This is the second, and final, post in the series about starting off on a Rails application. In the first post the basis for a “Planets” application was created. I ended up with a database (model) and a functioning mechanism around that database that let me create, edit, and delete records (views). All of that was knitted together into a working application by a controller. However, those views have no validation on them. That means the database is not protected from bad data. I’ll fix that here and then focus a lot on how Rails apps are tested.