[SQL문제풀기] Weather Observation Station 6

문제

Weather Observation Station 6 | HackerRank

Query a list of CITY names beginning with vowels (a, e, i, o, u).

https://www.hackerrank.com/challenges/weather-observation-station-6/problem?isFullScreen=true

MySQL

내가 작성한 정답1 - like

select city
from station
where city like 'i%' or city like 'e%' or city like 'a%' or city like 'o%' or city like 'u%';

내가 작성한 정답2 - 정규표현식

select city
from station
where city regexp '^[aeiou]'; // ^: 문자열의 시작

내가 작성한 정답3 - substring

select city
from station
where substring(city,1,1) in ('a','e','i','o','u');

내가 작성한 정답4 - left

select city
from station
where left(city,1) in ('a','e','i','o','u');

Oracle

내가 작성한 정답1 - like

select city 
from station
where city like 'I%' or city like 'E%' or city like 'A%' or city like 'O%' or city like 'U%';

내가 작성한 정답2 - 정규표현식 regexp_like

select city 
from station
where regexp_like(lower(city),'^[aeiou]');

내가 작성한 정답3 - substr

select city 
from station
where lower(substr(city,1,1)) in ('a','e','i','o','u');

MS SQL Server - MySQL과 유사

내가 작성한 정답1 - like

select city
from station
where city like 'i%' or city like 'e%' or city like 'a%' or city like 'o%' or city like 'u

내가 작성한 정답2 - like2

select city
from station
where city like '[aeiou]%';

내가 작성한 정답3 - substring

select city
from station
where substring(city,1,1) in ('a','e','i','o','u');

내가 작성한 정답4 - left

select city
from station
where left(city,1) in ('a','e','i','o','u');

DB2 - Oracle과 유사

내가 작성한 정답1 - like

select city 
from station
where city like 'I%' or city like 'E%' or city like 'A%' or city like 'O%' or city like 'U%';

내가 작성한 정답2 - substr

select city
from station
where lower(substr(city,1,1)) in ('a','e','i','o','u');

정리!