Systems Analytics And Enterprise Management - 3

IT 7000 Systems Analytics & Enterprise Management EMBA

Week 3: ERD CASE STUDY

A university database contains information about professors (identified by social

security number, or SSN) and courses (identified by course_id). Professors teach

courses; each of the following situations concerns the Teaches relationship set.

Foreach situation, draw an ER diagram that describes it (assuming that no further

constraints hold).

1. Professors can teach the same course in several semesters, and each offering

must be recorded.

2. Professors can teach the same course in several semesters, and only the most

recent such offering needs to be recorded (assume this condition applies in all

subsequent questions)

3. Every professor must teach some course.

4. Every professor teaches exactly one course.

5. Every professor teaches exactly one course and every course must be taught by

some professor.

6. Now suppose that certain courses can be taught by the team of professors

jointly, but it is possible that no one professor in a team can teach the course.

✓ Model this situation introducing additional entity set, and relationship sets it necessary.

✓ Design and draw an ER diagram for the following collection of data. Use only the basic ER model.