Northwind does not go as far as actually adjusting inventory (either from
Sales or Purchases), although most of the fields are there. As it is, it's
more of a View Existing Data than Input New Data application.
My guess is that one reason it doesn't go further is because there's a whole
series of business rules that would need to be addressed, and too many
people would criticize (or take as gospel rather than giving any thought to)
whatever decision was made for a "sample" database (and where would *you*
stop adding functionality to a "sample" db?):
- when exactly do you want to take something out of inventory? When ordered?
when shipped?
- FIFO?, LIFO?
- How do you want to handle OutOfStocks (partial or full)? Backorders?
Returns?
- When are invoices generated (when ordered or when shipped?)
- what gets invoiced when OutOfStocks or BackOrders are involved?
(everything? just what you are able to ship? some other combination?)
- what's the mechanism for adding to On Order (i.e., Purchases from
suppliers)?
- what's the mechanism for moving product from OnOrder to InStock?
(presumably upon receipt)
- any mechanism to return product to supplier (and remove from InStock)?
HTH,