You receive a task from the university to design a database for the university’s registration system. You are told that each student has a student id, email, name, and GPA. Every student is uniquely identified by their student id. Each course has an id, name, and credits. Each course is uniquely identified by its course id. Each professor has a staff id, email and name. Each professor is uniquely identified by their staff id. Draw an ER diagram that captures each of the following scenario (5 ER diagrams in total):

1. Each course is taught by one or more professors and each professor can teach zero or many courses. Students can register for zero or many courses and each course must have at least one student taking it. The university tells you that every time a student registers for a course, they want to keep track of the semester when the student registers. If the student registers the same course twice at different semesters, they want to be able to keep track of both registrations.

2. Now, the university does not think that it is necessary to keep track student’s registration on the same course multiple times. They just want to keep track only the last semester that the student registers for the course. For example, if Sam registers for CSci 4707 on Fall 2021 and Spring 2022, we only need to keep track of the registration on Spring 2022. HINT: you cannot really specify which semester we want to keep in the database as this is the application logic not the database logic. What you can do is to ensure each registrations only appear once.