sql 循环有关问题

sql 循环问题
帮忙解决呀，急呀。谢谢各位。
    Table
   ID     ProjectID   ParentProjectID              Projectname
  1                0                        Null                      平台0
  2                1                       Null                       平台1
3                   2                         0                           项目0-1
4                  3                          2                           项目0-1-1
5                 4                           3                           项目0-1-1-1
6                    5                        3                           项目0-1-1-2
7                    6                        1                          项目1-1
8                   7                         6                          项目1-1-1
9                      8                      7                           项目1-1-1-1


我如何通过sql语句去循环查询，平台0下面的所有归属于平台0的项目，如何查询归于项目0-1 下面的所有项目。
请各位帮忙指导，谢谢。
------解决方案--------------------

if object_id('tempdb..#TB1','U') is not null drop table #TB1
go 
CREATE TABLE #TB1
(
	ID INT
  ,  ProjectID INT
  ,ParentProjectID INT
  ,Projectname NVARCHAR(200)
)
INSERT INTO #TB1
SELECT  1,                0 ,                       Null  ,                    N'平台0'  union all
SELECT  2 ,               1  ,                     Null    ,                   N'平台1'  union all
SELECT 3 ,                 2    ,                     0,                           N'项目0-1'  union all
SELECT 4,                3,                          2 ,                          N'项目0-1-1'  union all