qt对mysql的查询窗口

#include <QApplication>
#include <QSqlDatabase>
#include <QSqlQuery>
#include <QSqlError>
#include <QTextEdit>
#include <QPushButton>
#include <QVBoxLayout>
#include <QLineEdit>

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    // 连接数据库
    QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");
    db.setHostName("localhost");
    db.setDatabaseName("testdb");
    db.setUserName("root");
    db.setPassword("password");
    if (!db.open()) {
        qDebug() << "无法连接到数据库:" << db.lastError().text();
        return -1;
    }

    // 创建主窗口
    QWidget window;
    QVBoxLayout *layout = new QVBoxLayout(&window);

    QLineEdit *queryEdit = new QLineEdit(&window);
    layout->addWidget(queryEdit);

    QPushButton *executeButton = new QPushButton("执行查询", &window);
    layout->addWidget(executeButton);

    QTextEdit *resultEdit = new QTextEdit(&window);
    resultEdit->setReadOnly(true);
    layout->addWidget(resultEdit);

    // 连接按钮信号和槽
    QObject::connect(executeButton, &QPushButton::clicked, [&]() {
        QString queryString = queryEdit->text();
        QSqlQuery query;
        if (!query.exec(queryString)) {
            resultEdit->setText("查询失败:" + query.lastError().text());
        } else {
            resultEdit->clear();
            while (query.next()) {
                QString result = "";
                for (int i = 0; i < query.record().count(); ++i) {
                    result += query.value(i).toString() + "\t";
                }
                resultEdit->append(result);
            }
        }
    });

    window.show();
    return app.exec();
}