Ruby on rails Rails 5.2.3-显示按相关记录总数排序的类别树

我目前正在使用渲染500+个类别和子类别（它们可以达到3级深度）

现在，我想做的是：

仅显示关联的类别/子类别 交易

按以下顺序排列这些类别：

• 这些关联交易的

  ：金额的总和

• 并按层次对其进行排序

打印每个类别名称旁边的总数

下面是我希望实现的一个例子：

Travel = $1500
Travel > Air = $1000
Travel > Ground = $250
Business = $500
Business > Services = $250
Business > Services > Marketing = $75
# etc...

这就是我的模型的样子：

class Category < ApplicationRecord
  has_many :transactions
  has_ancestry
end

class Transaction < ApplicationRecord
  belongs_to :account
  belongs_to :category
end

类别

到目前为止，我几乎能够做到：

# app/controllers/categories_controller.rb
def index
  # Get all of the root categories
  @primary_categories = Category.where(ancestry: nil)
end

# app/views/categories/index.html.erb
<% @primary_categories.each do |primary_category| %>
  <% primary_category_total = Transaction.where(account_id: current_user, category_id: primary_category.subtree).sum(:amount) %>

  <% if primary_category_total != 0.0 %> 
    <%= link_to primary_category.name, category_path(primary_category) %>
    <%= number_to_currency primary_category_total %>

    <% if primary_category.has_children? && primary_category_total != 0.0 %> 
      <% primary_category.children.each do |secondary_category| %>
        <% secondary_category_total = Transaction.where(account_id: current_user, category_id: primary_category.subtree).sum(:amount) %>

        <% if secondary_category_total != 0.0 %> 
          <%= link_to secondary_category.name, category_path(secondary_category) %>
          <%= number_to_currency secondary_category_total %>

          <% if secondary_category.has_children? && secondary_category_total != 0.0 %>
            <% secondary_category.children.each do |tertiary_category| %>
            <% tertiary_category_total = Transaction.where(account_id: current_user, category_id: primary_category.subtree).sum(:amount) %>

            <% if tertiary_category_total != 0.0 %> 
              <%= link_to tertiary_category.name, category_path(tertiary_category) %>
              <%= number_to_currency tertiary_category.transactions.sum(:amount) %>
# etc...

#app/controllers/categories_controller.rb
def索引
#获取所有根类别
@primary_categories=类别。其中（祖先：无）
结束
#app/views/categories/index.html.erb
#等等。。。

但这会产生大量令人痛苦的查询，而且速度非常慢，更不用说我现在的视图中有一堆复杂的代码。当然，它们不是按总数排序的

---

我还应该怎么做呢？

买主须知：

下面的所有内容都应视为伪代码。我没有测试任何一个，我没有试图让它复制粘贴就绪。这只是帮助您开始重构的一个起点

在您的模型中 您希望从视图中获取类似于

Transaction.where（帐户\u id:current\u用户，类别\u id:primary\u category.subtree）的内容。sum（：amount）

您可以创建一个方法和/或范围来返回事务总数。例如：

# app/views/categories/_category.html.erb
<% @categories.each do |category| %>
  <% category_total = category.user_transaction_amount(current_user) %>
  <% return if category_total == 0.0 %>
  <%= link_to category.name, category_path(category) %>
  <%= number_to_currency category_total %>
  <% if category.has_children? && category_total != 0.0 %> 
      <% category.children.each do |secondary_category| %>
        <%= render category, category: secondary_category %>
      <% end %>
  <% end %>
<% end %>


# app/views/categories/index.html.erb
<% @primary_categories.each do |primary_category| %>
  <% render 'categories', category: primary_category %>
<% end %>

#app/models/transaction.rb
范围：按用户分类，->（用户，分类）do
其中（帐户：用户，类别：category.subtree）
结束
#app/models/category.rb
def用户\交易\金额（用户）
交易。按用户分类（用户、自身）。金额（：金额）
结束

在控制器中 你应该照顾孩子们。你知道你会需要它们，所以马上去做。（有理由的，见下文）

你提到500多个类别，这是分页的吗？如果是，请在中进行

在你看来 注意重复的代码？试着用刷子把它擦干。例如：

# app/views/categories/_category.html.erb
<% @categories.each do |category| %>
  <% category_total = category.user_transaction_amount(current_user) %>
  <% return if category_total == 0.0 %>
  <%= link_to category.name, category_path(category) %>
  <%= number_to_currency category_total %>
  <% if category.has_children? && category_total != 0.0 %> 
      <% category.children.each do |secondary_category| %>
        <%= render category, category: secondary_category %>
      <% end %>
  <% end %>
<% end %>


