Ruby on rails Rails多态关联显示在控制台中，但不在视图中

在我正在开发的一个应用程序中，我遇到了一个问题，即在用户和食谱的饮食要求之间匹配多态关联。在控制台中，我可以实现这一点——如果我将饮食需求ID等于“[2]”的用户与具有相同孩子的食谱相匹配，它就会起作用

然而，当我运行应用程序时，尽管调用了相同的用户和配方，但比较这两个用户和配方的方法计算结果为“false”

希望这是清楚的，这里有一个小代码来解释这一点：

在控制台中

one = User.first
two = Recipe.first
one.dietary_requirement_ids.any? && ((one.dietary_requirement_ids & two.dietary_requirement_ids) == one.dietary_requirement_ids)
# returns true, as it should

但是，在视图中…

我使用视图可访问的帮助器方法，如下所示：

  def dietary_requirement_matcher(one, two)
    one.dietary_requirement_ids.any? && ((one.dietary_requirement_ids & two.dietary_requirement_ids) == one.dietary_requirement_ids)
  end

因此：

<% Recipe.all.each do |recipe| %>
    <li><%= dietary_requirement_matcher(@user, recipe) %></li>
  <% end %> 
<!-- which all return false, including those that shouldn't! -->

@user.inspect

调出正确的用户。但是，

@user.dietary\u requirement\u ids.inspect

调出一个空数组（尽管仍在控制台中工作）

我已经检查了用户和配方是否都正确保存在控制台中

---

这里有一些额外的代码，可以很方便地解决这个问题：

型号

配方

has_many :dietary_requirements, as: :classifiable

使用者

饮食需求

belongs_to :classifiable, polymorphic: true

控制器

@recipes = Recipe.all
@user = current_user #auth method - debug shows this picking up the correct user in the view, albeit not their dietary requirements

查看（不完整，用于在修复此问题时进行调试）

---

我在想，这可能是建立多态性关联的方式：饮食需求可能属于

用户

，也可能属于

配方

，因为您在两者上都使用了

：classifiable

参考列。我也遇到过类似的问题，我的解决方案是向多态类添加两个独立的引用列，如下所示：

• 饮食需求

  属于：所有者，多态性：真

  ，

  属于：处理器，多态性：真

  。然后将以下列添加到

  膳食需求

  表中：

  所有者id、所有者类型、处理者id、处理者类型

• 配方<代码>有许多：饮食要求，如：：处理器

• 用户<代码>有许多：饮食要求，如：：所有者

---

谢谢@Dimitry\u N-我希望尽可能避免对模型进行重组，因为它在其他地方运行良好。在控制台中，我可以访问具有单一共享饮食需求的用户和食谱（即，两者都包含“素食者”，ID:2），这只是为了转移到我正在努力解决的视图。这对你有意义吗？下面继续……如果我只是感到困惑，请告诉我，但我的理解是，使用多态关系意味着不需要额外的列。不是这样吗？（在其他地方，我刚刚使用了两个连接模型，因为它有很多贯穿性，而且生活更简单！）我添加了页面在加载数据时如何查看数据的日志，希望这有助于揭示问题。再次感谢。另一个更新-我已经了解了你的意思，共享DR具有可分类的_类型“Recipe”，而SQLite正在寻找可分类的_类型“User”。有没有办法克服这个问题，或者我需要按照你的建议进行调整？谢谢你的帮助——它似乎让我找到了问题的根源，帮助我理解了一个负载。我现在会找到解决办法的，我听到了）。我认为使用多态关联的主要原因是避免创建不必要的联接表。在您的情况下，这将是UserDietaryRequests和RecepieDietaryRequirements，而不是使用具有三个类和无联接表的多态关联。是的，你可以按你想要的方式调整类型。这里有一个类似的问题，我在不久前发布过。看一看：明白了，谢谢你的帮助。我会玩一出戏，然后再打给你！

belongs_to :classifiable, polymorphic: true

@recipes = Recipe.all
@user = current_user #auth method - debug shows this picking up the correct user in the view, albeit not their dietary requirements

<ul>
  <% Recipe.all.each do |recipe| %>
    <li><%= recipe.name %> = <%= dietary_requirement_matcher(@user, recipe) %></li>
  <% end %>
</ul>

<p><%= dietary_requirement_matcher(@user, Recipe.first) %></p> <!-- returns false, when I'm after true -->
<p><%= @user.dietary_requirements.inspect %></p> <!-- returns '#<ActiveRecord::Associations::CollectionProxy []>' -->

Started GET "/fridges/meals" for 151.229.93.203 at 2015-02-17 16:26:42 +0000
Processing by FridgesController#meals as HTML
#code for matching User Ingredients to Recipe Ingredients      
User Load (0.7ms)  SELECT  "users".* FROM "users" WHERE "users"."id" = ? LIMIT 1  [["id", 2]]
   (0.3ms)  SELECT COUNT(*) FROM "recipes"
  Recipe Load (0.3ms)  SELECT "recipes".* FROM "recipes"
  Ingredient Exists (0.2ms)  SELECT  1 AS one FROM "ingredients" INNER JOIN "recipe_ingredients" ON "ingredients"."id" = "recipe_ingredients"."ingredient_id" WHERE "recipe_ingredients"."recipe_id" = ? LIMIT 1  [["recipe_id", 1]]
  Fridge Load (0.2ms)  SELECT  "fridges".* FROM "fridges" WHERE "fridges"."user_id" = ? LIMIT 1  [["user_id", 2]]
   (0.2ms)  SELECT "ingredients".id FROM "ingredients" INNER JOIN "fridge_ingredients" ON "ingredients"."id" = "fridge_ingredients"."ingredient_id" WHERE "fridge_ingredients"."fridge_id" = ?  [["fridge_id", 5]]
   (0.2ms)  SELECT "ingredients".id FROM "ingredients" INNER JOIN "recipe_ingredients" ON "ingredients"."id" = "recipe_ingredients"."ingredient_id" WHERE "recipe_ingredients"."recipe_id" = ?  [["recipe_id", 1]]
  CACHE (0.0ms)  SELECT "ingredients".id FROM "ingredients" INNER JOIN "recipe_ingredients" ON "ingredients"."id" = "recipe_ingredients"."ingredient_id" WHERE "recipe_ingredients"."recipe_id" = ?  [["recipe_id", 1]]
   (0.2ms)  SELECT "dietary_requirements".id FROM "dietary_requirements" WHERE "dietary_requirements"."classifiable_id" = ? AND "dietary_requirements"."classifiable_type" = ?  [["classifiable_id", 2], ["classifiable_type", "User"]]
  Ingredient Load (0.2ms)  SELECT "ingredients".* FROM "ingredients" INNER JOIN "recipe_ingredients" ON "ingredients"."id" = "recipe_ingredients"."ingredient_id" WHERE "recipe_ingredients"."recipe_id" = ?  [["recipe_id", 1]]
  Ingredient Exists (0.1ms)  SELECT  1 AS one FROM "ingredients" INNER JOIN "recipe_ingredients" ON "ingredients"."id" = "recipe_ingredients"."ingredient_id" WHERE "recipe_ingredients"."recipe_id" = ? LIMIT 1  [["recipe_id", 2]]
  CACHE (0.0ms)  SELECT "ingredients".id FROM "ingredients" INNER JOIN "fridge_ingredients" ON "ingredients"."id" = "fridge_ingredients"."ingredient_id" WHERE "fridge_ingredients"."fridge_id" = ?  [["fridge_id", 5]]
   (0.1ms)  SELECT "ingredients".id FROM "ingredients" INNER JOIN "recipe_ingredients" ON "ingredients"."id" = "recipe_ingredients"."ingredient_id" WHERE "recipe_ingredients"."recipe_id" = ?  [["recipe_id", 2]]
  CACHE (0.0ms)  SELECT "ingredients".id FROM "ingredients" INNER JOIN "recipe_ingredients" ON "ingredients"."id" = "recipe_ingredients"."ingredient_id" WHERE "recipe_ingredients"."recipe_id" = ?  [["recipe_id", 2]]
  Ingredient Exists (0.1ms)  SELECT  1 AS one FROM "ingredients" INNER JOIN "recipe_ingredients" ON "ingredients"."id" = "recipe_ingredients"."ingredient_id" WHERE "recipe_ingredients"."recipe_id" = ? LIMIT 1  [["recipe_id", 3]]
  Ingredient Exists (0.1ms)  SELECT  1 AS one FROM "ingredients" INNER JOIN "recipe_ingredients" ON "ingredients"."id" = "recipe_ingredients"."ingredient_id" WHERE "recipe_ingredients"."recipe_id" = ? LIMIT 1  [["recipe_id", 4]]
  Rendered shared/_matcher.html.erb (21.3ms)
  CACHE (0.0ms)  SELECT "recipes".* FROM "recipes"
  CACHE (0.0ms)  SELECT  1 AS one FROM "ingredients" INNER JOIN "recipe_ingredients" ON "ingredients"."id" = "recipe_ingredients"."ingredient_id" WHERE "recipe_ingredients"."recipe_id" = ? LIMIT 1  [["recipe_id", 1]]
  CACHE (0.0ms)  SELECT "ingredients".id FROM "ingredients" INNER JOIN "fridge_ingredients" ON "ingredients"."id" = "fridge_ingredients"."ingredient_id" WHERE "fridge_ingredients"."fridge_id" = ?  [["fridge_id", 5]]
