afgnsu/bullet

●Bullet (檢查N+1查詢)

●Bullet (檢查N+1查詢)

1. 配置

$ rails _5.2.8.1_ new n+1

$ cd n+1

$ rails db:migrate

$ rails g scaffold User name

$ rails g scaffold Order item price:integer user:references

vi app/models/order.rb  #新增 belongs_to :user
vi app/models/user.rb   #新增 has_many :orders

2. 部屬 Bullet

$ vi Gemfile  #在 gem 'rails' 後加入 gem 'bullet', group: 'development'

$ bundle

$ rails g bullet:install

3. 修改

vi app/views/users/index.html.erb  #加入
========================================
 <td><%= user.orders.count %></td>
 <td><%= user.orders.sum(&:price) %></td>
========================================

4. 測試

$ rails s -b 0.0.0.0

打開瀏覽器 http://localhost:3000

• 修正前 => @user = User.all

• 修正後 => @user = User.all.includes(:orders)

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