Question

An ER model contains:
• Student with attributes: StudentID, Name, Age 
• Course with attributes: CourseID, Title 
• A many-to-many relationship Enrols between Student and Course, with attribute Grade In the relational design, a separate table is needed to capture the relationship and its attribute. 
The correct schema design is?

• A. The Enrols relationship can be represented as a table with columns: StudentID, CourseID, Grade only, with no foreign keys
• B. The relational schema will have three tables: Student, Course, Enrols, where Enrols includes StudentID and CourseID as foreign keys referencing Student and Course
• C. The relational schema can merge Enrols into Student table without violating normalization
• D. The relational schema will have two tables only: Student and Course, since Enrols is many-to-many and does not require a separate table

Hint:

Whenever you see a Many-to-Many relationship in an ER diagram, remember: $N$ entities $+ 1$ relationship $= N+1$ tables. For 1:N relationships, you usually only need $N$ tables (by using a Foreign Key in the "Many" side).

Answer 1

The Correct Option is B