select distinct(city) from station where city regexp'^[AEIOUaeiou]';

WITH CTE AS( SELECT CASE WHEN SUBSTRING(LOWER(CITY), 1, 1) IN ( 'a', 'e', 'i', 'o','u') THEN CITY ELSE NULL END AS CITY FROM STATION ) SELECT CITY FROM CTE WHERE CITY IS NOT NULL

(SELECT DISTINCT CITY FROM STATION WHERE CITY LIKE ("A%" )) UNION (SELECT DISTINCT CITY FROM STATION WHERE CITY LIKE ("E%" )) UNION (SELECT DISTINCT CITY FROM STATION WHERE CITY LIKE ("I%" )) UNION (SELECT DISTINCT CITY FROM STATION WHERE CITY LIKE ("O%" )) UNION (SELECT DISTINCT CITY FROM STATION WHERE CITY LIKE ("U%" ));

SELECT DISTINCT(CITY) FROM STATION WHERE LOWER(LEFT(CITY, 1)) IN ('a','e','i','o','u');

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%';