Setting up models for tutor website

Question

I'm wondering what the best way would be to set up models in Ruby on Rails for a tutoring website.

I would like the users to register (I have no particular way in mind but I'm assuming I'll go with one of the more popular ruby gems). They can then choose to be either tutors or students or both. Should I make a tutors model, a students model and have them inherit basic info from the authentication? Or would it be better to have a users model where all the basic info goes (birthday, gender) and then have student/tutor inherit from that?

score 1 · Answer 1 · answered Jul 22 '13 at 11:57

I would have a User model with the basic information and then something like this:

class User
  has_many :course_students
  has_many :student_courses, through: :course_students, class_name: "Course"

  has_many :course_tutors
  has_many :tutored_courses, through: :course_tutors, class_name: "Course"

end

class Course
  has_many :course_students
  has_many :students, through: :course_students, class_name: "User"

  has_many :course_tutors
  has_many :tutors, through: :course_tutors, class_name: "User"
end

class CourseStudent
  belongs_to :course
  belongs_to :student, class_name: "User"
end

class CourseTutor
  belongs_to :course
  belongs_to :tutor, class_name: "User"
end

This way a user can easily be a tutor and student and just has to have the shared information. I'd probably insert dedicated tutor/student models, if the need arises.

What about `student_courses` and `tutored_courses`? What would those look like? This seems like overkill. — Adam Grant, Jul 22 '13 at 13:01

score 0 · Accepted Answer · answered Jul 22 '13 at 09:52

0

I think it is better for Student and Tutor to inherit from your User model. You can choose to still keep the data in the same database table using STI in rails.

This approach will ensure that there is a clear separation of responsibility in your domain, while re-using the same authentication (and later authorization) flow.

answered Jul 22 '13 at 09:52

pungoyal

1,768
15
17

The only problem I see with this is that STI can cause a bunch of nil fields. So for instance, students will not have a fee, as they will be paying the fee to tutors. That will cause every student to have a null field in the fee column. Isn't that a poor design choice? – DaniG2k Jul 22 '13 at 10:15
if you begin to see that happening, then split out the data into separate tables. http://railscasts.com/episodes/394-sti-and-polymorphic-associations is a brilliant resource on the subject. – pungoyal Jul 22 '13 at 10:31

Setting up models for tutor website

2 Answers2