SQL Server 2017

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CREATE TABLE Taco_Val
(
    ID          INT IDENTITY(1,1),
    AuditID     VARCHAR(5),
    CreditID    VARCHAR(10),
    TS          DATETIME,
    Val         BIT
);

INSERT INTO Taco_Val
VALUES
 ('a1', 1, '2018-08-09 19:24:39.823',   1),--> Started 
 ('ac', 1, '2018-08-09 20:53:07.273',   0),
 ('as', 1, '2018-08-09 21:04:40.670',   0),
 ('a9', 1, '2018-08-09 21:14:17.660',   1),--> Another Seq
 ('av', 1, '2018-08-09 21:38:56.910',   1),
 ('ad', 1, '2018-08-09 21:48:46.180',   1),
 ('an', 1, '2018-08-09 22:00:15.650',   0),
 ('a4', 1, '2018-08-09 22:08:26.517',   1),-->Another Seq
 ('a8', 1, '2018-08-09 22:16:16.253',   0),
 ('a3', 1, '2018-08-09 22:16:24.247',   1),-->Another Seq
 ('ai', 1, '2018-08-09 22:18:59.143',   1),
 ('a3', 1, '2018-08-09 22:42:48.780',   1),
 ('ao', 1, '2018-08-09 22:51:21.117',   1),
 ('am', 1, '2018-08-09 23:01:13.777',   0),
 ('ac', 1, '2018-08-09 23:07:13.237',   0),
 ('ab', 1, '2018-08-09 23:16:38.257',   0),
 ('ay', 1, '2018-08-10 15:12:02.473',   1),-->Another Seq
 ('ae', 1, '2018-08-10 15:20:54.263',   0);
18 rows affected

;WITH reset AS
(
SELECT AuditID, 
       CreditID, 
       TS, 
       Val,
       CASE WHEN Val=1 AND COALESCE(LAG(Val) OVER (PARTITION BY CreditID ORDER BY CreditID, TS), 0) = 0
            THEN 1 ELSE 0 END AS Rst        
FROM   Taco_Val
)
  , [group] AS
    (
    SELECT AuditID, 
           CreditID, 
           TS, 
           Val, 
           SUM(Rst) OVER (PARTITION BY CreditID ORDER BY CreditID, TS) AS Grp
    FROM   reset
    )
    SELECT (SELECT AuditID FROM [group] WHERE CreditID = g.CreditID AND TS = MIN(g.TS)) AuditID, 
           CreditID,
           MIN(TS) as StartTS, 
           1 as Val,
           DATEDIFF(MINUTE, MIN(TS), MAX(TS)) as Duration
    FROM   [group] g
    GROUP BY CreditID, Grp;


AuditID
CreditID
StartTS
Val
Duration


a1
1
2018-08-09 19:24:39.823
1
100

a9
1
2018-08-09 21:14:17.660
1
46

a4
1
2018-08-09 22:08:26.517
1
8

a3
1
2018-08-09 22:16:24.247
1
60

ay
1
2018-08-10 15:12:02.473
1
8


/* A reset point for 1st row of every partition or when 
  current val = 1 and previous = 0 */
SELECT AuditID, 
       CreditID, 
       TS, 
       Val,
       CASE WHEN Val=1 AND COALESCE(LAG(Val) OVER (PARTITION BY CreditID ORDER BY CreditID, TS), 0) = 0
            THEN 1 ELSE 0 END AS Rst        
FROM   Taco_Val


