I have a before_save in my Message model defined like this:
before_save
Message
class Message < ActiveRecord::Base before_save lambda { foo(
update_all won't trigger callbacks
update_all
my_message.update_all(:created_at => ...) # OR Message.update_all({:created_at => ...}, {:id => my_message.id})
http://apidock.com/rails/ActiveRecord/Base/update_all/class