艺术家 Group_by 嵌套属性 Order_date

Question

我创建了一个功能强大的电子商务平台，会员可以在其中购买歌曲。一切正常，但我想按月在我的索引页面中对我的所有订单进行分组。

目前，我可以将每张专辑与其对应的艺术家分组，并将每首订购歌曲与其对应的专辑分组。但现在我想按月份对订单进行分组。

如何按订单表中的 order_date 对艺术家进行分组，以便按月份组织所有内容？

Ex. of what I've like to do 

Month 1 Orders 
Artist1
  Album1                      ###List of Albums Corresponding to an Artist 
    --Song1 (10 0rders)          
    --Song3 (5 Orders)
  Album2 
    --Song5 (2 Orders)        ###Ordered Songs Corresponding to an Album 

Month 2 Orders
Artist2
  Album1 
    --Song2 (1 Order)
Artist3
  Album3 
    --Song5 (1 Order)

模型

class Order < ActiveRecord::Base
  attr_accessible :artist_id, :album_id, :song_id, :user_id, :order_date

  belongs_to :song
  belongs_to :user

end

class Artist < ActiveRecord::Base
  attr_accessible :name

  has_many :albums
  has_many :songs, :through => :albums
  has_many :orders, :through => :songs

end

class Album < ActiveRecord::Base
  attr_accessible :name, :artist_id

  belongs_to :artist
  has_many :songs
  has_many :orders, :through => :songs

end

class Song < ActiveRecord::Base
  attr_accessible :artist_id, :album_id, :title, :price

  belongs_to :album
  has_many :orders

end

控制器

###How Can I Group Artists by the order_date in my Orders Table?

def index    
  @artists = Artist.includes(:orders).where('orders.id IS NOT NULL')
end

观看次数

   <% @artists.each do |artist| %>             ###Lists All Artists with Orders
     <h3><%= artist.name %></h3>

     <% artist.albums.each do |album| %>      ###Lists All Albums corresponding to Artist
       <h4><%= album.name %></h4>

         <% album.songs.each do |song| %>     ###Lists All Ordered Songs corresponding to Albums

           <% if song.orders.count >= 1 %>
             (<%= song.orders.count %>)
             <%= song.title %>
             $<%= song.price %><br>
           <% end %>

         <% end %> 


     <% end %>

   <% end %>

Answer 1

您可以通过此行获得订单列表：

<% @order_months.sort.each do |month, orders| %>

然后你又跳回到你的完整艺术家列表中：

   <% @artists.each do |artist| %>             ###Lists All Artists with Orders

相反，我认为您需要类似的东西

   <% orders.each do |order| %>
     <% order.artists.each do |artist| %>
       <% artist.albums.each do |album| %> 
         <% album.songs.each do |song| %>
             <%= song.name %>

要获得 order.artists，您需要修改模型：

class Order < ActiveRecord::Base
  attr_accessible :artist_id, :album_id, :song_id, :user_id, :order_date

  belongs_to :song
  belongs_to :user

  has_many :albums, through: :song
  has_many :artists, through: :albums

end

Answer 2

这就是我最终解决问题的方式

控制器

@orders = Order.find(:all, :order => 'order_date, id', :limit => 50)

观看次数

<% @orders.sort.group_by { |order| order.order_date.beginning_of_month }.each do |month, orders| %>
  <h3><%= month.strftime('%B') %> </h3>

  <% orders.group_by { |order| order.song.album.artist }.each do |artist, orders| %>
    <h4><%= artist.name %> </h4>

    <% orders.group_by { |order| order.song.album }.each do |album, orders| %>
      <h5><%= album.name %> </h5>

        <% orders.group_by { |order| order.song }.each do |song, orders| %>
          <p>(<%= orders.count %>) <%= song.title %> </p>
          <p><%= song.price %> </p>
        <% end %>

    <% end %>

  <% end %>

<% end %>