ActiveRecord relationships can sometimes be a little confusing to newcomers; and even when you’ve got the big picture down, you might need help remembering the small details, like where to put the foreign key.

To that end, I created a simple flowchart that guides you through the process of setting up your ActiveRecord associations.

It's available as a PDF for printing, and covered by the Creative Commons license. You can find it at http://www.idolhands.com/ruby-on-rails/rails-activerecord-relationships-flowchart/

Feedback welcomed!