몸과 마음이 건전한 SW 개발자

문제 링크https://www.hackerrank.com/challenges/weather-observation-station-11/problem?isFullScreen=true Weather Observation Station 11 | HackerRankQuery a list of CITY names not starting or ending with vowels.www.hackerrank.com정답 코드select distinct city from station where city not like '[aeiou]%[aeiou]';풀이 과정city의 앞 문자가 a e i o u로 시작하지 않고 뒷 문자가 a e i o u로 끝나지 않고 라는 명제가 있다.'[^aeiou]%' and '%[^aeiou]'이..

문제 링크https://www.hackerrank.com/challenges/weather-observation-station-8/problem?isFullScreen=true Weather Observation Station 8 | HackerRankQuery CITY names that start AND end with vowels.www.hackerrank.com정답 코드select distinct city from station where city like '[aeiou]%[aeiou]';풀이 과정앞 뒤로 a e i o u가 있는 city를 찾는다.느낀점이 문제도 마찬가지로 city를 가공해서 풀 수도 있다.정규표현식을 사용해서 조금이라도 더 빠르게 성능을 향상시킬 수 있다.하지만 데이터 양이 적..

문제 링크https://www.hackerrank.com/challenges/weather-observation-station-7/problem?isFullScreen=true Weather Observation Station 7 | HackerRankQuery the list of CITY names ending with vowels (a, e, i, o, u) from STATION.www.hackerrank.com최적화 코드SELECT DISTINCT CITYFROM STATIONWHERE CITY LIKE '%[aeiou]';아쉬운 코드 (내코드)select distinct city from station where right(city, 1) in ('a', 'e', 'i', 'o', 'u');풀..

문제 링크https://www.hackerrank.com/challenges/weather-observation-station-5/problem?isFullScreen=true Weather Observation Station 5 | HackerRankWrite a query to print the shortest and longest length city name along with the length of the city names.www.hackerrank.com 정답 코드SET NOCOUNT ON;SELECT TOP 1 CITY, LEN(CITY)FROM STATIONORDER BY LEN(CITY) ASC, CITY ASC;SELECT TOP 1 CITY, LEN(CITY)FROM STATION..

문제 링크https://www.hackerrank.com/challenges/weather-observation-station-4/problem?isFullScreen=true Weather Observation Station 4 | HackerRankFind the number of duplicate CITY names in STATION.www.hackerrank.com정답 코드SET NOCOUNT ON;SELECT COUNT(CITY) - COUNT(DISTINCT CITY)FROM STATION;/*Enter your query here.Please append a semicolon ";" at the end of the query and enter your query in a single lin..