Question

以下是我的查询：

select (
    case when activity_type=3 then 'share_count_secret' 
         when activity_type=4 then 'download_count_secret' 
         when activity_type=5 then 'copy_count_secret' end
    )as activity_type ,
    count(distinct user_account_id_fk) as counts
from  activities 
where  target_id = 522556 
and activity_type in(3,4,5) 
group by activity_type;

以下是上述查询的输出：

 activity_type         counts
  share_count           2
  download_count        2

但我想要输出：

 share_count     download_count
  2                   2

Answer 1

您可以尝试使用conditional aggregation

select 
  count(case when activity_type=3 then user_account_id_fk end) as 'share_count_secret',
  count(case when activity_type=4 then user_account_id_fk end) as 'download_count_secret'
  count(case when activity_type=5 then user_account_id_fk end) as 'copy_count_secret'
  from  activities 
  where  target_id = 522556 and activity_type in(3,4,5)

Answer 2

如果您使用的是SQL Server（我也看到您也标记了MySQL）。您可以尝试透视

;WITH CTE
AS
(
    SELECT 
        ( 
            CASE 
               WHEN activity_type = 3 THEN 'share_count_secret' 
               WHEN activity_type = 4 THEN 'download_count_secret' 
               WHEN activity_type = 5 THEN 'copy_count_secret' 
             END 
        ) AS activity_type, 
        COUNT(DISTINCT user_account_id_fk) AS counts 
        FROM   activities 
            WHERE  target_id = 522556 
                AND activity_type IN( 3, 4, 5 ) 
            GROUP  BY activity_type
)
SELECT
    *
    FROM CTE
    PIVOT
    (
        SUM(counts)
        FOR
        activity_type IN
        (
            [share_count_secret],
            [download_count_secret],
            [copy_count_secret]
        )
    )PVT

Answer 3

我认为这段代码可以为您提供帮助：

    select 
(case when activity_type=3 then count(user_account_id_fk)  else 0) as 'share_count_secret',
(case when  activity_type=4 then count(user_account_id_fk)  else 0) as 'download_count_secret',
(case when activity_type=5 then count(user_account_id_fk)  else 0) as 'copy_count_secret'
  from  activities 
 where  target_id = 522556 and activity_type in(3,4,5)

希望将行值转换为列

3 个答案: