A polymorphic association allows a model to belong_to different types of other models. Here I show how to make a single comment model belong to articles, photos, and events. (11 minutes)

Handling multiple models in a single form is easy with accepts_nested_attributes_for. Here you will also learn how to add and remove nested records through JavaScript. (11 minutes)

Postgres offers full-text searching right out of the box. This episode shows how to write queries from scratch, apply tools like Texticle and pg_search, and optimize performance through indexes. (16 minutes)

Postgres is a feature-packed relational database that every Rails developer should consider using. Here you will learn how to install it, add it to a new application, and transition from an existing SQLite app using the "taps" gem. (8 minutes)

Rails has great internationalization (I18n) support making it easy to translate static text into other languages, but how do we translate database content? Learn how using Globalize 3 in this episode. (5 minutes)

One of the most common security issues in a Rails application is the mass-assignment vulnerability which allows a user to set any attribute on the model. Learn how to prevent it in this episode. (6 minutes)

A many-to-many association can be edited through check boxes in a form. Here I show how to do this with a has_many through association complete with clickable labels. (6 minutes)

Sphinx is a full-text search engine for use with MySQL or PostgreSQL. Learn how to add Thinking Sphinx by defining an index on your model and searching with various options. (10 minutes)

MetaWhere provides a way to do complex find conditions without SQL in Active Record. MetaSearch makes it easy to create search forms with many find options. (8 minutes)

The new Active Record query methods in Rails 3 might seem like magic at first. But in this episode I unravel how it works by browsing the Rails 3 source code. (11 minutes)