在 SQL 中使用 PIVOT 正确地将行转换为列

Question

我已经设法将现有的行转换为列，但是转换不是生成 1 行，而是生成具有相同容器的 2 行。这是我的数据集。

SELECT distinct c.container, c.attribute, c.value, c.property from cars c
WHERE c.container = 'VOLVO'

---------------------------------------------------
| CONTAINER |  ATTRIBUTE |   VALUE   | PROPERTY |
|  VOLVO    |    TIRE    |   DUNLOP  |     A    |
|  VOLVO    |    SEATS   |     4     |     A    |
|  VOLVO    |    PRICE   |   25,000  |     B    |
|  VOLVO    |    COLOR   |    BLUE   |     A    |
|  VOLVO    |    MODEL   |    XC90   |     A    |


SELECT * FROM cars
PIVOT( max(value) for attribute IN ([TIRE],[SEATS],[PRICE],[COLOR],[MODEL])) P
WHERE container = 'VOLVO'

---------------------------------------------------------------------------
| CONTAINER |  PROPERTY |    TIRE    | SEATS |   PRICE  |  COLOR  |  MODEL
---------------------------------------------------------------------------
| VOLVO     |     A     |   DUNLOP   |   4   |   NULL   |  BLUE   |  XC90
| VOLVO     |     B     |   NULL     |  NULL |  25,000  |  NULL   |  NULL

我如何合并这两行并产生这个结果？

---------------------------------------------------------------------------
| CONTAINER |  PROPERTY |    TIRE    | SEATS |   PRICE  |  COLOR  |  MODEL
---------------------------------------------------------------------------
| VOLVO     |     A     |   DUNLOP   |   4   |  25,000  |  BLUE   |  XC90

谢谢！

Answer 1

你需要省略 属性:

SELECT * FROM (
  select CONTAINER, VALUE, ATTRIBUTE from cars
) S
PIVOT( max(value) for attribute IN ([TIRE],[SEATS],[PRICE],[COLOR],[MODEL])) P
WHERE container = 'VOLVO'

结果：

CONTAINER   TIRE    SEATS   PRICE   COLOR   MODEL
VOLVO       DUNLOP  4       25,000  BLUE    XC90

SQL Fiddle