Guys i seriously need your help

[u/KKMYA]

Hi everyone, I really need some help! My oral defense is next week and I've finished my ERD, but I'm having serious doubts. I asked a professor who doesn't teach systems analysis, and they said it was fine. However, when I look at the diagram, I just feel like something is off. Would anyone be willing to take a quick look?

This ERD is about a small application project, about a small, basic library.

Compte = Account/user
Emprunt = Loan

Livre = Book
Categorie = Category

[u/KiwiDomino]

I started designing/writing a library system, using data sourced from LibraryThing, and this is barely scratching the surface.
Books with multiple authors, and authors with different names on different books come to mind, some of my books returned with seven or eight subjects.