[LeetCode] 1179. Reformat Department Table

😎풀이

1. Department 테이블 조회
2. id를 기준으로 데이터 그룹화
3. Jan을 기준으로 합계 반환, 없다면 NULL
4. 12월까지 반복
5. 반복된 결과 조회

SELECT id,
SUM(IF(month='Jan', revenue, NULL)) AS Jan_Revenue,
SUM(IF(month='Feb', revenue, NULL)) AS Feb_Revenue,
SUM(IF(month='Mar', revenue, NULL)) AS Mar_Revenue,
SUM(IF(month='Apr', revenue, NULL)) AS Apr_Revenue,
SUM(IF(month='May', revenue, NULL)) AS May_Revenue,
SUM(IF(month='Jun', revenue, NULL)) AS Jun_Revenue,
SUM(IF(month='Jul', revenue, NULL)) AS Jul_Revenue,
SUM(IF(month='Aug', revenue, NULL)) AS Aug_Revenue,
SUM(IF(month='Sep', revenue, NULL)) AS Sep_Revenue,
SUM(IF(month='Oct', revenue, NULL)) AS Oct_Revenue,
SUM(IF(month='Nov', revenue, NULL)) AS Nov_Revenue,
SUM(IF(month='Dec', revenue, NULL)) AS Dec_Revenue
FROM Department
Group BY id;