class CreateSettings < ActiveRecord::Migration def self.up create_table :settings do |t| t.string :var, :null => false t.text :value, :null => true t.integer :thing_id, :null => true t.string :thing_type, :limit => 30, :null => true t.timestamps end add_index :settings, [ :thing_type, :thing_id, :var ], :unique => true end def self.down drop_table :settings end end