渴望负载多态

Question

使用Rails 3.2，这段代码有什么问题？@reviews = @user.reviews.includes(:user, :reviewable).where('reviewable_type = ? AND reviewable.shop_type = ?', 'Shop', 'cafe')它引发此错误：无法急切加载多态关联：可审查如果我删除该reviewable.shop_type = ?条件，它将起作用。如何根据reviewable_type和过滤reviewable.shop_type（实际上是shop.shop_type）？