Question

我做了rails db:migrate:reset和rails db:migrate，然后访问localhost:3000发现了错误 ActiveRecord::RecordNotFound in WelcomeController#index Couldn't find User with 'id'=9。在此命令之前，我已将db从SQLite3更改为postgre以便在heroku上进行部署。

宝石文件

group :development, :test do
  gem 'sqlite3', '1.3.13'
end

group :production do
  gem 'pg', '0.20.0'
end

application_controller.rb

lass ApplicationController < ActionController::Base
  protect_from_forgery with: :exception

  private
  def current_user
    @current_user ||=User.find(session[:user_id]) if session[:user_id]
  end


  helper_method :current_user

  def authorize
    redirect_to new_session_path, alert: 'plz sign in or sign up' if current_user.nil?
  end

  def admin_authorize
    redirect_to new_session_path,
    alert: "Only for Admin!" unless current_user.admin
  end
end

错误日志

Started GET "/" for 127.0.0.1 at 2019-02-27 15:39:23 +0900
Processing by WelcomeController#index as HTML
  Rendering welcome/index.html.erb within layouts/application
  Rendered welcome/index.html.erb within layouts/application (1.8ms)
  User Load (0.1ms)  SELECT  "users".* FROM "users" WHERE "users"."id" = ? LIMIT ?  [["id", 9], ["LIMIT", 1]]
  ↳ app/controllers/application_controller.rb:6
  Rendered shared/_navigation.html.erb (4.4ms)
Completed 500 Internal Server Error in 42ms (ActiveRecord: 0.1ms)



ActiveRecord::RecordNotFound (Couldn't find User with 'id'=9):

app/controllers/application_controller.rb:6:in `current_user'
app/views/shared/_navigation.html.erb:14:in `_app_views_shared__navigation_html_erb__2712194429362090156_70209715304560'
app/views/layouts/application.html.erb:11:in `_app_views_layouts_application_html_erb__2819014747178102869_70209752482340'

Answer 1

您应该在下面尝试

  def current_user
    @current_user ||=User.find_by_id(session[:user_id]) if session[:user_id]
  end

find_by_id是查找器方法，如果不存在通过会话提供的ID的记录，它将返回nil。此外，您可以添加过滤器以使会话过期为session[:user_id] = nil

以重定向到登录页面

我在Rails API应用中遇到了以下情况，

User.find_by_id(session[:user_id]) || redirect_to(new_user_session_url)

找不到'id'= 9的用户

1 个答案: