vendor/rails/activerecord/test/models/vertex.rb

   1 # This class models a vertex in a directed graph.
   2 class Vertex < ActiveRecord::Base
   3   has_many :sink_edges, :class_name => 'Edge', :foreign_key => 'source_id'
   4   has_many :sinks, :through => :sink_edges
   5
   6   has_and_belongs_to_many :sources,
   7     :class_name => 'Vertex', :join_table => 'edges',
   8     :foreign_key => 'sink_id', :association_foreign_key => 'source_id'
   9 end