如果包含在两个组中，则按分组计数并分开

Question

不确定这个问题是否重复。

下面我有一个简化的table

User	Interest
Jason	Art
Jason	Sport
Sam	Sport
Sam	Art
Steve	Sport
Desmond	Sport
Tania	Art

这是我想要达到的结果

Interest	Count
Art	2
Sport	2
Both	2

我设法通过此查询

创建了一个子查询来实现 Both 数据的值

SELECT COUNT(USER) FROM (
SELECT User, COUNT(DISTINCT Interest) as interest_type FROM table WHERE interest_type = 2)

但是对于在Art和Sport中独占Interest的用户来说是不分开的。

Answer 1

您可以在此处使用条件聚合：

WITH cte AS (
    SELECT User,
           CASE WHEN COUNT(CASE WHEN Interest = 'Art' THEN 1 END) > 0 AND
                     COUNT(CASE WHEN Interest = 'Sport' THEN 1 END) > 0
                THEN 'Both'
                WHEN COUNT(CASE WHEN Interest = 'Art' THEN 1 END) > 0
                THEN 'Art'
                ELSE 'Sport' END AS Interest
    FROM yourTable
    GROUP BY User
)

SELECT Interest, COUNT(*) AS Count
FROM cte
GROUP BY Interest;

在 MySQL 或 BigQuery 上，我们可以将上面的内容缩短为：

WITH cte AS (
    SELECT User,
           CASE WHEN SUM(Interest = 'Art') > 0 AND SUM (Interest = 'Sport') > 0
                THEN 'Both'
                WHEN SUM(Interest = 'Art') > 0
                THEN 'Art'
                ELSE 'Sport' END AS Interest
    FROM yourTable
    GROUP BY User
)

SELECT Interest, COUNT(*) AS Count
FROM cte
GROUP BY Interest;

Answer 2

假设您的数据库支持 over() 子句：

select
      case when num_interests = 1 then interest else 'both' end as interest
    , count(distinct user) as "Count"
from (
    select
      interest
    , user
    , count(*) over(partition by user) as num_interests
    from yourTable
    ) d
group by
      case when num_interests = 1 then interest else 'both' end

如果包含在两个组中，则按分组计数并分开

Count Group By and Separate If Included in Both Group

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