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(device_id) as cnt,GROUP_CONCAT(device_id SEPARATOR';')as device_list from user_profile group by university having cnt<=2