Exercise No. 37: Online Auction Website
Transfer the following verbal description into an ERM
a) Customers (Cust-#) register a login (Username) for the online auction website. (They have to enter several information e.g. bank-details).
b) Each customer has a login identity, composed of username and password.
c) A customer can act as a buyer or a seller. As a seller he can start several auctions (A-#), as a buyer he can bid for auctions.
d) The auctions are classified into several categories (Cat-#). Each auction belongs to one category.
e) At the start, the seller has to choose the duration (Dur-ID) (e.g. 1 day, 2 days,. 10 days) of the auction and can upload one or more images (that can be sample or self-made images). Images (Image-ID) can be used in several auctions.
f) Each auction has product-specific information (Info-ID) (e.g. performance, wattage, water consumption etc.) Furthermore, at least one method of payment (Pay-#) and method of delivery (Delivery-#) must be specified.
g) Moreover, each customer can send and receive messages (Message-ID). It is not possible to address a message to more than one person.
h) Each customer has an evaluation scale (Eval-#), which may change over time.
i) One buyer wins the auction. After winning an auction, the buyer has to evaluate the seller.