Ruby on rails Rails—为什么在这种情况下不使用即时加载？

我有这3种型号，它们之间有着千丝万缕的联系：

class Wine < ActiveRecord::Base
  has_many :varietals, :conditions => "varietals.status = 1"
  has_many :grapes, :through => :varietals
end

class Grape < ActiveRecord::Base
  has_many :varietals
  has_many :wines, :through => :varietals
end

class Varietal < ActiveRecord::Base
  belongs_to :wine
  belongs_to :grape
end

@records = Wine.where(conditions).includes({:varietals => :grape})

如何在主请求中加载grapes以使每个grapes都没有请求？

尝试以下方法：

Wine.includes(:varietals).includes(:grapes).where(conditions)

如果有效，不要问我为什么；）

Wine.includes(:varietals).includes(:grapes).where(conditions)