Ruby on rails 你有很多或属于你的作品吗

我有两种型号：

class Answer < ActiveRecord::Base
  belongs_to :user
  belongs_to :question
  has_many :edits, dependent: :destroy
end

class Question < ActiveRecord::Base
  belongs_to :user
  has_many :answers, dependent: :destroy
end

它给我零分

irb(main):026:0> q.answers.size
    => 0

但当我写这篇文章时：

Answer.where(:question_id => q.id).size

它给了我1

那我该怎么办？

如果您需要它-答案和问题迁移：

class CreateAnswers < ActiveRecord::Migration
  def change
    #execute "DROP TABLE #{:answers} CASCADE" 

    create_table :answers do |t|
      t.text :body
      t.references :user, index: true, foreign_key: true
      t.references :question, index: true, foreign_key: true

      t.timestamps null: false
    end
  end
end

class CreateQuestions < ActiveRecord::Migration
  def change
    #execute "DROP TABLE #{:questions} CASCADE" 
    create_table :questions do |t|
      t.string :title
      t.text :body
      t.references :user, index: true, foreign_key: true

      t.timestamps null: false
    end
  end
end

classcreateanswers

你需要在你的关系中使用相反的选项

 class Answer < ActiveRecord::Base
   belongs_to :user
   belongs_to :question, inverse_of: answers
   has_many :edits, dependent: :destroy
 end

 class Question < ActiveRecord::Base
   belongs_to :user
   has_many :answers, inverse_of: question, dependent: :destroy
 end

Rails将为您执行此操作（在内存中）：

---

q.answers你需要在你的关系中使用选项的倒数

 class Answer < ActiveRecord::Base
   belongs_to :user
   belongs_to :question, inverse_of: answers
   has_many :edits, dependent: :destroy
 end

 class Question < ActiveRecord::Base
   belongs_to :user
   has_many :answers, inverse_of: question, dependent: :destroy
 end

Rails将为您执行此操作（在内存中）：

q.answers尝试重新加载问题
q.reload
@Deepak帮助很大，谢谢！尝试重新加载问题
q.reload
@Deepak它很有帮助，谢谢！
 a.question = q

q.answers << a