CELKO (9/6/2012)
SELECT CONVALESCE (upc, family_upc) AS item_upc, purchase_dateFROM Inventory
ORDER BY item_upc, purchase_date;
CONVALESCE? I can't find these on any SQL books, just medicine.
The design is poor? it might be but it's not the actual design, just an example to ask for help.
Your solution won't work because it's not what the OP needs.