Q1: ER modelling & logical design.
An information system is required for an online auction site, based on the following speci?cation:
Only registered users can use the site. Private users can either sell or bid, but commercial users are only allowed to sell via the site. Apart from user information, the database should also store information about items that are put up for sale. Customers can place a bid for an item or can cancel their bidding. They can also increase their previous offer. The database is meant to track all transactions and it is not intended to delete or modify previously entered data.
Develop an entity-relationship diagram annotated with multiplicities, and translate your design into SQL “CREATE TABLE” statements.