QT += sql

#include <Qtsql>

//创建数据库tbTest，创建表tbTest
void initDb()
{
    QsqlDatabase dbConn = QsqlDatabase::addDatabase("QsqlITE");
    dbConn.setDatabaseName("tbTest.db");
    if (!dbConn.open())
    {
        QMessageBox::information(this,tr("message"),tr("open database fail"));
        qDebug("open fail");
        return;
    }
    QsqlQuery query;
    query.exec(QObject::tr(
                   "create table tbTest(id int,name varchar(30));"));

}

#include <Qtsql>

    QsqlQuery query;
    QString strsql;
    strsql = tr("select * from tbTest;");
    query.exec(strsql);
    while (query.next())
    {
    //查询到的数据
    }