CREATE TABLE BOM(PID INT,ID INT)
INSERT INTO BOM SELECT 801,101
INSERT INTO BOM SELECT 801,102
INSERT INTO BOM SELECT 801,103
INSERT INTO BOM SELECT 801,601
INSERT INTO BOM SELECT 601,101
INSERT INTO BOM SELECT 601,105
INSERT INTO BOM SELECT 601,501
INSERT INTO BOM SELECT 501,106
INSERT INTO BOM SELECT 501,121
GO

CREATE FUNCTION F_GETROOT(@PID INT)
RETURNS INT
AS
BEGIN
    DECLARE @ID INT
    WHILE EXISTS(SELECT 1 FROM BOM WHERE ID=@PID)
    BEGIN
        SET @ID=@PID
        SELECT @PID=PID FROM BOM WHERE ID=@ID
    END
    RETURN @PID
END
GO

SELECT PID=DBO.F_GETROOT(PID),ID FROM BOM
GO

/*
PID         ID
----------- ----------- 
801         101
801         102
801         103
801         601
801         101
801         105
801         501
801         106
801         121
*/


DROP FUNCTION F_GETROOT
DROP TABLE BOM
GO




--生成测试数据
create table BOM_1(Item int,bom_head varchar(20),bom_child varchar(20),number int,products_attribute  varchar(20))
insert into BOM_1 select 1 ,'A' ,'A1',1,'采购'
insert into BOM_1 select 2 ,'A' ,'A2',2,'生产'
insert into BOM_1 select 3 ,'A2','A3',3,'生产'
insert into BOM_1 select 4 ,'A2','A4',2,'采购'
insert into BOM_1 select 5 ,'A3','A5',2,'采购'
insert into BOM_1 select 6 ,'A3','A6',1,'采购'
insert into BOM_1 select 7 ,'B' ,'B1',1,'采购'
insert into BOM_1 select 8 ,'B' ,'B2',2,'生产'
insert into BOM_1 select 9 ,'B2','B3',3,'生产'
insert into BOM_1 select 10,'B2','B4',2,'采购'
insert into BOM_1 select 11,'B3','B5',2,'采购'
insert into BOM_1 select 12,'B3','B6',2,'采购'
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_stock(@bom_head varchar(20))
returns @t table(bom varchar(20),number int)
as
begin 
    declare @level int
    declare @a table(bom varchar(20),number int,products_attribute varchar(20),[level] int)
    set @level=1

    if exists(select 1 from BOM_1 where bom_head=@bom_head)    
    insert into @a 
    select bom_child,number,products_attribute,@level 
    from BOM_1 
    where bom_head=@bom_head
    
    while exists(select 1 from @a where [level]=@level and products_attribute='生产')
    begin
        set @level=@level+1
        insert into @a(bom,number,products_attribute,[level])
        select a.bom_child,a.number,a.products_attribute,@level 
        from BOM_1 a,@a b
        where a.bom_head=b.bom and b.[level]=@level-1
    end
    
    insert into @t(bom,number) select bom,number from @a where products_attribute='采购'
    return
end
go


--执行调用，取父节点'A'一个标准配置分解的采购信息及数量
select * from dbo.f_stock('A')






--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
*/

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

with Tree 
as
(select * from T where preid=0 --為0
union all
select a.* from T a join Tree b on b.ID=a.preid)
select * from Tree

declare @T table([id] int,[preid] int)
Insert @T
select 1,0 union all
select 2,1 union all
select 3,1 union all
select 4,3 union all
select 5,3 union all
select 6,5 union all
select 7,6
;with Tree 
as
(select * from @T where preid=1 --如1時
union all
select a.* from @T a join Tree b on b.ID=a.preid)
select * from Tree


(7 個資料列受到影響)
id          preid
----------- -----------
2           1
3           1
4           3
5           3
6           5
7           6

(6 個資料列受到影響)

declare @T table([id] int,[preid] int)
Insert @T
select 1,0 union all
select 2,1 union all
select 3,1 union all
select 4,3 union all
select 5,3 union all
select 6,5 union all
select 7,6;

declare @i int 
set @i=1;

with cet 
as
(
select * from @t
where id=@i
union all
select a.* from @t a,cet b
where a.preid=b.id
)
select * from cet

id          preid
----------- -----------
1           0
2           1
3           1
4           3
5           3
6           5
7           6

(7 行受影响)

DECLARE @t TABLE(ID char(3),PID char(3),Name nvarchar(10))
INSERT @t SELECT '001',NULL ,'山东省'
UNION ALL SELECT '002','001','烟台市'
UNION ALL SELECT '004','002','招远市'
UNION ALL SELECT '003','001','青岛市'
UNION ALL SELECT '005',NULL ,'四川省'
UNION ALL SELECT '006','005','清远市'
UNION ALL SELECT '007','006','小分市'
declare @id char(3)
set @id='002'
declare @t_level table(id char(3),pid char(3),level int)
declare @level int
set @level=1
 insert @t_level select id,pid,@level  from @t where pid=@id
 while @@rowcount>0
  begin
   set @level=@level +1
   insert into @t_level 
   select a.[id], a.pid ,@level 
   from @t a , @t_level b
    where a.pid =b.[id] and b.[level]=@level-1
  end
 select * from @t_level