页面加载不必要的查询 Ruby On Rails答案

【问题标题】：Page loads unnecessary queries Ruby On Rails页面加载不必要的查询 Ruby On Rails
【发布时间】：2019-04-07 02:26:54
【问题描述】：

我有一个奇怪的问题，我网站的每个包含数据库查询的页面都会加载一些额外的项目。我以前从未遇到过这个问题，尝试检查所有控制器但没有发现任何问题。这是我加载（或刷新）主页时的输出示例：

=> Booting Puma
=> Rails 5.1.6 application starting in development
=> Run `rails server -h` for more startup options
Puma starting in single mode...
* Version 3.12.0 (ruby 2.5.0-p0), codename: Llamas in Pajamas
* Min threads: 5, max threads: 5
* Environment: development
* Listening on tcp://0.0.0.0:3000
Use Ctrl-C to stop
Started GET "/c/wines" for 127.0.0.1 at 2018-11-02 15:55:30 -0400 (0.3ms)  SELECT "schema_migrations"."version" FROM "schema_migrations" ORDER BY "schema_migrations"."version" ASC
Processing by CatalogsController#show as HTML
Parameters: {"id"=>"wines"}
Catalog Load (0.2ms)  SELECT  "catalogs".* FROM "catalogs" WHERE "catalogs"."slug" = ? LIMIT ?  [["slug", "wines"], ["LIMIT", 1]]
Rendering catalogs/show.html.haml within layouts/application (0.2ms) SELECT COUNT(*) FROM "categories" WHERE "categories"."catalog_id" = ? [["catalog_id", 1]] (0.2ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 1


Category Exists (0.3ms)  SELECT  1 AS one FROM "categories" WHERE "categories"."catalog_id" = 1 AND "categories"."open" = ? LIMIT ?  [["open", "t"], ["LIMIT", 1]]
  Category Load (0.9ms)  SELECT "categories".* FROM "categories" WHERE "categories"."catalog_id" = 1 AND "categories"."open" = ?  [["open", "t"]]
  CACHE Category Load (0.0ms)  SELECT "categories".* FROM "categories" WHERE "categories"."catalog_id" = 1 AND "categories"."open" = ?  [["open", "t"]]
  CACHE Category Load (0.1ms)  SELECT "categories".* FROM "categories" WHERE "categories"."catalog_id" = 1 AND "categories"."open" = ?  [["open", "t"]]
  Product Load (0.8ms)  SELECT "products".* FROM "products" WHERE "products"."catalog_id" = 1 AND "products"."open" = ? AND "products"."category_id" = 1  [["open", "t"]]
  Catalog Load (0.7ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."id" = 1
  Product Load (0.3ms)  SELECT "products".* FROM "products" WHERE "products"."catalog_id" = 1 AND "products"."open" = ? AND "products"."category_id" = 2  [["open", "t"]]
  CACHE Catalog Load (0.0ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."id" = 1
  Rendered catalogs/show.html.haml within layouts/application (142.7ms)
  Rendered application/_favicon.html.haml (11.1ms)
  Catalog Load (0.4ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."open" = ?  [["open", "t"]]
  Rendered shared/_navbar.html.haml (23.7ms)
  CACHE Catalog Load (0.0ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."open" = ?  [["open", "t"]]
  Rendered shared/_footer.html.haml (15.7ms)
Completed 200 OK in 937ms (Views: 890.8ms | ActiveRecord: 9.4ms)


Started GET "/uploads/catalog/photo/1/hero-8.png" for 127.0.0.1 at 2018-11-02 15:55:31 -0400
Started GET "/" for 127.0.0.1 at 2018-11-02 15:55:31 -0400
Processing by StaticController#home as HTML
Started GET "/uploads/product/photo/4/pc_pistachio.png" for 127.0.0.1 at 2018-11-02 15:55:31 -0400
Started GET "/uploads/product/photo/7/pc_pistachio.png" for 127.0.0.1 at 2018-11-02 15:55:31 -0400
Started GET "/uploads/product/photo/1/pc_creame.png" for 127.0.0.1 at 2018-11-02 15:55:31 -0400
Started GET "/uploads/product/photo/10/pc_pistachio.png" for 127.0.0.1 at 2018-11-02 15:55:31 -0400
  Rendering static/home.html.haml within layouts/application
  Catalog Load (0.3ms)  SELECT  "catalogs".* FROM "catalogs" WHERE "catalogs"."open" = ? ORDER BY created_at ASC LIMIT ?  [["open", "t"], ["LIMIT", 6]]
   (0.3ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 1
  CACHE  (0.0ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 1
  Product Exists (0.4ms)  SELECT  1 AS one FROM "products" WHERE "products"."catalog_id" = 1 LIMIT ?  [["LIMIT", 1]]
  Product Load (0.9ms)  SELECT  "products".* FROM "products" WHERE "products"."catalog_id" = 1 LIMIT ?  [["LIMIT", 6]]
  Catalog Load (0.2ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."id" = 1
  Category Load (0.2ms)  SELECT "categories".* FROM "categories" WHERE "categories"."id" IN (1, 2)
   (0.2ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 2
  Product Exists (0.2ms)  SELECT  1 AS one FROM "products" WHERE "products"."catalog_id" = 2 LIMIT ?  [["LIMIT", 1]]
  Product Load (0.2ms)  SELECT  "products".* FROM "products" WHERE "products"."catalog_id" = 2 LIMIT ?  [["LIMIT", 6]]
  Catalog Load (0.1ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."id" = 2
  Category Load (0.2ms)  SELECT "categories".* FROM "categories" WHERE "categories"."id" = 3
   (0.2ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 3
  Product Exists (0.1ms)  SELECT  1 AS one FROM "products" WHERE "products"."catalog_id" = 3 LIMIT ?  [["LIMIT", 1]]
  Product Load (0.1ms)  SELECT  "products".* FROM "products" WHERE "products"."catalog_id" = 3 LIMIT ?  [["LIMIT", 6]]
  Catalog Load (0.1ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."id" = 3
  Category Load (0.2ms)  SELECT "categories".* FROM "categories" WHERE "categories"."id" = 2
  Rendered static/home.html.haml within layouts/application (95.0ms)
  Rendered application/_favicon.html.haml (15.0ms)
  Catalog Load (0.2ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."open" = ?  [["open", "t"]]
  Rendered shared/_navbar.html.haml (19.9ms)
  CACHE Catalog Load (0.0ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."open" = ?  [["open", "t"]]
  Rendered shared/_footer.html.haml (18.0ms)
Completed 200 OK in 400ms (Views: 389.1ms | ActiveRecord: 4.3ms)


Started GET "/" for 127.0.0.1 at 2018-11-02 15:55:31 -0400
Started GET "/" for 127.0.0.1 at 2018-11-02 15:55:31 -0400
Processing by StaticController#home as HTML
Started GET "/" for 127.0.0.1 at 2018-11-02 15:55:31 -0400
Started GET "/" for 127.0.0.1 at 2018-11-02 15:55:31 -0400
Processing by StaticController#home as HTML
  Rendering static/home.html.haml within layouts/application
Processing by StaticController#home as HTML
  Catalog Load (0.5ms)  SELECT  "catalogs".* FROM "catalogs" WHERE "catalogs"."open" = ? ORDER BY created_at ASC LIMIT ?  [["open", "t"], ["LIMIT", 6]]
  Rendering static/home.html.haml within layouts/application
Processing by StaticController#home as HTML
  Catalog Load (0.4ms)  SELECT  "catalogs".* FROM "catalogs" WHERE "catalogs"."open" = ? ORDER BY created_at ASC LIMIT ?  [["open", "t"], ["LIMIT", 6]]
  Rendering static/home.html.haml within layouts/application
   (0.3ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 1
  CACHE  (0.0ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 1
  Product Exists (0.1ms)  SELECT  1 AS one FROM "products" WHERE "products"."catalog_id" = 1 LIMIT ?  [["LIMIT", 1]]
  Product Load (0.2ms)  SELECT  "products".* FROM "products" WHERE "products"."catalog_id" = 1 LIMIT ?  [["LIMIT", 6]]
  Catalog Load (0.2ms)  SELECT  "catalogs".* FROM "catalogs" WHERE "catalogs"."open" = ? ORDER BY created_at ASC LIMIT ?  [["open", "t"], ["LIMIT", 6]]
   (0.1ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 1
  Catalog Load (0.1ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."id" = 1
  CACHE  (0.0ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 1
  Product Exists (0.2ms)  SELECT  1 AS one FROM "products" WHERE "products"."catalog_id" = 1 LIMIT ?  [["LIMIT", 1]]
  Rendering static/home.html.haml within layouts/application
   (0.4ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 1
  Catalog Load (0.2ms)  SELECT  "catalogs".* FROM "catalogs" WHERE "catalogs"."open" = ? ORDER BY created_at ASC LIMIT ?  [["open", "t"], ["LIMIT", 6]]
  Product Load (0.3ms)  SELECT  "products".* FROM "products" WHERE "products"."catalog_id" = 1 LIMIT ?  [["LIMIT", 6]]
   (0.1ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 1
  CACHE  (0.0ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 1
  Category Load (0.2ms)  SELECT "categories".* FROM "categories" WHERE "categories"."id" IN (1, 2)
  Catalog Load (0.1ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."id" = 1
  CACHE  (0.0ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 1
  Product Exists (0.2ms)  SELECT  1 AS one FROM "products" WHERE "products"."catalog_id" = 1 LIMIT ?  [["LIMIT", 1]]
  Category Load (0.3ms)  SELECT "categories".* FROM "categories" WHERE "categories"."id" IN (1, 2)
  Product Load (0.4ms)  SELECT  "products".* FROM "products" WHERE "products"."catalog_id" = 1 LIMIT ?  [["LIMIT", 6]]
  Product Exists (0.4ms)  SELECT  1 AS one FROM "products" WHERE "products"."catalog_id" = 1 LIMIT ?  [["LIMIT", 1]]
   (0.2ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 2
  Product Exists (0.1ms)  SELECT  1 AS one FROM "products" WHERE "products"."catalog_id" = 2 LIMIT ?  [["LIMIT", 1]]
  Product Load (0.2ms)  SELECT  "products".* FROM "products" WHERE "products"."catalog_id" = 2 LIMIT ?  [["LIMIT", 6]]
  Catalog Load (0.1ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."id" = 2
  Category Load (0.1ms)  SELECT "categories".* FROM "categories" WHERE "categories"."id" = 3
   (0.2ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 3
  Product Exists (0.1ms)  SELECT  1 AS one FROM "products" WHERE "products"."catalog_id" = 3 LIMIT ?  [["LIMIT", 1]]
   (0.2ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 2
  Catalog Load (0.1ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."id" = 1
  Product Load (0.2ms)  SELECT  "products".* FROM "products" WHERE "products"."catalog_id" = 1 LIMIT ?  [["LIMIT", 6]]
  Product Exists (0.4ms)  SELECT  1 AS one FROM "products" WHERE "products"."catalog_id" = 2 LIMIT ?  [["LIMIT", 1]]
  Product Load (0.3ms)  SELECT  "products".* FROM "products" WHERE "products"."catalog_id" = 2 LIMIT ?  [["LIMIT", 6]]
  Catalog Load (0.2ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."id" = 2
  Catalog Load (0.1ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."id" = 1
  Product Load (0.4ms)  SELECT  "products".* FROM "products" WHERE "products"."catalog_id" = 3 LIMIT ?  [["LIMIT", 6]]
  Category Load (0.2ms)  SELECT "categories".* FROM "categories" WHERE "categories"."id" IN (1, 2)
