언어별 개발자 분류하기

문제

코드

WITH CODE_SUM AS (
    SELECT
        (SELECT SUM(CODE) FROM SKILLCODES WHERE CATEGORY = 'Front End') AS FRONT_END,
        (SELECT SUM(CODE) FROM SKILLCODES WHERE NAME = 'Python') AS PYTHON,
        (SELECT SUM(CODE) FROM SKILLCODES WHERE NAME = 'C#') AS CSHARP
),
CTE AS (
    SELECT
        CASE
            WHEN SKILL_CODE & c.FRONT_END > 0 AND SKILL_CODE & c.PYTHON > 0 THEN 'A'
            WHEN SKILL_CODE & c.CSHARP > 0 THEN 'B'
            WHEN SKILL_CODE & c.FRONT_END > 0 THEN 'C'
        END AS GRADE,
        ID, EMAIL
    FROM DEVELOPERS, CODE_SUM c
)
SELECT *
FROM CTE
WHERE GRADE IS NOT NULL
ORDER BY GRADE, ID;

 

출처: 프로그래머스 코딩 테스트 연습, https://school.programmers.co.kr/learn/courses/30/lessons/276036