dependent => destroy on a "has_many through" association

ruby-on-rails activerecord has-many-through
blogofsongs picture blogofsongs · Sep 9, 2009 · Viewed 39.1k times · Source

Apparently dependent => destroy is ignored when also using the :through option.

So I have this...

class Comment < ActiveRecord::Base
  has_many :comment_users, :dependent => :destroy
  has_many :users, :through => :comment_users
  ...
end

...but deleting a Comment does not result in the associated comment_user records getting deleted.

What's the recommended approach, then, for cascade deletes when using :through?

Thanks

Answer

blogofsongs picture blogofsongs · Sep 9, 2009

Apparently :dependent is not ignored!

The real issue was that I was calling Comment.delete(id) which goes straight to the db, whereas I now use Comment.destroy(id) which loads the Comment object and calls destroy() on it. This picks up the :dependent => :destroy and all is well.

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