从多列的一行中获取SQL查询结果

Question

我有一个带有以下记录的UPC表

SKU         ATTR_NAME       ATTR_VALUE
---------   ---------       ----------
38890630    COLOR           Black
38890630    DISC            Y
38890630    SIZE            8

我想要的输出如下

SKU         COLOR     SIZE
---------   ------    ----
38890630    Black      8

我尝试了多种方法，但无法获得所需的输出。 有人可以帮忙吗？

Answer 1

您可以使用条件聚合：

select sku,
       max(case when attr_name = 'COLOR' then attr_value end) as color,
       max(case when attr_name = 'DISC' then attr_value end) as disc,
       max(case when attr_name = 'SIZE' then attr_value end) as size
from t
group by sku;

Answer 2

您可以使用PIVOT查询：

WITH UPC_TABLE AS (
    SELECT 38890630 AS SKU, 'COLOR' AS ATTR_NAME, 'BLACK' AS ATTR_VALUE FROM DUAL
    UNION ALL SELECT 38890630 AS SKU, 'DISC' AS ATTR_NAME, 'Y' AS ATTR_VALUE FROM DUAL
    UNION ALL SELECT 38890630 AS SKU, 'SIZE' AS ATTR_NAME, '8' AS ATTR_VALUE FROM DUAL
)
SELECT * FROM 
     UPC_TABLE PIVOT (MAX(ATTR_VALUE) AS ATTR_VALUE FOR (ATTR_NAME) IN (
          'COLOR' AS COLOR
      ,   'DISC' AS DISC
      ,   'SIZE' AS SIZE_FIELD
     )

）;