SQL2005的CTE

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use  test
go
if   object_id ( ' Tempdb..#T ' )  is   not   null
     drop   table  #T
create   table  #T(ID  int ,Name  nvarchar ( 100 ),parentID  int )
insert  #T  select   1 , ' A ' , 0
insert  #T  select   2 , ' B ' , 1
insert  #T  select   3 , ' C ' , 1
insert  #T  select   4 , ' D ' , 3
insert  #T  select   5 , ' E ' , 2

go

with  t2(ID,Name,parentID,Ord,Lev)
as
( select   * ,Ord = cast ( right ( ' 0000 ' + rtrim (ID), 4 )  as   nvarchar ( max )),Lev = cast ( 0   as   int )  from  #T  where  ParentID = 0
union   all
select  b. * ,Ord = a.Ord + cast ( right ( ' 0000 ' + rtrim (b.ID), 4 )  as   nvarchar ( max )),Lev = cast (a.Lev + 1   as   int ) from  #T b  join  t2  a  on  b.ParentID = a.ID
)
select  顯示 = replicate ( char ( 9 ),lev) + Name  from  T2  order   by  ord  option (maxrecursion  0 ) -- 用空格替換制表符時用space(lev*2)/replicate(char(9),lev)

/**/ /*
顯示
---------------------------------
A
  B
    E
  C
    D

(5 個資料列受到影響)
*/


; with  t2
as
( select   * ,Ord = cast (Name  as   nvarchar ( max )),lev = 0   from  #T  where  ParentID = 0
union   all
select  b. * ,Ord = cast (a.Ord + char ( 9 ) + b.Name  as   nvarchar ( max )),a.lev + 1   from  #T b  join  t2  a  on  b.ParentID = a.ID 
)
select  
     [ 顯示 ] = Ord 
from  
    T2
order   by  ord 
option (maxrecursion  0 )
/**/ /*

顯示
--------------------
A
A    B
A    B    E
A    C
A    C    D

(5 個資料列受到影響)

*/

-- 2005多次调用连接时:
/**/ /*
;with T(COl)--可指定列名也可不指定
as
(......)
,T2(Co)
as
(......)
select * from T1 a join T2 b on a.Col=b.COl
*/