Question

Question 4 Needs Grading Q1) (2.5 Points ) We would like to design a database to keep track of a zoo. The following describes the business of the zoo: • The zoo employees are known as zookeepers. Each zookeeper has a name, a unique employee ID number, and a salary. Zookeepers may work in any number of exhibits but they have to be involved in at least one exhibit. A zookeeper does not have to work in an exhibit to head it. • The zoo has several exhibits. Each one has an exhibit name and a head zookeeper who is in charge of it. A zookeeper may head many exhibits, but each exhibit has at most one head. • Each zookeeper has at most one manager, who is another zookeeper. A zookeeper can manage any number of employees, including none. • The zoo has many animals. Each has a name, species, unique ID number, and a weekly budget for its care. Each animal is tended by at least one zookeeper, and may appear in at most one exhibit. Draw an E-R diagram that captures this information. Specify in the diagram the primary keys, the cardinality and participation constraints.

Answer 1

ER Diagram for Zoo Database:

The primary keys are:

Name Name M Exhibits works in -M- Zookeepers -M- Unique ID M Head zookeeper tended by Salary Managed by in 1 Animals Weekly budget Unique ID Managers Name Species

ZooKeepers - name, unique_ID,

Exhibits - Name,

Animals - Name, unique_ID

The cardinality of the ER diagram is represented as 1 to 1 or 1 to M or M to 1 or M to M. It is written on line connecting entity and relations

The participation constraints whether entity has total or partial participation. Total participation is represented by drawing double lines.