Sql 将行转换为列并计算总和

我有这个

我想要这个

但是我得到了这个

我的问题是

SELECT   SID, 
         NAME, 
         SUBJECT, ( 
         CASE 
                  WHEN EXAMTYPE IN ('ASSIGNMENTS', 
                                    'PRACTICAL') THEN SUM(MARKS) 
                  ELSE 0 
         END) AS "ASSIGNMENTS + PRACTICAL", ( 
         CASE 
                  WHEN EXAMTYPE = 'WRITTEN' THEN SUM(MARKS) 
                  ELSE 0 
         END) AS "WRITTEN"
FROM     MARKSHEET 
WHERE    EXAMTYPE IN ('ASSIGNMENTS', 
                      'PRACTICAL', 
                      'WRITTEN') 
GROUP BY SID, 
         NAME, 
         SUBJECT, 
         EXAMTYPE

我正在使用IBMDB2。

---

我将永远感激任何/所有的帮助。谢谢大家!

您需要将case表达式放在sum（）中，比如

sum（case when…）

另外，从

group by子句中删除
examType
字段

SELECT   SID, 
         NAME, 
         SUBJECT, sum( 
         CASE 
                  WHEN EXAMTYPE IN ('ASSIGNMENTS', 
                                    'PRACTICAL') THEN MARKS 
                  ELSE 0 
         END) AS "ASSIGNMENTS + PRACTICAL", ( 
         sum(CASE 
                  WHEN EXAMTYPE = 'WRITTEN' THEN MARKS
                  ELSE 0 
         END) AS "WRITTEN"
FROM     MARKSHEET 
WHERE    EXAMTYPE IN ('ASSIGNMENTS', 'PRACTICAL', 'WRITTEN') 
GROUP BY SID, NAME, SUBJECT