Group up rows based on date overlapping - sql-server

Question

In a same id, if any of row's effective date and enddate overlaps then we need group it up in a unique id
In below image dategroup is the desired output column
Data is sorted in order by ID asc, EffectiveDate ASC, EndDate Desc
CREATE TABLE #DataTable (id int , EffectiveDate datetime, Enddate Datetime )
INSERT [dbo].#DataTable ([id], [EffectiveDate], [Enddate]) VALUES (1, CAST(N'2017-01-01 00:00:00.000' AS DateTime), CAST(N'2017-01-11 00:00:00.000' AS DateTime))
GO
INSERT [dbo].#DataTable ([id], [EffectiveDate], [Enddate]) VALUES (1, CAST(N'2017-01-02 00:00:00.000' AS DateTime), CAST(N'2017-01-05 00:00:00.000' AS DateTime))
GO
INSERT [dbo].#DataTable ([id], [EffectiveDate], [Enddate]) VALUES (1, CAST(N'2017-01-03 00:00:00.000' AS DateTime), CAST(N'2017-01-12 00:00:00.000' AS DateTime))
GO
INSERT [dbo].#DataTable ([id], [EffectiveDate], [Enddate]) VALUES (1, CAST(N'2017-01-06 00:00:00.000' AS DateTime), CAST(N'2017-01-09 00:00:00.000' AS DateTime))
GO
INSERT [dbo].#DataTable ([id], [EffectiveDate], [Enddate]) VALUES (1, CAST(N'2017-01-13 00:00:00.000' AS DateTime), CAST(N'2017-01-19 00:00:00.000' AS DateTime))
GO
INSERT [dbo].#DataTable ([id], [EffectiveDate], [Enddate]) VALUES (2, CAST(N'2017-02-01 00:00:00.000' AS DateTime), CAST(N'2017-02-11 00:00:00.000' AS DateTime))
GO
INSERT [dbo].#DataTable ([id], [EffectiveDate], [Enddate]) VALUES (2, CAST(N'2017-02-06 00:00:00.000' AS DateTime), CAST(N'2017-02-16 00:00:00.000' AS DateTime))
GO

Answer 1

Try this, Hope it helps. Not the most attractive code but it should work. I may clean it up later if I find some time.
;WITH cte_StepOne as
(
SELECT ROW_NUMBER() OVER (ORDER BY a.[id],
a.[EffectiveDate],
a.[Enddate]) AS SeqNo,
a.[id],
a.[EffectiveDate],
a.[Enddate],
b.[id] AS OverLapID,
b.[EffectiveDate] AS [OverLapEffectiveDate],
b.[Enddate] AS [OverLapEnddate]
FROM ##DataTable a
LEFT JOIN ##DataTable b
ON a.EffectiveDate BETWEEN b.EffectiveDate
AND b.EndDate
AND a.EffectiveDate <> b.EffectiveDate
AND a.EndDate <> b.EndDate --and a.ID <> b.ID
)
,cte_StepTwo AS
(
SELECT SeqNo,
id,
EffectiveDate,
Enddate,
LEAD(OverLapEffectiveDate, 1) OVER (ORDER BY SeqNo) AS LeadValue,LAG(id, 1) OVER (ORDER BY SeqNo) AS LeadValueID,
OverLapID,
OverLapEffectiveDate,
OverLapEnddate
FROM cte_StepOne
)
,cte_Result AS
(
SELECT id,
EffectiveDate,
Enddate,
CASE
WHEN LeadValue = EffectiveDate AND OverLapEffectiveDate IS NULL THEN ID
WHEN OverLapID IS NULL THEN LeadValueID + 1
ELSE OverLapID
END AS OverLapID,
CASE
WHEN LeadValue = EffectiveDate AND OverLapEffectiveDate IS NULL THEN EffectiveDate
ELSE OverLapEffectiveDate
END AS OverLapEffectiveDate,
CASE
WHEN LeadValue = EffectiveDate AND OverLapEffectiveDate IS NULL THEN Enddate
ELSE OverLapEnddate
END AS OverLapEnddate
FROM cte_StepTwo
)
SELECT DISTINCT id,
EffectiveDate,
Enddate,
DENSE_RANK() OVER (ORDER BY ID,OverLapID) AS DateGroup
FROM cte_Result
ORDER BY id,EffectiveDate
Result:

