delete child when parent is deleted is not working.

Question

Well the situation is bit more complicated than that !

I have a question model

class Question < ActiveRecord::Base
  has_many :answers, :dependent => :destroy

then an answer Model

class Answer < ActiveRecord::Base
  belongs_to :question, :counter_cache => true
  has_many :rep_events, :class_name => "RepEvent", :foreign_key => "event_id", :dependent => :destroy

and Finaly a rep_event model

class RepEvent < ActiveRecord::Base
  belongs_to :answer   
end

My rep event doesnt have any primary key. it only has event_id that acts like answer_id

When i destroy a Question, I want to delete everything that is related to it ( Question, Answers and Rep_Events ) Thats why I'm using :dependent => :destroy I tried to enter the console and test it but it gives me some error

NoMethodError: undefined method `eq' for nil:NilClass

This error is very general but I believe the problem is that my rep_event class does not have any "answer_id" field but only event_id. thats why I used foreign_key => "event_id" in my relationship.

Can anyone tell me what the problem is ?

Thank you

Answer 1

The foreign key is not present in the Answer model, instead RepEvent model has a foreign key called 'event_id' that acts like answer_id, and links to the Answer model. If this scenario is right you will have to do following changes in the RepEvent model

class RepEvent < ActiveRecord::Base
  belongs_to :answer, :foreign_key => event_id
end

and in your Answer model

class Answer < ActiveRecord::Base
  belongs_to :question, :counter_cache => true
  has_many :rep_events, :class_name => "RepEvent", :dependent => :destroy
end

Try this this must work.