如何在由 B 列分组的 A 列中具有 DISTINCT csv

Question

这是我在表 T1 中的示例数据

CREATE TABLE T1 (TRANS_ID INT , SCENARIO VARCHAR(50))
INSERT INTO T1 VALUES (1,'DA_HRNM'),(1,'DA_HRNM'),(2,'DA_KW'),(2,'DA_HRC'),(3,'DA_BOG'),(3,'DA_HRC'),(3,'DA_HRC')

我想写一个查询来返回以下输出 -

基本上我想要DISTINCT col SCENARIO GROUP BY TRANS_ID 中的逗号分隔值

Answer 1

你需要distinct和for xml path

sql fiddle demo

WITH onlyone as (
      SELECT DISTINCT TRANS_ID, SCENARIO
      FROM T1 T
)    
SELECT  DISTINCT p.TRANS_ID, 
        STUFF(( SELECT ',' + CAST(T.SCENARIO as varchar(10) )
                FROM onlyone T
                WHERE T.TRANS_ID = p.TRANS_ID
                ORDER BY T.SCENARIO
                FOR
                   XML PATH('')
                ), 1, 1, '') AS SCENARIO
FROM onlyone p