SELECT DISTINCT CITY FROM STATION WHERE (CITY LIKE 'A%' OR CITY LIKE 'E%' OR CITY LIKE 'I%' OR CITY LIKE 'O%' OR CITY LIKE 'U%') AND (CITY LIKE '%a' OR CITY LIKE '%e' OR CITY LIKE '%i' OR CITY LIKE '%o' OR CITY LIKE '%u')

This is the apporach which I had used to check all occurences:- SELECT DISTINCT city FROM station WHERE (city LIKE 'a%e' OR city LIKE 'a%a' OR city LIKE 'a%i' OR city LIKE 'a%o' OR city LIKE 'a%u') OR (city LIKE 'e%a' OR city LIKE 'e%e' OR city LIKE 'e%i' OR city LIKE 'e%o' OR city LIKE 'e%u') OR (city LIKE 'i%a' OR city LIKE 'i%e' OR city LIKE 'i%i' OR city LIKE 'i%o' OR city LIKE 'i%u') OR (city LIKE 'o%a' OR city LIKE 'o%e' OR city LIKE 'o%i' OR city LIKE 'o%o' OR city LIKE 'o%u') OR (city LIKE 'u%a' OR city LIKE 'u%e' OR city LIKE 'u%i' OR city LIKE 'u%o' OR city LIKE 'u%u');

SELECT DISTINCT city FROM station where city LIKE '[AEIOU]%[aeiou]';

As HackerRank uses DB2 Instead of MySQL and Oracle so other all answers are invalid This is the right version , since DB2 doesn't support -1 we've used length function to get last character

select distinct CITY from STATION where (substr(CITY,1,1) in ('A','E','I','O','U')) AND (substr(CITY,LENGTH(CITY),1) in ('a','e','i','o','u'));

SELECT DISTINCT CITY FROM STATION WHERE UPPER(SUBSTR(CITY,1,1)) IN ('A','E','I','O','U') AND UPPER(SUBSTR(CITY,LENGTH(CITY),1)) IN ('A','E','I','O','U');