   (0.2ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 2
  Category Load (0.2ms)  SELECT "categories".* FROM "categories" WHERE "categories"."id" IN (1, 2)
   (0.2ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 2
  Product Exists (0.1ms)  SELECT  1 AS one FROM "products" WHERE "products"."catalog_id" = 2 LIMIT ?  [["LIMIT", 1]]
  Product Load (0.2ms)  SELECT  "products".* FROM "products" WHERE "products"."catalog_id" = 2 LIMIT ?  [["LIMIT", 6]]
  Catalog Load (0.2ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."id" = 2
  Category Load (0.1ms)  SELECT "categories".* FROM "categories" WHERE "categories"."id" = 3
   (0.2ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 3
  Product Exists (0.1ms)  SELECT  1 AS one FROM "products" WHERE "products"."catalog_id" = 3 LIMIT ?  [["LIMIT", 1]]
  Category Load (0.1ms)  SELECT "categories".* FROM "categories" WHERE "categories"."id" = 3
  Product Exists (0.1ms)  SELECT  1 AS one FROM "products" WHERE "products"."catalog_id" = 2 LIMIT ?  [["LIMIT", 1]]
  Product Load (0.3ms)  SELECT  "products".* FROM "products" WHERE "products"."catalog_id" = 3 LIMIT ?  [["LIMIT", 6]]
  Catalog Load (0.1ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."id" = 3
  Catalog Load (0.4ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."id" = 3
  Product Load (0.6ms)  SELECT  "products".* FROM "products" WHERE "products"."catalog_id" = 2 LIMIT ?  [["LIMIT", 6]]
   (0.2ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 3
  Product Exists (0.1ms)  SELECT  1 AS one FROM "products" WHERE "products"."catalog_id" = 3 LIMIT ?  [["LIMIT", 1]]
  Product Load (0.1ms)  SELECT  "products".* FROM "products" WHERE "products"."catalog_id" = 3 LIMIT ?  [["LIMIT", 6]]
  Catalog Load (0.1ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."id" = 3
  Category Load (0.1ms)  SELECT "categories".* FROM "categories" WHERE "categories"."id" = 2
  Catalog Load (0.2ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."id" = 2
  Category Load (0.1ms)  SELECT "categories".* FROM "categories" WHERE "categories"."id" = 3
  Category Load (0.1ms)  SELECT "categories".* FROM "categories" WHERE "categories"."id" = 2
  Category Load (0.1ms)  SELECT "categories".* FROM "categories" WHERE "categories"."id" = 2
  Rendered static/home.html.haml within layouts/application (206.4ms)
  Rendered application/_favicon.html.haml (6.5ms)
   (0.2ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 3
  Product Exists (0.1ms)  SELECT  1 AS one FROM "products" WHERE "products"."catalog_id" = 3 LIMIT ?  [["LIMIT", 1]]
  Product Load (0.1ms)  SELECT  "products".* FROM "products" WHERE "products"."catalog_id" = 3 LIMIT ?  [["LIMIT", 6]]
  Catalog Load (0.1ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."id" = 3
  Category Load (0.1ms)  SELECT "categories".* FROM "categories" WHERE "categories"."id" = 2
  Rendered static/home.html.haml within layouts/application (195.5ms)
  Rendered application/_favicon.html.haml (0.1ms)
  Rendered static/home.html.haml within layouts/application (246.3ms)
  Rendered static/home.html.haml within layouts/application (255.3ms)
  Rendered application/_favicon.html.haml (0.1ms)
  Rendered application/_favicon.html.haml (0.0ms)
  Catalog Load (0.2ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."open" = ?  [["open", "t"]]
  Rendered shared/_navbar.html.haml (13.9ms)
  CACHE Catalog Load (0.0ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."open" = ?  [["open", "t"]]
  Rendered shared/_footer.html.haml (9.7ms)
  Catalog Load (0.2ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."open" = ?  [["open", "t"]]
  Rendered shared/_navbar.html.haml (3.2ms)
  Catalog Load (0.3ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."open" = ?  [["open", "t"]]
  Catalog Load (0.2ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."open" = ?  [["open", "t"]]
  Rendered shared/_navbar.html.haml (3.2ms)
  Rendered shared/_navbar.html.haml (14.3ms)
  CACHE Catalog Load (0.0ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."open" = ?  [["open", "t"]]
  CACHE Catalog Load (0.0ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."open" = ?  [["open", "t"]]
  CACHE Catalog Load (0.0ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."open" = ?  [["open", "t"]]
  Rendered shared/_footer.html.haml (5.9ms)
  Rendered shared/_footer.html.haml (3.0ms)
  Rendered shared/_footer.html.haml (6.0ms)
Completed 200 OK in 859ms (Views: 853.1ms | ActiveRecord: 3.5ms)


