题解 | #删除记录(一)#
删除记录(一)
http://www.nowcoder.com/practice/d331359c5ca04a3b87f06b97da42159c
# 时间做差函数 timestampdiff(unit,time1,time2)
# unit 一般可以为second,minute,hour,day,month,year
DELETE FROM exam_record
WHERE TIMESTAMPDIFF(MINUTE, start_time, submit_time) < 5
and score < 60