题解 | #SQL类别高难度试卷得分的截断平均值#
SQL类别高难度试卷得分的截断平均值
https://www.nowcoder.com/practice/a690f76a718242fd80757115d305be45
# 写思路：截断总分：sum(score)-max(score)-min(score)
# 截断个数 count(score)-2
# 如果个数少于3
# if(count(score)<3,0,(sum(score)-max(score)-min(score))/(count(score)-2))
# select tag,difficulty,round(if(count(score)<3,0,(sum(score)-max(score)-min(score))/(count(score)-2)),1) clip_avg_score
# from examination_info ei join exam_record using(exam_id)
# where tag='SQL' and difficulty='hard'
# 思路二： score not in min和max avg(score)
select 'SQL' tag,'hard' difficulty, round(avg(score),1) clip_avg_score
from exam_record
where exam_id in (select exam_id from examination_info where tag='SQL' and difficulty='hard')
and score not in (select min(score) from exam_record)
and score not in (select max(score) from exam_record)
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