将 Money 对象转换添加到 Rails 3.1 中的求和查询

发布于 2024-12-26 13:57:28 字数 828 浏览 1 评论 0原文

另一个菜鸟问题看起来应该很简单：

感谢这里收到的帮助，我可以轻松获得所选交易的总和：

@trip_hash = transactions.sum(:amount_cents, :group => :trip_id)

但是，问题是 :amount_cents 列代表一个原始 Money 对象，需要在之前进行转换求和以适应货币兑换。 “由”过程组成的资金看起来像这样：

composed_of :amount, 
          :class_name => "Money", 
          :mapping => [%w(amount_cents cents), %w(currency currency_as_string)], 
          :constructor => Proc.new { |cents, currency| Money.new(cents || 0, currency || Money.default_currency) }, 
          :converter => Proc.new { |value| value.respond_to?(:to_money) ? value.to_money : raise(ArgumentError, "Can't convert #{value.class} to Money") }

我可以轻松调用：

transactions.map(&:amount).inject(:+)

获得转换后的总计，但我不知道如何在分组的上下文中执行此操作。

再次非常感谢您的帮助！

原文

Another noob question that seems like it should be simple:

Thanks to the help received here, I can easily get a sum of selected transactions:

@trip_hash = transactions.sum(:amount_cents, :group => :trip_id)

The issue, however, is that the :amount_cents column represents a raw Money object that needs to be transformed before summing in order to accommodate currency exchange. The Money "composed of" Procs look like this:

composed_of :amount, 
          :class_name => "Money", 
          :mapping => [%w(amount_cents cents), %w(currency currency_as_string)], 
          :constructor => Proc.new { |cents, currency| Money.new(cents || 0, currency || Money.default_currency) }, 
          :converter => Proc.new { |value| value.respond_to?(:to_money) ? value.to_money : raise(ArgumentError, "Can't convert #{value.class} to Money") }

I can easily call:

transactions.map(&:amount).inject(:+)

to get a transformed grand total, but I can't figure out how to do it in the context of the groupings.

Many thanks, again, for the help!

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

静若繁花 2025-01-02 13:57:28

经过大量的抚摸和阅读，但最终弄清楚了以下内容：

trip_hash = bankroll.transactions.group_by(&:trip_id).map {|tr,t| Hash[tr, t.map(&:amount).inject(:+)]}

=>[{0=>#<Money cents:137693 currency:USD>}, {7=>#<Money cents:-39509 currency:USD>}, {10=>#<Money cents:50009 currency:USD>}]

地图中的地图做到了！哈希化使其易于查看，并且保留 Money 对象以用于格式化目的......

Took a lot of canoodling and reading, but finally figured out the following:

trip_hash = bankroll.transactions.group_by(&:trip_id).map {|tr,t| Hash[tr, t.map(&:amount).inject(:+)]}

=>[{0=>#<Money cents:137693 currency:USD>}, {7=>#<Money cents:-39509 currency:USD>}, {10=>#<Money cents:50009 currency:USD>}]

Map within the map did it! Hashifying makes it view friendly, and it retains the Money object for formatting purposes....

回复收藏 0 原文

~没有更多了~