询问了一个同事才知道还有递归算法CTE，简单试用了一下，还不错。
(
indexid int,
textvalue nvarchar(20),
parentid int
)
插入一些测试数据：
insert into test values(1,'10',0)
insert into test values(2,'20',0)
insert into test values(3,'30',0)
insert into test values(4,'40',0)
insert into test values(5,'50',0)
insert into test values(10,'100',1)
insert into test values(11,'110',1)
insert into test values(12,'120',1)
insert into test values(100,'1000',10)
insert into test values(110,'1100',10)
insert into test values(120,'1200',10)
insert into test values(130,'1300',10)
insert into test values(1000,'10000',100)
insert into test values(1100,'11000',100)
insert into test values(1200,'12000',100)
insert into test values(1300,'13000',100)
insert into test values(20,'200',2)
insert into test values(21,'210',2)
insert into test values(22,'220',2)
insert into test values(200,'2000',20)
insert into test values(210,'2100',20)
执行测试Sql语句：
GO
WITH DirectReports (indexid, textvalue,parentid,Level)
AS
(
SELECT e.indexid, e.textvalue,e.parentid, 0 AS Level
FROM test AS e where indexid=1 --起始节点
UNION ALL
SELECT e.indexid, e.textvalue,e.parentid,Level + 1
FROM test AS e
INNER JOIN DirectReports AS d
ON e.parentid = d.indexid
)
SELECT indexid, textvalue,parentid,Level FROM DirectReports
GO
执行结果如图：