Question

在Rails 3.2.15中，我正在尝试建立一个名为TopicInterest的has-many-through模型，将Users与Topics关联，将另一个属性保存在TopicInterest中，名为interest_type。在（我认为）通过对TopicInterest的create（）调用成功建立连接之后，我无法通过控制台中的TopicInterest获取主题或用户：

irb(main):008:0> newjoin = TopicInterest.create(topic_id: mongo.id, user_id: me.id)
   (0.4ms)  BEGIN
  SQL (0.6ms)  INSERT INTO "topic_interests" ("created_at", "interest_type", "topic_id", "updated_at", "user_id") VALUES ($1, $2, $3, $4, $5) RETURNING "id"  [["created_at", Fri, 01 Aug 2014 16:10:00 UTC +00:00], ["interest_type", nil], ["topic_id", 1], ["updated_at", Fri, 01 Aug 2014 16:10:00 UTC +00:00], ["user_id", 1]]
   (6.4ms)  COMMIT
=> #<TopicInterest id: 2, user_id: 1, topic_id: 1, interest_type: nil, created_at: "2014-08-01 16:10:00", updated_at: "2014-08-01 16:10:00">
irb(main):009:0> newjoin.save
   (0.3ms)  BEGIN
   (0.3ms)  COMMIT
=> true
irb(main):010:0> newjoin.topic
NoMethodError: undefined method `topic' for #<TopicInterest:0x007fae2a06cc70>
    from /Users/duncanmalashock/.rvm/gems/ruby-1.9.3-p448@diver/gems/activemodel-3.2.15/lib/active_model/attribute_methods.rb:407:in `method_missing'
    from /Users/duncanmalashock/.rvm/gems/ruby-1.9.3-p448@diver/gems/activerecord-3.2.15/lib/active_record/attribute_methods.rb:149:in `method_missing'
    from (irb):10
    from /Users/duncanmalashock/.rvm/gems/ruby-1.9.3-p448@diver/gems/railties-3.2.15/lib/rails/commands/console.rb:47:in `start'
    from /Users/duncanmalashock/.rvm/gems/ruby-1.9.3-p448@diver/gems/railties-3.2.15/lib/rails/commands/console.rb:8:in `start'
    from /Users/duncanmalashock/.rvm/gems/ruby-1.9.3-p448@diver/gems/railties-3.2.15/lib/rails/commands.rb:41:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'

用户模型：

class User < ActiveRecord::Base
  # Include default devise modules. Others available are:
  # :confirmable, :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable

  # Setup accessible (or protected) attributes for your model
  attr_accessible :first_name, :last_name, :email, :password, :password_confirmation, :remember_me
  has_many :topics, through: :topic_interests
end

主题模型：

class Topic < ActiveRecord::Base
  attr_accessible :name, :description
  has_many :users, through: :topic_interests
end

TopicInterest模型：

class TopicInterest < ActiveRecord::Base
  attr_accessible :interest_type, :user_id, :topic_id
end

我做错了什么？非常感谢您的帮助。

Answer 1

您需要在belongs_to模型中添加topic_interest.rb个引用

class TopicInterest < ActiveRecord::Base
  attr_accessible :interest_type, :user_id, :topic_id
  belongs_to :topic
  belongs_to :user
end

修改

由于 Duncan Malashock 检测到此模型中缺少另一个直接关联，我在此处添加以供正确参考。

user.rb和topic.rb模型也应与topic_interests直接关联。

需要在两个提到的模型中添加has_many :topic_interests。

Has-many-through模型：NoMethodError

1 个答案: