页面加载不必要的查询Rails

Question

我有一个奇怪的问题，我的网站的每一页包含数据库查询加载一些额外的项目。我以前从来没有遇到过这个问题，我试过检查所有的控制器，但是没有发现任何问题。以下是加载(或刷新)主页时输出的示例

=> 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:我和其他控制器也有类似的问题。

一开始，我认为这是一个包，因为我没有添加任何新代码。如果你需要更多控制器的代码，请告诉我。非常感谢您的时间和帮助。

更新

应用主计长：

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

我有三种型号:目录，类别和产品。

目录模型：

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

类别模式：

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)

但是，必须提到的是，主页HTML (HAML)与需要查询的其他页面(例如，目录显示页)也有类似的问题：

= 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..。

Answer 1

如果不实际运行代码，那么很多事情都很难帮助。

首先，让自己熟悉命名事物的良好做法。@catalogs.each do |pc|是不-不，应该是@catalogs.each do |catalog|.

if !@products.empty?和@product.count，它们触发了两个查询，我的建议是将计数写入@products_count并替换为空？用@product_count > 0

在模型中使用scope替换像.where(open: true)这样的东西

在@products.includes(:catalog, :category)中，您可以删除catalog，因为您已经按目录遍历了产品，并且可以使用pc (或如我前面所建议的：catalog)而不是product.catalog。

如果catalog_category_product_url不使用任何花哨的东西，只使用ids (例如catalog/5/category/2/product/23)，那么您可以执行catalog_category_product_url(product.catalog_id, product.category_id, product)来防止一些额外的查询(特别是当您忘记使用急切加载或不想从db加载一大块数据时)。