Active Record Basics — Ruby on Rails Guides

Active Record BasicsThis guide is an introduction to Active Record.After reading this guide, you will know: How Active Record fits into the Model-View-Controller (MVC) paradigm. What Object Relational Mapping and Active Record patterns are and how they are used in Rails. How to use Active Record models to manipulate data stored in a relational database. Active Record schema naming conventions. The concepts of database migrations, validations, callbacks, and associations.