请求示例应用程序的主页时，我收到以下错误消息（遵循 Michael Hartl 的教程第 11 章）：
"ActiveRecord::HasManyThroughSourceAssociationNotFoundError in Pages#home"
"在模型关系中找不到源关联：followed_id。尝试 'has_many :followed_users, :through => :relationships, :source => '。它是以下之一：追随者或：已关注？”
这真的很奇怪，因为我完全按照教程的说明进行操作。我什至复制粘贴了每一个代码片段。
我的用户模型（摘录）：
class User < ActiveRecord::Base
has_many :relationships, foreign_key: "follower_id", dependent: :destroy
has_many :followed_users, through: :relationships, source: "followed_id"
has_many :reverse_relationships, foreign_key: "followed_id", class_name: "Relationship", dependent: :destroy
has_many :followers, through: :reverse_relationships, source: :follower
我的关系模型：
class Relationship < ActiveRecord::Base
attr_accessible :followed_id
belongs_to :follower, class_name: "User"
belongs_to :followed, class_name: "User"
validates :follower_id, presence: true
validates :followed_id, presence: true
end
我的迁移文件：
class CreateRelationships < ActiveRecord::Migration
def change
create_table :relationships do |t|
t.integer :follower_id
t.integer :followed_id
t.timestamps
end
add_index :relationships, :follower_id
add_index :relationships, :followed_id
add_index :relationships, [:follower_id, :followed_id], unique: true
end
end
我一直在尝试解决这个问题，但我根本不知道问题可能是什么（教程中的确切代码副本）。