void InitMultipleSQL()
{
    QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");
    db.setDatabaseName("./lyshark.db");
     if (!db.open())
     {
            std::cout &lt;&lt; db.lastError().text().toStdString()&lt;&lt; std::endl;
            return;
     }

    // 執(zhí)行SQL創(chuàng)建User表并插入測試數據
    // https://www.cnblogs.com/lyshark
    db.exec("DROP TABLE User");
    db.exec("CREATE TABLE User ("
                    "id INTEGER PRIMARY KEY AUTOINCREMENT, "
                    "name VARCHAR(40) NOT NULL)"
         );

    db.exec("INSERT INTO User(name) VALUES('lyshark')");
    db.exec("INSERT INTO User(name) VALUES('root')");
    db.exec("INSERT INTO User(name) VALUES('admin')");

    // 創(chuàng)建第二張表,與第一張表通過姓名關聯(lián)起來
    db.exec("DROP TABLE UserAddressList");
    db.exec("CREATE TABLE UserAddressList("
            "id INTEGER PRIMARY KEY AUTOINCREMENT, "
            "name VARCHAR(40) NOT NULL, "
            "address VARCHAR(128) NOT NULL"
            ")");

    db.exec("INSERT INTO UserAddressList(name,address) VALUES ('lyshark','192.168.1.1')");
    db.exec("INSERT INTO UserAddressList(name,address) VALUES ('lyshark','192.168.1.2')");
    db.exec("INSERT INTO UserAddressList(name,address) VALUES ('lyshark','192.168.1.3')");
    db.exec("INSERT INTO UserAddressList(name,address) VALUES ('root','192.168.10.10')");
    db.exec("INSERT INTO UserAddressList(name,address) VALUES ('root','192.168.10.11')");
    db.exec("INSERT INTO UserAddressList(name,address) VALUES ('admin','192.168.100.100')");

    db.commit();
    db.close();
}

初始化表結構以后就得到了兩張表，當程序運行時默認在構造函數處填充第一個ComBox組件，也就是執(zhí)行一次數據庫查詢，并將結果通過ui->comboBox_1->addItem();放入到第一個組件內。

QSqlDatabase db;

// https://www.cnblogs.com/lyshark
MainWindow::MainWindow(QWidget *parent) :QMainWindow(parent),ui(new Ui::MainWindow)
{
    ui-&gt;setupUi(this);
    InitMultipleSQL();

    db = QSqlDatabase::addDatabase("QSQLITE");
    db.setDatabaseName("./lyshark.db");
     if (!db.open())
     {
            std::cout &lt;&lt; db.lastError().text().toStdString()&lt;&lt; std::endl;
            return;
     }

     QSqlQuery query;
     query.exec("select * from User;");
     QSqlRecord rec = query.record();

     while(query.next())
     {
         int index_name = rec.indexOf("name");
         QString data_name = query.value(index_name).toString();
         ui-&gt;comboBox-&gt;addItem(data_name);
     }
}

MainWindow::~MainWindow()
{
    delete ui;
}

代碼運行后第一個ComBox會顯示所有用戶名:

此時回到UI編輯界面，我們在第一個ComBox上轉到槽函數on_comboBox_activated(const QString &arg1)上面。

當用戶選擇第一個ComBox選擇框時，自動查詢數據庫中與該選擇框對應的字段，并關聯(lián)到第二個選擇框內，代碼如下:

void MainWindow::on_comboBox_activated(const QString &amp;arg1)
{
    std::cout &lt;&lt; "www.lyshark.com Name = " &lt;&lt; arg1.toStdString()&lt;&lt;std::endl;

    if(db.open())
    {
        QSqlQuery query;
        query.prepare("select * from UserAddressList where name = :x");
        query.bindValue(":x",arg1);
        query.exec();

        QSqlRecord rec = query.record();

        ui-&gt;comboBox_2-&gt;clear();
        while(query.next())
        {
            int index = rec.indexOf("address");
            QString data_ = query.value(index).toString();
            ui-&gt;comboBox_2-&gt;addItem(data_);
        }
    }
}

最終關聯(lián)效果如下，當選擇用戶是自動關聯(lián)到所維護的主機列表上面: