Question

我正在尝试查找数据库中出现次数最少的所有俱乐部，并显示该俱乐部名称及其出现的次数。以下是我尝试过的解决方案

select club, MIN(num) 
from 
    (select count(club) as num 
     from member 
     order by club)

但是此代码引发错误：

SQL0119N在GROUP BY子句中未指定在SELECT子句，HAVING子句或ORDER BY子句中指定的以“ CLUB”开头的表达式，或者在带有列的SELECT子句，HAVING子句或ORDER BY子句中函数，未指定GROUP BY子句。

我是SQL新手-有人可以告诉我哪里出了问题以及如何解决此问题吗？

Answer 1

您可以使用fetch first n rows only语法：

SELECT      club, COUNT(*)
FROM        members
GROUP BY    club
ORDER BY    2 ASC
FETCH FIRST 1 ROWS ONLY

Answer 2

您正在朝着正确的方向前进。您需要进行两次汇总。

WITH Member_Count AS (SELECT club, COUNT(*) AS counted
                      FROM Members
                      GROUP BY club)
SELECT club, counted
FROM Member_Count 
WHERE counted = (SELECT MIN(counted)
                 FROM Member_Count)

在SQL表的行中查找最小值

2 个答案: