Question

我正在尝试以下列格式获取SQL结果：

+------------+--------------+
|   regions| quarter_values| 
+------------+--------------+
|    A     |  0,2,0,2      | 
|    B     |  1,3,4,5      |  
|    C     |  2,6,2,0      |  
+------------+--------------+

但是通过以下查询，它会提供 Error Code: 1111. Invalid use of group function

  SELECT r.regions,       
          group_concat( 
          sum( CASE WHEN r.request_type="create" and quarter(created_at)= 1 THEN 1 ELSE 0 END) ,
          sum( CASE WHEN r.request_type="create" and quarter(created_at)= 2 THEN 1 ELSE 0 END) ,
          sum( CASE WHEN r.request_type="create" and quarter(created_at)= 3 THEN 1 ELSE 0 END) ,
          sum( CASE WHEN r.request_type="create" and quarter(created_at)= 4 THEN 1 ELSE 0 END) ) as 'quarter_values'    
           FROM  requests r group by r.regions;

有关此查询的任何帮助吗？

Answer 1

您无法嵌套聚合函数。

但是你不需要使用GROUP_CONCAT，只需要普通的连接。

SELECT regions, 
    CONCAT_WS(',',
      sum( CASE WHEN r.request_type="create" and quarter(created_at)= 1 THEN 1 ELSE 0 END) ,
      sum( CASE WHEN r.request_type="create" and quarter(created_at)= 2 THEN 1 ELSE 0 END) ,
      sum( CASE WHEN r.request_type="create" and quarter(created_at)= 3 THEN 1 ELSE 0 END) ,
      sum( CASE WHEN r.request_type="create" and quarter(created_at)= 4 THEN 1 ELSE 0 END) 
    ) as quarter_values
FROM requests r 
group by r.regions;

在mysql查询中使用group_concat和case的总和

1 个答案: