QT 连接SQLLite的代码

请见下方示例代码：

#include <QCoreApplication>
#include <QtSql>

int main()
{
    // 连接数据库
    QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");
    db.setDatabaseName("test.db");
    if (!db.open())
    {
        qDebug() << "Failed to connect to database.";
        return -1;
    }

    // 创建表
    QSqlQuery query;
    if(query.exec("CREATE TABLE t_person (id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, age INTEGER)"))
    {
        qDebug() << "Create table success.";
    }
    else
    {
        qDebug() << "Failed to create table.";
        return -1;
    }

    // 添加数据
    QString name = "Tom";
    int age = 20;
    if (query.prepare("INSERT INTO t_person(name, age) VALUES(:name,:age)"))
    {
        query.bindValue(":name", name);
        query.bindValue(":age", age);
        if (query.exec())
        {
            qDebug() << "Insert data success.";
        }
        else
        {
            qDebug() << "Failed to insert data.";
            return -1;
        }
    }
    else
    {
        qDebug() << "Failed to prepare insert data.";
        return -1;
    }

    // 查询数据
    if (query.exec("SELECT id, name, age FROM t_person"))
    {
        while (query.next())
        {
            int id = query.value(0).toInt();
            QString name = query.value(1).toString();
            int age = query.value(2).toInt();
            qDebug() << "id=" << id << ", name=" << name << ", age=" << age;
        }
    }
    else
    {
        qDebug() << "Failed to select data.";
        return -1;
    }

    // 关闭数据库
    db.close();

    return 0;
}

以上示例代码包括了连接数据库、创建表、添加数据以及查询数据的过程，请根据具体情况进行相应修改。