How to find the previous and current row difference - sql

This table has 2 rows for each id, not more than 2 rows for the id
id date amt
-------------------
001 01/01/2012 100
001 01/12/2011 200
002 01/01/2013 100
002 01/12/2012 200
003 12/08/2012 500
003 31/12/2011 200
...
I want to display the max(date) of row for each id with current and previous row amt differnce
Expected Output
id date amt
------------------
001 01/01/2012 100
002 01/01/2013 100
003 12/08/2012 300
...
How to do this?

You can try with this:
DECLARE #tbl TABLE (id VARCHAR(10), date DATE, amt INT)
INSERT #tbl VALUES
('001', CONVERT(DATE, '01/01/2012', 103), 100),
('001', CONVERT(DATE, '01/12/2011', 103), 200),
('002', CONVERT(DATE, '01/01/2013', 103), 100),
('002', CONVERT(DATE, '01/12/2012', 103), 200),
('003', CONVERT(DATE, '12/08/2012', 103), 500),
('003', CONVERT(DATE, '31/12/2011', 103), 200),
-- Added to display the one id - one row situation
('004', CONVERT(DATE, '14/02/2011', 103), 999),
('000', CONVERT(DATE, '02/02/2012', 103), 100),
('100', CONVERT(DATE, '09/09/2011', 103), 999)
;WITH a AS
(
SELECT id
, amt
, date
, ROW_NUMBER() OVER (PARTITION BY id ORDER BY date ASC) num
, COUNT(*) OVER (PARTITION BY id) cnt
FROM #tbl
)
SELECT t1.id
, t1.date
, ABS(t1.amt - t2.amt)
FROM a t1
JOIN a t2 ON (t1.id = t2.id AND t1.num = t2.num + 1)
OR (t1.id = t2.id AND t2.cnt = 1)
Difference of first and second row for ids 1 and 2 is -100 so I added the ABS function that returns absolute value.
I also added sample data to show how the situation is handled when there is only one record per id.

Try this:
WITH CTE
AS
(
SELECT *,
ROW_NUMBER() OVER(PARTITION BY Id ORDER BY Date DESC) AS Rownum
FROM Table1
), CTE2
AS
(
SELECT
id,
date,
amt, ROW_NUMBER() OVER(ORDER BY Id) AS rank
FROM CTE c1
WHERE rownum = 1
)
SELECT
id,
date,
amt - ISNULL((SELECT c2.amt
FROM CTE2 c2
WHERE c1.rank - c2.rank = 1), 0)
FROM CTE2 c1;
SQL Fiddle Demo

Related

Loop within id and combine dates between rows in SQL [duplicate]

I have a table in the following format
Id StartDate EndDate Type
1 2012-02-18 2012-03-18 1
1 2012-03-17 2012-06-29 1
1 2012-06-27 2012-09-27 1
1 2014-08-23 2014-09-24 3
1 2014-09-23 2014-10-24 3
1 2014-10-23 2014-11-24 3
2 2015-07-04 2015-08-06 1
2 2015-08-04 2015-09-06 1
3 2013-11-01 2013-12-01 0
3 2018-01-09 2018-02-09 0
I found similar questions here, but not something that could help me solve my problem. I want to merge rows that has the same Id, Type and overlapping date periods.
The result from the above table should be
Id StartDate EndDate Type
1 2012-02-18 2012-09-27 1
1 2014-08-23 2014-11-24 3
2 2015-07-04 2015-09-06 1
3 2013-11-01 2013-12-01 0
3 2018-01-09 2018-02-09 0
In another server, I was able to do it with the following restrictions and the query below:
Didn't care about the Type column, but just the Id
Had a newer version of SQL Server (2012), but now I have 2008 which the code is not compatible
SELECT Id
, MIN(StartDate) AS StartDate
, MAX(EndDate) AS EndDate
FROM (
SELECT *
, SUM(CASE WHEN a.EndDate = a.StartDate THEN 0
ELSE 1
END
) OVER (ORDER BY Id, StartDate) sm
FROM (
SELECT Id
, StartDate
, EndDate
, LAG(EndDate, 1, NULL) OVER (PARTITION BY Id ORDER BY Id, EndDate) EndDate
FROM #temptable
) a
) b
GROUP BY Id, sm
Any advice how I can
Include Type on the process
Make it work on SQL Server 2008
This approach uses an additional temp table to identify the groups of overlapping dates, and then performs a quick aggregate based on the groupings.
SELECT *, ROW_NUMBER() OVER (ORDER BY Id, Type) AS UID,
ROW_NUMBER() OVER (ORDER BY Id, Type) AS GroupId INTO #G FROM #TempTable
WHILE ##ROWCOUNT <> 0 BEGIN
UPDATE T1 SET
GroupId = T2.GroupId
FROM #G T1
INNER JOIN (
SELECT T1.UID, CASE WHEN T1.GroupId < T2.GroupId THEN T1.GroupId ELSE T2.GroupId END
FROM #G T1
LEFT OUTER JOIN #G T2
ON T1.Id = T2.Id AND T1.Type = T2.Type AND T1.GroupId <> T2.GroupId
AND T1.StartDate <= T2.EndDate AND T2.StartDate <= T1.EndDate
) T2 (UID, GroupId)
ON T1.UID = T2.UID
WHERE T1.GroupId <> T2.GroupId
END
SELECT Id, MIN(StartDate) AS StartDate, MAX(EndDate) AS EndDate, Type
FROM #G G GROUP BY GroupId, Id, Type
This returns the expected values
Id StartDate EndDate Type
----------- ---------- ---------- -----------
1 2012-02-18 2012-09-27 1
1 2014-08-23 2014-11-24 3
2 2015-07-04 2015-09-06 1
3 2013-11-01 2013-12-01 0
3 2018-01-09 2018-02-09 0
This is 2008 compatible. A CTE really is the best way to link up all overlapping records in my opinion. The date overlap logic came from this thread: SO Date Overlap
I added extra data that's more complex to make sure that it's working as expected.
DECLARE #Data table (Id INT, StartDate DATE, EndDate DATE, Type INT)
INSERT INTO #data
SELECT 1,'2/18/2012' ,'3/18/2012', 1 UNION ALL
select 1,'3/17/2012','6/29/2012',1 UNION ALL
select 1,'6/27/2012','9/27/2012',1 UNION ALL
select 1,'8/23/2014','9/24/2014',3 UNION ALL
select 1,'9/23/2014','10/24/2014',3 UNION ALL
select 1,'10/23/2014','11/24/2014',3 UNION ALL
select 2,'7/4/2015','8/6/2015',1 UNION ALL
select 2,'8/4/2015','9/6/2015',1 UNION ALL
select 3,'11/1/2013','12/1/2013',0 UNION ALL
select 3,'1/9/2018','2/9/2018',0 UNION ALL
select 4,'1/1/2018','1/2/2018',0 UNION ALL --many non overlapping dates
select 4,'1/4/2018','1/5/2018',0 UNION ALL
select 4,'1/7/2018','1/9/2018',0 UNION ALL
select 4,'1/11/2018','1/13/2018',0 UNION ALL
select 4,'2/7/2018','2/8/2018',0 UNION ALL --many overlapping dates
select 4,'2/8/2018','2/9/2018',0 UNION ALL
select 4,'2/9/2018','2/10/2018',0 UNION all
select 4,'2/10/2018','2/11/2018',0 UNION all
select 4,'2/11/2018','2/12/2018',0 UNION all
select 4,'2/12/2018','2/13/2018',0 UNION all
select 4,'3/7/2018','3/8/2018',0 UNION ALL --many overlapping dates, second instance of id 4, type 0
select 4,'3/8/2018','3/9/2018',0 UNION ALL
select 4,'3/9/2018','3/10/2018',0 UNION all
select 4,'3/10/2018','3/11/2018',0 UNION all
select 4,'3/11/2018','3/12/2018',0 UNION all
select 4,'3/12/2018','3/13/2018',0
;
WITH cdata
AS (SELECT Id,
d.Type,
d.StartDate,
d.EndDate,
CurrentStart = d.StartDate
FROM #Data d
WHERE
NOT EXISTS (
