MySQL按分組日期范圍排序

Question

我有一個具有以下四個范圍的模型：

scope :active, -> { where("start_at <= '#{Time.now.utc}' AND end_at > '#{Time.now.utc}'") }
scope :ended, -> { where("end_at < '#{Time.now.utc}'") }
scope :coming_soon, -> { where("start_at > '#{Time.now.utc}' AND start_at < '#{Time.now.utc+6.hours}'") }

我希望能夠做類似的事情（偽代碼，只是試圖給出一個想法）：

Model.all.order(active, coming_soon, ended)

結果將是該表中的所有行， coming_soon先滿足active約束的行排序，然后再滿足coming_soon約束的行排序，最后再滿足ended約束的所有行排序。

Answer 1

我添加了以下范圍，它似乎已經解決了我的問題：

scope :time_sorted, -> { 
    select("events.*, CASE 
      WHEN start_at <= '#{Time.now.utc}' AND end_at > '#{Time.now.utc}' THEN 1
      WHEN end_at < '#{Time.now.utc}' THEN 2
      WHEN start_at > '#{Time.now.utc}' AND start_at < '#{Time.now.utc+6.hours}' THEN 3 ELSE 4
      END AS formula")
    .order("formula ASC")
}