Question

当我尝试添加新针时，我不能。相反，我得到了这个错误：

NoMethodError in PinsController#create

undefined method `name' for #<pin:0x000001011b9638>

应用程序跟踪|框架跟踪|完整跟踪

app/controllers/pins_controller.rb:48:in `block in create'
app/controllers/pins_controller.rb:47:in `create'

请求

参数：

{"utf8"=>"✓",
"authenticity_token"=>"n9E2nob/KBzu20PEzYoQWXnibAUR5TH6iPWNd66383k=",
"pin"=>{"description"=>"stea"},
"commit"=>"Create Pin"}

pins_controller.rb

def create

@pin = current_user.pins.new(params[:pin])

respond_to do |format|
  if @pin.save
    format.html { redirect_to @pin, notice: 'Pin was successfully created.' }
    format.json { render json: @pin, status: :created, location: @pin }
  else
    format.html { render action: "new" }
    format.json { render json: @pin.errors, status: :unprocessable_entity }
  end
 end
end

应用程序/模型/ user.rb

class User < ActiveRecord::Base

devise :database_authenticatable, :registerable,
     :rememberable, :trackable, :validatable

attr_accessible :email, :password, :password_confirmation, :remember_me, :name

has_many :pins, :dependent => :destroy
end

的routes.rb

Omrails::Application.routes.draw do
 resources :pins

 devise_for :users

 root :to => 'pages#home'
 get 'about' => 'pages#about'

应用程序/模型/ pin.rb

class Pin < ActiveRecord::Base
  attr_accessible :description

  validates :description, presence: true
    validates :name, presence: true

  belongs_to :user
    validates :user_id, presence: true
 end

分贝/迁移/ create_pins

class CreatePins < ActiveRecord::Migration
  def change
    create_table :pins do |t|
      t.string :description

      t.timestamps
    end
  end
end

分贝/迁移/ add_user_id_to_pins.rb

class AddUserIdToPins < ActiveRecord::Migration
  def change
    add_column :pins, :user_id, :integer
    add_index :pins, :user_id
  end
end

分贝/迁移/ add_name_to_users.rb

class AddNameToUsers < ActiveRecord::Migration
  def change
    add_column :users, :name, :string
  end
end

关于出了什么问题的任何想法？

不确定它是否相关，但过去常常起作用。我能够沿着Mattan Griffel's One Month Rails course -- Add Assoc bt Pins and Users video跟随直到2950，然后我意识到我必须跳回到定制设计，因为我忘了添加简单的表格。

现在添加了简单的表格，我正在努力前进 - 并且卡在这里:(

更新：我运行了迁移重做来创建引脚并将用户ID添加到引脚。然后我删除了验证名称行。现在，当我创建pin

时，我收到以下错误

ActiveRecord::UnknownAttributeError in PinsController#new

unknown attribute: user_id 
app/controllers/pins_controller.rb:29:in `new'

pins_controller.rb

  def new
    @pin = current_user.pins.new

    respond_to do |format|
      format.html # new.html.erb
      format.json { render json: @pin }
    end
  end

非常感谢帮助

分贝/ schema.rb

ActiveRecord::Schema.define(:version => 20130828163738) do

  create_table "pins", :force => true do |t|
    t.string   "description"
    t.datetime "created_at",  :null => false
    t.datetime "updated_at",  :null => false
  end

  create_table "users", :force => true do |t|
    t.string   "email",                  :default => "", :null => false
    t.string   "encrypted_password",     :default => "", :null => false
    t.string   "reset_password_token"
    t.datetime "reset_password_sent_at"
    t.datetime "remember_created_at"
    t.integer  "sign_in_count",          :default => 0
    t.datetime "current_sign_in_at"
    t.datetime "last_sign_in_at"
    t.string   "current_sign_in_ip"
    t.string   "last_sign_in_ip"
    t.datetime "created_at",                             :null => false
    t.datetime "updated_at",                             :null => false
  end

  add_index "users", ["email"], :name => "index_users_on_email", :unique => true
  add_index "users", ["reset_password_token"], :name =>     "index_users_on_reset_password_token", :unique => true

end

Answer 1

您正在验证:name模型中是否存在Pin，但它没有:name字段。您的User已。

只需从validates :name, presence: true模型中删除Pin（第5行）。

Rails在尝试保存您的Pin模型时会运行所有验证。当遇到:name上的状态验证时，它会检查@pin.name是否为空。但问题是你的Pin模型没有名称方法。所以它引发了这个错误。

如果您确实希望Pin模型拥有name，请将其添加到pins表：

$ rails g migration add_name_to_pins name:string
$ rake db:migrate

Rins（一个月Rails）PinsController中的NoMethodError #create - 无法添加新引脚

1 个答案: