13_weather_observation_station_8.sql

/*
Weather Observation Station 8

Query the list of CITY names from STATION which have vowels (i.e., a, e, i, o, and u) 
as both their first and last characters. Your result cannot contain duplicates.

- Input Format
The STATION table is described as follows:
    +-------------+--------------+
    | Field       |  Type        |
    +-------------+--------------+
    | ID          | NUMBER       |
    | CITY        | VARCHAR2(21) |
    | STATE       | VARCHAR2(2)  |
    | LAT_N       | NUMBER       |
    | LONG_W      | NUMBER       |
    +-------------+--------------+

where LAT_N is the northern latitude and LONG_W is the western longitude.
*/

SELECT 
    DISTINCT city
FROM 
    station
WHERE 
    city RLIKE '^[aeiouAEIOU].*[aeiouAEIOU]$'
;