Add some files.

.gitignore

@@ -1,4 +1,5 @@
 /.bundle/
+vendor/bundle
 /.yardoc
 Gemfile.lock
 /_yardoc/

example.activerecord

@@ -0,0 +1,62 @@
+require 'active_record'
+ 
+ActiveRecord::Base.logger = Logger.new(STDERR)
+ActiveRecord::Base.colorize_logging = false
+ 
+ActiveRecord::Base.establish_connection(
+    :adapter => "sqlite3",
+    :dbfile  => ":memory:"
+)
+ 
+ActiveRecord::Schema.define do
+    create_table :albums do |table|
+        table.column :title, :string
+        table.column :performer, :string
+    end
+ 
+    create_table :tracks do |table|
+        table.column :album_id, :integer
+        table.column :track_number, :integer
+        table.column :title, :string
+    end
+end
+ 
+class Album < ActiveRecord::Base
+    has_many :tracks
+end
+ 
+class Track < ActiveRecord::Base
+    belongs_to :album
+end
+ 
+album = Album.create(:title => 'Black and Blue',
+    :performer => 'The Rolling Stones')
+album.tracks.create(:track_number => 1, :title => 'Hot Stuff')
+album.tracks.create(:track_number => 2, :title => 'Hand Of Fate')
+album.tracks.create(:track_number => 3, :title => 'Cherry Oh Baby ')
+album.tracks.create(:track_number => 4, :title => 'Memory Motel ')
+album.tracks.create(:track_number => 5, :title => 'Hey Negrita')
+album.tracks.create(:track_number => 6, :title => 'Fool To Cry')
+album.tracks.create(:track_number => 7, :title => 'Crazy Mama')
+album.tracks.create(:track_number => 8,
+    :title => 'Melody (Inspiration By Billy Preston)')
+ 
+album = Album.create(:title => 'Sticky Fingers',
+    :performer => 'The Rolling Stones')
+album.tracks.create(:track_number => 1, :title => 'Brown Sugar')
+album.tracks.create(:track_number => 2, :title => 'Sway')
+album.tracks.create(:track_number => 3, :title => 'Wild Horses')
+album.tracks.create(:track_number => 4,
+    :title => 'Can\'t You Hear Me Knocking')
+album.tracks.create(:track_number => 5, :title => 'You Gotta Move')
+album.tracks.create(:track_number => 6, :title => 'Bitch')
+album.tracks.create(:track_number => 7, :title => 'I Got The Blues')
+album.tracks.create(:track_number => 8, :title => 'Sister Morphine')
+album.tracks.create(:track_number => 9, :title => 'Dead Flowers')
+album.tracks.create(:track_number => 10, :title => 'Moonlight Mile')
+ 
+puts Album.find(1).tracks.length
+puts Album.find(2).tracks.length
+ 
+puts Album.find_by_title('Sticky Fingers').title
+puts Track.find_by_title('Fool To Cry').album_id

lib/timecost/environment.rb

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+require 'active_record'
+ 
+ActiveRecord::Base.logger = Logger.new(STDERR)
+ActiveRecord::Base.colorize_logging = false
+ 
+ActiveRecord::Base.establish_connection(
+    :adapter => "sqlite3",
+    :dbfile  => ":memory:"
+)
+ 
+ActiveRecord::Schema.define do
+    create_table :albums do |table|
+        table.column :title, :string
+        table.column :performer, :string
+    end
+ 
+    create_table :tracks do |table|
+        table.column :album_id, :integer
+        table.column :track_number, :integer
+        table.column :title, :string
+    end
+end
+