Question

Create a database ER model using the following information please:

A small university is in the process of creating its first database system, and you are the chief architect of this system. This university does not have majors, faculties, and departments, but it does have programs. A program usually has 5 courses (in real situation, a program usually has much more courses, but to make the test data preparation easier, we set this number as 5), For simplicity, all the courses in a program are required and fixed. Prerequisite is not considered.

This university runs in a two-semester system: every year has Winter semester and Fall semester. In every semester, a course may be offered once or not be offered. A course-offering entity is necessary. A professor may teach any courses, and will teach one or more courses each semester. A student may register in a few programs. A course is passed when the grade is 60 or more.

Every person in the campus, a student or a professor, has an ID. This ID is uniformly managed, that means all the IDs are from the same pool, there is no special digit can be used to distinguish professors or students.

Please explain how you created the model.

Answer 1

Both student and Professor are sub-entity of super entity Person, in person his/her ID, name is stored.
Professor teaches one or many courses, but there is suppose to be one and only one professor for each course. There is another attribute semester, as every semester professor can teach different course(s). So a professor can have one or many course and course must have one and only one professor.
Student may be registered to few programs or zero program, and a program may have some student or zero student as it is not mandatory that a student mus be registered to atleast one program or a program should have atleast one student registered in it. So it shares 0 to many relationship from both side.
Student is offered courses every semester, and student are suppose to have atleast one course, and it may happen that a course is not offered to any student in a particular semester. So Student is suppose to have one or many course and a course may be offered to 0 or many students. Two extra attributes are there when a course is offered: 1) semester, as which semester which course was offered to which student, and 2) grade, as student score some grade in course they are offered so to know how much the student scored.

ER DIAGRAM: