Rails活動記錄有很多關聯錯誤

Question

我現在正在學習Rails，並且在運行rake db：seed時注意到了這個問題。 老實說，我不確定問題是什么，因為一切似乎都運行良好，並且所有關聯似乎也都正常運行。

錯誤信息：

rake aborted! ActiveRecord::HasManyThroughSourceAssociationNotFoundError: Could not find the source association(s) "author" or :author in model Post. Try 'has_many :author, :through => :post, :source => <name>'. Is it one of user, category, comments, comment_users, likes, or like_users?
/home/houtai/hr.glass/ourz/db/seeds.rb:102:in `<top (required)>'
Tasks: TOP => db:seed

這是我的種子的一個例子：

User.create!({
  first_name: 'Mark',
  last_name: 'Wong',
  bio: 'bla',
  email: 'mark@gmail.com',
  password: 'test',
  password_confirmation: 'test',
  profile_pic: 'http://houtaiwong.com/img/profile.jpg'
  })

User.create!({
  first_name: 'Hou',
  last_name: 'Wong',
  bio: 'bla',
  email: 'test@gmail.com',
  password: 'test',
  password_confirmation: 'test',
  profile_pic: 'https://pmcdeadline2.files.wordpress.com/2016/02/alicia-vikander-the-danish-girl.jpg'
})

Category.create!({
  name: 'Music'
})

Category.create!({
  name: 'Blog'
})

Category.create!({
  name: 'Video'
})

Category.create!({
  name: 'Picture'
  })

Post.create!({
  title: 'Music',
  content: 'text',
  author: User.find_by(first_name: 'Mark').id,
  category_id: Category.find_by(name: 'Music').id,
  end_time: '12/1/2016',
  image: 'https://pmcdeadline2.files.wordpress.com/2016/02/alicia-vikander-the-danish-girl.jpg'
})

這是我的關聯：

class User < ActiveRecord::Base
  authenticates_with_sorcery!

  # attr_accessor :remote_image_url, :first_name, :last_name, :bio, :emaily, :profile_pic

  validates :password, length: { minimum: 3 }, if: -> { new_record? || changes[:crypted_password] }
  validates :password, confirmation: true, if: -> { new_record? || changes[:crypted_password] }
  validates :password_confirmation, presence: true, if: -> { new_record? || changes[:crypted_password] }

  validates :email, uniqueness: true

  has_many :posts, foreign_key: :author

  has_many :active_relationships,  class_name:  "Relationship",
                                   foreign_key: "follower_id",
                                   dependent:   :destroy
  has_many :passive_relationships, class_name:  "Relationship",
                                   foreign_key: "followed_id",
                                   dependent:   :destroy
  has_many :following, through: :active_relationships,  source: :followed
  has_many :followers, through: :passive_relationships, source: :follower

  has_many :comments
  has_many :comment_posts, through: :comments, source: 'post'

  has_many :likes
  has_many :like_posts, through: :likes, source: 'post'

發布：

class Post < ActiveRecord::Base
  require 'time'

  belongs_to :user, foreign_key: :author
  belongs_to :category

  has_many :comments
  has_many :comment_users, through: :comments, source: 'user'

  has_many :likes
  has_many :like_users, through: :likes, source: 'user'

  validates :title, presence: true

Answer 1

在Post模型的關系中，您具有：

belongs_to :user, foreign_key: :author

這意味着rails關系不是用戶，不是author，但是由於您將foreign_key設置為author，因此ActiveRecord在數據庫中查找時，它將使用author_id字段。

因此，在您擁有的種子中：

Post.create!({
  title: 'Music',
  content: 'text',
  author: User.find_by(first_name: 'Mark').id,
  category_id: Category.find_by(name: 'Music').id,
  end_time: '12/1/2016',
  image: 'https://pmcdeadline2.files.wordpress.com/2016/02/alicia-vikander-the-danish-girl.jpg'
})

由於您已經以用戶身份聲明了該關系，因此無法識別作者密鑰。

兩種可能的解決方案是將您的種子更改為：

Post.create!({
  title: 'Music',
  content: 'text',
  user: User.find_by(first_name: 'Mark').id,
  category_id: Category.find_by(name: 'Music').id,
  end_time: '12/1/2016',
  image: 'https://pmcdeadline2.files.wordpress.com/2016/02/alicia-vikander-the-danish-girl.jpg'
})

或將您在Post中的關系更改為：

belongs_to :author, class_name: 'User'

這應該可以解決Could not find the source association(s) "author" or :author in model Post部分中Could not find the source association(s) "author" or :author in model Post但是您有很多關系，並且要通過那里的表格進行操作，可能需要更多信息才能獲得完整圖片。