Task2-2 E-R diagram-book collector (15 points) Scenario: a private book collector is designing a database to keep track of her purchases and book holdings. Consider the entity set Book with attributes title, author, publisher, pubDate, numberPages, condition, cost, and datePurchased. There is an entity set called Purchase with attributes purchaseDate, totalAmount, and any others you wish to add to describe book purchases. A purchase may include several books.

Requirement:

2-2.a . Create an E-R diagram to show how this entity set (Purchase) and its relationship to Book would be represented. Indicate primary keys. Stating any necessary assumptions, make a decision about the cardinality and participation constraints of the relationship, and add appropriate symbols to the E-R diagram.

2-2.b (5 points). Assume there is another entity called Seller to be added to the diagram. The book collector makes purchases from many sellers, but each purchase is made from one seller. Making up attributes as needed, add this entity and appropriate relationship(s) to the diagram.

Task2-3 ER-diagram-college students Scenario: there is a database to keep data about college students, their academic advisors, the clubs they belong to, the moderators of the clubs, and the activities that the clubs sponsor. Assume each student is assigned to one academic advisor, but an advisor counsels many students. Advisors do not have to be faculty members. Each student can belong to any number of clubs, and the clubs can sponsor any number of activities. The club must have some student members in order to exist. Each activity is sponsored by exactly one club, but there might be several activities scheduled for one day. Each club has one moderator, who might or might not be a faculty member. Draw a complete E-R diagram for this example. Include all constraints, for example, indicate primary keys, and state any necessary assumptions, make a decision about the cardinality and participation constraints of the relationship, and add appropriate symbols to the E-R diagram.