  CACHE (0.0ms)  SELECT "ingredients".id FROM "ingredients" INNER JOIN "recipe_ingredients" ON "ingredients"."id" = "recipe_ingredients"."ingredient_id" WHERE "recipe_ingredients"."recipe_id" = ?  [["recipe_id", 1]]
  CACHE (0.0ms)  SELECT "ingredients".id FROM "ingredients" INNER JOIN "recipe_ingredients" ON "ingredients"."id" = "recipe_ingredients"."ingredient_id" WHERE "recipe_ingredients"."recipe_id" = ?  [["recipe_id", 1]]
  CACHE (0.0ms)  SELECT  1 AS one FROM "ingredients" INNER JOIN "recipe_ingredients" ON "ingredients"."id" = "recipe_ingredients"."ingredient_id" WHERE "recipe_ingredients"."recipe_id" = ? LIMIT 1  [["recipe_id", 2]]
  CACHE (0.0ms)  SELECT "ingredients".id FROM "ingredients" INNER JOIN "fridge_ingredients" ON "ingredients"."id" = "fridge_ingredients"."ingredient_id" WHERE "fridge_ingredients"."fridge_id" = ?  [["fridge_id", 5]]
  CACHE (0.0ms)  SELECT "ingredients".id FROM "ingredients" INNER JOIN "recipe_ingredients" ON "ingredients"."id" = "recipe_ingredients"."ingredient_id" WHERE "recipe_ingredients"."recipe_id" = ?  [["recipe_id", 2]]
  CACHE (0.0ms)  SELECT "ingredients".id FROM "ingredients" INNER JOIN "recipe_ingredients" ON "ingredients"."id" = "recipe_ingredients"."ingredient_id" WHERE "recipe_ingredients"."recipe_id" = ?  [["recipe_id", 2]]
  CACHE (0.0ms)  SELECT  1 AS one FROM "ingredients" INNER JOIN "recipe_ingredients" ON "ingredients"."id" = "recipe_ingredients"."ingredient_id" WHERE "recipe_ingredients"."recipe_id" = ? LIMIT 1  [["recipe_id", 3]]
  CACHE (0.0ms)  SELECT  1 AS one FROM "ingredients" INNER JOIN "recipe_ingredients" ON "ingredients"."id" = "recipe_ingredients"."ingredient_id" WHERE "recipe_ingredients"."recipe_id" = ? LIMIT 1  [["recipe_id", 4]]
#code for matching the User and Recipe Dietary Requirements
  CACHE (0.0ms)  SELECT "recipes".* FROM "recipes"
  CACHE (0.0ms)  SELECT "dietary_requirements".id FROM "dietary_requirements" WHERE "dietary_requirements"."classifiable_id" = ? AND "dietary_requirements"."classifiable_type" = ?  [["classifiable_id", 2], ["classifiable_type", "User"]]
  CACHE (0.0ms)  SELECT "dietary_requirements".id FROM "dietary_requirements" WHERE "dietary_requirements"."classifiable_id" = ? AND "dietary_requirements"."classifiable_type" = ?  [["classifiable_id", 2], ["classifiable_type", "User"]]
  CACHE (0.0ms)  SELECT "dietary_requirements".id FROM "dietary_requirements" WHERE "dietary_requirements"."classifiable_id" = ? AND "dietary_requirements"."classifiable_type" = ?  [["classifiable_id", 2], ["classifiable_type", "User"]]
  CACHE (0.0ms)  SELECT "dietary_requirements".id FROM "dietary_requirements" WHERE "dietary_requirements"."classifiable_id" = ? AND "dietary_requirements"."classifiable_type" = ?  [["classifiable_id", 2], ["classifiable_type", "User"]]
  Recipe Load (0.4ms)  SELECT  "recipes".* FROM "recipes"  ORDER BY "recipes"."id" ASC LIMIT 1
  CACHE (0.0ms)  SELECT "dietary_requirements".id FROM "dietary_requirements" WHERE "dietary_requirements"."classifiable_id" = ? AND "dietary_requirements"."classifiable_type" = ?  [["classifiable_id", 2], ["classifiable_type", "User"]]
  DietaryRequirement Load (0.2ms)  SELECT "dietary_requirements".* FROM "dietary_requirements" WHERE "dietary_requirements"."classifiable_id" = ? AND "dietary_requirements"."classifiable_type" = ?  [["classifiable_id", 2], ["classifiable_type", "User"]]
  Rendered fridges/meals.html.erb within layouts/application (42.3ms)
  Cuisine Load (0.3ms)  SELECT "cuisines".* FROM "cuisines"
  Category Load (0.2ms)  SELECT "categories".* FROM "categories"
  Rendered shared/_header.html.erb (3.3ms)
Completed 200 OK in 593ms (Views: 579.3ms | ActiveRecord: 4.2ms)