Inventory db query

[DuLaus]

Hi

I have to keep a running total of parts on hand (widgets) before ordering from
the wholesaler, then do another query if all are sold out on that day (just in
time delivery). The inventory column would be the maximum in stock that day,
and the sales would represent how many sold today.

Can anyone advise how to subtract the sales table (part) from the widgets
table (part). The part numbers will also be different from the example I have
given and could be something like XA-44, B2533 etc, depending on suppliers
(widgets) table.

Thanks

Widgets table

Part Inventory Description

A1 3 copper
A2 5 zinc
A2 7 gold


Sales table

Part Date Sold CustomerID

A2 11-Jul-05 41444
A3 11-Jul-05 53453
A1 11-Jul-05 82546
A1 19-Jul-05 21355

[DuLaus]

Hi

Would maintaining an running inventory be better with using numbers for
comparison in these tables. What I was thinking of was having another column in
the sales table (sold) and sold being equal to 1. This would be inserted at
time of order in the sales table (sold) column.

Thanks