Answer 2

This answer takes the approach of trying to identify records for which the running DateGroup counter should be incremented. Ultimately, we will assign a value of 1 to such records. With this assignment in hand, we can then simply take a cumulative sum to generate the DateGroup.
-- this CTE identifies all new ID records
WITH cte1 AS (
SELECT t.ID, t.EffectiveDate, t.EndDate
FROM
(
SELECT ID, EffectiveDate, EndDate,
ROW_NUMBER() OVER (PARTITION BY ID ORDER BY EffectiveDate) rn
FROM yourTable
) t
WHERE t.rn = 1
),
-- this CTE identifies all records whose both effective and end dates
-- do not fall within the range of the start ID record
cte2 AS (
SELECT t1.ID, t1.EffectiveDate, t1.EndDate
FROM yourTable t1
INNER JOIN cte1 t2
ON t1.ID = t2.ID AND
t1.EffectiveDate NOT BETWEEN t2.EffectiveDate AND t2.EndDate AND
t1.EndDate NOT BETWEEN t2.EffectiveDate AND t2.EndDate
),
-- this CTE returns the original table with a new column, amount, which
-- contains a value of 1 should that record cause the DateGroup to be
-- incremented by 1
cte3 AS (
SELECT t1.ID, t1.EffectiveDate, t1.EndDate,
CASE WHEN t2.ID IS NOT NULL OR t3.ID IS NOT NULL THEN 1 ELSE 0 END AS amount
FROM yourTable t1
LEFT JOIN cte1 t2
ON t1.ID = t2.ID AND
t1.EffectiveDate = t2.EffectiveDate AND
t1.EndDate = t2.EndDate
LEFT JOIN cte2 t3
ON t1.ID = t3.ID AND
t1.EffectiveDate = t3.EffectiveDate AND
t1.EndDate = t3.EndDate
)
-- finally, take a cumulative sum of the 'amount' column to generate the DateGroup
SELECT t1.ID,
t1.EffectiveDate,
t1.EndDate,
SUM(t2.amount) AS DateGroup
FROM cte3 t1
INNER JOIN cte3 t2
ON t1.ID >= t2.ID AND
t1.EffectiveDate >= t2.EffectiveDate
GROUP BY t1.id, t1.EffectiveDate, t1.EndDate;
Output:
Demo here:
Rextester
Data used:
CREATE TABLE yourTable (ID int, EffectiveDate datetime, EndDate datetime);
INSERT INTO yourTable
VALUES
(1, '2017-01-01 00:00:00.000', '2017-01-11 00:00:00.000'),
(1, '2017-01-02 00:00:00.000', '2017-01-05 00:00:00.000'),
(1, '2017-01-03 00:00:00.000', '2017-01-12 00:00:00.000'),
(1, '2017-01-06 00:00:00.000', '2017-01-09 00:00:00.000'),
(1, '2017-01-13 00:00:00.000', '2017-01-19 00:00:00.000'),
(2, '2017-02-01 00:00:00.000', '2017-02-11 00:00:00.000'),
(2, '2017-02-06 00:00:00.000', '2017-02-16 00:00:00.000');

Answer 3

What about this? It's simpler that other solutions posted:
WITH
CTE_GetFirstRecordForEachId AS
(
SELECT
id,
EffectiveDate,
Enddate,
rn = ROW_NUMBER() OVER (PARTITION BY id ORDER BY EffectiveDate, EndDate)
FROM
#DataTable
),
CTE_GetOutOfDateRange AS
(
SELECT
a.*,
OutOfDateRange =
CASE WHEN (b.EffectiveDate>=a.EffectiveDate AND b.EffectiveDate<=b.Enddate) OR (b.Enddate>=a.EffectiveDate AND b.Enddate<=b.Enddate)
THEN 0
ELSE 1
END
FROM
#DataTable a
INNER JOIN
CTE_GetFirstRecordForEachId b ON a.id = b.id AND b.rn=1
)
SELECT
id,
Effectivedate,
Enddate,
DateGroup = DENSE_RANK() OVER (ORDER BY id, OutOfDateRange)
FROM
CTE_GetOutOfDateRange
ORDER BY
id, Effectivedate, Enddate
Output:
id Effectivedate Enddate DateGroup
----------- ----------------------- ----------------------- --------------------
1 2017-01-01 00:00:00.000 2017-01-11 00:00:00.000 1
1 2017-01-02 00:00:00.000 2017-01-05 00:00:00.000 1
1 2017-01-03 00:00:00.000 2017-01-12 00:00:00.000 1
1 2017-01-06 00:00:00.000 2017-01-09 00:00:00.000 1
1 2017-01-13 00:00:00.000 2017-01-19 00:00:00.000 2
2 2017-02-01 00:00:00.000 2017-02-11 00:00:00.000 3
2 2017-02-06 00:00:00.000 2017-02-16 00:00:00.000 3