SELECT * FROM #Data x WHERE x.StartDate < d.StartDate AND d.StartDate <= x.EndDate AND d.EndDate >= x.StartDate AND d.Id = x.Id AND d.Type = x.Type --get first records for overlapping ranges
)
UNION ALL
SELECT d.Id,
d.Type,
StartDate = CASE WHEN d2.StartDate < d.StartDate THEN d2.StartDate ELSE d.StartDate END,
EndDate = CASE WHEN d2.EndDate > d.EndDate THEN d2.EndDate ELSE d.EndDate END,
CurrentStart = d2.StartDate
FROM cdata d
INNER JOIN #Data d2
ON (
d.StartDate <= d2.EndDate
AND d.EndDate >= d2.StartDate
)
AND d2.Id = d.Id
AND d2.Type = d.Type
AND d2.StartDate > d.CurrentStart)
SELECT cdata.Id, cdata.Type, cdata.StartDate, EndDate = MAX(cdata.EndDate)
FROM cdata
GROUP BY cdata.Id, cdata.Type, cdata.StartDate
This looks like a Packing Intervals problem. See the post by Itzik Ben-Gan for all the details and what indexes he recommends to make it work efficiently. He presents a solution without recursive CTE.
Two notes.
The query below assumes that intervals are [closed; open), i.e. StartDate is inclusive and EndDate is exclusive. This way to represent such data is often the most convenient. (in the same sense as having arrays as zero-based instead of 1-based is usually more convenient in programming languages).
I added a RowID column to have unambiguous sorting.
Sample data
DECLARE #T TABLE
(
RowID int IDENTITY,
id int,
StartDate date,
EndDate date,
tp int
);
INSERT INTO #T(Id, StartDate, EndDate, tp) VALUES
(1, '2012-02-18', '2012-03-18', 1),
(1, '2012-03-17', '2012-06-29', 1),
(1, '2012-06-27', '2012-09-27', 1),
(1, '2014-08-23', '2014-09-24', 3),
(1, '2014-09-23', '2014-10-24', 3),
(1, '2014-10-23', '2014-11-24', 3),
(2, '2015-07-04', '2015-08-06', 1),
(2, '2015-08-04', '2015-09-06', 1),
(3, '2013-11-01', '2013-12-01', 0),
(3, '2018-01-09', '2018-02-09', 0);
-- Make EndDate an opened interval, make it exclusive
-- [Start; End)
UPDATE #T
SET EndDate = DATEADD(day, 1, EndDate)
;
Recommended indexes
-- indexes to support solutions
CREATE UNIQUE INDEX idx_start_id ON T(id, tp, StartDate, RowID);
CREATE UNIQUE INDEX idx_end_id ON T(id, tp, EndDate, RowID);
Query
Read the Itzik's post to understand what is going on. He has nice illustrations there. In short, each timestamp (start or end) is treated as an event. Each event has a + or - type. Each time we encounter a + event (some interval starts) we increase the running counter. Each time we encounter a - event (some interval ends) we decrease the running counter. When the running counter is 0 it means that the streak of overlapping intervals is over.
I took Itzik's query as is and simply changed the column names to match your names.
