create table tb(ID int, DATETIME datetime ,code varchar(2))  
insert into tb values('1','2012-7-7','A')  
insert into tb values('1','2012-7-7','B')  
insert into tb values('1','2012-7-17','C')  
insert into tb values('1','2012-7-24','D' )  
go  
  
select ID, CODE,[DATETIME]=stuff((select ','+[DATETIME] from tb  where ID=tb.ID for xml path('')), 1, 1, '')  
from tb  
group by ID 
  
/*  
ID    A     B       C          D
  
----------- --------------------  
1  2012-7-7 2012-7-7 2012-7-17 2012-7-24

------解决方案--------------------

http://topic.csdn.net/u/20080612/22/c850499f-bce3-4877-82d5-af2357857872.html

------解决方案--------------------

SQL code
if object_id('[tb]') is not null drop table [tb]
go
create table [tb]([ID] int,[DATETIME] datetime,[CODE] varchar(1))
insert [tb]
select 1,'2012-7-7','A' union all
select 1,'2012-7-7','B' union all
select 1,'2012-7-17','C' union all
select 1,'2012-7-24','D' union all
select 2,'2012-7-11','A' union all
select 2,'2012-7-11','B' union all
select 3,'2012-7-16','A' union all
select 3,'2012-7-16','B' union all
select 3,'2012-7-17','C' union all
select 3,'2012-7-23','D'
go

declare @sql varchar(8000)
select @sql=isnull(@sql+',','')
  +'max(case when code='''+code+''' then convert(varchar(10),datetime,120) end) as ['+code+']'
from
(select distinct code from tb) t

exec('select id,'+@sql+' from tb group by id')

/**
id          A          B          C          D
----------- ---------- ---------- ---------- ----------
1           2012-07-07 2012-07-07 2012-07-17 2012-07-24
2           2012-07-11 2012-07-11 NULL       NULL
3           2012-07-16 2012-07-16 2012-07-17 2012-07-23

(3 行受影响)

**/