Weather Observation Station 5

Weather Observation Station 5

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.

 

 

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정답)

SELECT city 
        ,length 
FROM (SELECT city 
            ,LENGTH(city) length 
            ,ROW_NUMBER() OVER(ORDER BY LENGTH(city) DESC ,city ASC ) L
            ,ROW_NUMBER() OVER(ORDER BY LENGTH(city) ASC ,city ASC ) S 
      FROM station ) 
WHERE L = 1 OR S =1 ;

서브쿼리를 써야겠다는 생각과   ROWNUM을 써봐야겠다는 생각은 했는데 뭔가 이상해서

RANK함수를 쓰고싶었는데 혼돈의 카오스..ㅋㅋㅋ뭔가 어렵다.. EASY 난이도인데..열심히 해야지 😂

 

*ROW_NUMBER() : ORDER BY 된 결과에 순번을 매기고 싶을때 사용한다

ROW_NUMBER() OVER(ORDER BY 정렬칼럼)