The underlying sales orders are stored in a table, SO_Main. These have a status of 0 for unprocessed orders. Lines of items (products) are stored in the SO_Lines table and are linked to a sales order via the SO_History table. SO_history links to SO_Main via the InvoiceID column, and SO_History links to SO_Lines via the InvoiceHistoryID column.
If you open the Inventory maintenance form, there are two places you can see unprocessed sales for a particular product:
1. The Order -> Unprocessed sales tab
This tab has it's data fed to it from the stored procedure usp_JIWA_Inventory_BuildGrid_OnUnprocessedSalesOrders - if you examine the queries in that stored procedure you'll see the root of the unprocessed sales information
2. The S.O.H. -> Warehouse Summary tab
This tab has it's data fed to it from the stored procedure usp_JIWA_Warehouse_SOH_Summary
You can identify which queries are used by using a profile trace whilst using the application. Often data is lazy loaded, so the data is not read until the tab is pressed - as is the case with the above two tabs - so you could start a profile trace, press the tab and then in the profile trace it will show the SQL query(s) issued.