WITH C1 AS
-- let e = end ordinals, let s = start ordinals
(
SELECT
RowID, id, tp, StartDate AS ts, +1 AS EventType,
NULL AS e,
ROW_NUMBER() OVER(PARTITION BY id, tp ORDER BY StartDate, RowID) AS s
FROM #T
UNION ALL
SELECT
RowID, id, tp, EndDate AS ts, -1 AS EventType,
ROW_NUMBER() OVER(PARTITION BY id, tp ORDER BY EndDate, RowID) AS e,
NULL AS s
FROM #T
),
C2 AS
-- let se = start or end ordinal, namely, how many events (start or end) happened so far
(
SELECT C1.*,
ROW_NUMBER() OVER(PARTITION BY id, tp ORDER BY ts, EventType DESC, RowID) AS se
FROM C1
),
C3 AS
-- For start events, the expression s - (se - s) - 1 represents how many sessions were active
-- just before the current (hence - 1)
--
-- For end events, the expression (se - e) - e represents how many sessions are active
-- right after this one
--
-- The above two expressions are 0 exactly when a group of packed intervals
-- either starts or ends, respectively
--
-- After filtering only events when a group of packed intervals either starts or ends,
-- group each pair of adjacent start/end events
(
SELECT id, tp, ts,
((ROW_NUMBER() OVER(PARTITION BY id, tp ORDER BY ts) - 1) / 2 + 1)
AS grpnum
FROM C2
WHERE COALESCE(s - (se - s) - 1, (se - e) - e) = 0
)
SELECT id, tp, MIN(ts) AS StartDate, DATEADD(day, -1, MAX(ts)) AS EndDate
FROM C3
GROUP BY id, tp, grpnum
ORDER BY id, tp, StartDate;
Result
+----+----+------------+------------+
| id | tp | StartDate | EndDate |
+----+----+------------+------------+
| 1 | 1 | 2012-02-18 | 2012-09-27 |
| 1 | 3 | 2014-08-23 | 2014-11-24 |
| 2 | 1 | 2015-07-04 | 2015-09-06 |
| 3 | 0 | 2013-11-01 | 2013-12-01 |
| 3 | 0 | 2018-01-09 | 2018-02-09 |
+----+----+------------+------------+
create table #table
(Id int,StartDate date, EndDate date, Type int)
insert into #table
values
('1','2012-02-18','2012-03-18','1'),('1','2012-03-19','2012-06-19','1'),
('1','2012-06-27','2012-09-27','1'),('1','2014-08-23','2014-09-24','3'),
('1','2014-09-23','2014-10-24','3'),('1','2014-10-23','2014-11-24','3'),
('2','2015-07-04','2015-08-06','1'),('2','2015-08-04','2015-09-06','1'),
('3','2013-11-01','2013-12-01','0'),('3','2018-01-09','2018-02-09','0')
select ID,MIN(startdate)sd,MAX(EndDate)ed,type from #table
group by ID,TYPE,YEAR(startdate),YEAR(EndDate)
this can be easily achieved by using some window-functions and CTE's. Here is the solution
DECLARE #table TABLE
(id INT,
StartDate DATE,
EndDate DATE,
[Type] INT
);
INSERT INTO #table(Id, StartDate, EndDate, [Type]) VALUES
(1, '2012-02-18', '2012-03-18', 1),
(1, '2012-03-17', '2012-06-29', 1),
(1, '2012-06-27', '2012-09-27', 1),
(1, '2014-08-23', '2014-09-24', 3),
(1, '2014-09-23', '2014-10-24', 3),
(1, '2014-10-23', '2014-11-24', 3),
(2, '2015-07-04', '2015-08-06', 1),
(2, '2015-08-04', '2015-09-06', 1),
(3, '2013-11-01', '2013-12-01', 0),
(3, '2018-01-09', '2018-02-09', 0);
WITH C1 AS
(
SELECT *,
MAX(EndDate) OVER(PARTITION BY Id, [Type]
ORDER BY StartDate, EndDate
ROWS BETWEEN UNBOUNDED PRECEDING AND 1 PRECEDING) AS PrevEnd
FROM #table
