Question

我正在努力从Rails 3升级到Rails 4.我有一个范围定义似乎正在放弃where子句和其他应用范围。

我有这些模特：

class GoalWeightSet < ActiveRecord::Base
  has_many :goal_weight_set_nutrients, -> {order(:nutrient_id).includes(:nutrient)}, :inverse_of=>:goal_weight_set, :dependent=>:destroy, :autosave=>true
end

class GoalWeightSetNutrient < ActiveRecord::Base
  belongs_to :goal_weight_set, :inverse_of=>:goal_weight_set_nutrients

  scope :model_weights, -> {where(:index=>false)}
  scope :model, -> {where(:index => false)}
end

我认为在Rails 4中使用这两个范围之间存在完全不同的行为

# this is broken, it should have a where clause
GoalWeightSet.first.goal_weight_set_nutrients.model.count
   (2.8ms)  SELECT COUNT(*) FROM "goal_weight_set_nutrients"
=> 37288

# this is what I expect 
GoalWeightSet.first.goal_weight_set_nutrients.model_weights.count
   (0.4ms)  SELECT COUNT(*) FROM "goal_weight_set_nutrients" WHERE "goal_weight_set_nutrients"."goal_weight_set_id" = $1 AND "goal_weight_set_nutrients"."index" = 'f'  [["goal_weight_set_id", 8]]
=> 31

scope :model在Rails 3中工作正常。为什么这个范围试图加载所有对象？名为＆＃39; model＆＃39;？

的范围是否有特殊之处

以下是您可以运行的要点，显示错误：https://gist.github.com/johnnaegle/9647941

Answer 1

据我所知，关联上的“模型”意味着Rails 4中的不同之处：

Klass.where("1=0").model
=> Klass(id: integer)

如此有效，您不能将模型用作范围名称。

为什么这些范围定义在通过关联使用时具有不同的行为

1 个答案: