private void button1_Click(object sender, EventArgs e) { cmd = new MySqlCommand("insert into bill values(?a,?b,?c,?d,?e,?f)", con); cmd.Parameters.AddWithValue("?a", textBox1.Text); cmd.Parameters.AddWithValue("?b", comboBox2.Text); cmd.Parameters.AddWithValue("?c", dateTimePicker1.Text); cmd.Parameters.AddWithValue("?d", textBox2.Text); cmd.Parameters.AddWithValue("?e", textBox4.Text); cmd.Parameters.AddWithValue("?f", comboBox1.Text); cmd.ExecuteNonQuery(); int pcode = 0; int count = Convert.ToInt32(textBox2.Text); for (i = 0; i < count; i++) { cmd1 = new MySqlCommand("insert into bill_order values(?in,?rt,?qt,?ta,?bn)", con); cmd1.Parameters.AddWithValue("?in", item[i].Text); cmd1.Parameters.AddWithValue("?rt", rate[i].Text); cmd1.Parameters.AddWithValue("?qt", qty[i].Text); cmd1.Parameters.AddWithValue("?ta", textBox4.Text); cmd1.Parameters.AddWithValue("?bn", textBox1.Text); cmd1.ExecuteNonQuery(); cmd2 = new MySqlCommand("select * from packing_product where prod_name=?pc", con); cmd2.Parameters.AddWithValue("?pc", item[i].Text); dr = cmd2.ExecuteReader(); if (dr.Read()) { pcode = Convert.ToInt32(dr["prod_code"]); } dr.Close(); cmd2 = new MySqlCommand("update stock set total_qty=total_qty-?qt where typeofproduct='packing product' and prod_code=?pc", con); cmd2.Parameters.AddWithValue("?qt", qty[i].Text); cmd2.Parameters.AddWithValue("?pc", pcode); cmd2.ExecuteNonQuery(); cmd2 = new MySqlCommand("select total_qty from stock where prod_code=?pc", con); cmd2.Parameters.AddWithValue("?pc", pcode); dr = cmd2.ExecuteReader(); if (dr.Read()) { if (Convert.ToInt32(dr["total_qty"]) <= 3) { MessageBox.Show(item[i].Text + " remaining only " + dr[0]); } } dr.Close(); // updating stock as per product } if (comboBox2.Text == "Cash") { MessageBox.Show("Payment Successful...!"); } else { toa = Convert.ToInt32(textBox4.Text); bno = Convert.ToInt32(textBox1.Text); Form7 f7 = new Form7(bno, toa); f7.Show(); } Hide(); }