Latest Screencasts (page 7)

Did you know ActiveRecord provides class methods for performing calculations on models? You can even use these methods through associations.

Learn how to use with_scope - a very powerful method which will allow your custom find methods to accept any find options. Just like magic!

Move a find into the model to clean up the controllers and remove duplication. Also see how you can call these custom find methods through an association.

No need to pass foreign keys in find conditions, just do the find through a has_many association.

Shorten simple finds considerably and improve readability by using the dynamic find_all_by and find_by methods.