求一递归算法

[wzllin]

表结构
id parentid isdel
1 0
2 0
3 0
4 1
5 1
6 2
7 2
8 4
9 8
10 9
要求写一递归算法，输入某个id，把他的子项的isdel字段的值设为1
例如 输入 0，则表中的所以行的isdel都为1

[-狙击手-]

--生成测试数据
create table BOM(ID INT,PID INT,MSG VARCHAR(1000))
insert into BOM select 1,0,NULL
insert into BOM select 2,1,NULL
insert into BOM select 3,1,NULL
insert into BOM select 4,2,NULL
insert into BOM select 5,3,NULL
insert into BOM select 6,5,NULL
insert into BOM select 7,6,NULL
go

--创建用户定义函数用于取每个父节点下子节点的采购配置信息
create function f_getChild(@ID VARCHAR(10))
returns @t table(ID VARCHAR(10),PID VARCHAR(10),Level INT)
as
begin
    declare @i int
    set @i = 1
    insert into @t select ID,PID,@i from BOM where PID = @ID
    
    while @@rowcount<>0
    begin
        set @i = @i + 1
        
        insert into @t 
        select 
            a.ID,a.PID,@i 
        from 
            BOM a,@t b 
        where 
            a.PID=b.ID and b.Level = @i-1
    end
    return
end
go

--执行查询
select ID from dbo.f_getChild(3)
go

--输出结果
/*
ID
----
5
6
7
*/

update bom
set MSG  = 1
where id in(select ID from dbo.f_getChild(0) )

select * from bom



--删除测试数据
drop function f_getChild
drop table BOM

[fa_ge]

http://blog.csdn.net/fa_ge/archive/2007/11/21/1895742.aspx