Add support for commenting on, and replying to, diary entries.

db/migrate/010_diary_comments.rb

@@ -0,0 +1,21 @@
+class DiaryComments < ActiveRecord::Migration
+  def self.up
+    create_table "diary_comments", myisam_table do |t|
+      t.column "id",             :bigint,   :limit => 20, :null => false
+      t.column "diary_entry_id", :bigint,   :limit => 20, :null => false
+      t.column "user_id",        :bigint,   :limit => 20, :null => false
+      t.column "body",           :text,                   :null => false
+      t.column "created_at",     :datetime,               :null => false
+      t.column "updated_at",     :datetime,               :null => false
+    end
+
+    add_primary_key "diary_comments", ["id"]
+    add_index "diary_comments", ["diary_entry_id", "id"], :name => "diary_comments_entry_id_idx", :unique => true
+
+    change_column "diary_comments", "id", :bigint, :limit => 20, :null => false, :options => "AUTO_INCREMENT"
+  end
+
+  def self.down
+    drop_table "diary_comments"
+  end
+end