最近，在论坛中，遇到了不少比较难的sql问题，虽然自己都能解决，但发现过几天后，就记不起来了，也忘记解决的方法了。
所以，觉得有必要记录下来，这样以后再次碰到这类问题，也能从中获取解答的思路。
sql2008 树形结构分组
http://bbs.csdn.net/topics/390634930
ID DeprtID DeprtName
1 0 1
2 1 2
3 1 3
4 2 4
5 3 5
6 4 6
7 5 7
分组后效果
ID DeprtID DeprtName
1 0 1
2 1 2
4 2 4
6 4 6
3 1 3
5 3 5
7 5 7
我的解法：
-
--drop table tb
-
-
create
table tb(
ID
int, DeprtID
int, DeprtName
varchar(
10))
-
-
insert
into tb
-
select
1,
0,
'1'
-
union all
select
2 ,
1 ,
'2'
-
union all
select
3 ,
1 ,
'3'
-
union all
select
4 ,
2 ,
'4'
-
union all
select
5 ,
3 ,
'5'
-
union all
select
6 ,
4 ,
'6'
-
union all
select
7 ,
5,
'7'
-
go
-
-
-
;with t
-
as
-
(
-
select
id,DeprtID,DeprtName,
1
as
level,
-
cast(
right(
'000'+
cast(
id
as
varchar),
3)
as
varchar(
max))
as
sort
-
from tb
-
where DeprtID =
0
-
-
union all
-
-
select tb.id,tb.DeprtID,tb.DeprtName,
level +
1 ,
-
cast(
sort+
right(
'000'+
cast(tb.id
as
varchar),
3)
as
varchar(
max))
-
from t
-
inner
join tb
-
on t.id = tb.DeprtID
-
)
-
-
select
id,deprtid,deprtname
-
from t
-
order
by
sort
-
/*
-
id deprtid deprtname
-
1 0 1
-
2 1 2
-
4 2 4
-
6 4 6
-
3 1 3
-
5 3 5
-
7 5 7
-
*/
这里还有个例子，就是递归查询后，按照树形来排序：
-
drop
table tb
-
-
create
table tb
-
(
-
id
int,
-
pid
int,
-
name
varchar(
20)
-
)
-
-
insert
into tb
-
select
1,
null,
'x'
-
union all
select
2,
1,
'a'
-
union all
select
3,
1,
'b'
-
union all
select
4,
2,
'aa'
-
union all
select
5,
3,
'bb'
-
go
-
-
-
;with t
-
as
-
(
-
select
id,pid,
name,
1
as
level,
-
cast(
right(
'000'+
cast(
id
as
varchar),
3)
as
varchar(
max))
as
sort
-
from tb
-
where pid
is
null
-
-
union all
-
-
select tb.id,tb.pid,tb.name,
level +
1 ,
-
cast(
sort+
right(
'000'+
cast(tb.id
as
varchar),
3)
as
varchar(
max))
-
from t
-
inner
join tb
-
on t.id = tb.pid
-
)
-
-
select *
-
from t
-
order
by
sort
-
/*
-
id pid name level sort
-
1 NULL x 1 001
-
2 1 a 2 001002
-
4 2 aa 3 001002004
-
3 1 b 2 001003
-
5 3 bb 3 001003005
-
*/
