rails generate model Person name:string
rails generate model Followings person_id:integer follower_id:integer blocked:boolean

和模型中的以下代码

class Person < ActiveRecord::Base
  has_many :followers,:class_name => 'Followings',:foreign_key => 'person_id'
  has_many :following,:foreign_key => 'follower_id' 
end

并在您撰写的“跟随”类中对应

class Followings < ActiveRecord::Base
  belongs_to :person
  belongs_to :follower,:class_name => 'Person'
end

你可以让你的名字更清楚(我特别不喜欢跟随名字),但这应该让你开始.