我如何得到:

id       Name       Value
1          A          4
1          B          8
2          C          9

to

id          Column
1          A:4, B:8
2          C:9

当前回答

使用Replace函数和FOR JSON PATH

SELECT T3.DEPT, REPLACE(REPLACE(T3.ENAME,'{"ENAME":"',''),'"}','') AS ENAME_LIST
FROM (
 SELECT DEPT, (SELECT ENAME AS [ENAME]
        FROM EMPLOYEE T2
        WHERE T2.DEPT=T1.DEPT
        FOR JSON PATH,WITHOUT_ARRAY_WRAPPER) ENAME
    FROM EMPLOYEE T1
    GROUP BY DEPT) T3

有关示例数据和更多方法,请点击这里

其他回答

不需要光标…while循环就足够了。

------------------------------
-- Setup
------------------------------

DECLARE @Source TABLE
(
  id int,
  Name varchar(30),
  Value int
)

DECLARE @Target TABLE
(
  id int,
  Result varchar(max) 
)


INSERT INTO @Source(id, Name, Value) SELECT 1, 'A', 4
INSERT INTO @Source(id, Name, Value) SELECT 1, 'B', 8
INSERT INTO @Source(id, Name, Value) SELECT 2, 'C', 9


------------------------------
-- Technique
------------------------------

INSERT INTO @Target (id)
SELECT id
FROM @Source
GROUP BY id

DECLARE @id int, @Result varchar(max)
SET @id = (SELECT MIN(id) FROM @Target)

WHILE @id is not null
BEGIN
  SET @Result = null

  SELECT @Result =
    CASE
      WHEN @Result is null
      THEN ''
      ELSE @Result + ', '
    END + s.Name + ':' + convert(varchar(30),s.Value)
  FROM @Source s
  WHERE id = @id

  UPDATE @Target
  SET Result = @Result
  WHERE id = @id

  SET @id = (SELECT MIN(id) FROM @Target WHERE @id < id)
END

SELECT *
FROM @Target

八年后……Microsoft SQL Server vNext数据库引擎最终增强了Transact-SQL,以直接支持分组字符串连接。社区技术预览版本1.0添加了STRING_AGG函数,CTP 1.1为STRING_AGG函数添加了WITHIN GROUP子句。

参考:https://msdn.microsoft.com/en-us/library/mt775028.aspx

我使用了这种方法,可能更容易掌握。获取一个根元素,然后连接到具有相同ID但不是“正式”名称的选项

  Declare @IdxList as Table(id int, choices varchar(max),AisName varchar(255))
  Insert into @IdxLIst(id,choices,AisName)
  Select IdxId,''''+Max(Title)+'''',Max(Title) From [dbo].[dta_Alias] 
 where IdxId is not null group by IdxId
  Update @IdxLIst
    set choices=choices +','''+Title+''''
    From @IdxLIst JOIN [dta_Alias] ON id=IdxId And Title <> AisName
    where IdxId is not null
    Select * from @IdxList where choices like '%,%'

使用XML路径不会完美地连接你可能期望…它会将“&”替换为“&”,也会混淆<”和“>” ...也许还有其他一些事情,不确定……但是你可以试试这个

我想到了一个变通办法…您需要替换:

FOR XML PATH('')
)

:

FOR XML PATH(''),TYPE
).value('(./text())[1]','VARCHAR(MAX)')

...或者NVARCHAR(MAX)如果这是你使用的。

为什么SQL没有一个串联聚合函数?这是PITA。

使用Stuff和for xml路径操作符将行连接到字符串:Group By两列——>

CREATE TABLE #YourTable ([ID] INT, [Name] CHAR(1), [Value] INT)

INSERT INTO #YourTable ([ID],[Name],[Value]) VALUES (1,'A',4)
INSERT INTO #YourTable ([ID],[Name],[Value]) VALUES (1,'B',8)
INSERT INTO #YourTable ([ID],[Name],[Value]) VALUES (1,'B',5)
INSERT INTO #YourTable ([ID],[Name],[Value]) VALUES (2,'C',9)

-- retrieve each unique id and name columns and concatonate the values into one column
SELECT 
  [ID], 
  STUFF((
    SELECT ', ' + [Name] + ':' + CAST([Value] AS VARCHAR(MAX)) -- CONCATONATES EACH APPLICATION : VALUE SET      
    FROM #YourTable 
    WHERE (ID = Results.ID and Name = results.[name] ) 
    FOR XML PATH(''),TYPE).value('(./text())[1]','VARCHAR(MAX)')
  ,1,2,'') AS NameValues
FROM #YourTable Results
GROUP BY ID


SELECT 
  [ID],[Name] , --these are acting as the group by clause
  STUFF((
    SELECT ', '+  CAST([Value] AS VARCHAR(MAX)) -- CONCATONATES THE VALUES FOR EACH ID NAME COMBINATION 
    FROM #YourTable 
    WHERE (ID = Results.ID and Name = results.[name] ) 
    FOR XML PATH(''),TYPE).value('(./text())[1]','VARCHAR(MAX)')
  ,1,2,'') AS  NameValues
FROM #YourTable Results
GROUP BY ID, name

DROP TABLE #YourTable