Active Record CallbacksThis guide teaches you how to hook into the life cycle of your Active Record objects.After reading this guide, you will know: When certain events occur during the life of an Active Record object. How to register, run, and skip callbacks that respond to these events. How to create relational, association, conditional, and transactional callbacks. How to create objects that encapsulate common behavior for your callbacks to be reused.| Ruby on Rails Guides
Active Record AssociationsThis guide covers the association features of Active Record.After reading this guide, you will know how to: Declare associations between Active Record models. Understand the various types of Active Record associations. Use the methods added to your models by creating associations.| Ruby on Rails Guides