NoMethodError：未定义的方法“密码”创建用户时

Question

这是我的 User_Controller，普通脚手架

class UsersController < ApplicationController
  # GET /users
  # GET /users.json
  def index
    @users = User.all

    respond_to do |format|
      format.html # index.html.erb
      format.json { render json: @users }
    end
  end

  # GET /users/1
  # GET /users/1.json
  def show
    @user = User.find(params[:id])

    respond_to do |format|
      format.html # show.html.erb
      format.json { render json: @user }
    end
  end

  # GET /users/new
  # GET /users/new.json
  def new
    @user = User.new
    respond_to do |format|
      format.html # new.html.erb
      format.json { render json: @user }
    end
  end

  # GET /users/1/edit
  def edit
    @user = User.find(params[:id])
  end

  # POST /users
  # POST /users.json
  def create
    @user = User.new(params[:user])
    respond_to do |format|
      if @user.save
        format.html { redirect_to @user, notice: 'User was successfully created.' }
        format.json { render json: @user, status: :created, location: @user }
      else
        format.html { render action: "new" }
        format.json { render json: @user.errors, status: :unprocessable_entity }
      end
    end
  end

  # PUT /users/1
  # PUT /users/1.json
  def update
    @user = User.find(params[:id])

    respond_to do |format|
      if @user.update_attributes(params[:user])
        format.html { redirect_to @user, notice: 'User was successfully updated.' }
        format.json { head :ok }
      else
        format.html { render action: "edit" }
        format.json { render json: @user.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /users/1
  # DELETE /users/1.json
  def destroy
    @user = User.find(params[:id])
    @user.destroy

    respond_to do |format|
      format.html { redirect_to users_url }
      format.json { head :ok }
    end
  end
end

这是我正在处理的用户模型（User.rb）：

class User < ActiveRecord::Base
  has_and_belongs_to_many :roles
  attr_accessible :username, :email, :fname, :lname, :password, :password_confirmation
  validates :password, :presence => true,
                   :confirmation => true,
                   :length => {:within => 6..30}
end

当我创建这个模型时，我忘记了用户应该有一个“密码”属性。所以我对密码进行了迁移。但从那时起，每当我创建用户时，我都会收到此错误：

NoMethodError: undefined method `password' for #<User:0x00000100b11560>

对于格式不佳感到抱歉

Answer 1

将它们标记为属性

class User < ActiveRecord::Base
  attr_accessible :password, :password_confirmation
end

---

更新 11-2015

在当前的 Rails 中，此方法已更改为 attr_accessor。您不必将确认声明为属性，只需 confirmation: true 就足够了。

class User < ActiveRecord::Base
  attr_accessor :password

  validates :password, presence: true, length: { in: 6..20 }, confirmation: true
end

Answer 2

确保用户表中有密码列，登录 mysql 并执行 DESC users

要么您可能错过了运行迁移，要么您的迁移应该有一些问题