rails / acts_as_nested_set

ActsAsNestedSet
==============
 
This acts_as extension provides Nested Set functionality.  Nested Set is similiar to Tree, but with the added feature that you can select the children and all of their descendents with a single query.  A good use case for this is a threaded post system, where you want to display every reply to a comment without multiple selects.
 
 
Example
=======
 
  class Product < ActiveRecord::Base
    acts_as_nested_set
  end
 
 
Copyright (c) 2007 David Heinemeier Hansson, released under the MIT license