SQL查詢從冗余行產生逗號分隔的列？

Question

我有兩個表，它們連接在一起並存儲在臨時表中。

臨時表包含以下形式的數據：

|ID|Name |Code|  
|1 | 100 |AAAA|
|1 | 100 |AAAB|
|1 | 100 |AAAA|
|2 | 200 |AAAZ|
more...

現在，我想要以下形式的結果，

╔════╦═════════════════════╗
║ ID ║ Name ║   Code       ║
╠════╬═════════════════════╣
║  1 ║ 100  ║   AAAA, AAAB ║
║  2 ║ 200  ║   AAAZ       ║
╚════╩═════════════════════╝

因此，我編寫了以下查詢，產生了類似的輸出，所以我的問題是，還有其他方法可以實現這一點。

SELECT Distinct BSE_ID
    ,BSE_Name
    ,STUFF((
            SELECT ', ' + CAST(EBS_ExternalCode AS VARCHAR(100)) [text()]
            FROM #tmpBkgSvc
            WHERE BSE_ID = T.BSE_ID
            FOR XML PATH('')
                ,TYPE
            ).value('.', 'NVARCHAR(MAX)'), 1, 2, ' ') EBS_ExternalCode
FROM #tmpBkgSvc T

Answer 1

嘗試這個

Create function Fun
(
    @id int, @name varchar(100)
)
returns varchar(max)
as
begin 

       Declare @code varchar(max)
       Select @code = isnull(@code+',','')+s.code
       from (Select distinct code 
              from table 
               where name = @name and id = @id) s
       Return @code
end

Select id,name,[dbo].Fun(id,Name) 'Code' from table group by id,name

Answer 2

嘗試這樣， Use group By In the Code column

SELECT Distinct ID, Name
    ,STUFF((
            SELECT ', ' + CAST(Code AS VARCHAR(100)) [text()]
            FROM DataTable
            WHERE ID = T.ID Group By Code //group by does the magic here
            FOR XML PATH('')
                ,TYPE
            ).value('.', 'NVARCHAR(MAX)'), 1, 2, ' ') Code 
FROM DataTable T

Answer 3

使用交叉應用而不是子查詢

SELECT T.BSE_ID, T.NAME, MAX(STUFF(A.BSE_ID_LIST, 1, 1, '')) AS BSE_ID_LIST
FROM #tmpBkgSvc T
CROSS APPLY (
    SELECT ', ' + CAST(EBS_ExternalCode AS VARCHAR(100))
    FROM #tmpBkgSvc T1
    WHERE T1.BSE_ID = T.BSE_ID
    GROUP BY T1.EBS_ExternalCode 
    ORDER BY T1.EBS_ExternalCode 
    FOR XML PATH('')
) AS A (BSE_ID_LIST)
GROUP BY T.BSE_ID, T.NAME