SQL Query 用于生成矩阵，如 SQL Server 中的输出查询相关表

Question

我有三张桌子：

产品

ProductID   ProductName
1           Cycle
2           Scooter
3           Car

顾客

CustomerID  CustomerName
101         Ronald
102         Michelle
103         Armstrong
104         Schmidt
105         Peterson

交易

TID   ProductID CustomerID TranDate   Amount
10001 1         101        01-Jan-11  25000.00
10002 2         101        02-Jan-11  98547.52
10003 1         102        03-Feb-11  15000.00
10004 3         102        07-Jan-11  36571.85
10005 2         105        09-Feb-11  82658.23
10006 2         104        10-Feb-11  54000.25
10007 3         103        20-Feb-11  80115.50
10008 3         104        22-Feb-11  45000.65

我写了一个查询来对这样的事务进行分组：

 SELECT P.ProductName AS Product,
       C.CustName AS Customer,
       SUM(T.Amount) AS Amount
FROM   Transactions AS T
       INNER JOIN Product AS P
            ON  T.ProductID = P.ProductID
       INNER JOIN Customer AS C
            ON  T.CustomerID = C.CustomerID
WHERE T.TranDate BETWEEN '2011-01-01' AND '2011-03-31'
GROUP BY
       P.ProductName,
       C.CustName
ORDER BY
       P.ProductName

结果如下：

 Product Customer   Amount
Car     Armstrong  80115.50
Car     Michelle   36571.85
Car     Schmidt    45000.65
Cycle   Michelle   15000.00
Cycle   Ronald     25000.00
Scooter Peterson   82658.23
Scooter Ronald     98547.52
Scooter Schmidt    54000.25

我需要这样的 MATRIX 形式的查询结果：

 Customer  |------------ Amounts ---------------
Name      |Car      Cycle     Scooter  Totals
Armstrong  80115.50 0.00      0.00     80115.50
Michelle   36571.85 15000.00  0.00     51571.85
Ronald     0.00     25000.00  98547.52 123547.52
Peterson   0.00     0.00      82658.23 82658.23
Schmidt    45000.65 0.00      54000.25 99000.90

请帮助我在 SQL Server 2005 中实现上述结果。使用多个视图甚至临时表对我来说都很好。

原文由 Nagesh 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 1

您可以使用 SQL Server 的 PIVOT 运算符

SELECT  *
FROM    (
          SELECT  P.ProductName
                  , C.CustName
                  , T.Amount
          FROM    Transactions AS T
                  INNER JOIN Product AS P ON  T.ProductID = P.ProductID
                  INNER JOIN Customer AS C ON  T.CustomerID = C.CustomerID
          WHERE   T.TranDate BETWEEN '2011-01-01' AND '2011-03-31'
        ) s
PIVOT   (SUM(Amount) FOR ProductName IN ([Car], [Cycle], [Scooter])) pvt

测试数据

;WITH q AS (
  SELECT  [Product] = 'Car', [Customer] = 'Armstrong', [Amount] = 80115.50
  UNION ALL SELECT 'Car', 'Michelle', 36571.85
  UNION ALL SELECT 'Car', 'Schmidt', 45000.65
  UNION ALL SELECT 'Cycle', 'Michelle', 15000.00
  UNION ALL SELECT 'Cycle', 'Ronald', 25000.00
  UNION ALL SELECT 'Scooter', 'Peterson', 82658.23
  UNION ALL SELECT 'Scooter', 'Ronald', 98547.52
  UNION ALL SELECT 'Scooter', 'Schmidt', 54000.25
)
SELECT  Customer
        , Car = ISNULL(Car, 0)
        , Cycle = ISNULL(Cycle, 0)
        , Scooter = ISNULL(Scooter, 0)
        , Total = ISNULL(Car, 0) + ISNULL(Cycle, 0) + ISNULL(Scooter, 0)
FROM    (
          SELECT  *
          FROM    q
        ) s
PIVOT   (SUM(Amount) FOR Product IN ([Car], [Cycle], [Scooter])) pvt

输出

Customer   Car       Cycle     Scooter   Total
Armstrong  80115.50  0.00      0.00      80115.50
Michelle   36571.85  15000.00  0.00      51571.85
Peterson   0.00      0.00      82658.23  82658.23
Ronald     0.00      25000.00  98547.52  123547.52
Schmidt    45000.65  0.00      54000.25  99000.90

原文由 Lieven Keersmaekers 发布，翻译遵循 CC BY-SA 2.5 许可协议

Answer 2

我们可以使用枢轴创建矩阵，这可以通过数据框轻松完成

product|Key|Value
A      |P  |10|
A      |Q  |40|
B      |R  |50|
B      |S  |50|

 val newdf=df.groupBy("product").pivot("key").sum("value")

 |product|P   |Q   |R   |S   |
|B      |null|null|  50|  50|
|A      |  10|  40|null|null|

我们可以替换 null 也可以进行计算

原文由 shashidhar reddy 发布，翻译遵循 CC BY-SA 4.0 许可协议