题解 | 今天的刷题量(一)

select name,count(*) cnt
from submission s
join subject su on su.id=s.subject_id
where s.create_time = CURDATE()
group by name,su.id
order by cnt desc,su.id

当前系统日期CURDATE()

当前系统日期前一天DATE_SUB(CURDATE(),INTERVAL 1 DAY)