Query the list of CITY names starting with vowels (i.e., a, e, i, o, or u) from STATION. Your result cannot contain duplicates.

Mysql uniqe Vowels

Start with
select  DISTINCT CITY from STATION where CITY rlike '^[a,e,i,o,u]';

End with
select  DISTINCT CITY from STATION where CITY rlike '[a,e,i,o,u]$';

Both Start and end
select  DISTINCT CITY from STATION where CITY rlike '^[a,e,i,o,u].*[a,e,i,o,u]$';

SELECT DISTINCT CITY from STATION where CITY REGEXP '^[^aeiou].*[^aeiou]$';

SELECT DISTINCT CITY
FROM STATION
WHERE CITY NOT REGEXP '^[aeiouAEIOU]';