require "rubygems"
require "dm-core"
require "dm-constraints"

DataMapper.setup(:default, {
  :adapter  => 'mysql',
  :database => "constraint_test",
  :username => 'root',
  :password => '',
  :host     => '127.0.0.1',
  :encoding => 'UTF-8'
})

class Post
  include DataMapper::Resource
  has n, :comments, :constraint => :destroy

  property :id,         Serial
  property :body,       Text
end

class Comment
  include DataMapper::Resource

  belongs_to :post

  property :id,         Serial
  property :body,       Text
end

DataMapper.auto_migrate!

post = Post.create(:body => "hello world")
comments = post.comments.create(:body => "hello brazil")
comments = post.comments.create(:body => "hello canada")

puts "the post has #{post.comments.length} comments"
post.destroy
puts "after destroy the post now has #{post.comments.length} comments"