Set 3 문제

Set 3 문제

 

 

Population Density Difference

 

SELECT MAX(population) - MIN(population)
FROM city;

 

 

Weather Observation Station 11

 

SELECT DISTINCT city
FROM station
WHERE LEFT(city, 1) NOT IN ('a', 'e', 'i', 'o', 'u')
OR RIGHT(city, 1) NOT IN ('a', 'e', 'i', 'o', 'u');

 

 

Weather Observation Station 13

 

SELECT TRUNCATE(SUM(lat_n), 4)
FROM station
WHERE lat_n > 38.7880
AND lat_n < 137.2345;

 

 

Top Competitors

 

SELECT H.hacker_id
     , H.name
FROM Submissions as S
     INNER JOIN Hackers as H ON S.hacker_id = H.hacker_id
     INNER JOIN Challenges as C ON S.challenge_id = C.challenge_id
     INNER JOIN Difficulty as D ON C.difficulty_level = D.difficulty_level
WHERE D.score = S.score
GROUP BY H.hacker_id
       , H.name
HAVING COUNT(DISTINCT S.submission_id) > 1
ORDER BY COUNT(H.hacker_id) DESC
       , H.hacker_id;