在铁轨中的红宝石中按日期降序排序

Question

我希望按日期降序排序我的列表作为"新用户列表",在数据库中我有一个列是

t.datetime "created_at",                                      null: false  

这是新用户注册的时间,在视图中,我有这样的代码:

%table.table.table-striped.table-hover
      %thead
      %h3 New Users
      %hr
        %th Name
        %th Company
        %th Role
        %th Created date
        %th{:width => '50'}
        %th{:width => '50'}
        %th{:width => '50'}
      %tbody
      - @users.each do |user|
        -if user.role == "trial-member"
          - @created_at.sort{|a,b| b.created_at <=> a.created_at}.each do |created_at|
            %tr
            %td
              = user.first_name
              = user.last_name
            %td= user.company
            %td= user.role
            %td= user.created_at
            %td= link_to 'Approve', edit_user_path(user),  {:class => 'btn btn-success btn-sm'}

但是这给出了一个错误"nil:NilClass的未定义方法`sort'",我该如何按表创建日期对表中的列表进行排序呢？谢谢.

Answer 1

在你的控制器中:

@users = User.order('created_at DESC')

只需添加:order('created_at DESC')在你的逻辑中你正在获取@users.

在您看来,您现在可以摆脱- @created_at.sort{|a,b| b.created_at <=> a.created_at}.each:

%h3 New Users
%table.table.table-striped.table-hover
  %thead
    %tr
      %th Name
      %th Company
      %th Role
      %th Created date
      %th{:width => '50'}
      %th{:width => '50'}
      %th{:width => '50'}
  %tbody
    - @users.each do |user|
      -if user.role == "trial-member"
        %tr
          %td
            = user.first_name
            = user.last_name
          %td= user.company
          %td= user.role
          %td= user.created_at
          %td= link_to 'Approve', edit_user_path(user),  {:class => 'btn btn-success btn-sm'}

您看到的错误是因为@created_at它不是可枚举的对象,因此它不响应sort.