用于将列转换为表头的Sql语句

Question

这是我有一个示例表

CustomerName|Items customer 1 |Item 1 customer 1 |Item 2 customer 1 |Item 3 customer 2 |Item 1 customer 2 |Item 4 customer 3 |Item 2 customer 4 |Item 5 customer 5 |Item 6

我需要将表格转换为

CustomerName|Item 1|Item 2|Item 3|Item 4|Item 5|Item 6| customer 1 | X | X | X | | | | customer 2 | X | | | X | | | customer 3 | | X | | X | | | customer 4 | | | | | X | | customer 5 | | | | | | X |

我尝试了PIVOT，在SAP HANA中无效。

我们非常感谢任何建议。

Answer 1

SAP HANA未提供可在其他DBMS中找到的非标准SQL运算符“PIVOT”。 对于永久转换，例如在ETL期间，您可以使用流程图功能PIVOT / UNPIVOT自动执行转换。

对于即时转换，没有内置功能，您必须自己编写代码。

Answer 2

好的，试试这个：

SELECT CustomerName,
   MAX(CASE WHEN ROWN=1 THEN "Items" ELSE NULL END) AS Item1,
   MAX(CASE WHEN ROWN=2 THEN "Items" ELSE NULL END) AS Item2,
   MAX(CASE WHEN ROWN=3 THEN "Items" ELSE NULL END) AS Item3,
   MAX(CASE WHEN ROWN=4 THEN "Items" ELSE NULL END) AS Item4,
   MAX(CASE WHEN ROWN=5 THEN "Items" ELSE NULL END) AS Item5,
   MAX(CASE WHEN ROWN=6 THEN "Items" ELSE NULL END) AS Item6,
FROM 
  (SELECT CustomerName, Items, 
          row_number() over (PARTITION BY CustomerName) AS ROWN
FROM TABLE_NAME ORDER BY CustomerName)
                GROUP BY CustomerName;

其中TABLE_NAME是源表的名称。