How to get id values after saving an ActiveRecord model in rails

For people who looking for on create in model, below is the way:

class User < ActiveRecord::Base  
...  
  after_create :do_something

  def self.do_something
   user_id = id #this will have last created id
   # use this according to your needs
  end
...
end

Just call user.id after you've saved.