몸과 마음이 건전한 SW 개발자

문제 링크https://www.hackerrank.com/challenges/full-score/problem?isFullScreen=true Top Competitors | HackerRankQuery a list of top-scoring hackers.www.hackerrank.com정답 코드select H.hacker_id, H.name from submissions as Sjoin challenges as C on S.challenge_id = C.challenge_id join difficulty as D on C.difficulty_level = D.difficulty_leveljoin hackers as H on H.hacker_id = S.hacker_idwhere S.score = D...

문제 링크https://www.hackerrank.com/challenges/the-report/problem?isFullScreen=true The Report | HackerRankWrite a query to generate a report containing three columns: Name, Grade and Mark.www.hackerrank.com틀린 코드select if(gra.grade >= 8, stu.name, null), gra.grade, stu.marks from students as stuleft join grades as gra on stu.marks >= gra.min_mark and stu.marks 정답 코드SELECT CASE WHEN G.Gra..

문제 링크https://www.hackerrank.com/challenges/average-population-of-each-continent/problem?isFullScreen=true Average Population of Each Continent | HackerRankQuery the names of all continents and their respective city populations, rounded down to the nearest integer.www.hackerrank.com틀린 코드 1select co.continent, floor(avg(ci.population)) from city as ci left join country as co on ci.countrycode = co..

문제 링크https://www.hackerrank.com/challenges/weather-observation-station-14/problem?isFullScreen=true Weather Observation Station 14 | HackerRankQuery the greatest value of the Northern Latitudes from STATION that are under 137.2345 and truncated to 4 decimal places.www.hackerrank.com정답 코드select top(1) cast(lat_n as decimal(10, 4)) from stationwhere lat_n

문제 링크https://www.hackerrank.com/challenges/weather-observation-station-13/problem?isFullScreen=true Weather Observation Station 13 | HackerRankQuery the sum of Northern Latitudes having values greater than 38.7880 and less than 137.2345, truncated to 4 decimal places.www.hackerrank.com정답 코드SELECT CAST(SUM(LAT_N) AS DECIMAL(10, 4))FROM STATION WHERE LAT_N > 38.7880 AND LAT_N 느낀점MS SQL Server에는 TR..

문제 링크https://www.hackerrank.com/challenges/weather-observation-station-2/problem?isFullScreen=true Weather Observation Station 2 | HackerRankWrite a query to print the sum of LAT_N and the sum of LONG_W separated by space, rounded to 2 decimal places.www.hackerrank.com틀린 코드 1SELECT ROUND(SUM(LAT_N), 2), ROUND(SUM(LONG_W), 2) FROM STATION; 틀린 코드 2SELECT CAST(SUM(LAT_N) AS DECIMAL(10, 2)), CAST(SU..