gistfile1.txt

#!/usr/bin/env ruby -Ku
 
# encoding: utf-8
 
require 'rubygems'
require 'dm-core'
require 'pp'
DataMapper::Logger.new($stdout, :debug)
DataMapper.setup(:default, 'sqlite3:memory:')
 
class Customer
  include DataMapper::Resource
 
  property :id,   Serial
  property :name, String
  property :age,  Integer
 
  has n, :orders
end
 
class Order
  include DataMapper::Resource
 
  property :id,             Serial
  property :reference_code, String
 
  belongs_to :customer
end
 
DataMapper.auto_migrate!

pp Order.all