数据库允许输入错误的数据

Question

在下面的代码中，我尝试在gridview 或数据库中添加行，前提是日期输入正确。即使我输入了错误的日期，它也会在gridview 或数据库中添加行。它显示错误，说错误的日期，但仍然将错误的数据添加到数据库中。

private void btn_AddReservation_Click(object sender, EventArgs e)
{
    try
    {
        int clientId = Convert.ToInt32(txtClientId.Text);
        int roomNumber = Convert.ToInt32(cb_RoomNumber.SelectedValue);
        DateTime dateIn = dtPDateIn.Value;
        DateTime dateOut = dtPDateOut.Value;

        if(DateTime.Compare(dateIn.Date,DateTime.Now.Date) < 0)
        {
            MessageBox.Show("The Date In must be = or >  Today Date","Invalid Date In",MessageBoxButtons.OK,MessageBoxIcon.Warning);
        }
        else if(DateTime.Compare(dateOut.Date,dateIn.Date) < 0)
        {
            MessageBox.Show("The Date Out must be = or >  Today Date", "Invalid Date Out", MessageBoxButtons.OK, MessageBoxIcon.Warning);
        }
        else
        {
            MessageBox.Show("Reservation Not Added ", "Add Reservation", MessageBoxButtons.OK, MessageBoxIcon.Error);
        }

        if (reservation.addReservation(roomNumber, clientId, dateIn, dateOut))
        {
            dGvReservations.DataSource = reservation.getAllReservations();
           
            room.setRoomFree(roomNumber, "No");
            MessageBox.Show("New Reservation Added ", "Add Reservation", MessageBoxButtons.OK, MessageBoxIcon.Information);
        }       
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message,"Add Reservation Error",MessageBoxButtons.OK,MessageBoxIcon.Error);
    }  
}

Answer 1

这是一个可行的解决方案：

1. 检查日期是否正确
2. 在其他情况下（日期正确），请按如下所示插入

private void btn_AddReservation_Click(object sender, EventArgs e)
    {

        try
        {

            int clientId = Convert.ToInt32(txtClientId.Text);
            int roomNumber = Convert.ToInt32(cb_RoomNumber.SelectedValue);
            DateTime dateIn = dtPDateIn.Value;
            DateTime dateOut = dtPDateOut.Value;


            if (DateTime.Compare(dateIn.Date, DateTime.Now.Date) < 0)
            {
                MessageBox.Show("The Date In must be = or >  Today Date", "Invalid Date In", MessageBoxButtons.OK, MessageBoxIcon.Warning);
            }
            else if (DateTime.Compare(dateOut.Date, dateIn.Date) < 0)
            {
                MessageBox.Show("The Date Out must be = or >  Today Date", "Invalid Date Out", MessageBoxButtons.OK, MessageBoxIcon.Warning);
            }
            else
            {
                // Date is correct, you insert it in db.

                bool success = reservation.addReservation(roomNumber, clientId, dateIn, dateOut);
                if (success)
                {
                    dGvReservations.DataSource = reservation.getAllReservations();

                    room.setRoomFree(roomNumber, "No");
                    MessageBox.Show("New Reservation Added ", "Add Reservation", MessageBoxButtons.OK, MessageBoxIcon.Information);
                }
                else
                {
                    MessageBox.Show("Error inserting ", "There was an error inserting the new reservation in the database", MessageBoxButtons.OK, MessageBoxIcon.Information);
                }
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message, "Add Reservation Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
        }

    }