Ruby on Rails Guides: Active Record Validations and Callbacks

This guide teaches you how to hook into the life cycle of your Active Record objects. You will learn how to validate the state of objects before they go into the database, and how to perform custom operations at certain points in the object life cycle. After reading this guide and trying out the presented concepts, we hope that you’ll be able to: Understand the life cycle of Active Record objects

[kattton]

validates_associatedてのは知らなかった。あとで全部に付与しよう。

[seapig_dolphin]

validates

[ainame]

Active RecordのValidationを調べる

[takuma510]

Validation周り