如何解决一次计算最小,中位数,最大值
请帮助我根据成绩表AT ONCE计算学生的MIN,MEDIAN和MAX分数。结果表:id,student_id,得分
我找到了使用以下代码获取中位数的方法,但它仅返回中位数。如何添加最小和最大?非常感谢
SELECT AVG(SCORE)::INT AS MEDIAN
FROM
(SELECT *,row_number() over(order by score desc) as desc_sc,row_number() over(order by score asc) as asc_sc
FROM result
) as a
WHERE asc_sc IN (desc_sc,desc_sc+1,desc_sc-1)
解决方法
您可以尝试:
SELECT AVG(SCORE)::INT AS MEDIAN,min_score,max_score
FROM
(SELECT *,MIN(score) over (ORDER BY score ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) as min_score,MAX(score) over (ORDER BY score ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) as max_score,row_number() over(order by score desc) as desc_sc,row_number() over(order by score asc) as asc_sc
FROM result
) as a
WHERE asc_sc IN (desc_sc,desc_sc+1,desc_sc-1)
,
您可以使用如下语法:
SELECT DISTINCT
MIN(score) OVER () as min_score,MAX(score) OVER () as max_score,PERCENTILE_CONT(0.5) WITHIN GROUP (ORDER BY SCORE) OVER () as median
FROM result;
某些数据库支持median()
函数。在这些数据库中,您可以使用:
SELECT MIN(score) as min_score,MAX(score) as max_score,MEDIAN(score) as median_score
FROM result;
版权声明:本文内容由互联网用户自发贡献,该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容, 请发送邮件至 dio@foxmail.com 举报,一经查实,本站将立刻删除。