How to identify sales Order for an orphan delivery

Summary: Orphan Delivery and Sales Order Association

Content (required): Once the delivery is unassigned either due to back order or due to changes at the sales order level, delivery_id column in wsh_delivery_assignments is removed. We have a requirement to keep track of all the deliveries that are created for sales orders. Could you please suggest what would be the way to achieve it?

select wnd.delivery_id, wdd.delivery_detail_id

from wsh_new_deliveries wnd, wsh_delivery_assignments wda, wsh_delivery_details wdd

where wda.delivery_id=wnd.delivery_id

and wdd.delivery_detail_id=wda.delivery_detail_id;