database concepts

Database design: conceptual model

Discount warehouseHonest Bob's Discount Warehouse Scenario

Honest Bob’s Discount Warehouse of 23 Dubious Lane Cheapside NT 8023 needs a computerised invoicing system. Because Honest Bob is a cheapskate they are still using a paper-based system.

The organisation has a number of customers, which are all businesses (Honest Bob’s does not deal with the general public, which avoids all the problems with GST). Information kept on customers includes their ABN (CustABN), business name and address (which includes the address, suburb, state and postcode). Because Honest Bob’s is keen on keeping their customers and having them return time after time, the prices there are suspiciously cheap.

When a customer purchases products they are given an invoice that lists the items purchased. Generally customers purchase a number of different items of varying quantities each time. If a customer decides that they haven’t got enough of a particular item, instead of increasing the quantity for that item, Honest Bob’s staff just add it again to the bottom of the invoice and give the new, updated copy to the customer.

Details on the invoice include the customer details, an invoice number, a date, an item number, its description, price, quantity ordered, subtotals for each item line and an invoice total.