题解 | #学生数不大于2的学校的学生情况#
学生数不大于2的学校的学生情况
https://www.nowcoder.com/practice/183822a9122642c491c61ec4d479fddb
select university, count(distinct id) as cnt, group_concat(distinct device_id order by id separator ';') as device_list from user_profile group by university having cnt<=2
这题还是考察的分组连接函数group_concat()语法。