I created a simple example as a sanity check and still can not seem to destroy an item on either side of a has_and_belongs_to_many relationship in rails.

Whenever I try to delete an object from either table, I get the dreaded NameError / "uninitialized constant" error message.

To demonstrate, I created a sample rails app with a Boy class and Dog class. I used the basic scaffold for each and created a linking table called boys_dogs. I then added a simple before_save routine to create a new 'dog' any time a boy was created and establish a relationship, just to get things setup easily.

dog.rb

class Dog < ActiveRecord::Base  
  has_and_belongs_to_many :Boys  
end  

boy.rb

class Boy < ActiveRecord::Base  
  has_and_belongs_to_many :Dogs  

  def before_save  
    self.Dogs.build( :name => "Rover" )  
  end  

end  

schema.rb

ActiveRecord::Schema.define(:version => 20100118034401) do

  create_table "boys", :force => true do |t|
    t.string   "name"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

  create_table "boys_dogs", :id => false, :force => true do |t|
    t.integer  "boy_id"
    t.integer  "dog_id"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

  create_table "dogs", :force => true do |t|
    t.string   "name"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

end

I've seen lots of posts here and elsewhere about similar problems, but the solutions are normally using belongs_to and the plural/singular class names being confused. I don't think that is the case here, but I tried switching the habtm statement to use the singular name just to see if it helped (with no luck). I seem to be missing something simple here.

The actual error message is:

NameError in BoysController#destroy
uninitialized constant Boy::Dogs

The trace looks like:

/Library/Ruby/Gems/1.8/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:105:in const_missing'
(eval):3:indestroy_without_callbacks'
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.4/lib/active_record/callbacks.rb:337:in destroy_without_transactions'
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.4/lib/active_record/transactions.rb:229:insend'
...

Thanks.