Я пытаюсь ответить на пробелы и острова, используя столбец «Идентификатор приращения», создаю его, если он не существует, и оконную функцию ROW_NUMBER
CREATE TABLE T1
([equipmentNumber] int, [snapshotDate] datetime, [status] varchar(6), [previousSnapshotDate] datetime, [prevStatus] varchar(9), [statusChangeFlag] int)
;
INSERT INTO T1
([equipmentNumber], [snapshotDate], [status], [previousSnapshotDate], [prevStatus], [statusChangeFlag])
VALUES
(123456, '2018-04-29 00:00:00', 'ONHIRE', '2018-04-28 00:00:00', 'AVAILABLE', 1),
(123456, '2018-04-30 00:00:00', 'ONHIRE', '2018-04-29 00:00:00', 'ONHIRE', 0),
(123456, '2018-05-01 00:00:00', 'ONHIRE', '2018-04-30 00:00:00', 'ONHIRE', 0),
(123456, '2018-05-02 00:00:00', 'REPAIR', '2018-05-01 00:00:00', 'ONHIRE', 1),
(123456, '2018-05-03 00:00:00', 'REPAIR', '2018-05-02 00:00:00', 'REPAIR', 0),
(123456, '2018-05-04 00:00:00', 'ONHIRE', '2018-05-03 00:00:00', 'REPAIR', 1),
(654321, '2018-04-30 00:00:00', 'REPAIR', '2018-04-29 00:00:00', 'AVAILABLE', 1),
(654321, '2018-05-01 00:00:00', 'REPAIR', '2018-04-30 00:00:00', 'REPAIR', 0),
(654321, '2018-05-02 00:00:00', 'REPAIR', '2018-05-01 00:00:00', 'REPAIR', 0)
;
;WITH cteX
AS(
SELECT
Id = ROW_NUMBER()OVER(ORDER BY T.equipmentNumber, T.snapshotDate)
,T.equipmentNumber
,T.snapshotDate
,T.[status]
,T.previousSnapshotDate
,T.prevStatus
,T.statusChangeFlag
FROM dbo.T1 T
),cteIsland
AS(
SELECT
Island = X.Id - ROW_NUMBER()OVER(ORDER BY X.Id)
,*
FROM cteX X
WHERE X.[status] = 'REPAIR'
)
SELECT * FROM cteIsland
Обратите внимание на столбец Island
Island Id equipmentNumber status
3 4 123456 REPAIR
3 5 123456 REPAIR
4 7 654321 REPAIR
4 8 654321 REPAIR
4 9 654321 REPAIR
Используя столбец Island
, вы можете получить необходимый ответ с помощью этого TSQL
;WITH cteX
AS(
SELECT
Id = ROW_NUMBER()OVER(ORDER BY T.equipmentNumber, T.snapshotDate)
,T.equipmentNumber
,T.snapshotDate
,T.[status]
,T.previousSnapshotDate
,T.prevStatus
,T.statusChangeFlag
FROM dbo.T1 T
),cteIsland
AS(
SELECT
Island = X.Id - ROW_NUMBER()OVER(ORDER BY X.Id)
,*
FROM cteX X
WHERE X.[status] = 'REPAIR'
)
SELECT
AvgDuration =SUM(Totals.IslandCounts) / (COUNT(Totals.IslandCounts) * 1.0)
FROM
(
SELECT
IslandCounts = COUNT(I.Island)
,I.equipmentNumber
FROM cteIsland I
GROUP BY I.equipmentNumber
) Totals
Ответ
AvgDuration
2.50000000000000
Вот SQLFiddle