UC3001 – Enroll in Subject Implementation

Initiating actor: Student Other actors: None

Description: Student registers for an available course module matching their faculty division and selects an associated professor who oversees that course instance.

Scenario:

1. System displays the Student Menu interface.
2. Student selects the option to "Enroll in Subject".
3. System outputs a full list of registered students, and the user selects their unique Student ID.
4. System identifies the student's faculty association and filters all valid available subjects:

   SELECT s.Id, s.Name 
   FROM Subject s 
   JOIN Student st ON s.Faculty_Id = st.Faculty_Id 
   WHERE st.Id = ?;
   

Student selects a target Subject ID from the listing.

5. System queries and displays all professors affiliated with the faculty offering that selected subject:

   SELECT p.Id, p.Name, p.Surname 
   FROM Professor p 
   JOIN Subject s ON p.Faculty_Id = s.Faculty_Id 
   WHERE s.Id = ?;
   

Student selects a specific Professor ID.

6. System performs an validation check to ensure a duplicate active enrollment does not already exist:

   SELECT * FROM Student_Subject WHERE Student_Id = ? AND Subject_Id = ?;
   

7. If no prior enrollment is found, the system saves the record using the baseline registration status:

   INSERT INTO Student_Subject (Student_Id, Subject_Id, Professor_Id, Status, Enrollment_Date, Absences_Count)
   VALUES (?, ?, ?, 'Enrolled', CURRENT_DATE, 0);
   

8. System prints a terminal message confirming that course enrollment completed successfully.

Implementation Screenshots