Create table GroupInfo([Id] int,[GroupName] nvarchar(50),[ParentGroupId] int)

 Insert GroupInfo

 select 0,'某某大学',null union all

 select 1,'外语学院',0 union all

 select 2,'英语专业',1 union all

 select 3,'日语专业',1 union all

 select 4,'英语专业一班',2 union all

 select 5,'英语专业二班',2 union all

 select 6,'日语专业一班',3 union all

 select 7,'日语专业二班',3 union all

 select 8, '法学院',0 union all

 select 9, '刑法学专业',8 union all

 select 10,'经济法学专业',8 union all

 select 11,'刑法学专业一班',9 union all

 select 12,'刑法学专业二班',9 union all

 select 13,'经济法学专业一班',10 union all

 select 14,'经济法学专业二班',10 

 --根据指定的节点向下获取所有子节点

 with

 CTE

 as

 (

     select * from GroupInfo where Id=1

     union all

     select G.* from CTE inner join GroupInfo as G

     on CTE.Id=G.ParentGroupId

 )

 select * from CTE order by Id

 --根据指定的节点向上获取所有父节点

 with

 CTE

 as

 (

     select * from GroupInfo where Id=14

     union all

     select G.* from CTE inner join GroupInfo as G

     on CTE.ParentGroupId=G.Id

 )

 select * from CTE order by Id

 --构造递归路径

 with

 CTE

 as

 (

     select Id,GroupName,ParentGroupId,GroupPath=CAST( GroupName as nvarchar(max)) from GroupInfo where Id=1

     union all

     select G.*,CAST(CTE.GroupPath+'//'+G.GroupName as nvarchar(max)) as GroupPath from CTE

     inner join GroupInfo as G

     on CTE.Id=G.ParentGroupId

 )

 select * from CTE

 --通过id字段的字符串的拼接，形成sort字段，再通过sort排序，来实现同一分支上的节点放到一起

 WITH

 CTE

 AS

 (

     SELECT * ,CAST(RIGHT('' + CAST([Id] AS VARCHAR), 3) AS VARCHAR(MAX)) AS sort FROM GroupInfo

     WHERE ParentGroupId = 0

     UNION ALL

     SELECT   GroupInfo.* ,CAST(sort + RIGHT('' + CAST(GroupInfo.[Id] AS VARCHAR),3) AS VARCHAR(MAX)) AS sort

     FROM CTE

     INNER JOIN GroupInfo ON CTE.Id = GroupInfo.ParentGroupId

 )

 SELECT * FROM CTE ORDER BY sort 

 --查询节点层级

 WITH CTE AS (

     SELECT *,1 AS [Level] FROM GroupInfo WHERE ParentGroupId=0

     UNION ALL

     SELECT G.*,CTE.Level+1 FROM GroupInfo as G

     JOIN CTE ON CTE.Id =G.ParentGroupId

 )

 SELECT * FROM CTE