First, both files need to be ordered according to their common key. Item number is the primary key of the inventory master file, and we will assume that this file is already in the proper sequence. Since the Line Item file contains the details of the Invoice file, it is probably organized by Invoice Number at this time. It is therefore necessary to sort this file on the Item Number field to place it in the same order as the Inventory file.
This process involves simply opening the file and invoking ACL’s Sort feature.