SQL Server 2019

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Microsoft SQL Server 2019 (RTM-CU6) (KB4563110) - 15.0.4053.23 (X64) 
	Jul 25 2020 11:26:55 
	Copyright (C) 2019 Microsoft Corporation
	Express Edition (64-bit) on Windows Server 2019 Standard 10.0 <X64> (Build 17763: ) (Hypervisor)



CREATE TABLE test (
    Sr     int
  , Date   Date
  , O      DECIMAL(8,2)
  , H      DECIMAL(8,2)
  , L      DECIMAL(8,2)
  , C      DECIMAL(8,2)
);
INSERT INTO test VALUES
  ( 1,'2020-09-15', 93.25, 93.30, 93.30, 93.25)
, ( 2,'2020-09-16', 98.55, 98.55, 98.55, 98.55)
, ( 3,'2020-09-17',100.98, 99.99,100.98, 99.99)
, ( 4,'2020-09-18',102.05,102.05,102.05,102.05)
, ( 5,'2020-09-19',103.00,103.90,103.90,103.00)
, ( 6,'2020-09-20',104.08,104.23,104.23,104.08)
, ( 7,'2020-09-21',104.90,104.60,105.00,104.00)
, ( 8,'2020-09-22',104.60,104.60,104.60,104.60)
, ( 9,'2020-09-23',105.90,105.90,105.90,105.90)
, (10,'2020-09-24',104.40,104.40,105.00,103.51)
, (11,'2020-09-25',105.18,105.18,105.18,105.18)
, (12,'2020-09-26',103.00,102.60,103.52,102.60)
, (13,'2020-09-27',100.00,100.00,100.00,100.00)
, (14,'2020-09-28', 99.40, 98.95, 99.78, 98.95)
, (15,'2020-09-29', 99.00, 99.00, 99.00, 99.00)
, (16,'2020-09-30',100.01,100.90,101.00,100.01)
, (17,'2020-10-01',102.00,102.70,102.70,102.00)
, (18,'2020-10-02',102.70,102.00,102.70,102.00)
, (19,'2020-10-03',103.30,103.30,103.30,103.30)
;
19 rows affected

WITH cte AS (
        SELECT *
             , (O + H + L + C)/4 AS Close_HA
          FROM test
     )
   , calc AS (
        SELECT t1.*, C AS Open_HA FROM cte AS t1 WHERE Sr = 1 UNION ALL
        SELECT t1.*
             , CAST((t2.Close_HA + t2.Open_HA) / 2.0 AS DECIMAL(8,2))
          FROM cte  AS t1
          JOIN calc AS t2
            ON t1.Sr = t2.Sr + 1
     )
SELECT * FROM calc ORDER BY Sr
;


Sr
Date
O
H
L
C
Close_HA
Open_HA


1
2020-09-15
93.25
93.30
93.30
93.25
93.275000
93.25

2
2020-09-16
98.55
98.55
98.55
98.55
98.550000
93.26

3
2020-09-17
100.98
99.99
100.98
99.99
100.485000
95.91

4
2020-09-18
102.05
102.05
102.05
102.05
102.050000
98.20

5
2020-09-19
103.00
103.90
103.90
103.00
103.450000
100.13

6
2020-09-20
104.08
104.23
104.23
104.08
104.155000
101.79

7
2020-09-21
104.90
104.60
105.00
104.00
104.625000
102.97

8
2020-09-22
104.60
104.60
104.60
104.60
104.600000
103.80

9
2020-09-23
105.90
105.90
105.90
105.90
105.900000
104.20

10
2020-09-24
104.40
104.40
105.00
103.51
104.327500
105.05

11
2020-09-25
105.18
105.18
105.18
105.18
105.180000
104.69

12
2020-09-26
103.00
102.60
103.52
102.60
102.930000
104.94

13
2020-09-27
100.00
100.00
100.00
100.00
100.000000
103.94

14
2020-09-28
99.40
98.95
99.78
98.95
99.270000
101.97

15
2020-09-29
99.00
99.00
99.00
99.00
99.000000
100.62

16
2020-09-30
100.01
100.90
101.00
100.01
100.480000
99.81

17
2020-10-01
102.00
102.70
102.70
102.00
102.350000
100.15

18
2020-10-02
102.70
102.00
102.70
102.00
102.350000
101.25

19
2020-10-03
103.30
103.30
103.30
103.30
103.300000
101.80

Sr	Date	O	H	L	C	Close_HA	Open_HA
1	2020-09-15	93.25	93.30	93.30	93.25	93.275000	93.25
2	2020-09-16	98.55	98.55	98.55	98.55	98.550000	93.26
3	2020-09-17	100.98	99.99	100.98	99.99	100.485000	95.91
4	2020-09-18	102.05	102.05	102.05	102.05	102.050000	98.20
5	2020-09-19	103.00	103.90	103.90	103.00	103.450000	100.13
6	2020-09-20	104.08	104.23	104.23	104.08	104.155000	101.79
7	2020-09-21	104.90	104.60	105.00	104.00	104.625000	102.97
8	2020-09-22	104.60	104.60	104.60	104.60	104.600000	103.80
9	2020-09-23	105.90	105.90	105.90	105.90	105.900000	104.20
10	2020-09-24	104.40	104.40	105.00	103.51	104.327500	105.05
11	2020-09-25	105.18	105.18	105.18	105.18	105.180000	104.69
12	2020-09-26	103.00	102.60	103.52	102.60	102.930000	104.94
13	2020-09-27	100.00	100.00	100.00	100.00	100.000000	103.94
14	2020-09-28	99.40	98.95	99.78	98.95	99.270000	101.97
15	2020-09-29	99.00	99.00	99.00	99.00	99.000000	100.62
16	2020-09-30	100.01	100.90	101.00	100.01	100.480000	99.81
17	2020-10-01	102.00	102.70	102.70	102.00	102.350000	100.15
18	2020-10-02	102.70	102.00	102.70	102.00	102.350000	101.25
19	2020-10-03	103.30	103.30	103.30	103.30	103.300000	101.80