JPA @ManyToOne no mappedBy attribute exist
Why doesn't the @ManyToOne JPA specification have a mappedBy attribute? @ManyToOne has both unidirectional and bidirectional relationships, but @OneToMany has only unidirectional relationships. Why is that?
Because the spec mandates that in a bidirectional OneToMany/ManyToOne association, the Many side must be the owner side (and thus doesn't need a mappedBy attribute), and the One side must be the inverse side (and thus needs a mappedBy attribute).