how to get data comma seprated

DECLARE @list VARCHAR(MAX)
SELECT @list = COALESCE(@list+',' ,'') + Name
FROM tablename where Id=@id
SELECT @list

declare @str varchar(1000)

SELECT @str= coalesce(@str + ', ', '') + a.X FROM (SELECT CONVERT(varchar(100),dateEnterd) AS X  from TableName where ID=1 and name='ab' and [add]='test') a

SELECT TOP 1 ID,NAME,[add],@str FROM TableNAme WHERE ID=1 and name='ab' and [add]='test' ORDER BY ID ASC

my table commadate having below data 

id	name	add	dateEnterd
1	ab	test	1988-08-23
1	ab	test	1989-08-23
1	ab	test	1990-08-23
1	ab	test	1991-05-01




SELECT ROW_NUMBER() OVER(order by dateEnterd asc)as ID,dateEnterd INTO #TempcomDate
FROM commadate

DECLARE @SR INT
DECLARE @ID INT
DECLARE @strDate NVARCHAR(MAX)

SET @SR=1
SET @ID=(SELECT MAX(ID) FROM #TempcomDate)
SET @strDate=''

WHILE(@SR<=@ID)
BEGIN
IF(@SR>1)BEGIN SET @strDate+=',' END
SET @strDate+=CONVERT(NVARCHAR(50), (SELECT dateEnterd FROM #TempcomDate WHERE ID=@SR))
SET @SR=@SR+1
END
SELECT DISTINCT id,name,[add],@strDate AS dateEnterd from dbo.commadate 
DROP TABLE #TempcomDate


O/P
id	name	add	dateEnterd
1	ab	test	1988-08-23,1989-08-23,1990-08-23,1991-05-01