Question

我有订单模型，下面会返回string text = "41sugar1100"; string[] array = text.Split('sugar');。

Order.all

但是，[ [0] #<Order:0x007f9d9e236de0> { :id => 15, :user_id => 2, :artist_id => nil, :address_id => 18, :paid_at => nil, :payment_type => "bank", :guid => "c8e22764774adc6825348b8874b581e8", :created_at => Mon, 24 Aug 2015 19:42:09 JST +09:00, :updated_at => Mon, 24 Aug 2015 19:45:38 JST +09:00, :ordered_at => Mon, 24 Aug 2015 19:45:37 JST +09:00, :total => 43890 }, [1] #<Order:0x007f9d9e2367a0> { :id => 12, :user_id => 2, :artist_id => nil, :address_id => 18, :paid_at => nil, :payment_type => "bank", :guid => "274b4a8653395023125a4724139efc09", :created_at => Mon, 24 Aug 2015 19:10:38 JST +09:00, :updated_at => Mon, 24 Aug 2015 19:41:25 JST +09:00, :ordered_at => Mon, 24 Aug 2015 19:41:22 JST +09:00, :total => 48689 }, [2] #<Order:0x007f9d9e236318> { :id => 11, :user_id => 2, :artist_id => nil, :address_id => 14, :paid_at => Mon, 24 Aug 2015 19:10:38 JST +09:00, :payment_type => "credit_card", :guid => "b075f4a6f31c32942152f7d50d2bd098", :created_at => Mon, 24 Aug 2015 19:03:39 JST +09:00, :updated_at => Mon, 24 Aug 2015 19:10:38 JST +09:00, :ordered_at => Mon, 24 Aug 2015 19:10:38 JST +09:00, :total => 5010 }, [3] #<Order:0x007f9d9e235e40> { :id => 10, :user_id => nil, :artist_id => nil, :address_id => nil, :paid_at => nil, :payment_type => nil, :guid => "916ff17977cb176c5e5740faab92a08c", :created_at => Sat, 22 Aug 2015 19:30:38 JST +09:00, :updated_at => Sat, 22 Aug 2015 19:30:38 JST +09:00, :ordered_at => nil, :total => 0 }, [4] #<Order:0x007f9d9e2356c0> { :id => 9, :user_id => 1, :artist_id => nil, :address_id => 9, :paid_at => nil, :payment_type => "bank", :guid => "a4f1dd11ad035d1747a37776b062021f", :created_at => Sat, 22 Aug 2015 19:30:04 JST +09:00, :updated_at => Tue, 01 Sep 2015 00:00:09 JST +09:00, :ordered_at => Sat, 22 Aug 2015 00:00:00 JST +09:00, :total => 5010 }, [5] #<Order:0x007f9d9e2342c0> { :id => 8, :user_id => 1, :artist_id => nil, :address_id => 9, :paid_at => Thu, 20 Aug 2015 19:30:04 JST +09:00, :payment_type => "credit_card", :guid => "b816503b6b95d35455262cd4d8b9e822", :created_at => Sat, 22 Aug 2015 19:30:04 JST +09:00, :updated_at => Sat, 22 Aug 2015 19:30:04 JST +09:00, :ordered_at => Wed, 19 Aug 2015 19:30:04 JST +09:00, :total => 0 }会返回

Order.sum(:total)

和Order.sum(:total) (0.4ms) SELECT SUM("orders"."total") FROM "orders" 12000返回

Order.pluck(:total)

那么，发生了什么？我怎样才能得到正确的价值？

感谢许多评论。

我有默认范围，但只有订单，

Order.pluck(:total)
CACHE (0.0ms)  SELECT "orders"."total" FROM "orders"  ORDER BY   "orders"."created_at" DESC
[
    [0] nil,
    [1] nil,
    [2] nil,
    [3] nil,
    [4] 2000,
    [5] 10000
]

。这会影响这个问题吗？

这是＆＃39; Order.all＆＃39;查询。

   default_scope { order(created_at: :desc) }

Order Load (1.0ms) SELECT "orders".* FROM "orders" ORDER BY "orders"."created_at" DESC Item Load (0.4ms) SELECT "items".* FROM "items" WHERE "items"."order_id" = $1 [["order_id", 20]] Flower Load (0.7ms) SELECT "flowers".* FROM "flowers" WHERE "flowers"."type" IS NULL AND "flowers"."item_id" = $1 ORDER BY "flowers"."created_at" ASC LIMIT 1 [["item_id", 8]]返回

Order.all.map(&:total)

抱歉延迟回复...

这是我对orders.html.erb的结果，我只使用myapp_development和myapp_test数据库。

[ [ 0] 43890, [ 1] 48689, [ 2] 5010, [ 3] 0, [ 4] 5010, [ 5] 0 ]

Answer 1

您提供的信息是矛盾的。

我想你看看不同的数据库。

让我解释为什么我这么认为。

事实＃1 根据Order.all输出，我们有：

#<Order id: 15, total: 43890.0>
#<Order id: 12, total: 48689.0>
#<Order id: 11, total: 5010.0>
#<Order id: 10, total: 0.0>
#<Order id: 9,  total: 5010.0>
#<Order id: 8,  total: 0.0>

此处的

total属性与数据库中的内容相同。即使您在Order模型中定义了具有相同名称的方法，该属性也不应受其影响。

事实＃2 根据Order.pluck(:total)输出，我们有：

#<Order id: 15, total: nil>
#<Order id: 12, total: nil>
#<Order id: 11, total: nil>
#<Order id: 10, total: nil>
#<Order id: 9,  total: 2000>
#<Order id: 8,  total: 10000>

同样，此处的total属性与数据库中的内容相同。同样，它不会受到模型中定义的方法的影响。

现在我们看到事实1 与事实2 相矛盾。我几乎可以肯定你在这里看不同的数据库。

确保您不会产生矛盾结果的最佳方法是创建一个包含此内容的新页面：

<!-- orders.html.erb -->

<table>
  <tr>
    <td>Order.count</td>
    <td><%= Order.count %></td>
  </tr>
  <tr>
    <td>Order.sum(:total)</td>
    <td><%= number_with_delimiter Order.sum(:total) %></td>
  </tr>
  <tr>
    <td>Order.pluck(:total)</td>
    <td><%= Order.pluck(:total) %></td>
  </tr>
  <tr>
    <td>Order.all.map(&amp;:total)</td>
    <td><%= Order.all.map(&:total) %></td>
  </tr>
</table>

<% Order.all.each do |o| %>
  <p>
    <code><%= o.inspect %></code>
  </p>
<% end %>

并提供此页面的输出以供进一步探索。

基本上我的要求是：

检查您没有使用两个不同的数据库
如果＃1无用，请使用给定的ERB模板创建新操作并分享其输出。

Answer 2

如果Order.pluck(:total)返回的内容与Order.all.map(&:total)不同，那么＆＃39; total＆＃39;方法可能在某处定义，因此会覆盖列属性方法。您可以通过以下方式检查此方法的源文件名和行：

Order.new.method(:total).source_location

应该参考activerecord-4.2.4/lib/active_record/attribute_methods.rb。如果它没有，那么这就是您意外覆盖ActiveRecord方法的地方。

ActiveRecord sum和pluck方法返回奇怪的值

2 个答案: