轨道由数

Question

查看活动记录组我有模态车辆的标题和日期 +----------------------+----------------+ | title | dates | +----------------------+----------------+ | BMW X6 | 2017-05-22 | | Audi A6 | 2017-05-20 | | BMW X6 | 2017-05-20 |
| Volkswagen Passat B6 | 2017-05-20 | | Volkswagen Passat B5 | 2017-05-20 | | Audi A6 | 2017-05-22 | | Volkswagen Passat B5 | 2017-05-22 | +----------------------+----------------+

我想通过计数 输出表显示日期威集团 +----------------------+----------------+--------------+ | title | 2017-05-22 | 2017-05-21 | +----------------------+----------------+--------------+ | BMW X6 | 1 | 1 | | Audi A6 | 1 | 1 | | Volkswagen Passat B6 | 0 | 1 | | Volkswagen Passat B5 | 1 | 1 | +----------------------+----------------+--------------+

Answer 1

我不知道，但给一试这个：

@dates = [] 
    @titles = [] 
    @count = [] 
    (start_date..end_date).each do |date| 
     vehicles = Vehicle.where("DATE(dates) = ?", date) 
     vehicles.each do |vehicle| 
     res = Vehicle.where("DATE(dates) = ? and title = ?", date, vehicle.title).count 
     dates << date 
     titles << vehicle.title 
     count << res 
     end 
    end 

    <table> 
    <tr> 
    <th>title</th> 
    <% @dates.uniq.each do |date| %> 
     <th> <%= date %></th> 
    <% end %> 
    </tr> 

    <% dates.length.times do |i| %> 
     <tr> 
     <td><%= @titles[i] %></td> 
     <td><%= @count[i] %></td> 
     </tr> 
    <% end %> 
    </table>