铁轨排名

Question

我想创建一个用户排名.它应该按添加事件的数量对用户进行排序.

那是我的档案:

User.rb:

class User < ActiveRecord::Base
  has_many :events
  #...
end

ranking.html.erb:

<tr>
    <% User.all.each  do |user| %> 
    <td> <%= user.name %></td>
    <td> <%= user.events_count %></br></td> 
<% end %>
 </tr>

schema.rb:

create_table "users", force: true do |t|
  #...
  t.integer  "events_count", default: 0
end

怎么做？

Answer 1

我猜你想要使用计数器缓存.

Event.rb:

class Event < ActiveRecord::Base
  belongs_to :user, counter_cache: true
end

ranking.html.erb:

<tr>
  <% User.order(events_count: :desc).each do |user| %>
    ...