如何在關聯模型中計算滿足條件的記錄？

Question

好的，我有兩個模型...

Jiraissue：

class Jiraissue < ActiveRecord::Base
  # JIRA uses a singular table name for this model
  set_table_name 'jiraissue'
  has_one :severity
end

嚴重程度：

class Severity < ActiveRecord::Base
  belongs_to :jiraissue
end

我正在嘗試獲取所有jiraissue.severity =“ S1”的Jiraissues的計數

現在事實證明，jiraissue表具有優先級列，因此我可以在模型中使用此技巧...

Jiraissue：

class Jiraissue < ActiveRecord::Base
  # JIRA uses a singular table name for this model
  set_table_name 'jiraissue'
  has_one :severity

  def self.count_priority(priority)
    where("PRIORITY = ?",priority).count()
  end

end

然后在視圖中執行類似...

<%= (1..4).map {
  |priority| Jiraissue.biit.bugs.recent.count_priority(priority)
  }.inspect %>

我如何為Jiraissue做類似的事情以獲取count_severity方法？

這只是行不通（我也不希望如此）...

  def self.count_severity(severity)
    where("severity = ?",severity).count()
  end

但是我完全感到困惑。

Answer 1

Jiraissue.joins(:severities).where(:severities => {:severity => "S1"}).count

Answer 2

模型

def self.count_priority(priority)
  where("PRIORITY = ?",priority).size
end

控制者

def index
  @jiraissues = Jiraissue.count_priority('S1')
end

不行嗎