add 'removed' flag to books (used instead of actual removal)

app/models/book.rb

@@ -5,6 +5,8 @@ class Book < ActiveRecord::Base
 
   validate :isbn_is_valid
 
+  default_scope order('created_at DESC').where(:removed => false)
+
   def isbn_is_valid
     true
   end

db/migrate/20101130031704_add_removed_to_book.rb

@@ -0,0 +1,9 @@
+class AddRemovedToBook < ActiveRecord::Migration
+  def self.up
+    add_column :books, :removed, :boolean, :default => false
+  end
+
+  def self.down
+    remove_column :books, :removed
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 20101128042909) do
+ActiveRecord::Schema.define(:version => 20101130031704) do
 
   create_table "books", :force => true do |t|
     t.string   "isbn",        :limit => 13
@@ -22,6 +22,7 @@
     t.datetime "created_at"
     t.datetime "updated_at"
     t.integer  "user_id"
+    t.boolean  "removed",                                                 :default => false
   end
 
   create_table "users", :force => true do |t|