Associate a user to his playlists

db/migrate/20110830110346_add_user_id_to_playlists.rb

@@ -0,0 +1,9 @@
+class AddUserIdToPlaylists < ActiveRecord::Migration
+  def self.up
+    add_column :playlists, :user_id, :integer
+  end
+
+  def self.down
+    remove_column :playlists, :user_id
+  end
+end