[MySQL] 데이터에서 중앙값(Median) 찾기

https://www.hackerrank.com/challenges/weather-observation-station-20/problem

Weather Observation Station 20 | HackerRank

https://yahwang.github.io/posts/48

SQL로 TOP N, 상위 퍼센트 데이터 검색하기 - YA-Hwang 기술 블로그

 

set @idx = -1;

select round(avg(LAT_N), 4)
from (select @idx := @idx + 1 as ROW_NUM, LAT_N
      from STATION
      order by LAT_N) as Sub
where Sub.ROW_NUM in (floor(@idx / 2), ceil(@idx / 2));

-- MySQL 8.0 버전부터 순위 관련 함수 지원
select round(LAT_N, 4)
from (select LAT_N, percent_rank() over (order by LAT_N) as PERCENT
            from STATION) as Sub
where Sub.percent = 0.5;