Sql Rails中多个命名\u作用域的预加载计数

我在下列课程中有一门课

class Service < ActiveRecord::Base
    has_many :incidents
end

class Incident < ActiveRecord::Base
    belongs_to :service

    named_scope :active, lambda ...
    named_scope :inactive, lambda ...
end

这将预取一个计数，但我不确定如何对两个不同的计数进行预取 命名范围

使用计数器缓存不是一个选项，因为数据库是由非rails代码写入的

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欢迎任何帮助

我最后为此写了一篇文章

<% Service.all.each do |s| %>
    <%= s.active.count =>
    <%= s.inactive.count =>
<% end %>

# In Service class
def self.fetch_incident_counts
  select('services.*, count(incidents.id) as acknowledged_incident_count').
    joins('left outer join incidents on incidents.service_id = services.id').
    where('incidents.service_id = services.id AND ... same conditions as active scope').
    group('services.id')
end