gistfile1.txt

require 'rubygems'
gem 'dm-core'
require 'dm-core'

require 'pp'

DataMapper.setup(:default, 'sqlite3::memory:')
DataMapper::Logger.new(STDOUT, :info)
DataObjects::Sqlite3.logger = DataObjects::Logger.new(STDOUT, 0)

class User
  include DataMapper::Resource

  property :id, Serial
  property :name, String
  property :value, BigDecimal
  
  has n, :posts
  
  before :save do
     puts 'hello world'
     true
   end
end

class Post
  include DataMapper::Resource
  
  property :id, Serial
  property :title, String
  property :user_id, Integer
  
  belongs_to :user
  has n, :comments
end

class Comment
  include DataMapper::Resource
  
  property :id, Serial
  property :from, String
  property :content, String
  
  belongs_to :post
end

DataMapper.auto_migrate!

pp User.all(User.posts.comments.from => "John")