SQL連接和分組

Question

我需要一個TSQL版本的group_concat Simmilar到此處找到的示例：

Policy   Destination   ID
-------------------------
PolA     DestA         1    
PolA     DestA         2    
PolB     DestB         3     
PolB     DestB         4    
PolC     DestC         5
PolC     DestC         6
PolC     DestD         7   

輸出應如下所示：

PolA   DestA   1,2
PolB   DestB   3,4
PolC   DestC   5,6
PolC   DestD   7

分組是基於前兩列的唯一性，然后是第三列的並置輸出。

我找到了此鏈接，但只考慮了2列

任何幫助，將不勝感激。

Answer 1

在MSSQL Synax中：

SELECT Policy, Destination, STRING_AGG ( [ID], ',' ) IDs
FROM Table

Answer 2

您可以嘗試以下方法：

SELECT G.Policy, G.Destination,
    stuff(
    (select cast(',' as varchar(max)) + U.ID
    from yourtable U
    WHERE U.Policy = G.Policy and U.Destination = G.Destination
    order by U.Policy
    for xml path('')
    ), 1, 1, '') AS IDs
FROM yourtable G group BY G.Policy, G.Destination

Answer 3

我只是為您創建PolA示例表，只需將CTE替換為您的表，請嘗試以下操作：

WITH ABC
as
(
select   'PolA' as Policy,'DestA' as Destination,'1' as ID  
UNION ALL 
select 'PolA','DestA','2'
)

SELECT Policy, Destination,
 STUFF((SELECT ',' + A.ID FROM ABC as A WHERE A.Policy = B.Policy FOR XML PATH('')),1,1,'') as ID
FROM ABC as B
GROUP BY B.policy, B.Destination