I am new to Access and trying to build out a vendor management database. I have a table with Purchase Requisitions and a table with Change Orders. Both have the Purchase Order number as the Foreign Key. I am trying to build a query or report that will give me the total cost of the Purchase Order (requisition amount + all change orders listed individually). However, what I end up getting are 2 lines that each have the requisition amount + one change order. I've spent quite a bit of time trying to figure out how to get what I want, using a Sum IIF expression (using the PurchaseOrder column), but cannot figure out how to make it work. Any help would be greatly appreciated.