$($a$)$ Suppose someone uses the following table to store information about a course and information

about the lecturer of the course, which may lead to some potential problems when the data are

modified, added and removed. Suggest a better way to store the above mentioned information.

$(2$ marks$)$

$($b$)$ What are the purposes of primary keys and foreign keys? What integrity rules should be

enforced to the primary keys and foreign keys? Explain your answer.

$(4$ marks$)$

$($c$)$ What are the advantages of using a database to store and manage data $($i$.$e$.,$ rather than doing it

manually$).$

$(4$ marks$)$

$($d$)$

$(2$ marks$)$

$($e$)$ Referring to the following descriptions, draw the ER diagrams of the entities "Course",

"Student", "Department", "Professor" and their relationships using Crow's Foot Model. For

the relationship, mark both the cardinality and the connectivity. You do not need to list the

attributes of each entity, and do not need to mark the primary and foreign keys. Note that the

ER diagram must be drawn in the form that can be directly implemented in the relation

database.

Each student belongs to one department. Each professor works for a department. One

professor serves as the head of the department which he$/$she works in$.$ Each department

must have a head.

Each student can take several courses at the same time. The student may not take any

course.

Each professor teaches multiple courses. Each course is taught by one professor. The

professor may not teach any course.

Each professor supervises at least one student. Each student is supervised by one

professor.