# app/views/categories/index.html.erb
<% @primary_categories.each do |primary_category| %>
  <% render 'categories', category: primary_category %>
<% end %>

#app/views/categories/_category.html.erb
#app/views/categories/index.html.erb

---

这仍然需要一些改进。视图模板应该主要是html语句，这是100%ruby。你可能会把这些都放到一个助手中，或者甚至直接从一个控制器操作中删除。

经过一段时间的尝试，一个错误（基于Jacob的错误）我想出了一个解决方案，它的性能显著提高，消除了控制器和视图的复杂性，并且完成了我第一篇文章中要求列表中的所有事情

我仍然认为有优化和清理的空间，但这里是：

app/models/transaction.rb

  scope :by_user_category, ->(user, category) do 
    where(account: user.accounts, category: category.subtree)
  end

  def balance(user)
    Transaction.by_user_category(user, self).sum(:amount)
  end

  def self.spending_by(user)
    categories_with_spending = []

    categories_depth_0 = Category.where(ancestry: nil) # Get the root categories
    categories_depth_0.each do |cat_depth_0|
      category_depth_0_balance = cat_depth_0.balance(user)

      if category_depth_0_balance < 0  # "Root category exists and has a balance"
        categories_depth_1_with_spending = []
        categories_depth_1 = Category.find_by_id(cat_depth_0).children # Get the sub-categories

        if !categories_depth_1.empty? # "Sub-category exists"
          categories_depth_1.each do |cat_depth_1|
            category_depth_1_balance = cat_depth_1.balance(user)

            if category_depth_1_balance < 0 # "Sub-category exists and has a balance"
              categories_depth_2_with_spending = []
              categories_depth_2 = Category.find_by_id(cat_depth_1).children

              if !categories_depth_2.empty? # Sub-category has child
                categories_depth_2.each do |cat_depth_2|
                  category_depth_2_balance = cat_depth_2.balance(user)

                  if category_depth_2_balance < 0  # Sub-category child has a balance
                    categories_depth_2_with_spending << {
                      category: cat_depth_2,
                      balance: category_depth_2_balance
                    }
                  end
                end
              end

              if categories_depth_2_with_spending != nil
                # Passing child sub-categories to parent sub-categories
                categories_depth_1_with_spending << {
                  category: cat_depth_1,
                  balance: category_depth_1_balance,
                  sub_categories: categories_depth_2_with_spending.sort_by { |c| c[:balance] }
                }
              end
            end
          end

          if categories_depth_1_with_spending != nil
            # Passing sub-categories to root category
            categories_with_spending << {
              category: cat_depth_0,
              balance: category_depth_0_balance,
              sub_categories: categories_depth_1_with_spending.sort_by { |c| c[:balance] }
            }
          end
        else
          # "Root exists but has no sub-categories"
          categories_with_spending << {
            category: cat_depth_0,
            balance: category_depth_0_balance
          }
        end
      end
    end

    return categories_with_spending.sort_by { |c| c[:balance] }
  end

  def index
    @categories = Category.spending_by(current_user)
  end

  <% @categories.each do |cat_depth_0| %>
    <section class="app-card app-amount-summary app-categories__card">
      <%= render 'category_depth_0', category: cat_depth_0 %>

      <% if cat_depth_0[:sub_categories] %>
        <ul class="app-category-list">
          <% cat_depth_0[:sub_categories].each do |cat_depth_1| %>
            <%= render 'category_depth_1', category: cat_depth_1 %>
          <% end %>
        </ul>
      <% end %>
    </section>
  <% end %>

<header class="app-card-header">
  <h3 class="app-card-header__h3">
    <%= link_to category[:category].name, category_path(category[:category].id) %>
  </h3>
  <p class="app-card-header__balance"><%= number_to_currency category[:balance] %></p>
</header>

app/models/category.rb

  scope :by_user_category, ->(user, category) do 
    where(account: user.accounts, category: category.subtree)
  end

  def balance(user)
    Transaction.by_user_category(user, self).sum(:amount)
  end

  def self.spending_by(user)
    categories_with_spending = []

    categories_depth_0 = Category.where(ancestry: nil) # Get the root categories
    categories_depth_0.each do |cat_depth_0|
      category_depth_0_balance = cat_depth_0.balance(user)

      if category_depth_0_balance < 0  # "Root category exists and has a balance"
        categories_depth_1_with_spending = []
        categories_depth_1 = Category.find_by_id(cat_depth_0).children # Get the sub-categories

