In: Computer Science
Consider an ONLINE_AUCTION database system in which members
(buyers and sellers) participate in the sale of items. Design an
ER/EER diagram for this ONLINE_AUCTION database. The data
requirements for this system are summarized as follows:
• The online site has members, each of whom is identified by a
unique member number and is described by an e-mail address, name,
password, home address, and phone number.
• A member may be a buyer or a seller. A buyer has a shipping
address recorded in the database. A seller has a bank account
number and routing number recorded in the database.
• Items are placed by a seller for sale and are identified by a
unique item number assigned by the system. Items are also described
by an item title, a description, starting bid price, bidding
increment, the start date of the auction, and the end date of the
auction.
• Items are also categorized based on a fixed classification
hierarchy (for example, a modem may be classified as COMPUTER →
HARDWARE → MODEM).
• Buyers make bids for items they are interested in. Bid price and
time of bid is recorded. The bidder at the end of the auction with
the highest bid price is declared the winner and a transaction
between buyer and seller may then proceed.
• The buyer and seller may record feedback regarding their
completed transactions. Feedback contains a rating of the other
party participating in the transaction (1–10) and a comment.