[leetcode] [SQL] Reformat Department Table

문제 설명

문제 풀이

SELECT id
     , SUM(CASE WHEN month = 'Jan' THEN revenue ELSE NULL END) AS jan_Revenue
     , SUM(CASE WHEN month = 'Feb' THEN revenue ELSE NULL END) AS Feb_Revenue
     , SUM(CASE WHEN month = 'Mar' THEN revenue ELSE NULL END) AS Mar_Revenue
     , SUM(CASE WHEN month = 'Apr' THEN revenue ELSE NULL END) AS Apr_Revenue
     , SUM(CASE WHEN month = 'May' THEN revenue ELSE NULL END) AS May_Revenue
     , SUM(CASE WHEN month = 'Jun' THEN revenue ELSE NULL END) AS Jun_Revenue
     , SUM(CASE WHEN month = 'Jul' THEN revenue ELSE NULL END) AS Jul_Revenue
     , SUM(CASE WHEN month = 'Aug' THEN revenue ELSE NULL END) AS Aug_Revenue
     , SUM(CASE WHEN month = 'Sep' THEN revenue ELSE NULL END) AS Sep_Revenue
     , SUM(CASE WHEN month = 'Oct' THEN revenue ELSE NULL END) AS Oct_Revenue
     , SUM(CASE WHEN month = 'Nov' THEN revenue ELSE NULL END) AS Nov_Revenue
     , SUM(CASE WHEN month = 'Dec' THEN revenue ELSE NULL END) AS Dec_Revenue
FROM department
GROUP BY id