我的逻辑正确吗？我正在尝试计算在 foreach 循环中读取的每个循环的总量？

Question

所以我在 foreach 循环中抓取每一行并计算它的价格。我设法做到了，但我似乎无法弄清楚如何将所有计算的行存储到一个变量中并将 1 个计算的答案插入数据库。

private void btnSubmitConsultation_Click(object sender, EventArgs e)
{ 
    string cMedication = string.Empty;
    string cQuantity = string.Empty;
    string cAppointment = string.Empty;
    foreach (DataGridViewRow row in this.dataPrescription.Rows)
    {
        cMedication = row.Cells[0].Value.ToString();
        cQuantity = row.Cells[1].Value.ToString();
        cAppointment = txtAppointmentID.Text;

        if (cAppointment == "NO APPOINTMENT HAS BEEN MADE")
        {
            MessageBox.Show("Please make an appointment first at the Nurse counter", "WARNING");
        }
        else
        {
            this.calculateTotal(cMedication, cQuantity, cAppointment);
        }
    }

}

private void calculateTotal(string cMedication, string cQuantity, string cAppointment)
{
    string strConnectionString = ConfigurationManager.ConnectionStrings["HConnection"].ConnectionString;
    SqlConnection con = new SqlConnection(strConnectionString);

    string insertPayment = "INSERT INTO PAYMENT (amount, appointmentID) " +
        "VALUES (@insertAmount, @insertAppointment)";

    using (SqlConnection connection = new SqlConnection(strConnectionString))
    {
        using (SqlCommand cmdPayment = new SqlCommand(insertPayment, connection))
        {
            string strPrice = "SELECT medicationPrice FROM MEDICATION WHERE medicationName= @getName";
            SqlCommand cmdPrice = new SqlCommand(strPrice, con);
            cmdPrice.Parameters.AddWithValue("@getName", cMedication);

            con.Open();
            SqlDataReader readPrice = cmdPrice.ExecuteReader();
            if (readPrice.Read())
            {
                string getPrice = readPrice["medicationPrice"].ToString();
                double doublePrice = Convert.ToDouble(getPrice);
                double doubleQuantity = Convert.ToDouble(cQuantity);

                double result = doublePrice * doubleQuantity;

                for (int i = 0; i < dataPrescription.Rows.Count; i++)
                {
                    double total = result * i;
                string answer = result.ToString();
                    MessageBox.Show(answer);
                    cmdPayment.Parameters.AddWithValue("@insertAmount", answer);
                }


            }

            readPrice.Close();
            con.Close();

            cmdPayment.Parameters.AddWithValue("@insertAppointment", txtAppointmentID.Text);

            connection.Open();
            cmdPayment.ExecuteNonQuery();
            connection.Close();

        }
    }
}

Answer 1

您必须将命令文本更改为插入语句。

connection.Open();
cmdPayment.CommandText = insertPayment;
cmdPayment.ExexuteNonQuerry();