Hi. so this is actually a continuation from another question of mineHere but i was advised to start a new thread as the original question was already answered.

This is the result of previous question answered :

code for the listbox - datagridview interaction

At the top of the code so its public

``Dim dt As New DataTable``

``grd_order.DataSource = dt``

in private sub for product list

``````Private Sub product_list(ByVal pid As String)
Dim getproduct As String = "SELECT FLD_PRODUCT_ID,FLD_PRICE FROM TBL_PRODUCTS_A154287 WHERE FLD_PRODUCT_ID='" & pid & "'"
Dim getcolumns As String = "SELECT FLD_QTY,FLD_SUBTOTAL FROM TBL_ORDERITEM_A154287 WHERE FLD_PRODUCT_ID='" & pid & "'"
End Sub``````

http://imgur.com/a/TKu0K

Now i want to know how to calculate the subtotal? because user can key in the quantity of the product they want. like in the picture : CK005 | 850 | , quantity and subtotal cells are empty. how would i get the value from cell Price and cell Quantity? to calculate the subtotal : `Subtotal = valueFromQtyCell * valueFromPriceCell` and put it into cell Subtotal for each its own row. Then get each value from column subtotal of each row and add them up as the Total Price; `TotalPrice = valueFromSubtotalCellOfEachRow` this im assuming needs a loop?

I found this article for you which should help explain it. Basically you need to use the SELECT statement to create the data for the other columns.

You could also work with `DGV.Rows(r).Cells(c).Value` in some loops. Remember to cast the `Value` to the proper type.

This helped me; for future reference.

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