任何人都可以帮我解决这个错误。当我更新我的数据库值时，我收到以下错误。
错误： 未定义的方法`update_attributes＆＃39;为零：NilClass
我的代码片段如下所示。
视图/用户/ index.html.erb：
<h1>This is index page</h1>
<center>
<p>Enter data</p>
<div class="option">
<p><%= link_to "Click here to enter data",users_new_path %></p>
<p><%= link_to "Display data",users_show_path%></p>
</div>
</center>
视图/用户/ show.html.erb
<h1>Show your data</h1>
<center>
<ul>
<% @user.each do |t| %>
<li>
<%= t.name %> |
<%= t.email %> |
<%= t.password%> |
<%= t.created_at %>
<%= link_to "edit",users_edit_path(:id => t.id) %>
</li>
<% end %>
</ul>
<div class="back_btn">
<a href="/users/index"><button type="button" class="btn-custom " style="cursor:pointer;">Back</button></a>
</div>
</center>
视图/用户/ new.html.erb：
<h1>Enter your data here</h1>
<center>
<%= form_for @user ,:url => {:action => "create"} do |f| %>
<div class="div_reg">
<p>
<label for="username" class="uname" data-icon="u" >username </label>
<%= f.text_field:name,placeholder:"Enter your user name" %>
</p>
<p>
<label for="username" class="uname" data-icon="u" >Email </label>
<%= f.text_field:email,placeholder:"enter your email" %>
</p>
<p>
<label for="username" class="uname" data-icon="u" >Password </label>
<%= f.password_field:password,placeholder:"Enteryour password" %>
</p>
<p>
<label for="username" class="uname" data-icon="u" >Password </label>
<%= f.password_field :password_confirmation %>
</p>
<center>
<%= f.submit "Submit",:class => 'btn-custom' %>
</center>
<div class="back_btn">
<a href="/users/index"><button type="button" class="btn-custom " style="cursor:pointer;">Back</button></a>
</div>
</div>
<% end %>
</center>
<% if @user.errors.any? %>
<ul class="Signup_Errors">
<% for message_error in @user.errors.full_messages %>
<li><%= message_error %></li>
<% end %>
</ul>
<% end %>
视图/用户/ edit.html.erb：
<h1>Edit your data here</h1>
<center>
<%= form_for @user ,:url => {:action => "update"} do |f| %>
<div class="div_reg">
<p>
<label for="username" class="uname" data-icon="u" >username </label>
<%= f.text_field:name,placeholder:"Enter your user name" %>
</p>
<p>
<label for="username" class="uname" data-icon="u" >Email </label>
<%= f.text_field:email,placeholder:"enter your email" %>
</p>
<p>
<label for="username" class="uname" data-icon="u" >Password </label>
<%= f.password_field:password,placeholder:"Enteryour password" %>
</p>
<p>
<label for="username" class="uname" data-icon="u" >Password </label>
<%= f.password_field :password_confirmation %>
</p>
<center>
<%= f.submit "Update",:class => 'btn-custom' %>
</center>
<div class="back_btn">
<a href="/users/index"><button type="button" class="btn-custom " style="cursor:pointer;">Back</button></a>
</div>
</div>
<% end %>
</center>
<% if @user.errors.any? %>
<ul class="Signup_Errors">
<% for message_error in @user.errors.full_messages %>
<li><%= message_error %></li>
<% end %>
</ul>
<% end %>
控制器/ users_controller.rb：
class UsersController < ApplicationController
def index
end
def new
@user=User.new
end
def create
@user=User.new(users_param);
if @user.save
flash[:notice]="You signed up successfully"
flash[:color]="valid"
redirect_to :action => 'index'
else
flash[:alert]="You have not signed up successfully"
flash[:color]="invalid"
redirect_to :action => 'new'
end
end
def show
@user=User.all
end
def edit
@user=User.new
end
def update
@user=User.find_by_id(params[:id])
if @user.update_attributes(update_params)
flash[:notice]="Your data is updated succesfully"
flash[:color]="valid"
redirect_to :action => 'show'
else
flash[:alert]="Your data could not update,Please check it..!!"
flash[:color]="invalid"
redirect_to :action => 'edit'
end
end
private
def users_param
params.require(:user).permit(:name, :email, :password,:password_confirmation)
end
def update_params
params.require(:user).permit(:name,:email,:password,:password_confirmation)
end
end
配置/ routes.rb中：
Rails.application.routes.draw do
root "users#index"
get "users/new" => "users#new"
get "users/index" => "users#index"
post "users/create" => "users#create"
get "users/show" => "users#show"
get "users/edit" => "users#edit"
post "users/update" => "users#update"
end
模型/ user.rb：
class User < ActiveRecord::Base
#attr_accessor :password
#attr_accessor :name
#attr_accessor :email
EMAIL_REGEX = /\A[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}\z/i
validates :name, :presence => true, :uniqueness => true, :length => { :in => 3..20 }
validates :email, :presence => true, :uniqueness => true, :format => EMAIL_REGEX
validates :password, :confirmation => true
validates_length_of :password, :in => 6..20, :on => :create
end
请帮我解决给定的错误。我使用的是rails version-4和ruby 1.9.3。
答案 0 :(得分：2)
路线错误，他们没有考虑:id参数。因此，操作无法加载相应的用户。
上面的代码中有几个错误。它是一个相当简单的脚手架，您应该使用rails g scaffold并生成一个脚手架，以便您可以学习如何正确使用Rails约定。
可以删除所有这些路线
get "users/new" => "users#new"
get "users/index" => "users#index"
post "users/create" => "users#create"
get "users/show" => "users#show"
get "users/edit" => "users#edit"
post "users/update" => "users#update"
并替换为资源
resources :users
编辑应加载现有资源，而不是创建新资源。
def edit
@user = User.find(params[:id])
end
同样适用于更新。使用find，以便在找不到资源时引发它。
def update
@user = User.find(params[:id])
同样，还有很多需要完成的清理工作。我建议你开始从默认的脚手架中读取代码并相应地修改你的代码。
答案 1 :(得分：0)
我已经清理了你的控制器和routes.rb。看看是否有帮助 控制器/ users_controller.rb：
class UsersController < ApplicationController
def index
@user = User.all
end
def new
@user = User.new
end
def create
@user = User.new(users_params)
if @user.save
flash[:notice] = 'You signed up successfully'
flash[:color] = 'valid'
redirect_to action: 'index'
else
flash[:alert] = 'You have not signed up successfully'
flash[:color] = 'invalid'
redirect_to action: 'new'
end
end
def show
@user = User.find(params[:id])
end
def edit
@user = User.find(params[:id])
end
def update
@user = User.find(params[:id])
if @user.update_attributes(users_params)
flash[:notice] = 'Your data is updated succesfully'
flash[:color] = 'valid'
redirect_to action: 'show'
else
flash[:alert] = 'Your data could not update,Please check it..!!'
flash[:color] = 'invalid'
redirect_to action: 'edit'
end
end
private
def users_params
params.require(:user).permit(:name, :email, :password, :password_confirmation)
end
end
配置/ routes.rb中：
Rails.application.routes.draw do
root 'users#index'
resources: :users
end