void MainWindow::on_pushButton_clicked()
{
      QStringList strlist = QsqlDatabase::drivers();
      for(int i = 0; i < strlist.size();i++)
      {
          qDebug()<<strlist.at(i);
      }

      QsqlDatabase db = QsqlDatabase::addDatabase("QsqlITE");
      db.setDatabaseName("mytest.db");  //在工程目录新建一个mytest.db的文件
      if(!db.open())
      {
          qDebug()<<"open fail!";
          return ;
      }
      QsqlQuery query(db);

      bool bsuccess =
       query.exec("create table person (id int primary key,"
                   "firstname varchar(20),lastname varchar(20))");   //创建一个表
       query.exec("insert into person values(101,'Danny','Young')");
       query.exec("insert into person values(102,'Christine','Holand')");
       query.exec("insert into person values(103,'Lars','Gordon')");
       query.exec("insert into person values(104,'Roberto','Robitaille')");
       query.exec("insert into person values(105,'Maria','Papadopoulos')");
       if(!bsuccess)
       {
           qDebug()<< "table is error";
       }
       else
       {
           qDebug()<<"table is ok";
       }

       QsqlTableModel *model = new QsqlTableModel;
       model->setTable("person");
       model->setEditStrategy(QsqlTableModel::OnManualSubmit);
       model->select();
       ui->tableView->setModel(model);
       ui->tableView->show();
}