Completed 200 OK in 802ms (Views: 795.7ms | ActiveRecord: 4.0ms)


Completed 200 OK in 849ms (Views: 842.5ms | ActiveRecord: 3.7ms)


Started GET "/" for 127.0.0.1 at 2018-11-02 15:55:32 -0400
Processing by StaticController#home as HTML
Completed 200 OK in 858ms (Views: 851.2ms | ActiveRecord: 3.8ms)


  Rendering static/home.html.haml within layouts/application
  Catalog Load (0.2ms)  SELECT  "catalogs".* FROM "catalogs" WHERE "catalogs"."open" = ? ORDER BY created_at ASC LIMIT ?  [["open", "t"], ["LIMIT", 6]]
   (0.2ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 1
  CACHE  (0.0ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 1
  Product Exists (0.3ms)  SELECT  1 AS one FROM "products" WHERE "products"."catalog_id" = 1 LIMIT ?  [["LIMIT", 1]]
  Product Load (0.6ms)  SELECT  "products".* FROM "products" WHERE "products"."catalog_id" = 1 LIMIT ?  [["LIMIT", 6]]
  Catalog Load (0.4ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."id" = 1
  Category Load (0.2ms)  SELECT "categories".* FROM "categories" WHERE "categories"."id" IN (1, 2)
   (0.5ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 2
  Product Exists (0.2ms)  SELECT  1 AS one FROM "products" WHERE "products"."catalog_id" = 2 LIMIT ?  [["LIMIT", 1]]
  Product Load (0.2ms)  SELECT  "products".* FROM "products" WHERE "products"."catalog_id" = 2 LIMIT ?  [["LIMIT", 6]]
  Catalog Load (0.1ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."id" = 2
  Category Load (0.2ms)  SELECT "categories".* FROM "categories" WHERE "categories"."id" = 3
   (0.2ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 3
  Product Exists (0.1ms)  SELECT  1 AS one FROM "products" WHERE "products"."catalog_id" = 3 LIMIT ?  [["LIMIT", 1]]
  Product Load (0.4ms)  SELECT  "products".* FROM "products" WHERE "products"."catalog_id" = 3 LIMIT ?  [["LIMIT", 6]]
  Catalog Load (0.3ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."id" = 3
  Category Load (0.5ms)  SELECT "categories".* FROM "categories" WHERE "categories"."id" = 2
  Rendered static/home.html.haml within layouts/application (58.7ms)
  Rendered application/_favicon.html.haml (9.7ms)
  Catalog Load (0.2ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."open" = ?  [["open", "t"]]
  Rendered shared/_navbar.html.haml (16.9ms)
  CACHE Catalog Load (0.0ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."open" = ?  [["open", "t"]]
  Rendered shared/_footer.html.haml (11.7ms)
Completed 200 OK in 261ms (Views: 254.4ms | ActiveRecord: 4.7ms)

我的静态控制器：

class StaticController < ApplicationController
  def home
    @catalogs = Catalog.all.where(open: true).order('created_at ASC').limit(6)
    # @products = Product.all.includes(:catalog, :category).where(open: true).order('created_at DESC').take(8)
  end

  def about
    @catalogs = Catalog.all.where(open: true)
    @categories = Category.all.where(open: true)
    @products = Product.all.where(open: true)
  end

  def download_pdf
    send_file "#{Rails.root}/app/assets/docs/1_s.pdf", type: "application/pdf", x_sendfile: true
  end
end

