Composite Primary KeysThis guide is an introduction to composite primary keys for database tables.After reading this guide you will be able to: Create a table with a composite primary key Query a model with a composite primary key Enable your model to use a composite primary key for queries and associations Create forms for models that use composite primary keys Extract composite primary keys from controller parameters Use database fixtures for tables with composite primary keys| Ruby on Rails Guides
Active Record Connection Adapters Table Definition Represents the schema of an SQL table in an abstract way. This class provides methods for manipulating the schema representation.| api.rubyonrails.org
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
Configuring Rails ApplicationsThis guide covers the configuration and initialization features available to Rails applications.After reading this guide, you will know: How to adjust the behavior of your Rails applications. How to add additional code to be run at application start time.| 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.| Ruby on Rails Guides
