[لسه مبتدئ]

انا تابعت دورة الاستاذ خالد السعداني في دورة المبيعات
بس هو مكملش ازاي اخصم من المخزن
ممكن يا جماعة تساعدوني
انا اسف
ده كود حفظ الفاتورة
    Private Sub btnSave_Click(sender As Object, e As EventArgs) Handles btnSave.Click

        If state = "add" Then


            Dim StrInser As String = "Insert Into TBL_ORDERS (order_date, SalesMan, Des, ID_Customer) values(@order_date, @SalesMan , @Des, @ID_Customer)"
            cmd = New OleDb.OleDbCommand(StrInser, con)

            cmd.Parameters.Add(New OleDb.OleDbParameter("@order_date", OleDb.OleDbType.Date)).Value = DtOrder.Value.Date
            cmd.Parameters.Add(New OleDb.OleDbParameter("@SalesMan", OleDb.OleDbType.VarChar)).Value = txtSalesMan.Text
            cmd.Parameters.Add(New OleDb.OleDbParameter("@Des", OleDb.OleDbType.VarChar)).Value = txtDes.Text
            cmd.Parameters.Add(New OleDb.OleDbParameter("@ID_Customer", OleDb.OleDbType.Integer)).Value = txtCustId.Text

            con.Open()
            cmd.ExecuteNonQuery()




            cmd = New OleDb.OleDbCommand("select max (id) from TBL_ORDERS", con)

            Dim dr As OleDb.OleDbDataReader = cmd.ExecuteReader
            dr.Read()
            Dim Id_Order As Integer = dr(0)
            dr.Close()


            ''''''''

            Dim ID_Product, Qty As Integer
            Dim Price2, Amount As Double

            StrInser = "Insert into TBL_ORDER_DETALIS (ID_Product, id_order, qty, price2, amount) values (@ID_Product, @id_order, @qty, @price2, @amount) "



            For i As Integer = 0 To DGVProduct.RowCount - 2
                ID_Product = DGVProduct.Rows(i).Cells(0).Value
                Qty = DGVProduct.Rows(i).Cells(2).Value
                Price2 = DGVProduct.Rows(i).Cells(3).Value
                Amount = DGVProduct.Rows(i).Cells(4).Value

                cmd = New OleDb.OleDbCommand(StrInser, con)



                cmd.Parameters.Add(New OleDb.OleDbParameter("@ID_Product", OleDb.OleDbType.Integer)).Value = ID_Product
                cmd.Parameters.Add(New OleDb.OleDbParameter("@id_order", OleDb.OleDbType.Integer)).Value = Id_Order
                cmd.Parameters.Add(New OleDb.OleDbParameter("@qty", OleDb.OleDbType.Integer)).Value = Qty
                cmd.Parameters.Add(New OleDb.OleDbParameter("@price2", OleDb.OleDbType.Currency)).Value = Price2
                cmd.Parameters.Add(New OleDb.OleDbParameter("@amount", OleDb.OleDbType.Currency)).Value = Amount

                cmd.ExecuteNonQuery()
            Next
            con.Close()
            MsgBox("تمت الإضافة بنجاح", MsgBoxStyle.Information, "الإضافة")

        Else

            Dim strUbdate As String = "update tbl_orders set order_date = @order_date, salesman = @salesman, des = @des, id_customer = @id_customer where ID = " & Me.ID_ORDER
            cmd = New OleDb.OleDbCommand(strUbdate, con)

            cmd.Parameters.Add(New OleDb.OleDbParameter("@order_date", OleDb.OleDbType.Date)).Value = DtOrder.Value.Date
            cmd.Parameters.Add(New OleDb.OleDbParameter("@SalesMan", OleDb.OleDbType.VarChar)).Value = txtSalesMan.Text
            cmd.Parameters.Add(New OleDb.OleDbParameter("@Des", OleDb.OleDbType.VarChar)).Value = txtDes.Text
            cmd.Parameters.Add(New OleDb.OleDbParameter("@ID_Customer", OleDb.OleDbType.Integer)).Value = txtCustId.Text

            con.Open()
            cmd.ExecuteNonQuery()




            cmd = New OleDb.OleDbCommand("select max (id) from TBL_ORDERS", con)

            Dim dr As OleDb.OleDbDataReader = cmd.ExecuteReader
            dr.Read()
            Dim Id_Order As Integer = dr(0)
            dr.Close()


            cmd = New OleDb.OleDbCommand("Delete from TBL_ORDER_DETALIS where id_order = " & Id_Order, con)
            cmd.ExecuteNonQuery()


            ''''''''

            Dim ID_Product, Qty As Integer
            Dim Price2, Amount As Double

            strUbdate = "Insert into TBL_ORDER_DETALIS (ID_Product, id_order, qty, price2, amount) values (@ID_Product, @id_order, @qty, @price2, @amount) "



            For i As Integer = 0 To DGVProduct.RowCount - 2
                ID_Product = DGVProduct.Rows(i).Cells(0).Value
                Qty = DGVProduct.Rows(i).Cells(2).Value
                Price2 = DGVProduct.Rows(i).Cells(3).Value
                Amount = DGVProduct.Rows(i).Cells(4).Value

                cmd = New OleDb.OleDbCommand(strUbdate, con)



                cmd.Parameters.Add(New OleDb.OleDbParameter("@ID_Product", OleDb.OleDbType.Integer)).Value = ID_Product
                cmd.Parameters.Add(New OleDb.OleDbParameter("@id_order", OleDb.OleDbType.Integer)).Value = Id_Order
                cmd.Parameters.Add(New OleDb.OleDbParameter("@qty", OleDb.OleDbType.Integer)).Value = Qty
                cmd.Parameters.Add(New OleDb.OleDbParameter("@price2", OleDb.OleDbType.Currency)).Value = Price2
                cmd.Parameters.Add(New OleDb.OleDbParameter("@amount", OleDb.OleDbType.Currency)).Value = Amount

                cmd.ExecuteNonQuery()
            Next
            con.Close()
            MsgBox("تمت عملية التعديل بنجاح", MsgBoxStyle.Information, "التعديل")



        End If










    End Sub