ABAP CDS 中的透視表/反透視表

Question

是否可以在 ABAP CDS 查詢中進行數據透視查詢？ 有沒有辦法像我們在 SQL Server 和 MySQL 中一直做的那樣實現這一目標？

Answer 1

不，目前它在 ABAP CDS 和 HANA 中均不受本機支持。

您可以使用多種解決方法來模擬樞軸行為：

1. 使用COUNT和UNION ALL旋轉[示例]

    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. 通過CASE使用COUNT透視[示例]

    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 進行透視和分組[示例]

給定的片段是 HANA 示例，但它們可以適用於 ABAP CDS。 如果您提供案例的MCVE ，我們可以為您提供可能的解決方案。