--参考一下实例
--> 生成测试数据表:tb
IF NOT OBJECT_ID('[tb]') IS NULL
 DROP TABLE [tb]
GO
CREATE TABLE [tb](GUID INT IDENTITY,[col1] NVARCHAR(10),[col2] NVARCHAR(20))
INSERT [tb]
SELECT N'A','01' UNION ALL
SELECT N'B','01.01' UNION ALL
SELECT N'C','01.01.01' UNION ALL
SELECT N'F','01.01.01.01' UNION ALL
SELECT N'E','01.01.01.02' UNION ALL
SELECT N'D','01.01.01.03' UNION ALL
SELECT N'O','02' UNION ALL
SELECT N'P','02.01' UNION ALL
SELECT N'Q','02.01.01' 
GO
--SELECT * FROM [tb]

-->SQL查询如下:

---另一种方法
;WITH T AS
(
   SELECT *,PATH=CAST([COL1] AS VARCHAR(1000)) FROM TB A
       WHERE NOT EXISTS(
        SELECT 1 FROM TB 
     WHERE A.COL2 LIKE COL2+'%' 
   AND LEN(A.COL2)>LEN(COL2))
   UNION ALL
   SELECT A.*,CAST(PATH+'-->'+A.COL1 AS VARCHAR(1000))
   FROM TB A 
   JOIN T B 
        ON A.COL2 LIKE B.COL2+'%' 

           AND LEN(A.COL2)-3=LEN(B.COL2)
)

SELECT * FROM T ORDER BY LEFT(COL2,2)

/*

GUID        COL1        COL2                  PATH

----------- ---------- -------------------- --------------------

1           A          01                   A

2           B          01.01                A-->B

3           C          01.01.01             A-->B-->C

4           F          01.01.01.01          A-->B-->C-->F

5           E          01.01.01.02          A-->B-->C-->E

6           D          01.01.01.03          A-->B-->C-->D

7           O          02                   O

8           P          02.01                O-->P

9           Q          02.01.01             O-->P-->Q
(9 行受影响)

*/


;WITH T AS

(
    SELECT *,CAST(COL1  AS VARCHAR(1000)) AS PATH
    FROM  TB 
    WHERE COL2 NOT LIKE '%.%'
    UNION ALL
    SELECT A.*,CAST(B.PATH+'-->'+A.COL1 AS VARCHAR(1000))
    FROM TB A,T B
    WHERE A.COL2 LIKE B.COL2+'.[01-99][01-99]'
)

SELECT * FROM T 
ORDER BY LEFT(COL2,2)

/*

GUID        COL1        COL2                  PATH

----------- ---------- -------------------- --------------------

1           A          01                   A

2           B          01.01                A-->B

3           C          01.01.01             A-->B-->C

4           F          01.01.01.01          A-->B-->C-->F

5           E          01.01.01.02          A-->B-->C-->E

6           D          01.01.01.03          A-->B-->C-->D

7           O          02                   O

8           P          02.01                O-->P

9           Q          02.01.01             O-->P-->Q

 (9 行受影响)

*/