Rails 3 - has_and_belongs_to_many

Question

I have 2 models - Teacher and Subject. A want to connect them via Join table with name Qualification.

It looks like i

Answer 1

First, creating the table in a migration doesn't define your model. You have to create a Qualification model in app/models/qualification.rb:

class Qualification < ActiveRecord::Base
  belongs_to :subjects
  belongs_to :teachers
end

Second, if you're using Rails 3, throw out has_and_belongs_to_many and use has_many :through:

class Teacher < ActiveRecord::Base
  has_many :qualifications
  has_many :subjects, :through => :qualifications
end

class Subject < ActiveRecord::Base 
  has_many :qualifications
  has_many :teachers, :through => :qualifications
end