单表删除某条数据的所有子数据

表结构如下：

删除 id=1的数据，注意 此时要删除其所有子数据：其中还应包括pid='1','11','111'的数据

查询出与 id=1 相关的所有的数据id：

//==================

WITH Emp AS (
SELECT
ID,
Pid
FROM
City 
WHERE
ID = '1'
UNION ALL
SELECT
d.ID,
d.Pid
FROM
Emp
INNER JOIN City c ON c.Pid = Emp.ID
) SELECT
ID
FROM

Emp

//=========================

删除语句：

WITH Emp AS (

                        SELECT ID , Pid FROM City 

                        WHERE ID ='1' 

                        UNION ALL 

                            SELECT d.ID ,d.Pid FROM Emp 

                             INNER JOIN City d ON d.Pid = Emp.ID

                        ) 

                 DELETE City WHERE ID IN (SELECT ID FROM Emp)