I have a Deck object and a Card object with their corresponding tables.
(You
know a deck of cards.) When I destory a Deck it leaves orphaned cards
in
the database. Is there a way to set up the objects with ActiveRecord so
that
when a parent object is destoryed the child objects are destroyed as
well?
My code below.
class Deck < ActiveRecord::Base
has_many :cards
end
class Card < ActiveRecord::Base
belongs_to :deck
end
def destroy
Deck.find(params[:id]).destroy
redirect_to :action => ‘list’
end
Michael Whitman wrote:
I have a Deck object and a Card object with their corresponding tables.
(You know a deck of cards.) When I destory a Deck it leaves orphaned
cards in the database. Is there a way to set up the objects with
ActiveRecord so that when a parent object is destoryed the child objects
are destroyed as well? My code below.
Take a look at the :dependent option for has_many associations:
http://api.rubyonrails.com/classes/ActiveRecord/Associations/ClassMethods.html#M000530
:dependent - if set to :destroy all the associated objects are destroyed
alongside this object by calling their destroy method. If set to
:delete_all all associated objects are deleted without calling their
destroy method. If set to :nullify all associated objects? foreign keys
are set to NULL without calling their save callbacks. NOTE: :dependent
=> true is deprecated and has been replaced with :dependent => :destroy.
May not be set if :exclusively_dependent is also set.
So you want something like:
class Deck < ActiveRecord::Base
has_many :cards, :dependent => :destroy
end
class Card < ActiveRecord::Base
belongs_to :deck
end
hth