66 Weather Observation Station 6
https://www.hackerrank.com/challenges/weather-observation-station-6/problem?isFullScreen=true
Query the list of CITY names starting with vowels (i.e., a, e, i, o, or u) from STATION. Your result cannot contain duplicates.
Select distinct city From Station where city regexp '^[a,e,i,o,u]'
Weather Observation Station 6 ~ 12번 까지의 문제는 REGEXP를 활용한 문제로 난이도가 어렵지 않아서 이후 문제들은 코드카타 작성은 생략!