ActiveRecord::Base

@chloerei 是不是要用establish_connection？我也不懂，随便查查的：http://t.co/IwN7BZaS via @tualatrix

Active Record objects don’t specify their attributes directly, but rather infer them from the table definition with which they’re linked. Adding, removing, and changing attributes and their type is done directly in the database. Any change is instantly reflected in the Active Record objects. The mapping that binds a given Active Record class to a certain database table will happen automatically in most common cases, but can be overwritten for the uncommon ones.

Full article: http://api.rubyonrails.org/classes/ActiveRecord/Base.html...