Как убрано? )
[Dynamic Finders](https://github.com/lifo/docrails/blob/master/guides/source/active_record_querying.md)
For every field (also known as an attribute) you define in your table, Active Record provides a finder method. If you have a field called first_name on your Client model for example, you get find_by_first_name for free from Active Record. If you have a locked field on the Client model, you also get find_by_locked and methods.