How to get the value from cells of a datagridview table

[nadiam]

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

in private sub form load

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 reader As New OleDb.OleDbDataAdapter(getproduct, myconnection)
    Dim getcolumns As String = "SELECT FLD_QTY,FLD_SUBTOTAL FROM TBL_ORDERITEM_A154287 WHERE FLD_PRODUCT_ID='" & pid & "'"
    Dim reader2 As New OleDb.OleDbDataAdapter(getcolumns, myconnection)
    reader.Fill(dt)
    reader2.Fill(dt)
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?

[tinstaafl]

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.

[ddanbe]

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

[nadiam]

Adding And Updating A Calculated Column To DGV

This helped me; for future reference.