访问多级关联失败(活动记录)

Question

我无法弄清楚如何在我的视图中访问多级关联。

我有 3 个主要模型：类别、活动和投票(省略不相关的行(：

class Category < ApplicationRecord
belongs_to :user
# Many-to-many relationship with model Activity
has_and_belongs_to_many :activity, dependent: :destroy
# Link to votes
has_many :vote, through: :activity
end

class Activity < ApplicationRecord
belongs_to :user
# Many-to-many relationship with model Activity
has_and_belongs_to_many :category
# An Activity can have multiple votes
has_many :vote, dependent: :destroy
end

class Vote < ApplicationRecord
# Many (users and activities) to one (votes) relationship
belongs_to :user
belongs_to :activity
end

我在"类别"和"活动"之间有一个用于多对多关系的连接表。

我想完成的是，在"类别"视图中，显示该类别中的活动数以及该类别中的投票数(通过"活动投票"(。第一个工作正常：

<% @categories.each do |category| %>
<%= category.activity.ids.count %>
<% end %>

后者显示票数，没有(undefined method "vote"( - 与上面在同一块中：

<%= category.activity.vote.ids.count  %>

以下 2 行中没有一行我的类别控制器用于此目的：

def index
# With this I can already access the associated Activities, but not the Votes
@categories = Category.all()
end

def index
# Changing the Category controller as follows seems to have no effect on being able to access the number of votes
@categories = Category.joins({:activity => :vote}).group('category_id').order('COUNT(activities.id) DESC')
end

我这里一定错过了什么？

编辑：根据尼尔的建议，这就是我现在的观点：

<% @categories.each do |category| %>
<% category.activity.each do |activity| %>
<%= activity.vote.ids.count %>
<% end %>
<% end %>

Answer 1

我可以看到你的日志吗？

我想你在这里有很多活动

'<%= category.activity.vote.ids.count %>'

尝试从下面的代码中查找投票。

'<%= category.activity.first.vote.ids.count %>'