Prev | Current Page 443 | Next

Carl Reynolds and Paul Tymann

"Schaum's Outline of Principles of Computer Science"

Some customers require delivery, so the owner maintains relationships with several local movers.
The owner wants to keep track of customers in order to do a better job of marketing. In particular, they
know that some customers are particularly interested in certain types of antiques, and they??™d like to be
able to find, for example, all those customers interested in cameo jewelry.
For business auditing and tax purposes, it??™s very important that the database tracks expenditures and
revenues. The owner wants to track what they spent for each item, and what they earned in selling it.
These requirements also mean that they have to track store expenses like rent and heat, and their
employee expenses (they employ two part-time people to help run the store).
8.3 An inexperienced database designer suggested the following schema for one of the tables in the antique
store database:
Sales
Is this schema in 1NF?
Is this schema in 2NF?
Is this schema in 3NF?
If the answer to any of these questions is, ???No,??? redesign the table so that the result is in 3NF.
8.4 Two of the tables in the antique store database will be a table of Deliveries, and a table of
Delivery_Services. Here are the schemas for the two tables:
166 DATABASE [CHAP.


Pages:
431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455
noclegi hel tanie pensjonaty nad morzem Lokaty jednodniowe projekty domków letniskowych męskie skarpetki rowerowe