天气观测站20 Hackerrank

Question

WITH s AS (SELECT lat_n, ROW_NUMBER() OVER(ORDER BY lat_n) r
FROM station)
SELECT lat_n
FROM s
WHERE r = count(*)/2

我做错了什么？有人能帮忙吗？

我试图找出纬度的中位数，所以我想找出中间的元素。

Answer 1

在代码末尾附近使用聚合函数时，需要做一个小的更正:尝试如下：

WITH s AS (SELECT lat_n, ROW_NUMBER() OVER(ORDER BY lat_n) r FROM station) SELECT lat_n FROM s WHERE r = (SELECT count(*)/2 FROM station);