树型结构数据，求某结点的所有父结点的自定义函数

CREATE FUNCTION f_father(@dpcode varchar(9)) /*树型结构数据，求某结点的所有父结点的自定义函数*/
RETURNS @new table([dpcode] [varchar] (9) , --结点编码
[dpname] [varchar] (20) , --结点名称
[dpcode_p] [varchar] (9) --此结点的父结点编码
) AS
BEGIN
declare @temp table([dpcode] [varchar] (9) , --结点编码
[dpname] [varchar] (20) , --结点名称
[dpcode_p] [varchar] (9) --此结点的父结点编码
) --数据临时存放表
declare @t table([dpcode] [varchar] (9) , --结点编码
[dpname] [varchar] (20) , --结点名称
[dpcode_p] [varchar] (9) --此结点的父结点编码
) --中间临时表
declare @tt table([dpcode] [varchar] (9) , --结点编码
[dpname] [varchar] (20) , --结点名称
[dpcode_p] [varchar] (9) --此结点的父结点编码
) --中间交换临时表

delete @temp
delete @t
delete @tt
delete @new

insert into @temp select DPTCODE, DPTNAME, DPTCODE_P from base_dept
insert into @t select * from @temp where dpcode=@dpcode
insert into @new select * from @t --结果临时表
while ( 1=1)

begin
if (exists(select * from @t where dpcode ='001')) --当为根时，停止循环
begin
break
end
insert into @tt select * from @t --中间交换临时表
delete @t
insert into @t select * from @temp where dpcode in
(select dpcode_p from @tt)
delete @tt
insert into @new select * from @t
end
--insert into @new select * from @temp where dpcode=@dpcode

return
END