注意：我在其他控制器上也有类似的问题

一开始我以为是个包，因为我没有添加任何新代码。请让我知道您是否需要来自控制器的更多代码。非常感谢您的时间和帮助。

更新

应用控制器：

class ApplicationController < ActionController::Base
  protect_from_forgery with: :exception
  before_action :prepare_meta_tags, if: "request.get?"

  def prepare_meta_tags(options={})
    site_name   = "Alvian Imports Inc."
    title       = "Alvain Imports Inc."
    description = "For many years, Alvian imports alcohol accross Florida state and now it's time to grow. Absolutly new team with new products that will be loved by everyone. We have an exclusive partnership with Ponche Caribe and we are starting to deliver our products to Texas, California, Mexico, and Columbia. Our goal is to make alcohol importation better and faster, so our team is working hard to deliver wonderful products to your closest stores."
    image       = options[:image] || "app/assets/images/brand/logo.png"
    current_url = request.url

    # Let's prepare a nice set of defaults
    defaults = {
      site:        site_name,
      title:       title,
      image:       image,
      description: description,
      keywords:    %w[food food processor food service food and drink f&b food industry food and beverage service food & beverage food processing industry food and beverage manager food and beverage industry food service jobs food beverage beverage industry food service companies f&b service food service worker food industry jobs food service industry food & drink food drink food and beverage management types of food service f&b industry food and beverage department import imports alvian alvianimports miami usa florida],
      twitter: {
        site_name: site_name,
        site: '@IncAlvian',
        card: 'The Beverage Company. Ponche Caribe Curacao Blue & Liquors Exclusive Distributor Florida - Texas - California - Colombia Distributor. Must be 21 +',
        description: description,
        image: image
      },
      og: {
        url: current_url,
        site_name: site_name,
        title: title,
        image: image,
        description: description,
        type: 'website'
      }
    }

    options.reverse_merge!(defaults)

    set_meta_tags options
  end
end

Application.html.haml 代码：

!!!
%html(lang="en-US" class="region--#{controller.controller_name}")
  %head
    = display_meta_tags
    %meta(http-equiv="X-UA-Compatible" content="IE=edge,chrome=1")
    %meta{:content => "text/html; charset=UTF-8", "http-equiv" => "Content-Type"}/
    %meta{:content => "text/html; charset=UTF-8", "http-equiv" => "Content-Type"}/
    %meta{:charset => "utf-8"}/
    %meta{:content => "width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no", :name => "viewport"}/
    %meta{:content => "user-scalable=no, width=device-width, initial-scale=1.0", :name => "viewport"}/
    %meta{:content => "yes", :name => "apple-mobile-web-app-capable"}/
    %meta{:'http-equiv' => "X-UA-Compatible", :content => "IE=edge"}
    %meta{:name => "HandheldFriendly", :contnet => "true"}
    %meta{:name => "MobileOptimized", :content => "176"}
    = render 'application/favicon'
    %title #{content_for?(:title) ? yield(:title) : 'Alvian Imports'}
    = csrf_meta_tags
    = stylesheet_link_tag    'application', media: 'all'
    = analytics_init if GoogleAnalytics.valid_tracker?
  %body(class = '#{controller.controller_name}')
    %div(class="application-wrapper")
      = render partial: 'shared/navbar'
      = content_tag :main, class: "layout layout-#{controller.action_name}" do
        = yield
      = render partial: 'shared/footer'
    - unless params[:nojs]
      = javascript_include_tag 'application'

更新 2

我有 3 个模型：目录、类别和产品。

目录型号：

class Catalog < ApplicationRecord
    extend FriendlyId
    friendly_id :name, use: [:slugged, :history]

    mount_uploader :photo, PhotoUploader
    has_many :categories, dependent: :delete_all
    has_many :products, :through => :categories, :source => :catalog, dependent: :delete_all

