commit.rb

module Integrity
  class Commit
    include DataMapper::Resource

    property :id,           Integer,  :serial => true
    property :identifier,   String,   :nullable => false
    property :message,      String,   :nullable => false, :length => 255
    property :author,       String,   :nullable => false, :length => 255
    property :committed_at, DateTime, :nullable => false

    belongs_to :project, :class_name => "Integrity::Project"
  end
end

debugger_session.rb

(rdb:1) p self.commits
[#<Integrity::Commit id=7 identifier="4fdc7c15ab0829c55c2ef92b6878d61f637194cf" message="Alburn gympie osmosis uninterestedness mallowwort" author="microorganismal queanish <persiflate@example.org>" committed_at=#<DateTime: 1178487059/480,-1/12,2299161> project_id=8>, #<Integrity::Commit id=8 identifier="a5b8106f94d4622a974ea7bdafad1affb3de6ce2" message="Perlid muddleheaded maladventure scaphocephalic boomage crinite lignin uitotan" author="Ficula unhappily <fruitery@example.org>" committed_at=#<DateTime: 441932647/180,-1/12,2299161> project_id=8>]

(rdb:1) p self.commits.map {|c| c.committed_at.to_s }
["2009-12-15T18:57:00-02:00", "2009-12-15T18:56:00-02:00"]

(rdb:1) p self.commits(:order => [:committed_at.desc])
[]

project.rb

module Integrity
  class Project
    include DataMapper::Resource

    property :id,         Integer,  :serial => true
    property :name,       String,   :nullable => false
    property :permalink,  String
    property :uri,        URI,      :nullable => false, :length => 255
    property :branch,     String,   :nullable => false, :default => "master"
    property :command,    String,   :nullable => false, :length => 255, :default => "rake"
    property :public,     Boolean,  :default => true
    property :building,   Boolean,  :default => false
    property :created_at, DateTime
    property :updated_at, DateTime

    has n, :commits, :class_name => "Integrity::Commit"
  end
end