题解 | SQL14 SQL类别高难度试卷得分的截断平均值

用一个计算公式:

$\frac{\mathrm{总}\mathrm{数}-\mathrm{最}\mathrm{大}\mathrm{值}-\mathrm{最}\mathrm{小}\mathrm{值}}{\mathrm{总}\mathrm{个}\mathrm{数}-2}\backslash frac\{总数-最大值-最小值\}\{总个数-2\}$ 就是最终的答案。

select 
tag,
difficulty,
round((sum(score) - max(score) -min(score)) / (count(score) - 2), 1) as clip_avg_score
from examination_info as t1
join exam_record as t2
where t1.exam_id = t2.exam_id and tag = 'sql'
group by tag, difficulty
having difficulty = 'hard';