BOM 创建用户定义函数,每个子节点de父节点的信息

--生成测试数据
createtable BOM(ID int,parentID int,sClassName varchar(10))
insertinto BOM values(1,0,'1111'      )
insertinto BOM values(2,1,'1111_1'    )
insertinto BOM values(3,2,'1111-1-1'  )
insertinto BOM values(4,3,'1111-1-1-1')
insertinto BOM values(5,1,'1111-2'    )

go

--创建用户定义函数,每个子节点de父节点的信息
createfunction f_getParent(@IDint)
returnsvarchar(40)
as
begin
    declare@retvarchar(40)

    whileexists(select1from BOM where ID=@IDand parentID<>0)
    begin
        select@ID=b.ID,@ret=','+rtrim(b.ID)+isnull(@ret,'')
        from
            BOM a,BOM b
        where
            a.ID=@IDand b.ID=a.parentID
    end
   
    set@ret=stuff(@ret,1,1,'')
    return@ret
end
go

--执行查询
select ID,isnull(dbo.f_getParent(ID),'') as parentID from BOM
go

--输出结果
/*
ID          parentID                                
----------- ----------------------------------------
1          
2           1
3           1,2
4           1,2,3
5           1  
*/

--删除测试数据
dropfunction f_getParent
droptable BOM
go