Тип поля базы данных, хранящийся в двух временах

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using (SqlConnection connect = new SqlConnection(db.Connectionstring()))
           {
               using (SqlCommand command = new SqlCommand())
               {
                   string pro = "";
                   int qty;
                   int totqty;

                   int i=0;

                        foreach (DataGridViewRow rows in dataGridView1.Rows)
                        {

                            SqlConnection con1 = new SqlConnection(db.Connectionstring());
                            con1.Open();
                            SqlCommand cmd1 = new SqlCommand("select * from sales where empnames='" + comboBox1.Text + "' ", con1);
                            SqlDataReader dr = cmd1.ExecuteReader();

                            if (dr.HasRows)
                            {
                                //while (dr.Read())
                                //{
                                    SqlConnection con2 = new SqlConnection(db.Connectionstring());
                                    con2.Open();

                                    SqlCommand cmd2 = new SqlCommand("update sales set empnames=@empnames+'" + comboBox1.Text + "',  categories=@categories, weight=@weight,per=@per,wastage=@wastage,customer=@customer,party=@party  where date=@date ", con2);

                                   cmd2.Parameters.AddWithValue("@empnames", Convert.ToString((comboBox1.Text)));
                                    cmd2.Parameters.AddWithValue("@date", Convert.ToDouble(rows.Cells[0].Value));
                                    cmd2.Parameters.AddWithValue("@categories", Convert.ToString(rows.Cells[1].Value));
                                    cmd2.Parameters.AddWithValue("@weight", Convert.ToString((rows.Cells[2].Value)));
                                    cmd2.Parameters.AddWithValue("@per", Convert.ToDouble(rows.Cells[3].Value));
                                    cmd2.Parameters.AddWithValue("@wastage", Convert.ToString((rows.Cells[4].Value)));
                                    cmd2.Parameters.AddWithValue("@customer", Convert.ToDouble(rows.Cells[5].Value));
                                    cmd2.Parameters.AddWithValue("@party", Convert.ToString((rows.Cells[6].Value)));




                                    cmd2.ExecuteNonQuery();
                                    con2.Close();


                                    SqlConnection con4 = new SqlConnection(db.Connectionstring());
                                    con4.Open();
                                    SqlCommand cmd4 = new SqlCommand("update sales set amtcst='" + txt_netamount.Text + "', amtparty='" + txtparty.Text + "', amtfinal='" + txtfinal.Text + "' where empnames='" + comboBox1.SelectedText + "'", con4);
                                    cmd4.ExecuteNonQuery();
                                    con4.Close();

                          // }
                            }


                            else
                            {
                                SqlConnection con3 = new SqlConnection(db.Connectionstring());
                                con3.Open();
                                SqlCommand cmd3 = new SqlCommand("insert into sales(empnames,date,categories,weight,per,wastage,customer,party,amtcst,amtparty,amtfinal)values('" + comboBox1.Text + "', '" + rows.Cells[0].Value + "','" + rows.Cells[1].Value + "','" + rows.Cells[2].Value + "','" + rows.Cells[3].Value + "','" + rows.Cells[4].Value + "','" + rows.Cells[5].Value + "','" + rows.Cells[6].Value + "','" + txt_netamount.Text + "','" + txtparty.Text + "','" + txtfinal.Text + "')", con3);
                                cmd3.ExecuteNonQuery();
                                con3.Close();


                            }
                        }

                   }
               }

это мой скрипт вставки и обновления для моих c# 2010 win forms, у меня есть проблема в empnames insert in two times to data base.

Кто-нибудь подскажет мне идеи

Что я уже пробовал:

data base field type stored in two times

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