),
C2 AS
(
SELECT *,
SUM(StartFlag) OVER(PARTITION BY Id, [Type]
ORDER BY StartDate, EndDate
ROWS UNBOUNDED PRECEDING) AS GroupID
FROM C1
CROSS APPLY ( VALUES(CASE WHEN StartDate <= PrevEnd THEN NULL ELSE 1 END) ) AS A(StartFlag)
)
SELECT Id, [Type], MIN(StartDate) AS StartDate, MAX(EndDate) AS EndDate
FROM C2
GROUP BY Id, [Type], GroupID;

Merge rows if date columns are overlapping in TSQL

I have a table in the following format
Id StartDate EndDate Type
1 2012-02-18 2012-03-18 1
1 2012-03-17 2012-06-29 1
1 2012-06-27 2012-09-27 1
1 2014-08-23 2014-09-24 3
1 2014-09-23 2014-10-24 3
1 2014-10-23 2014-11-24 3
2 2015-07-04 2015-08-06 1
2 2015-08-04 2015-09-06 1
3 2013-11-01 2013-12-01 0
3 2018-01-09 2018-02-09 0
I found similar questions here, but not something that could help me solve my problem. I want to merge rows that has the same Id, Type and overlapping date periods.
The result from the above table should be
Id StartDate EndDate Type
1 2012-02-18 2012-09-27 1
1 2014-08-23 2014-11-24 3
2 2015-07-04 2015-09-06 1
3 2013-11-01 2013-12-01 0
3 2018-01-09 2018-02-09 0
In another server, I was able to do it with the following restrictions and the query below:
Didn't care about the Type column, but just the Id
Had a newer version of SQL Server (2012), but now I have 2008 which the code is not compatible
SELECT Id
, MIN(StartDate) AS StartDate
, MAX(EndDate) AS EndDate
FROM (
SELECT *
, SUM(CASE WHEN a.EndDate = a.StartDate THEN 0
ELSE 1
END
) OVER (ORDER BY Id, StartDate) sm
FROM (
SELECT Id
, StartDate
, EndDate
, LAG(EndDate, 1, NULL) OVER (PARTITION BY Id ORDER BY Id, EndDate) EndDate
FROM #temptable
) a
) b
GROUP BY Id, sm
Any advice how I can
Include Type on the process
Make it work on SQL Server 2008
This approach uses an additional temp table to identify the groups of overlapping dates, and then performs a quick aggregate based on the groupings.
SELECT *, ROW_NUMBER() OVER (ORDER BY Id, Type) AS UID,
ROW_NUMBER() OVER (ORDER BY Id, Type) AS GroupId INTO #G FROM #TempTable
WHILE ##ROWCOUNT <> 0 BEGIN
UPDATE T1 SET
GroupId = T2.GroupId
FROM #G T1
INNER JOIN (
SELECT T1.UID, CASE WHEN T1.GroupId < T2.GroupId THEN T1.GroupId ELSE T2.GroupId END
FROM #G T1
LEFT OUTER JOIN #G T2
ON T1.Id = T2.Id AND T1.Type = T2.Type AND T1.GroupId <> T2.GroupId
AND T1.StartDate <= T2.EndDate AND T2.StartDate <= T1.EndDate
) T2 (UID, GroupId)
ON T1.UID = T2.UID
WHERE T1.GroupId <> T2.GroupId
END
SELECT Id, MIN(StartDate) AS StartDate, MAX(EndDate) AS EndDate, Type
FROM #G G GROUP BY GroupId, Id, Type
This returns the expected values
Id StartDate EndDate Type
----------- ---------- ---------- -----------
1 2012-02-18 2012-09-27 1
1 2014-08-23 2014-11-24 3
2 2015-07-04 2015-09-06 1
3 2013-11-01 2013-12-01 0
3 2018-01-09 2018-02-09 0
This is 2008 compatible. A CTE really is the best way to link up all overlapping records in my opinion. The date overlap logic came from this thread: SO Date Overlap
I added extra data that's more complex to make sure that it's working as expected.
