select distinct city from STATION where LEFT(city,1) NOT IN ('a','e','i','o','u') OR RIGHT(city,1) NOT IN ('a','e','i','o','u')

SELECT DISTINCT CITY FROM STATION WHERE SUBSTR(CITY, 1, 1) NOT IN ('A', 'E', 'I', 'O', 'U') OR SUBSTR(CITY, LENGTH(CITY), 1) NOT IN ('A', 'E', 'I', 'O', 'U');

In mysql - SELECT DISTINCT CITY FROM STATION WHERE CITY NOT REGEXP '^[AEIOU].*[AEIOU]$';

select distinct city from station where substr(city,-1,1) not in ('a','o','i','e','u') or substr(city,1,1) not in ('a','o','i','e','u');

-- ORACLE SQL

select distinct city from station where NOT (REGEXP_LIKE(SUBSTR(CITY, 1, 1), '^[AEIOUaeiou]') AND REGEXP_LIKE(SUBSTR(CITY, -1, 1), '[AEIOUaeiou]$')) order by city;

The solution pass the test but In my solutions i have several problems :

return this results and i dont understand why:

Addison Agency Alanson Albany Albion Algonac Allerton Alton Andover Anthony Arlington Arrowsmith Athens Auburn