AuditID
CreditID
TS
Val
Rst


a1
1
2018-08-09 19:24:39.823
True
1

ac
1
2018-08-09 20:53:07.273
False
0

as
1
2018-08-09 21:04:40.670
False
0

a9
1
2018-08-09 21:14:17.660
True
1

av
1
2018-08-09 21:38:56.910
True
0

ad
1
2018-08-09 21:48:46.180
True
0

an
1
2018-08-09 22:00:15.650
False
0

a4
1
2018-08-09 22:08:26.517
True
1

a8
1
2018-08-09 22:16:16.253
False
0

a3
1
2018-08-09 22:16:24.247
True
1

ai
1
2018-08-09 22:18:59.143
True
0

a3
1
2018-08-09 22:42:48.780
True
0

ao
1
2018-08-09 22:51:21.117
True
0

am
1
2018-08-09 23:01:13.777
False
0

ac
1
2018-08-09 23:07:13.237
False
0

ab
1
2018-08-09 23:16:38.257
False
0

ay
1
2018-08-10 15:12:02.473
True
1

ae
1
2018-08-10 15:20:54.263
False
0


/* cumulative sum of each reset point */
;WITH reset AS
(
SELECT AuditID, 
       CreditID, 
       TS, 
       Val,
       CASE WHEN Val=1 AND COALESCE(LAG(Val) OVER (PARTITION BY CreditID ORDER BY CreditID, TS), 0) = 0
            THEN 1 ELSE 0 END AS Rst        
FROM   Taco_Val
)
    SELECT AuditID, 
           CreditID, 
           TS, 
           Val, 
           SUM(Rst) OVER (PARTITION BY CreditID ORDER BY CreditID, TS) AS Grp
    FROM   reset


AuditID
CreditID
TS
Val
Grp


a1
1
2018-08-09 19:24:39.823
True
1

ac
1
2018-08-09 20:53:07.273
False
1

as
1
2018-08-09 21:04:40.670
False
1

a9
1
2018-08-09 21:14:17.660
True
2

av
1
2018-08-09 21:38:56.910
True
2

ad
1
2018-08-09 21:48:46.180
True
2

an
1
2018-08-09 22:00:15.650
False
2

a4
1
2018-08-09 22:08:26.517
True
3

a8
1
2018-08-09 22:16:16.253
False
3

a3
1
2018-08-09 22:16:24.247
True
4

ai
1
2018-08-09 22:18:59.143
True
4

a3
1
2018-08-09 22:42:48.780
True
4

ao
1
2018-08-09 22:51:21.117
True
4

am
1
2018-08-09 23:01:13.777
False
4

ac
1
2018-08-09 23:07:13.237
False
4

ab
1
2018-08-09 23:16:38.257
False
4

ay
1
2018-08-10 15:12:02.473
True
5

ae
1
2018-08-10 15:20:54.263
False
5

AuditID	CreditID	StartTS	Val	Duration
a1	1	2018-08-09 19:24:39.823	1	100
a9	1	2018-08-09 21:14:17.660	1	46
a4	1	2018-08-09 22:08:26.517	1	8
a3	1	2018-08-09 22:16:24.247	1	60
ay	1	2018-08-10 15:12:02.473	1	8

AuditID	CreditID	TS	Val	Rst
a1	1	2018-08-09 19:24:39.823	True	1
ac	1	2018-08-09 20:53:07.273	False	0
as	1	2018-08-09 21:04:40.670	False	0
a9	1	2018-08-09 21:14:17.660	True	1
av	1	2018-08-09 21:38:56.910	True	0
ad	1	2018-08-09 21:48:46.180	True	0
an	1	2018-08-09 22:00:15.650	False	0
a4	1	2018-08-09 22:08:26.517	True	1
a8	1	2018-08-09 22:16:16.253	False	0
a3	1	2018-08-09 22:16:24.247	True	1
ai	1	2018-08-09 22:18:59.143	True	0
a3	1	2018-08-09 22:42:48.780	True	0
ao	1	2018-08-09 22:51:21.117	True	0
am	1	2018-08-09 23:01:13.777	False	0
ac	1	2018-08-09 23:07:13.237	False	0
ab	1	2018-08-09 23:16:38.257	False	0
ay	1	2018-08-10 15:12:02.473	True	1
ae	1	2018-08-10 15:20:54.263	False	0