求帮忙

[csdn_jiangl]

select '项目1','项目-1' union
select '项目1','项目-2' union
select '项目1','项目-3' union
select '项目2',''
--项目1，项目-1，项目-2，项目-3、项目2


有这样子的一组数据，需要得到“--项目1，项目-1，项目-2，项目-3、项目2”这样子的结果，求帮忙

[二月十六]

--测试数据
if not object_id(N'Tempdb..#T') is null
	drop table #T
Go
Create table #T([col1] VARCHAR(100),[col2] VARCHAR(100))
Insert #T
select '项目1','项目-1' union
select '项目1','项目-2' union
select '项目1','项目-3' union
select '项目2',''
Go
--测试数据结束
;WITH cte AS (
Select *,ROW_NUMBER()OVER(ORDER BY (SELECT 1)) AS num from #T
)
SELECT '=='+STUFF((
SELECT  (CASE WHEN  EXISTS( SELECT    b.col1
          FROM      cte b
          WHERE     a.num > b.num
                    AND (a.col1 = b.col1
                    OR a.col1 = b.col2)
        ) OR a.col1 =''  THEN '' ELSE ','+a.col1 END)+	
        (CASE WHEN EXISTS( SELECT    c.col2
          FROM      cte c
          WHERE     a.num > c.num
                    AND( a.col2 = c.col1
                    OR a.col2 = c.col2)
        ) OR a.col2 ='' THEN '' ELSE ','+	a.col2 END)
FROM    cte a
FOR XML PATH('')),1,1,'')

[leo_lesley]

--测试数据
if not object_id(N'Tempdb..#T') is null
    drop table #T
Go
Create table #T([col1] NVARCHAR(100),[col2] NVARCHAR(100))
Insert #T
select N'项目1',N'项目-1' union
select N'项目1',N'项目-2' union
select N'项目1',N'项目-3' union
select N'项目2',''
Go

SELECT STUFF(
(SELECT ',' + [col1] + CASE WHEN ISNULL([col2],'') = '' THEN '' ELSE ',' + [col2] END FROM (
SELECT [col1],STUFF((SELECT ','+[col2] FROM #T WHERE [col1] = T.[col1] FOR XML PATH('')),1,1,'')  [col2]
FROM #T T GROUP BY [col1]
) A FOR XML PATH('')) , 1,1,'')