--生成测试数据 
create table tb(id varchar(3) , pid varchar(3) , name varchar(10))
insert into tb values('001' , null  , '广东省')
insert into tb values('002' , '001' , '广州市')
insert into tb values('003' , '001' , '深圳市')
insert into tb values('004' , '002' , '天河区')
insert into tb values('005' , '003' , '罗湖区')
insert into tb values('006' , '003' , '福田区')
insert into tb values('007' , '003' , '宝安区')
insert into tb values('008' , '007' , '西乡镇')
insert into tb values('009' , '007' , '龙华镇')
insert into tb values('010' , '007' , '松岗镇')
go

--创建用户定义函数 
create function f_cid(@id varchar(10)) returns varchar(8000) 
as 
begin 
  declare @i int , @ret varchar(8000) 
  declare @t table(id varchar(10) , pid varchar(10) , level int) 
  set @i = 1 
  insert into @t select id , pid , @i from tb where id = @id 
  while @@rowcount <> 0 
  begin 
    set @i = @i + 1 
    insert into @t select a.id , a.pid , @i from tb a , @t b where a.pid = b.id and b.level = @i - 1
  end 
  select @ret = isnull(@ret , '') + id + ',' from @t 
  return left(@ret , len(@ret) - 1)
end 
go 

--执行查询 
select id , children = isnull(dbo.f_cid(id) , '') from tb group by id

drop table tb
drop function f_cid

/*
id   children                               
---- ---------------------------------------
001  001,002,003,004,005,006,007,008,009,010
002  002,004
003  003,005,006,007,008,009,010
004  004
005  005
006  006
007  007,008,009,010
008  008
009  009
010  010*/

（所影响的行数为 10 行）


create table tb(id varchar(3) , pid varchar(3) , name nvarchar(10))
insert into tb values('001' , null  , N'广东省')
insert into tb values('002' , '001' , N'广州市')
insert into tb values('003' , '001' , N'深圳市')
insert into tb values('004' , '002' , N'天河区')
insert into tb values('005' , '003' , N'罗湖区')
insert into tb values('006' , '003' , N'福田区')
insert into tb values('007' , '003' , N'宝安区')
insert into tb values('008' , '007' , N'西乡镇')
insert into tb values('009' , '007' , N'龙华镇')
insert into tb values('010' , '007' , N'松岗镇')
go

;with t as
(
    select id , cid = id from tb 
    union all
    select t.id , cid = tb.id 
    from t join tb on tb.pid = t.cid 
)
select id , cid = STUFF((SELECT ',' + rtrim(cid) FROM t WHERE id = tb.id FOR XML PATH('')) , 1 , 1 , '')
from tb
group by id
order by id
/*
id   cid
---- ---------------------------------------
001  001,002,003,005,006,007,008,009,010,004
002  002,004
003  003,005,006,007,008,009,010
004  004
005  005
006  006
007  007,008,009,010
008  008
009  009
010  010

(10 行受影响)
*/

;with t as
(
    select id , name , cid = id , path = cast(name as nvarchar(100)) from tb 
    union all
    select t.id , t.name , cid = tb.id , path = cast(tb.name as nvarchar(100))
    from t join tb on tb.pid = t.cid 
)
select id , name , 
       cid = STUFF((SELECT ',' + rtrim(cid) FROM t WHERE id = tb.id FOR XML PATH('')) , 1 , 1 , ''),
       path = STUFF((SELECT ',' + path FROM t WHERE id = tb.id FOR XML PATH('')) , 1 , 1 , '')
from tb
group by id , name
order by id
/*
id   name       cid                                         path
---- ---------- ------------------------------------------- ---------------------------------
001  广东省     001,002,003,005,006,007,008,009,010,004     广东省,广州市,深圳市,罗湖区,福田区,宝安区,西乡镇,龙华镇,松岗镇,天河区
002  广州市     002,004                                     广州市,天河区
003  深圳市     003,005,006,007,008,009,010                 深圳市,罗湖区,福田区,宝安区,西乡镇,