SQL Server 2012

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select @@version;


(No column name)


Microsoft SQL Server 2012 (SP4) (KB4018073) - 11.0.7001.0 (X64) 
	Aug 15 2017 10:23:29 
	Copyright (c) Microsoft Corporation
	Express Edition (64-bit) on Windows NT 6.3 <X64> (Build 9600: ) (Hypervisor)



CREATE TABLE [dbo].[MyTable] (
	[ID] [int] NOT NULL,
	[Price] [float] NOT NULL
)
INSERT INTO MyTable (ID, Price) 
VALUES 
(1,10),
 (2,9),
 (3,11),
 (4,8),
 (5,9),
 (6,11),
 (7,12),
 (8,7),
 (9,13),
 (10,15),
 (11,16),
 (12,21),
 (13,18),
 (14,20)
14 rows affected

--
select * 
  from MyTable 
 order by id
 


ID
Price


1
10

2
9

3
11

4
8

5
9

6
11

7
12

8
7

9
13

10
15

11
16

12
21

13
18

14
20


--
select id
     , price
     , row_number() over(partition by grp_id order by id) as [order]
  from (
         select id
              , price
              , sum(start_of_group) over(order by id) as grp_id
           from (
                  select id
                       , price
                       , case 
                           when lag(price)over(order by id) <= price then 0 else 1
                         end as start_of_group
                    from MyTable
                ) v0
       ) v1
 order by id
 


id
price
order


1
10
1

2
9
1

3
11
2

4
8
1

5
9
2

6
11
3

7
12
4

8
7
1

9
13
2

10
15
3

11
16
4

12
21
5

13
18
1

14
20
2