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@boyvanamstel
Created March 7, 2011 14:02
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Two ways to do many to many relations in RoR
# http://blog.hasmanythrough.com/2006/4/20/many-to-many-dance-off
# Join Table: Simple Associations
# Table:
create_table "dancers_movies", :id => false do |t|
t.column "dancer_id", :integer, :null => false
t.column "movie_id", :integer, :null => false
end
# Models:
class Dancer < ActiveRecord::Base
has_and_belongs_to_many :movies
end
class Movie < ActiveRecord::Base
has_and_belongs_to_many :dancers
end
# Join Model: Rich Associations
# Table:
create_table "appearances", do |t|
t.column "dancer_id", :integer, :null => false
t.column "movie_id", :integer, :null => false
t.column "character_name", :string
t.column "dance_numbers", :integer
end
# Models:
class Appearance < ActiveRecord::Base
belongs_to :dancer
belongs_to :movie
end
class Dancer < ActiveRecord::Base
has_many :appearances, :dependent => true
has_many :movies, :through => :appearances
end
class Movie < ActiveRecord::Base
has_many :appearances, :dependent => true
has_many :dancers, :through => :appearances
end
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