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

如果你启用了clr,你可以使用GitHub中的Group_Concat库

其他回答

没有看到任何交叉应用的答案,也不需要XML提取。这是凯文·费尔柴尔德的一个略有不同的版本。在更复杂的查询中使用它更快更容易:

   select T.ID
,MAX(X.cl) NameValues
 from #YourTable T
 CROSS APPLY 
 (select STUFF((
    SELECT ', ' + [Name] + ':' + CAST([Value] AS VARCHAR(MAX))
    FROM #YourTable 
    WHERE (ID = T.ID) 
    FOR XML PATH(''))
  ,1,2,'')  [cl]) X
  GROUP BY T.ID

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

使用Sql Server 2005及以上版本的另一种选择

---- test data
declare @t table (OUTPUTID int, SCHME varchar(10), DESCR varchar(10))
insert @t select 1125439       ,'CKT','Approved'
insert @t select 1125439       ,'RENO','Approved'
insert @t select 1134691       ,'CKT','Approved'
insert @t select 1134691       ,'RENO','Approved'
insert @t select 1134691       ,'pn','Approved'

---- actual query
;with cte(outputid,combined,rn)
as
(
  select outputid, SCHME + ' ('+DESCR+')', rn=ROW_NUMBER() over (PARTITION by outputid order by schme, descr)
  from @t
)
,cte2(outputid,finalstatus,rn)
as
(
select OUTPUTID, convert(varchar(max),combined), 1 from cte where rn=1
union all
select cte2.outputid, convert(varchar(max),cte2.finalstatus+', '+cte.combined), cte2.rn+1
from cte2
inner join cte on cte.OUTPUTID = cte2.outputid and cte.rn=cte2.rn+1
)
select outputid, MAX(finalstatus) from cte2 group by outputid

从http://groupconcat.codeplex.com安装SQLCLR聚合

然后你可以像这样写代码来得到你想要的结果:

CREATE TABLE foo
(
 id INT,
 name CHAR(1),
 Value CHAR(1)
);

INSERT  INTO dbo.foo
    (id, name, Value)
VALUES  (1, 'A', '4'),
        (1, 'B', '8'),
        (2, 'C', '9');

SELECT  id,
    dbo.GROUP_CONCAT(name + ':' + Value) AS [Column]
FROM    dbo.foo
GROUP BY id;

如果是SQL Server 2017或SQL Server Vnext, SQL Azure,您可以使用STRING_AGG如下所示:

SELECT id, STRING_AGG(CONCAT(name, ':', [value]), ', ')
FROM #YourTable 
GROUP BY id