题解 | #今天的刷题量(一)#
今天的刷题量(一)
https://www.nowcoder.com/practice/e18f56796ae94c3d885e61c8d57a950e
两个注意的点,
- 是order by是要先按cnt,再按照subject_id排序,此时就不能只对name进行分组,而应该加上subject_id,虽然对结果没有影响,但是这样更为严谨。
- 获取当天的日期使用函数curdate()
select name,count(name) as cnt from submission s1 left join subject s2 on s1.subject_id=s2.id where create_time = curdate() group by subject_id,name order by cnt desc,subject_id