بحاجة الى كود حفظ التعديل على datagridview

SqlConnection conn = new SqlConnection(@"Data Source=MAHMOUD-PC\SQLEXPRESS;Initial Catalog=testDataGridView;User ID=sa;Password=sa");
            SqlCommand cmd = new SqlCommand();
            try
            {
                for (int i = 0; i <= grdTest.Rows.Count - 2; i++)
                {
                    String queryString = String.Format("UPDATE Table_1 SET name='{0}',number={1} WHERE number={1}", grdTest.Rows.Cells[2].Value.ToString(), int.Parse(grdTest.Rows.Cells[1].Value.ToString()));
                    cmd.CommandText = queryString;
                    cmd.Connection = conn;
                    conn.Open();
                    cmd.ExecuteNonQuery();
                    cmd.Dispose();
                    conn.Close();
                }
            }
            catch (Exception e1) { MessageBox.Show(e1.Message); }