ruby on rails - Twice belongs_to maps back to the same table 'User' -

class comment < activerecord::base    belongs_to :commenter, :class_name => "user", :foreign_key => "commenter_user_id"    belongs_to :student, :class_name => "user", :foreign_key => "student_user_id" 

they both belong user.

i if done once because helps make more clearer or whatnot ...

but why twice map same table?!?!?

so, result comment columns this:

  [0] "id",   [1] "comment",   [2] "student_user_id",   [3] "commenter_user_id",   [4] "created_at",   [5] "updated_at",   [6] "partnership_id" 

please excuse if seems same previous question. me, it's not. or maybe didn't enough. hm.

a comment can posted commentator user , comment can posted student user best define way

class comment < activerecord::base    belongs_to :commenter, :class_name => "user", :foreign_key => "commenter_user_id"    belongs_to :student, :class_name => "user", :foreign_key => "student_user_id" 

rather defining this

class comment < activerecord::base    belongs_to :commenter    belongs_to :student