[SQL] 해커랭크 Weather Observation Station 5

문제

Query the two cities in STATION with the shortest and longest CITY names, as well as their respective lengths (i.e.: number of characters in the name). 

If there is more than one smallest or largest city, choose the one that comes first when ordered alphabetically.
The STATION table is described as follows:

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

https://www.hackerrank.com/challenges/weather-observation-station-5/problem?isFullScreen=true

Weather Observation Station 5 | HackerRank

예시

Sample Input
For example, CITY has four entries: DEF, ABC, PQRS and WXY.
Sample Output

ABC 3
PQRS 4

Explanation
When ordered alphabetically, the CITY names are listed as ABC, DEF, PQRS, and WXY, with lengths  and . The longest name is PQRS, but there are  options for shortest named city. Choose ABC, because it comes first alphabetically.
Note
You can write two separate queries to get the desired output. It need not be a single query.

문제 풀이

-- MIN 구하기
(SELECT city, char_length(city) AS length
FROM station
ORDER BY length, city
LIMIT 1)

UNION

-- MAX 구하기
(SELECT city, char_length(city) AS length
FROM station
ORDER BY length DESC, city
LIMIT 1)

---

SQL을 독학하시는 분들에게 도움이 되길 바라며,

혹 더 좋은 방법이 있거나 오류가 있다면 편하게 말씀 부탁드립니다.