[HackerRank/Advanced Select] The PADS

https://www.hackerrank.com/challenges/the-pads/problem 

The PADS | HackerRank

 

문제

풀이

SELECT CONCAT(Name, "(", LEFT(Occupation,1), ")") FROM OCCUPATIONS
ORDER BY Name;

SELECT CONCAT("There are a total of ", COUNT(occupation), " ", LOWER(Occupation), "s.")
FROM OCCUPATIONS
GROUP BY Occupation
ORDER BY COUNT(Occupation), Occupation

 

• CONCAT(문자열1, 문자열2, ..., 문자열 N) : 문자열1 + 문자열2 + ... + 문자열 N
• LOWER(문자열): 문자열을 소문자로 바꿔줌
• GROUP BY: 컬럼을 그룹화 할 때 사용함

https://extbrain.tistory.com/56

[MySQL] 그룹화하여 데이터 조회 (GROUP BY)