\r\n

\r\n <% if flash[:notice] %>\r\n

\r\n <%= flash[:notice] %>\r\n

\r\n <% end %>\r\n

\r\n

\r\n User info\r\n

\r\n

\r\n \r\n \r\n \r\n \r\n \r\n \r\n \r\n \r\n \r\n

\r\n name\r\n	\r\n
\r\n introduction\r\n	\r\n\r\n

\r\n

\r\n \r\n

\r\n New book\r\n

\r\n \r\n <%= form_with model:@user, local:true do |f| %>\r\n Title
\r\n <%= f.text_field :Title %>
\r\n Opinion
\r\n <%= f.text_field :Opinion %>
\r\n \r\n <% end %>\r\n \r\n

\r\n

Book detail

\r\n \r\n <% @book.each do |book| %>\r\n \r\n \r\n\r\n \r\n \r\n \r\n \r\n <% end %>\r\n \r\n \r\n \r\n \r\n```\r\n```books/index_html\r\n\r\n\r\n\r\n \r\n \r\n \r\n\r\n

\r\n

\r\n <% if flash[:notice] %>\r\n

\r\n <%= flash[:notice] %>\r\n

\r\n <% end %>\r\n

\r\n

\r\n User info\r\n

\r\n

\r\n \r\n \r\n \r\n \r\n \r\n \r\n \r\n \r\n

\r\n name\r\n <%= current_user.name %>\r\n	\r\n
\r\n introduction\r\n <%= current_user.introduction %>\r\n	\r\n\r\n

\r\n

\r\n \r\n

\r\n New book\r\n

\r\n \r\n <%= form_with model:@book, local:true do |f| %>\r\n Title
\r\n <%= f.text_field :title %>
\r\n Opinion
\r\n <%= f.text_area :body %>\r\n 　　 <%= f.submit 'Create book' %>\r\n <% end %>\r\n \r\n

\r\n

Book detail

\r\n \r\n \r\n \r\n \r\n \r\n \r\n <% @books.each do |book| %>\r\n \r\n \r\n \r\n \r\n \r\n <% end %>\r\n \r\n

\r\n Title\r\n	\r\n Opinion\r\n
\r\n	\r\n <%= book.title %>\r\n	\r\n <%= book.body %>\r\n

\r\n

\r\n \r\n```\r\n```books_controller\r\nclass BooksController < ApplicationController\r\n def new\r\n @book = Book.new\r\n end\r\n\r\n def create\r\n @book = Book.new(book_params)\r\n @book.user_id = current_user.id\r\n @book.save\r\n redirect_to book_path(id: current_user)\r\n end\r\n\r\n def index\r\n @books = Book.all\r\n @book = Book.all\r\n @book = Book.new\r\n end\r\n\r\n def show\r\n @books = Book.find_by(id:params[:id])\r\n @users_id = params[:id]\r\n end\r\n\r\n def destroy\r\n end\r\n\r\n private\r\n\r\n def book_params\r\n params.require(:book).permit(:title, :body)\r\n end\r\nend\r\n\r\n```\r\n\r\n\r\n\r\n\r\n### \r\n\r\nrails 5\r\nよろしくお願いいたします","answerCount":1,"upvoteCount":0,"datePublished":"2021-09-10T08:32:01.156Z","dateModified":"2022-01-12T10:55:45.698Z","suggestedAnswer":[{"@type":"Answer","text":"nilの変数にはeachというメソッドは存在しない！\r\n\r\nとおっしゃってますんで、eachってくっついてる変数のナカミを片っ端から調べてみよう","dateModified":"2021-09-10T08:40:52.532Z","datePublished":"2021-09-10T08:40:52.532Z","upvoteCount":0,"url":"https://teratail.com/questions/358808#reply-489426","comment":[]}],"breadcrumb":{"@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"https://teratail.com","name":"トップ"}},{"@type":"ListItem","position":2,"item":{"@id":"https://teratail.com/tags/Cloud9","name":"Cloud9に関する質問"}},{"@type":"ListItem","position":3,"item":{"@id":"https://teratail.com/questions/358808","name":"Railsで投稿機能作成中にundefined method `each' for nil:NilClassという風になってしまいました"}}]}}}

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トップ Cloud9に関する質問Railsで投稿機能作成中にundefined method `each' for nil:NilClassという風になってしまいました

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Railsで投稿機能作成中にundefined method `each' for nil:NilClassという風になってしまいました

vandire_

総合スコア1

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投稿2021/09/10 08:32

前提・実現したいこと

railsで現在投稿機能を作成しています

発生している問題・エラーメッセージ

本を投稿後一覧画面に表示したいのですが
undefined method `each' for nil:NilClass
といったエラーが出てしまい解決ができません

