pivot-table - ABAP CDS 中的数据透视表/反透视表

Question

是否可以在 ABAP CDS 查询中进行数据透视查询？有没有一种方法可以像我们在 SQL Server 和 MySQL 中一直在做的那样实现这一点？

Answer 1

不，目前它在 ABAP CDS 和 HANA 中都不受本机支持。

您可以使用多种解决方法来模拟枢轴行为：

1. 与[示例]COUNT一起旋转UNION ALL

   select vendor_id, sum("E1") AS "E1", SUM("E2") AS "E2", SUM("E3") AS "E3"
   FROM
   (
   select vendor_id, COUNT(NUM) as "E1", 0 AS "E2" , 0 AS "E3"
   from "ABHISHEAGRAW".
   WHERE EMP_ID = 'E1' GROUP BY vendor_id
   union all
   select vendor_id, 0 AS “E1”, COUNT(NUM) as "E2", 0 AS "E3"
   from "ABHISHEAGRAW".
   WHERE EMP_ID = 'E2' GROUP BY vendor_id
   union all
   select vendor_id, 0 AS “E1”, 0 as "E2", COUNT(NUM) AS "E3"
   from "ABHISHEAGRAW".
   WHERE EMP_ID = 'E3' GROUP BY vendor_id
   ) GROUP BY vendor_id ORDER BY vendor_id
   

2. COUNT通过[示例]旋转CASE

   select vendor_id, sum("E1") AS "E1", SUM("E2") AS "E2", SUM("E3") AS "E3"
   FROM
   (
   select vendor_id, CASE (EMP_ID) WHEN 'E1'
   THEN 1
   ELSE 0
   END as "E1",
   CASE (EMP_ID) WHEN 'E2'
   THEN 1
   ELSE 0
   END as "E2",
   CASE (EMP_ID) WHEN 'E3'
   THEN 1
   ELSE 0
   END as "E3"
   from “ABHISHEAGRAW”.
   )GROUP BY vendor_id ORDER BY vendor_id
   

3. 使用 CASE 进行透视和分组[示例]

给定的片段是 HANA 示例，但它们可以适应 ABAP CDS。如果您提供案例的MCVE，我们可以为您提供可能的解决方案。