/*
递归查询 塗聚文
---SQL Server 2005环境下的实现：
*/
--生成测试数据
create table Dept(ID int,ParentID int,msg varchar(20))
insert into Dept select 1,0,'d'
insert into Dept select 2,1,'s'
insert into Dept select 3,1,'nl'
insert into Dept select 4,2,'d'
insert into Dept select 5,3,'s'
insert into Dept select 6,5,'f'
insert into Dept select 7,6,'d'
go
select * from Dept
Declare @Id Int
Set @Id = 1; ---在此修改父节点
With RootNodeCTE(Id,ParentID,msg)
As
(
Select ID,ParentID,msg From Dept
Where ParentID In (@Id)
Union All
Select Dept.ID,Dept.ParentID,Dept.msg From RootNodeCTE
Inner Join Dept
On RootNodeCTE.Id = Dept.ParentID
)
Select * From RootNodeCTE
---SQL Server 2000环境下的实现：
--生成测试数据 塗聚文 Geovin Du
create table Dept(ID int,ParentID int,msg varchar(20))
insert into Dept select 1,0,'d'
insert into Dept select 2,1,'s'
insert into Dept select 3,1,'nl'
insert into Dept select 4,2,'d'
insert into Dept select 5,3,'s'
insert into Dept select 6,5,'f'
insert into Dept select 7,6,'d'
go
select * from Dept
--创建用户定义函数
Create function [dbo].[GetChild](@ID varchar(10))
returns @t table(ID varchar(10),ParentID varchar(10),msg varchar(20),Level int)
as
begin
declare @i int
set @i = 1
insert into @t select @ID,@ID,null,0 --当前级，本级，如果不要的话可以注释掉或再加个参数来选择操作
insert into @t select ID,ParentID,msg,@i from Dept where ParentID = @ID
while @@rowcount<>0
begin
set @i = @i + 1
insert into @t
select
a.ID,a.ParentID,a.msg,@i
from
Dept a,@t b
where
a.ParentID=b.ID and b.Level = @i-1
end
return
end
--执行查询
select ID from dbo.GetChild(2)
go
--删除测试数据
drop function GetChild
drop table Dept