該当のソースコード

Show.html
1<!DOCTYPE html>
2<html>
3<head>
4 <meta charset="utf-8">
5 <link rel="stylesheet" href="bookers2/app/assets/stylesheets/users.scss">
6 <script src="https://kit.fontawesome.com/34c9407723.js" crossorigin="anonymous"></script>
7</head>
8<main class="user">
9     <p>
10     <% if flash[:notice] %>
11     <p id="notice">
12       <%= flash[:notice] %>
13     </p>
14    <% end %>
15    <div class="container">
16     <div class="row">
17      <div class="col-lg-4">
18         <h2>
19           User info
20         </h2>
21         <div class="userimg" src="assets/images/bou.jpg"></div>
22         <table class="table">
23            <tbody>
24                 <tr></tr>
25                 <th>
26                   name
27                 </th>
28                 <th>
29                 </th>
30                 <tr></tr>
31                 <th>
32                   introduction
33                 </th>
34                 <th>
35
36                 </th>
37            </tbody>
38         </table>
39         <div class="edit">
40            <button type="button" class="btn btn-outline-secondary btn-block">
41            <i class="fas fa-user-cog"></i>
42      </button>
43      <h2>
44        New book
45      </h2>
46      <td class="form">
47      <%= form_with model:@user, local:true do |f| %>
48      <p4>Title</p4><br>
49        <%= f.text_field :Title %><br>
50      <p4>Opinion</p4><br>
51        <%= f.text_field :Opinion %><br>
52      <button type="submit" class="btn btn-lg btn-success">
53       Create book
54      </button>
55      <% end %>
56      </td>
57      </div>
58         </div>
59         <div class="col-lg-8">
60           <h2>Book detail</h2>
61           <table class="table">
62            <% @book.each do |book| %>
63            <thead>
64             <tr>
65
66             </tr>
67            </thead>
68            <tbody>
69            </tbody>
70            <% end %>
71         </div>
72      </div>
73    </div>
74    </html>

books/index_html
1<!DOCTYPE html>
2<html>
3<head>
4 <meta charset="utf-8">
5 <link rel="stylesheet" href="bookers2/app/assets/stylesheets/users.scss">
6 <script src="https://kit.fontawesome.com/34c9407723.js" crossorigin="anonymous"></script>
7</head>
8<main class="user">
9     <p>
10     <% if flash[:notice] %>
11     <p id="notice">
12       <%= flash[:notice] %>
13     </p>
14    <% end %>
15    <div class="container">
16     <div class="row">
17      <div class="col-lg-8">
18         <h2>
19           User info
20         </h2>
21         <div class="userimg" src="assets/images/bou.jpg"></div>
22         <table class="table">
23            <tbody>
24                 <tr></tr>
25                 <th>
26                   name
27                   <%= current_user.name %>
28                 </th>
29                 <th>
30                 </th>
31                 <tr></tr>
32                 <th>
33                   introduction
34                   <%= current_user.introduction %>
35                 </th>
36                 <th>
37
38                 </th>
39            </tbody>
40         </table>
41         <div class="edit">
42            <button type="button" class="btn btn-outline-secondary btn-block">
43            <i class="fas fa-user-cog"></i>
44      </button>
45      <h2>
46        New book
47      </h2>
48      <td class="form">
49      <%= form_with model:@book, local:true do |f| %>
50      <p4>Title</p4><br>
51        <%= f.text_field :title %><br>
52      <p4>Opinion</p4><br>
53        <%= f.text_area :body %>
54    　　  <%= f.submit 'Create book' %>
55      <% end %>
56      </td>
57      </div>
58         </div>
59         <div class="col-lg-4">
60           <h2>Book detail</h2>
61           <table class="table">
62            <thead>
63             <th>
64              Title
65             </th>
66             <th>
67              Opinion
68             </th>
69            </thead>
70            <tbody>
71              <% @books.each do |book| %>
72              <tr>
73                 <td>
74                 </td>
75                 <td>
76                 <%= book.title %>
77                 </td>
78                 <td>
79                 <%= book.body %>
80                 </td>
81              </tr>
82              <% end %>
83            </tbody>
84           </table>
85         </div>
86      </div>
87    </div>
88    </html>

books_controller
1class BooksController < ApplicationController
2  def new
3    @book = Book.new
4  end
5
6  def create
7    @book = Book.new(book_params)
8    @book.user_id = current_user.id
9    @book.save
10    redirect_to book_path(id: current_user)
11  end
12
13  def index
14    @books = Book.all
15    @book = Book.all
16    @book = Book.new
17  end
18
19  def show
20    @books = Book.find_by(id:params[:id])
21    @users_id = params[:id]
22  end
23
24  def destroy
25  end
26
27  private
28
29  def book_params
30    params.require(:book).permit(:title, :body)
31  end
32end
33