[SQL] What is the best design for recurring courses system

I am working on a college management system project currently I am stuck on how I should design the recurring courses part in db and how it should connect to other parts of my system(quiz, grades,etc...).<br>

the problem I have with my current approach is that I can't find a way to store student registration (which can be multiple times for the same course if failed various times) and how I should store his grades with each registration with bloating every table with 3,4 foreign keys to know which course,and cycle this grade or registration belongs to whom or to which course

this is how I am doing right now

Continue reading...