SQL CTE 递归 查询省，市，区

 IF OBJECT_ID('tb') IS NOT NULL
  DROP TABLE tb
create table tb(id varchar(3) , pid varchar(3) , name varchar(10))
insert into tb values('' , null  , '广东省')
insert into tb values('' , '' , '广州市')
insert into tb values('' , '' , '深圳市')
insert into tb values('' , '' , '天河区')
insert into tb values('' , '' , '罗湖区')
insert into tb values('' , '' , '福田区')
insert into tb values('' , '' , '宝安区')
insert into tb values('' , '' , '西乡镇')
insert into tb values('' , '' , '龙华镇')
insert into tb values('' , '' , '松岗镇')
GO
SELECT * FROM tb AS t

DECLARE @ID VARCHAR(3)
--查询ID = '001'的所有子节点
SET @ID = ''
;WITH Temp AS (
  SELECT id,pid,NAME FROM tb AS t WHERE t.id=@ID
  UNION ALL
  SELECT t2.id,t2.pid,t2.NAME FROM tb t2 INNER JOIN Temp tm on t2.pid=tm.ID
)
SELECT * FROM Temp AS t WHERE id!=@ID