    # Important fields
    validates_presence_of :name
end

类别型号：

class Category < ApplicationRecord
    extend FriendlyId
    friendly_id :name, use: [:slugged, :history]

    belongs_to :catalog, :foreign_key => 'catalog_id'
    has_many :products, dependent: :delete_all

    # Important fields
    validates_presence_of :name

    def self.active
      where(status: 1)
    end
end

产品型号：

class Product < ApplicationRecord
    extend FriendlyId
    friendly_id :name, use: [:slugged, :history]

    mount_uploader :photo, PhotoUploader
    belongs_to :catalog, :foreign_key => 'catalog_id'
    belongs_to :category, :foreign_key => 'category_id'

    # Important fields
    validates_presence_of :name
end

控制台中的预期输出：

Started GET "/" for 127.0.0.1 at 2018-11-02 16:41:26 -0400
Processing by StaticController#home as HTML
  Rendering static/home.html.haml within layouts/application
  Catalog Load (0.2ms)  SELECT  "catalogs".* FROM "catalogs" WHERE "catalogs"."open" = ? ORDER BY created_at ASC LIMIT ?  [["open", "t"], ["LIMIT", 6]]
   (0.1ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 1
  CACHE  (0.0ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 1
  Product Exists (0.1ms)  SELECT  1 AS one FROM "products" WHERE "products"."catalog_id" = 1 LIMIT ?  [["LIMIT", 1]]
  Product Load (0.2ms)  SELECT  "products".* FROM "products" WHERE "products"."catalog_id" = 1 LIMIT ?  [["LIMIT", 6]]
  Catalog Load (0.1ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."id" = 1
  Category Load (0.2ms)  SELECT "categories".* FROM "categories" WHERE "categories"."id" IN (1, 2)
   (0.2ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 2
  Product Exists (0.1ms)  SELECT  1 AS one FROM "products" WHERE "products"."catalog_id" = 2 LIMIT ?  [["LIMIT", 1]]
  Product Load (0.1ms)  SELECT  "products".* FROM "products" WHERE "products"."catalog_id" = 2 LIMIT ?  [["LIMIT", 6]]
  Catalog Load (0.1ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."id" = 2
  Category Load (0.1ms)  SELECT "categories".* FROM "categories" WHERE "categories"."id" = 3
   (0.3ms)  SELECT COUNT(*) FROM "products" WHERE "products"."catalog_id" = 3
  Product Exists (0.3ms)  SELECT  1 AS one FROM "products" WHERE "products"."catalog_id" = 3 LIMIT ?  [["LIMIT", 1]]
  Product Load (0.2ms)  SELECT  "products".* FROM "products" WHERE "products"."catalog_id" = 3 LIMIT ?  [["LIMIT", 6]]
  Catalog Load (0.3ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."id" = 3
  Category Load (0.2ms)  SELECT "categories".* FROM "categories" WHERE "categories"."id" = 2
  Rendered static/home.html.haml within layouts/application (44.4ms)
  Rendered application/_favicon.html.haml (7.9ms)
  Catalog Load (0.2ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."open" = ?  [["open", "t"]]
  Rendered shared/_navbar.html.haml (15.8ms)
  CACHE Catalog Load (0.0ms)  SELECT "catalogs".* FROM "catalogs" WHERE "catalogs"."open" = ?  [["open", "t"]]
  Rendered shared/_footer.html.haml (8.9ms)
Completed 200 OK in 218ms (Views: 213.2ms | ActiveRecord: 3.1ms)

主页 HTML (HAML)，但必须提到的是，我在其他需要查询的页面（例如目录显示页面）上遇到了类似的问题：

= content_for :navbar_class, "navbar-dark"

