JPA,RELATIONSHIP BEGINEER MANY TO MANY with some complexity

Question

I have 4 Entities in My domain model which is an Professor College Department and Role. The use case are

1. Professor can only work for one college which makes One to Many Relation ship (College -> Professor)
2. Professor will have a Many Roles at college level (Admin, Food Inspector ??)
3. Professor can work for many departments (Many to Many)

4. In each department professor may have a different role

   class Professor {
       @ManyToOne
       private College workingWithCollege;
       @JoinTable(name = "professor_college_role",
                  joinColumns = @JoinColumn(name = "professor_id"),
                  inverseJoinColumns = @JoinColumn(name = "role_id"))
       @OneToMany
       private Collection<Role> roles;
    }
   
   class College {
   
   }
   
   
   class Department {
   
   }
   
   class DepartMentRole {
       @ManyToOne
       private Department department;
       @ManyToOne
       private Role role;
       //TODO: Dont know how exactly to solve this
   }
   
   class ProfessorDepartmentRole {
        @OneToOne
        private Professor professor;
        @OneToMany
        private Collection DepartmentRole;
   }
   

DO we really need Department Role how to connect a professor to a department and a role for that department

Answer 1

I would convert the ProfessorDepartmentRole class to a Many to Many (as suggested by KLibby). So to answer your question, we do retain the DepartmentRole class. Also, then you can remove the collection roles from Professor class since you can derive the roles via the 2 join tables.