我正在尝试根据同一张表中的 ProductID 在新列中获取“现金”、“支票”和“信用卡”总计。
表 - 付款
+-----------+------------+---------------+--------+
| ProductID | SaleDate | PaymentMethod | Amount |
+-----------+------------+---------------+--------+
| 3 | 2012-02-10 | Cash | 10 |
| 3 | 2012-02-10 | Cash | 10 |
| 3 | 2012-02-10 | Check | 15 |
| 3 | 2012-02-10 | Credit Card | 25 |
| 4 | 2012-02-10 | Cash | 5 |
| 4 | 2012-02-10 | Check | 6 |
| 4 | 2012-02-10 | Credit Card | 7 |
+-----------+------------+---------------+--------+
所需的输出 -
+------------+------+-------+-------------+-------+
| ProductID | Cash | Check | Credit Card | Total |
+------------+------+-------+-------------+-------+
| 3 | 20 | 15 | 25 | 60 |
| 4 | 5 | 6 | 7 | 18 |
+------------+------+-------+-------------+-------+
我试过 LEFT JOINing 同一张桌子,但没有任何成功。任何建议,将不胜感激。谢谢。
不成功和不完整的尝试 -
SELECT P.ProductID, Sum( PCash.Amount ) AS 'Cash', SUM( PCheck.Amount ) AS 'Check', SUM( PCredit.Amount) AS 'Credit Card'
FROM Payments AS P
LEFT JOIN Payments AS PCash ON P.ProductID = PCash.ProductID AND PCash.PaymentMethod = 'Cash'
LEFT JOIN Payments AS PCheck ON P.ProductID = PCheck.ProductID AND PCheck.PaymentMethod = 'Check'
LEFT JOIN Payments AS PCredit ON P.ProductID = PCredit.ProductID AND PCredit.PaymentMethod = 'Credit'
WHERE P.SaleDate = '2012-02-10' GROUP BY ProductID;