Railsで「お客様の商品次回購入時期を表示する」システムを作っています。

・Userテーブル：購入者情報登録済み  
→カラム：id, number, name

・Productテーブル：商品情報登録済み  
→カラム：id, number, brand, name, term

・Purchaseテーブル：フォームより入力  
→カラム：user_number, product_number

中間テーブル(Purchase)を作成し、登録済みのuser_numberとproduct_numberを  
form入力をして紐づくデータをUserテーブル,Productテーブルから取得  
という機能を実装中に以下のエラーメッセージが発生しました。

```

    NoMethodError in Purchases#index
    Showing /home/ec2-user/environment/RepeatAlart_app/app/views/purchases/index.html.erb where line #18 raised:
    
    undefined method `name' for 1:Integer
    Extracted source (around line #18):
    
```

```

    16　<tr>
    17　　<td><%= purchase.user_number %></td>
    18　　<td><%= purchase.user_number.name %></td>
    19　　<td><%= purchase.product_number.brand %></td>
    20　　<td><%= purchase.product_number.name %></td>
    21　　<td><%= purchase.created_at %></td> 
    
```

model

```

    class User < ApplicationRecord    
    validates :name, presence: true, length: { maximum: 50 }
    validates :number, presence: true
    has_many :purchases
    has_many :products, through: :purchases
    belongs_to :salon
    end
    
```

model

```

    class Product < ApplicationRecord
    validates :brand, presence: true
    validates :number, presence: true
    validates :name, presence: true
    validates :term, presence: true
    validates :name, uniqueness: true
    has_many :purchases
    has_many :users, through: :purchases
    belongs_to :salon
    end
    
```

model

```

    class Purchase < ApplicationRecord
        belongs_to :user, optional: true
        belongs_to :product, optional: true
        belongs_to :salon
    end
    
```

controller

```

    class PurchasesController < ApplicationController
      def index
        @purchases = Purchase.where(salon_id: current_salon.id)
        @purchase = Purchase.new
      end
    
      def create
        @purchase= Purchase.new(purchase_params.merge(salon_id: current_salon.id))
        if @purchase.save
          flash[:success] = "Success!"
          redirect_to "/purchases"
        else
          redirect_to "/purchases"
        end
      end
    
      def edit
          @purchase=Purchase.find(params[:id])
      end
    
      def update
          purchase=Purchase.find(params[:id])
          purchase.update(purchase_params)
          redirect_to "/purchases"
      end 
    
      def destroy
         Purchase.find(params[:id]).destroy
        flash[:success]= "deleted"
        redirect_to "/purchases"
      end
    
       private
    
         def purchase_params
          params.require(:purchase).permit(:user_number, :product_number)
         end  
    end
    
```

view

```

    <h1>購入商品一覧</h1>
            <table class="table">
                <thead>
                    <tr>
                     　 <th>お客様No.</th>
                    　  <th>お客様名</th>
                    　  <th>ブランド</th>
                     　 <th>商品名</th>
                    　  <th>購入日</th>
                    　  <th>次回購入推奨日</th>
                        <th colspan="2"></th>
                    </tr>
                </thead>
                <tbody>
                        <% @purchases.each do |purchase| %>
                    <tr>
                        <td><%= purchase.user_number %></td>
                        <td><%= purchase.user_number.name %></td>
                        <td><%= purchase.product_number.brand %></td>
                        <td><%= purchase.product_number.name %></td>
                        <td><%= purchase.created_at %></td>
                        <td><%= purchase.limit_date %></td>
                        <td><%= link_to "編集", "#", class:"btn btn-primary mr-3" %></td>
                        <td><%= link_to "削除", purchase, method: :delete, class:"btn btn-primary mr-3" %></td>
                        <% end %>
                    <tr>
                 </tbody>
            </table>      
    
    <h1>購入情報登録</h1>
    
    <div class="row">
      <div class="col-md-6 col-md-offset-3">
        <%= form_for(@purchase) do |f| %>
          <%= f.label :user_number %>
          <%= f.number_field :user_number, class: 'form-control' %>
          <%= f.label :product_number %>
          <%= f.number_field :product_number, class: 'form-control' %>
    
          <%= f.submit "購入情報登録", class: "btn btn-primary" %>
        <% end %>
      </div>
    </div>
    
```
CC BY-SA 4.0
2020-04-16T13:55:23.300
65687
2020-04-17T03:22:08.390
2020-04-16T16:53:43.510
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39661
question
ruby-on-rails ruby sqlite
Rails で中間テーブルへの保存と他テーブルからのデータ取得でエラーが出てしまう
`index.html.erb`内の  
`purchase.user_number.name`  
を  
`purchase.user.name`  
などに修正してみてください。
CC BY-SA 4.0
2020-04-17T03:22:08.390
65700
2020-04-17T03:22:08.390
442
65687
answer