Question

我目前正在构建一个我有书模型的应用程序。它在本地工作，没有任何问题。我将它部署到Heroku并运行rake db:migrate并尝试创建一本书

我遇到了ROLLBACK错误。

2018-03-29T07:29:59.748305+00:00 app[web.1]: D, [2018-03-29T07:29:59.748238 #4] DEBUG -- : [feda9269-2f19-4916-a87f-bc179fd52bec]   User Load (1.7ms)  SELECT  "users".* FROM "users" WHERE "users"."id" = $1 ORDER BY "users"."id" ASC LIMIT $2  [["id", 3], ["LIMIT", 1]]
2018-03-29T07:29:59.750826+00:00 app[web.1]: D, [2018-03-29T07:29:59.750763 #4] DEBUG -- : [feda9269-2f19-4916-a87f-bc179fd52bec]    (0.8ms)  BEGIN
2018-03-29T07:29:59.763631+00:00 app[web.1]: D, [2018-03-29T07:29:59.763526 #4] DEBUG -- : [feda9269-2f19-4916-a87f-bc179fd52bec]    (0.9ms)  ROLLBACK
2018-03-29T07:29:59.764270+00:00 app[web.1]: I, [2018-03-29T07:29:59.764208 #4]  INFO -- : [feda9269-2f19-4916-a87f-bc179fd52bec]   Rendering books/new.html.erb within layouts/application
2018-03-29T07:29:59.770061+00:00 app[web.1]: I, [2018-03-29T07:29:59.769996 #4]  INFO -- : [feda9269-2f19-4916-a87f-bc179fd52bec]   Rendered books/_form.html.erb (5.5ms)
2018-03-29T07:29:59.770167+00:00 app[web.1]: I, [2018-03-29T07:29:59.770113 #4]  INFO -- : [feda9269-2f19-4916-a87f-bc179fd52bec]   Rendered books/new.html.erb within layouts/application (5.8ms)
2018-03-29T07:29:59.771544+00:00 app[web.1]: I, [2018-03-29T07:29:59.771486 #4]  INFO -- : [feda9269-2f19-4916-a87f-bc179fd52bec]   Rendered layouts/_navbar.html.erb (0.7ms)
2018-03-29T07:29:59.771904+00:00 app[web.1]: I, [2018-03-29T07:29:59.771828 #4]  INFO -- : [feda9269-2f19-4916-a87f-bc179fd52bec]   Rendered layouts/_alerts.html.erb (0.2ms)
2018-03-29T07:29:59.772181+00:00 app[web.1]: I, [2018-03-29T07:29:59.772125 #4]  INFO -- : [feda9269-2f19-4916-a87f-bc179fd52bec] Completed 200 OK in 28ms (Views: 8.2ms | ActiveRecord: 3.4ms)

书籍控制器

class BooksController < ApplicationController
    before_action :find_book, only: [:show, :edit, :update, :destroy]
    before_action :book_owner, only: [:destroy, :edit, :update]
    def index
        @books = Book.all.order("created_at DESC")
    end

    def show
    end

    def new
        @book = current_user.books.build
        @categories = Category.all.map{ |c| [c.name, c.id] }
    end

    def create
        @book = current_user.books.build(book_params)
        @book.category_id = params[:category_id]
        if @book.save
            redirect_to books_path
        else
            render 'new'
        end
    end

    def edit
        @categories = Category.all.map{ |c| [c.name, c.id] }
    end

    def update
        @book.category_id = params[:category_id]
        if @book.update(book_params)
            redirect_to book_path(@book)
        else
            render 'edit'
        end
    end

    def destroy
        @book.destroy
        redirect_to root_path
    end


    private

    def book_params
        params.require(:book).permit(:title, :description, :author, :category_id)
    end

    def find_book
        @book = Book.find(params[:id])
    end

    def book_owner
        unless current_user.id == @book.user_id
            flash[:notice] = "You are not allowed to do that!"
            redirect_to @book
        end
    end

end

预订模型

class Book < ApplicationRecord
    belongs_to :user
    belongs_to :category
end

预订新视图

<%= simple_form_for @book, :html => { :multipart => true } do |f| %>
  <%= f.input :category_id, collection: @categories, prompt: "Select a category" %>
  <%= f.input :title, label: "Book Title" %>
  <%= f.input :author %>
  <%= f.input :description %>
  <%= f.button :submit, :class => "btn-outline-primary" %>
<% end %>

更新

Started POST "/books" for 127.0.0.1 at 2018-03-29 11:13:22 +0200
Processing by BooksController#create as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"UYKPhHA99zg5TMMwgKGk+h2OPPaCQkpkjohPRnRNQHlJB1eQF4Ooro4Tvx9VDSr3U6/H4AGoThu8jzkrwyMbUB==", "book"=>{"category_id"=>"", "title"=>"tesas", "author"=>"asdasd", "description"=>"asdasd"}, "commit"=>"Create Book"}
  User Load (0.3ms)  SELECT  "users".* FROM "users" WHERE "users"."id" = $1 ORDER BY "users"."id" ASC LIMIT $2  [["id", 1], ["LIMIT", 1]]
   (0.1ms)  BEGIN
   (0.3ms)  ROLLBACK
  Rendering books/new.html.erb within layouts/application
  Rendered books/_form.html.erb (10.0ms)
  Rendered books/new.html.erb within layouts/application (11.9ms)
  Rendered layouts/_navbar.html.erb (1.2ms)
  Rendered layouts/_alerts.html.erb (0.3ms)
Completed 200 OK in 52ms (Views: 46.3ms | ActiveRecord: 0.7ms)

Category_id是零，因为我还没有将它们设置在我的第二台笔记本电脑上，因为我无法使用Category.crection（Category.create（名称：＆＃34; SOMECATEGORY＆＃34;））这可以创建一个类别，但没有Category.connection它就不会工作在我的heroku应用程序中，我能够进行Category.connection和Category.create .. - 但即使在那之后它也无法工作。

我做错了什么？一如既往地感谢您的帮助！

Answer 1

您收到错误是因为记录无效。原因是您未正确分配category_id。

您需要将params[:category_id]更改为book_params[:category_id]

params [：category_id]将为您提供nil，验证检查将失败。

def create
  @book = current_user.books.build(book_params)
  @book.category_id = book_params[:category_id]
  if @book.save
    redirect_to books_path
  else
    render 'new'
  end
end

您需要对update操作进行相同的更改

Answer 2

更新

我想我发现了我的错误：我的user_id在通过网络创建时为零 - 我在控制台上创建了相同的记录并传递了参数user_id - voila，works。我的user_id参数以某种方式不会传递到heroku rails服务器，但它在本地计算机上传递。没有更改代码行。

这怎么可能？

Heroku在创建图书记录时抛出回滚错误

2 个答案: