如何在我的mysql中使用group_concat

Question

我有这个查询：

    select  IF(user_name IS NULL or user_name= '', distinct_id, user_name ) 
      as user_info, event, count(event) as event_count
    from mixpanel 
    where 
        (mixpanel.event = 'app_open' or 
         mixpanel.event = 'post_created' or 
         mixpanel.event = 'create_comment' or 
         mixpanel.event = 'class_opened' or
         mixpanel.event = 'post_read')
    AND
        class_id = 'AKSJSDKSD'

    group by event, user_name, distinct_id
    order by user_name desc

它给了我以下结果：

+-----------+------------+--------+ 
| user_info | event | event_count |
+-----------+------------+--------+ 
|  Ben Cho  | up    | 12          |
|  Lee Mar  | up    | 21          |
|  Lee Mar  | side  | 12          |
|  Lee Mar  | down  | 16          | 
|  Al  Gov  | up    | 14          |
|  Al  Gov  | down  | 13          | 
|  Al  Gov  | side  | 13          |
+-----------+------------+--------+

我需要的是聚合每个用户数据，如下所示：

+-----------+------------+--------+ 
| user_info | up | down | side
+-----------+------------+--------+ 
|  Ben Cho  | 12 |  0   |   0     | 
|  Lee Mar  | 21 |  16  |   12    |
|  Al  Gov  | 14 |  13  |   13    |
+-----------+------------+--------+

我怎样才能在mySql上实现这一点？

谢谢！

Answer 1

据我所知，你只想要条件聚合。没有必要group_concat()：

select (case when user_name IS NULL or user_name = '' then distinct_id else user_name
        end) as user_info,
       sum(mp.event = ('app_open')) as num_app_open,
       sum(mp.event = ('post_created')) as num_post_created,
       sum(mp.event = ('create_comment')) as num_create_comment
from mixpanel mp
where mp.event in ('app_open', 'post_created', 'create_comment') and
      class_id = '-KtmM9EACwDTR98a_yU9'
group by user_info
order by user_info desc;