SQL字符串中有错误:
-
不是别名计数(*)列
-
在条件不在的情况下没有组2表
尝试此查询:
SELECT activity
FROM ( SELECT activity, COUNT(*) AS Number FROM FRIENDS GROUP BY activity) AS getActivities
WHERE Number NOT IN (SELECT MIN(Number) FROM (SELECT activity, COUNT(*) AS Number FROM FRIENDS GROUP BY activity ) AS maximum)
AND Number NOT IN (SELECT MAX(Number) FROM (SELECT activity, COUNT(*) AS Number FROM FRIENDS GROUP BY activity) AS minimum)
