级联编码如何生成
现有分类表,字段:TypeID(int)   类型ID,TypeParentTypeID(int)类型的父ID,strText(varchar)内容,strFullLevelCode(varchar)ID级联码
如:
TypeID     TypeParentTypeID       strText       strFullLevelCode
1               0                                     a                   1
2               0                                     b                   2
10             1                                     c                   1.10    
20             2                                     d                   2.20
30             10                                   e                   1.10.30
40             30                                   f                   1.10.30.40
.
.
.
问:strFullLevelCode字段里的值,如何用程序实现.
请大虾赐教

------解决方案--------------------
create table t (TypeID int,TypeParentTypeID int,strText varchar(10))
insert into t select 1,0, 'a '
union all select 2,0, 'b '
union all select 10,1, 'c '
union all select 20,2, 'd '
union all select 30,10, 'e '
union all select 40,30, 'f ';
go
create function f_getstr(@TypeID int)
returns varchar(20)
as
begin
declare @returns varchar(20)
set @returns= ' ';
with cte_t(TypeID,TypeParentTypeID,lev)
as
(
select TypeID,TypeParentTypeID,0
from t where TypeID=@TypeID
union all
select a.TypeID,a.TypeParentTypeID,b.lev+1
from t a inner join cte_t b
on a.TypeID=b.TypeParentTypeID
)
select @returns=@returns+ '. '+ltrim(TypeID) from cte_t
order by TypeID
return stuff(@returns,1,1, ' ')
end
go
select TypeID,TypeParentTypeID,strFullLevelCode=dbo.f_getstr(TypeID) from t
go
drop function f_getstr
drop table t
go

/*
TypeID TypeParentTypeID strFullLevelCode
----------- ---------------- --------------------
1 0 1
2 0 2
10 1 1.10
20 2 2.20
30 10 1.10.30
40 30 1.10.30.40

(6 行受影响)

*/
------解决方案--------------------
strFullLevelCode(varchar)ID级联码
create table ta(TypeID int, TypeParentTypeID int, strText varchar(2) )
insert ta select 1, 0, 'a '
insert ta select 2, 0, 'b '
inser