%section(class="hero hero-homepage")
  %div(class="hh-container")
    %div(class="hh-carousel")
      - @catalogs.each do |catalog|
        %div(class="hhc-item")
          = link_to catalog, class: 'hhc-container' do
            %div(class="hhc-background" style="background-image: url(#{catalog.photo});")
            -# = image_tag(catalog.photo, lazy: true, class: "hhc-background")
            %div(class="hhc-caption")
              %h4(class="heading heading-1 is-light") #{catalog.name}
              - if !catalog.description.empty? 
                %p(class="text text-2 is-light is-transparent") #{truncate(catalog.description, :length => 112)}

%section(class="section")
  - @catalogs.each do |pc|
    - @products = Product.all.where(catalog_id: pc)
    %div(class="content")
      %div(class="header header-hr")
        %span
          %h4(class="heading heading-4") New #{pc.name}
        - if @products.count > 6
          %span
            = link_to "View all " + @products.count.to_s, pc, class: "link link-secondary link-arrow"
      %div(class="row")
        - if !@products.empty?
          - @products.includes(:catalog, :category).take(6).each do |p|
            %div(class="col-xs-6 col-md-4 col-lg-3")
              = link_to catalog_category_product_url(p.catalog, p.category, p), class: "block block-product" do
                = image_tag p.photo, alt: p.name, class: 'bp-photo', lazy: true
                %div(class="bp-desc")
                  %span
                    %h5(class="heading heading-5") #{p.name}
                  %span
                    %p(class="text text-3") 
                      %span.is-primary #{p.catalog.name} 
                      %span - #{p.category.name}
        - else
          %div(class="col-xs-12 is-centered")
            %h5(class="heading heading-5") Currently this list is empty.

更新 3

好的，我不明白问题的过程，但我决定重新创建数据库：

rake db:drop db:create db:migrate

解决了问题..

【问题讨论】：

您是否检查了控制器或 application_controller 中的 before_action 或 after_action？还要检查初始化程序..
@Md.FarhanMemon 我已经更新了我的问题，所以你可以看看我的application_controller.rb
是 single 页面加载的日志 sn-p 吗？因为它有多个按时间分隔的GET / 请求。
@anothermh 正确，先生，这是我的home page。我在任何其他页面上都得到了类似的输出，例如 show pages
你家的html呢？

标签： ruby-on-rails ruby terminal haml ruby-on-rails-5.1

【解决方案1】：

一大堆事情，如果不实际运行代码很难提供帮助。

首先，熟悉命名事物的良好做法。 @catalogs.each do |pc| 是一个禁忌，应该是 @catalogs.each do |catalog|。

if !@products.empty? 和@product.count，它们会触发两个查询，我的建议是将计数写入@products_count 并将其替换为空？ @product_count > 0

在模型中使用 scope 替换 .where(open: true) 之类的东西

在@products.includes(:catalog, :category) 中，您可以删除catalog，因为您已经按目录浏览产品并且可以使用pc（或我上面推荐的：catalog）代替product.catalog

如果 catalog_category_product_url 没有使用任何花哨的东西，而只是使用 id（例如 catalog/5/category/2/product/23），那么您可以使用 catalog_category_product_url(product.catalog_id, product.category_id, product) 来防止一些额外的查询（特别是如果您忘记使用预加载或不想要从数据库中加载大量数据）。

【讨论】：

非常感谢，这些信息对我来说非常有价值！
如果应用程序正在生产中，有类似 newrelic 或简单 rubygems 的东西可以分析您的日志文件，这样您就可以更轻松地找到那些缓慢的页面并专注于它们。
我确实使用gem bullet 来识别n+1 queries，但它只适用于:development。另外，我的日志是从开发中获取的，我在生产中没有任何问题。感谢您的回复！
子弹很棒。对于生产日志，这可能很有用github.com/wvanbergen/request-log-analyzer我最近派生了一个 sql 查询计数 gem，因此它也可以分隔缓存查询。那是一个包含 3000 多个 sql 查询的页面，我降到了 90 个！ github.com/TomK32/sql_queries_count
非常感谢，一定会尝试所有这些宝石！