Prepare > SQL > Aggregation > Weather Observation Station 19

Weather Observation Station 19 | HackerRank

 

문제

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Consider  p1(a,c) and p2(b,d) to be two points on a 2D plane where (a,b) are the respective minimum and maximum values of Northern Latitude (LAT_N) and (c,d) are the respective minimum and maximum values of Western Longitude (LONG_W) in STATION.

Query the Euclidean Distance between points p1 and p2 and format your answer to display 4 decimal digits.

 

=> p1 과 p2 의 유클리드 거리를 쿼리하라.

 

 

 

 

코드

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SELECT TRUNCATE(SQRT((b - a) * (b - a) + (d - c) * (d - c)), 4)

FROM
(SELECT 
MIN(LAT_N) AS a,
MAX(LAT_N) AS b,
MIN(LONG_W) AS c,
MAX(LONG_W) AS d
FROM STATION) AS K;

• a, b, c, d를 명확히 지정하는 서브쿼리 이용.(추후 문제에 이용할 작정)
• SQRT(~~~): 제곱근을 구해줌.

 

 

 

 

노트

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POWER(~~, n): ~~의 n 제곱 값

SELECT TRUNCATE(SQRT(POWER(a - b, 2) + POWER(c - d, 2)), 4)
FROM

(SELECT 
MIN(LAT_N) AS a,
MAX(LAT_N) AS b,
MIN(LONG_W) AS c,
MAX(LONG_W) AS d
FROM STATION) AS K;

SELECT TRUNCATE(SQRT(POWER(MIN(LAT_N) - MAX(LAT_N),2) + POWER(MIN(LONG_W) - MAX(LONG_W),2)),4)
FROM STATION;

 

 

두 번째 시도

SELECT ROUND(SQRT(POWER(MIN(LAT_N) - MAX(LAT_N), 2) + POWER(MIN(LONG_W) - MAX(LONG_W),2)),4) FROM STATION;

• 그냥 한 줄에 다 때려박음