gistfile1.rbx

# Right now if you do this and run rake db:automigrate (I'm using postgresql)
# it will generate a table called authors_books with one column called entity_id
# instead of adding 2 columns to the table (book_id, author_id).
#
# I think that means it is getting and using the parent model from the STI hierarchy
# This was an attempt to patch it up, it's working but it's breaking one spec
# http://github.com/lobo-tuerto/dm-core/commit/c2103bc1789c05685fb111194635fa13f5707ea9

class Entity
  include DataMapper::Resource

  property :id, Serial
  property :name, String
  property :type, Discriminator
end

class Book < Entity
  property :title, String
  has n, :authors, :through => Resource
end

class Author < Entity
  property :name, String
  has n, :books, :through => Resource
end


#This is the result
CREATE TABLE authors_books
(
  entity_id integer NOT NULL,
  CONSTRAINT authors_books_pkey PRIMARY KEY (entity_id)
)