MySQL数据库!" << db.lastError();
    else {
        QMessageBox::information(0, QObject::tr("提示"), QObject::tr("连接成功！"));
        QSqlQuery result = db.exec("select user from user;");
        
        while (result.next())
            qDebug() << result.value("user").toString();
    }
}

3. Remote connection to MySQL database in direct connection mode

bool createMySQLConn(const QString userName, const QString passWord,
    const QString dbName, const QString serverIP) {
    qDebug() << "Qt 6支持的数据库驱动有：" << QSqlDatabase::drivers();
    QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");
    db.setPort(3306); // MySQL数据库端口
    db.setUserName(userName); // 数据库用户名
    db.setPassword(passWord); // 数据库密码
    db.setDatabaseName(dbName); // 数据库名称
    db.setHostName(serverIP); // MySQL远程服务器IP地址

    return db.open();
}