Ruby on Rails: Model Association with multiple foreign keys

Question

I am working on a User model, and each user should be able to have both students and teachers. However, since student and teacher are both a t

Answer 1

You should separate out the teacher_student_links association into two associations:

  has_many :teacher_links, :foreign_key => :student_id, :dependent => :destroy, :class_name => "TeacherStudentLink"
  has_many :student_links, :foreign_key => :teacher_id, :dependent => :destroy, :class_name => "TeacherStudentLink"
  has_many :students, :through => :student_links
  has_many :teachers, :through => :teacher_links

You might need to add the foreign keys to the belongs_to association on TeacherStudentLink also

Update:

Regarding your second question about creating links, the following should work:

@user = User.find(params[:id])
@user.students << current_user

The TeacherStudentLink should be created automatically, and your associations should work if everything is set up correctly.