1- Design an EER diagram for a library as described below. Show relevant constraints. (40 points)

a. Each employee has an SSN, fname, lname, and address.

b. An employee is classified into one of three categories: managerial, research, and floor. Floor employees are paid by the hour and have an hourly wage rate. The other two categories have a salary. Research workers have a specialty, while managerial workers have a job title.

c. Customers are identified by their card number, and also have a fname, lname, and address.

d. Each book is identified by its LCN (Library of Congress Number). It has a title, and one or more authors.

e. An author has as a key an author code, since fname, lname does not suffice. We also keep track of their birth date and date of death.

f. Customers may check out books. We keep track of the date it was checked out, as well as the date of return if it has been returned.

g. Each time a book is checked out, we want to track which employee was involved in that transaction. Checking out a book can be handled by floor or research staff, but not managerial staff.

h. Each member of the floor staff has exactly one member of the managerial staff as a supervisor.

Your EER diagram of the library database. Make sure to include in your diagram the following whenever possible:

Entity types and relationship types

Union/Category

Specialization/Generalization

Cardinality constraints

Discuss any assumptions and justify your EER design choices