一次计算最小，中位数，最大值

编程问答 2022-08-12

问题描述

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;
maxmaxmedianminsqlsql