HackerRank[MySQL] : Weather Observation Station 20

Weather Observation Station 20

MEDIAN

Q

PERCENT_RANK

SELECT ROUND(LAT_N,4)
FROM (SELECT LAT_N, PERCENT_RANK() OVER(ORDER BY LAT_N) AS PERCENT 
      FROM STATION) AS TMP # FROM 절의 서브쿼리는 ALIAS 입력 필수
WHERE PERCENT = 0.5;

LIMIT

/*
SELECT COUNT(*)
FROM STATION

= 499 
*/

SELECT ROUND(LAT_N,4)
FROM STATION
WHERE LAT_N = (SELECT LAT_N FROM STATION ORDER BY LAT_N LIMIT 249, 1)