How to load the data from legacy in to three table format

Hi All,

Please help me in steps to prepare the data from the legacy system to upload to Demantra through custom model build, where we refer to 3 table structure i.e. Sales, Location, Item in txt or csv file.

In this case How to prepare the data for sales, location, item?

Which means, what columns should be present in each file and how establish the relationship between these three files)

We want to have structure as:

Item:

Product Code>> Product Description >> Category >> Category Description

                                                           >> Brand >> Brand Description

Location:

Org Code >> Org Description >> Operating Unit >> OU Description

Sales:

Org, Item, Order Quantity, Shipped Qty, Shipped Date.