        if !categories_depth_1.empty? # "Sub-category exists"
          categories_depth_1.each do |cat_depth_1|
            category_depth_1_balance = cat_depth_1.balance(user)

            if category_depth_1_balance < 0 # "Sub-category exists and has a balance"
              categories_depth_2_with_spending = []
              categories_depth_2 = Category.find_by_id(cat_depth_1).children

              if !categories_depth_2.empty? # Sub-category has child
                categories_depth_2.each do |cat_depth_2|
                  category_depth_2_balance = cat_depth_2.balance(user)

                  if category_depth_2_balance < 0  # Sub-category child has a balance
                    categories_depth_2_with_spending << {
                      category: cat_depth_2,
                      balance: category_depth_2_balance
                    }
                  end
                end
              end

              if categories_depth_2_with_spending != nil
                # Passing child sub-categories to parent sub-categories
                categories_depth_1_with_spending << {
                  category: cat_depth_1,
                  balance: category_depth_1_balance,
                  sub_categories: categories_depth_2_with_spending.sort_by { |c| c[:balance] }
                }
              end
            end
          end

          if categories_depth_1_with_spending != nil
            # Passing sub-categories to root category
            categories_with_spending << {
              category: cat_depth_0,
              balance: category_depth_0_balance,
              sub_categories: categories_depth_1_with_spending.sort_by { |c| c[:balance] }
            }
          end
        else
          # "Root exists but has no sub-categories"
          categories_with_spending << {
            category: cat_depth_0,
            balance: category_depth_0_balance
          }
        end
      end
    end

    return categories_with_spending.sort_by { |c| c[:balance] }
  end

  def index
    @categories = Category.spending_by(current_user)
  end

  <% @categories.each do |cat_depth_0| %>
    <section class="app-card app-amount-summary app-categories__card">
      <%= render 'category_depth_0', category: cat_depth_0 %>

      <% if cat_depth_0[:sub_categories] %>
        <ul class="app-category-list">
          <% cat_depth_0[:sub_categories].each do |cat_depth_1| %>
            <%= render 'category_depth_1', category: cat_depth_1 %>
          <% end %>
        </ul>
      <% end %>
    </section>
  <% end %>

<header class="app-card-header">
  <h3 class="app-card-header__h3">
    <%= link_to category[:category].name, category_path(category[:category].id) %>
  </h3>
  <p class="app-card-header__balance"><%= number_to_currency category[:balance] %></p>
</header>

app/views/categories/index.html.erb

  scope :by_user_category, ->(user, category) do 
    where(account: user.accounts, category: category.subtree)
  end

  def balance(user)
    Transaction.by_user_category(user, self).sum(:amount)
  end

  def self.spending_by(user)
    categories_with_spending = []

    categories_depth_0 = Category.where(ancestry: nil) # Get the root categories
    categories_depth_0.each do |cat_depth_0|
      category_depth_0_balance = cat_depth_0.balance(user)

      if category_depth_0_balance < 0  # "Root category exists and has a balance"
        categories_depth_1_with_spending = []
        categories_depth_1 = Category.find_by_id(cat_depth_0).children # Get the sub-categories

        if !categories_depth_1.empty? # "Sub-category exists"
          categories_depth_1.each do |cat_depth_1|
            category_depth_1_balance = cat_depth_1.balance(user)

            if category_depth_1_balance < 0 # "Sub-category exists and has a balance"
              categories_depth_2_with_spending = []
              categories_depth_2 = Category.find_by_id(cat_depth_1).children

              if !categories_depth_2.empty? # Sub-category has child
                categories_depth_2.each do |cat_depth_2|
                  category_depth_2_balance = cat_depth_2.balance(user)

                  if category_depth_2_balance < 0  # Sub-category child has a balance
                    categories_depth_2_with_spending << {
                      category: cat_depth_2,
                      balance: category_depth_2_balance
                    }
                  end
                end
              end

              if categories_depth_2_with_spending != nil
                # Passing child sub-categories to parent sub-categories
                categories_depth_1_with_spending << {
                  category: cat_depth_1,
                  balance: category_depth_1_balance,
                  sub_categories: categories_depth_2_with_spending.sort_by { |c| c[:balance] }
                }
              end
            end
          end

          if categories_depth_1_with_spending != nil
            # Passing sub-categories to root category
            categories_with_spending << {
              category: cat_depth_0,
              balance: category_depth_0_balance,
              sub_categories: categories_depth_1_with_spending.sort_by { |c| c[:balance] }
            }
          end
        else
          # "Root exists but has no sub-categories"
          categories_with_spending << {
            category: cat_depth_0,
            balance: category_depth_0_balance
          }
        end
      end
    end

    return categories_with_spending.sort_by { |c| c[:balance] }
  end

  def index
    @categories = Category.spending_by(current_user)
  end

  <% @categories.each do |cat_depth_0| %>
    <section class="app-card app-amount-summary app-categories__card">
      <%= render 'category_depth_0', category: cat_depth_0 %>