Answer 4

What about this (I am still testing it)
WITH Z AS
(SELECT * FROM (SELECT ID, [EffectiveDate], ENDDate
, LAG(ID) OVER (PARTITION BY ID ORDER BY EffectiveDate, ENDDate Desc) AS ID_Prec
, LAG(EffectiveDate) OVER (PARTITION BY ID ORDER BY EffectiveDate, ENDDate Desc) AS EffDate_Prec
, LAG(ENDDate) OVER (PARTITION BY ID ORDER BY EffectiveDate, ENDDate Desc) AS EndDate_Prec
, ROW_NUMBER() OVER (ORDER BY ID, EffectiveDate,ENDDate DESC) AS RN
, 1 AS DATEGROUP
FROM #DataTable ) C WHERE RN = 1
UNION ALL
SELECT A.ID, A.EffectiveDate, A.Enddate
, A.ID_Prec, A.EffDate_Prec
, A.EndDate_Prec
, A.RN
, CASE WHEN A.ID = A.ID_PREC AND (A.EffectiveDate <=A.EndDate_Prec /* OR A.EndDate>=A.EffDate_Prec*/) THEN Z.DATEGROUP
ELSE Z.DATEGROUP+1 END AS DATEGROUP
FROM (SELECT A.ID, A.EffectiveDate, A.ENDDate
, LAG(A.ID) OVER (PARTITION BY A.ID ORDER BY A.EffectiveDate, A.ENDDate Desc) AS ID_Prec
, LAG(A.EffectiveDate) OVER (PARTITION BY A.ID ORDER BY A.EffectiveDate, A.ENDDate Desc) AS EffDate_Prec
, LAG(A.ENDDate) OVER (PARTITION BY A.ID ORDER BY A.EffectiveDate, A.ENDDate Desc) AS EndDate_Prec
, ROW_NUMBER() OVER (ORDER BY A.ID, A.EffectiveDate,A.ENDDate DESC) AS RN
, 1 AS DATEGROUP
FROM #DataTable A) A
INNER JOIN Z ON A.RN -1= Z.RN
)
SELECT ID, EffectiveDate, Enddate, DATEGROUP FROM Z
Output:
ID EffectiveDate Enddate DATEGROUP
----------- ----------------------- ----------------------- -----------
1 2017-01-01 00:00:00.000 2017-01-11 00:00:00.000 1
1 2017-01-02 00:00:00.000 2017-01-05 00:00:00.000 1
1 2017-01-03 00:00:00.000 2017-01-12 00:00:00.000 1
1 2017-01-06 00:00:00.000 2017-01-09 00:00:00.000 1
1 2017-01-13 00:00:00.000 2017-01-19 00:00:00.000 2
2 2017-02-01 00:00:00.000 2017-02-11 00:00:00.000 3
2 2017-02-06 00:00:00.000 2017-02-16 00:00:00.000 3

Answer 5

guess you are missing some test scenario in your sample date.
;with CTE as
(
select *,ROW_NUMBER()over(order by id, effectivedate)rn
from #DataTable
)
,CTE1 AS
(
select *, 1 New_ID
from cte
where rn=1
union ALL
select c.id,c.effectivedate,c.enddate,c.rn
,case when c.effectivedate between c1.effectivedate
and c1.enddate
and c.id=c1.id then c1.New_ID
else c1.New_ID+1
END
from cte c
inner join cte1 c1
on c.rn=c1.rn+1
and c.rn>1 and c.rn<=7
)
select * from cte1
drop table #DataTable

Answer 6

this may help you. I posted here shortest and simplest version of tsql...
WITH CTE AS (
SELECT *,
ISNULL(LAG(EffectiveDate) OVER (PARTITION BY id ORDER BY id,EffectiveDate,Enddate),EffectiveDate) AS PreviousEffDate,
ISNULL(LAG(Enddate) OVER (PARTITION BY id ORDER BY id,EffectiveDate,Enddate),Enddate) AS PreviousEndDate
FROM #DataTable)
SELECT id,
EffectiveDate,
Enddate,
DENSE_RANK() OVER (ORDER BY id,CASE
WHEN EffectiveDate BETWEEN PreviousEffDate AND PreviousEndDate OR
Enddate BETWEEN PreviousEffDate AND PreviousEndDate OR
PreviousEffDate BETWEEN EffectiveDate AND Enddate OR
PreviousEndDate BETWEEN EffectiveDate AND Enddate
THEN 0
ELSE 1
END) AS DateGroup
FROM CTE
Result:

Answer 7

Have got this one from another forum; altered as per my requirement . looks simple and effective.
WITH C1 AS (
SELECT *,
CASE WHEN EffectiveDate <= MAX(ISnull(EndDate,'9999-12-31 00:00:00.000')) OVER(partition by id ORDER BY EffectiveDate ROWS BETWEEN UNBOUNDED PRECEDING AND 1 PRECEDING) THEN 0 ELSE 1 END AS isstart
FROM #DataTable
)
SELECT ID,EffectiveDate,EndDate,
SUM(isstart) OVER(ORDER BY ID ROWS UNBOUNDED PRECEDING) AS DG
FROM C1