      <% if cat_depth_0[:sub_categories] %>
        <ul class="app-category-list">
          <% cat_depth_0[:sub_categories].each do |cat_depth_1| %>
            <%= render 'category_depth_1', category: cat_depth_1 %>
          <% end %>
        </ul>
      <% end %>
    </section>
  <% end %>

<header class="app-card-header">
  <h3 class="app-card-header__h3">
    <%= link_to category[:category].name, category_path(category[:category].id) %>
  </h3>
  <p class="app-card-header__balance"><%= number_to_currency category[:balance] %></p>
</header>

app/views/categories/\u category\u depth\u 0.html.erb

  scope :by_user_category, ->(user, category) do 
    where(account: user.accounts, category: category.subtree)
  end

  def balance(user)
    Transaction.by_user_category(user, self).sum(:amount)
  end

  def self.spending_by(user)
    categories_with_spending = []

    categories_depth_0 = Category.where(ancestry: nil) # Get the root categories
    categories_depth_0.each do |cat_depth_0|
      category_depth_0_balance = cat_depth_0.balance(user)

      if category_depth_0_balance < 0  # "Root category exists and has a balance"
        categories_depth_1_with_spending = []
        categories_depth_1 = Category.find_by_id(cat_depth_0).children # Get the sub-categories

        if !categories_depth_1.empty? # "Sub-category exists"
          categories_depth_1.each do |cat_depth_1|
            category_depth_1_balance = cat_depth_1.balance(user)

            if category_depth_1_balance < 0 # "Sub-category exists and has a balance"
              categories_depth_2_with_spending = []
              categories_depth_2 = Category.find_by_id(cat_depth_1).children

              if !categories_depth_2.empty? # Sub-category has child
                categories_depth_2.each do |cat_depth_2|
                  category_depth_2_balance = cat_depth_2.balance(user)

                  if category_depth_2_balance < 0  # Sub-category child has a balance
                    categories_depth_2_with_spending << {
                      category: cat_depth_2,
                      balance: category_depth_2_balance
                    }
                  end
                end
              end

              if categories_depth_2_with_spending != nil
                # Passing child sub-categories to parent sub-categories
                categories_depth_1_with_spending << {
                  category: cat_depth_1,
                  balance: category_depth_1_balance,
                  sub_categories: categories_depth_2_with_spending.sort_by { |c| c[:balance] }
                }
              end
            end
          end

          if categories_depth_1_with_spending != nil
            # Passing sub-categories to root category
            categories_with_spending << {
              category: cat_depth_0,
              balance: category_depth_0_balance,
              sub_categories: categories_depth_1_with_spending.sort_by { |c| c[:balance] }
            }
          end
        else
          # "Root exists but has no sub-categories"
          categories_with_spending << {
            category: cat_depth_0,
            balance: category_depth_0_balance
          }
        end
      end
    end

    return categories_with_spending.sort_by { |c| c[:balance] }
  end

  def index
    @categories = Category.spending_by(current_user)
  end

  <% @categories.each do |cat_depth_0| %>
    <section class="app-card app-amount-summary app-categories__card">
      <%= render 'category_depth_0', category: cat_depth_0 %>

      <% if cat_depth_0[:sub_categories] %>
        <ul class="app-category-list">
          <% cat_depth_0[:sub_categories].each do |cat_depth_1| %>
            <%= render 'category_depth_1', category: cat_depth_1 %>
          <% end %>
        </ul>
      <% end %>
    </section>
  <% end %>

<header class="app-card-header">
  <h3 class="app-card-header__h3">
    <%= link_to category[:category].name, category_path(category[:category].id) %>
  </h3>
  <p class="app-card-header__balance"><%= number_to_currency category[:balance] %></p>
</header>

---

\u category\u depth\u 1.html.erb

的工作原理与

\u category\u depth\u 0.html.erb

完全相同，但结构不同，因此我跳过了这个示例。

谢谢Jacob，我将尝试一下您的方法。澄清一下，虽然我有500多个类别，但我只希望在我运行完所有事务总计后呈现30个类别，所以我没有任何分页（目前）。