DECLARE #Data table (Id INT, StartDate DATE, EndDate DATE, Type INT)
INSERT INTO #data
SELECT 1,'2/18/2012' ,'3/18/2012', 1 UNION ALL
select 1,'3/17/2012','6/29/2012',1 UNION ALL
select 1,'6/27/2012','9/27/2012',1 UNION ALL
select 1,'8/23/2014','9/24/2014',3 UNION ALL
select 1,'9/23/2014','10/24/2014',3 UNION ALL
select 1,'10/23/2014','11/24/2014',3 UNION ALL
select 2,'7/4/2015','8/6/2015',1 UNION ALL
select 2,'8/4/2015','9/6/2015',1 UNION ALL
select 3,'11/1/2013','12/1/2013',0 UNION ALL
select 3,'1/9/2018','2/9/2018',0 UNION ALL
select 4,'1/1/2018','1/2/2018',0 UNION ALL --many non overlapping dates
select 4,'1/4/2018','1/5/2018',0 UNION ALL
select 4,'1/7/2018','1/9/2018',0 UNION ALL
select 4,'1/11/2018','1/13/2018',0 UNION ALL
select 4,'2/7/2018','2/8/2018',0 UNION ALL --many overlapping dates
select 4,'2/8/2018','2/9/2018',0 UNION ALL
select 4,'2/9/2018','2/10/2018',0 UNION all
select 4,'2/10/2018','2/11/2018',0 UNION all
select 4,'2/11/2018','2/12/2018',0 UNION all
select 4,'2/12/2018','2/13/2018',0 UNION all
select 4,'3/7/2018','3/8/2018',0 UNION ALL --many overlapping dates, second instance of id 4, type 0
select 4,'3/8/2018','3/9/2018',0 UNION ALL
select 4,'3/9/2018','3/10/2018',0 UNION all
select 4,'3/10/2018','3/11/2018',0 UNION all
select 4,'3/11/2018','3/12/2018',0 UNION all
select 4,'3/12/2018','3/13/2018',0
;
WITH cdata
AS (SELECT Id,
d.Type,
d.StartDate,
d.EndDate,
CurrentStart = d.StartDate
FROM #Data d
WHERE
NOT EXISTS (
SELECT * FROM #Data x WHERE x.StartDate < d.StartDate AND d.StartDate <= x.EndDate AND d.EndDate >= x.StartDate AND d.Id = x.Id AND d.Type = x.Type --get first records for overlapping ranges
)
UNION ALL
SELECT d.Id,
d.Type,
StartDate = CASE WHEN d2.StartDate < d.StartDate THEN d2.StartDate ELSE d.StartDate END,
EndDate = CASE WHEN d2.EndDate > d.EndDate THEN d2.EndDate ELSE d.EndDate END,
CurrentStart = d2.StartDate
FROM cdata d
INNER JOIN #Data d2
ON (
d.StartDate <= d2.EndDate
AND d.EndDate >= d2.StartDate
)
AND d2.Id = d.Id
AND d2.Type = d.Type
AND d2.StartDate > d.CurrentStart)
SELECT cdata.Id, cdata.Type, cdata.StartDate, EndDate = MAX(cdata.EndDate)
FROM cdata
GROUP BY cdata.Id, cdata.Type, cdata.StartDate
This looks like a Packing Intervals problem. See the post by Itzik Ben-Gan for all the details and what indexes he recommends to make it work efficiently. He presents a solution without recursive CTE.
Two notes.
The query below assumes that intervals are [closed; open), i.e. StartDate is inclusive and EndDate is exclusive. This way to represent such data is often the most convenient. (in the same sense as having arrays as zero-based instead of 1-based is usually more convenient in programming languages).
I added a RowID column to have unambiguous sorting.
Sample data
DECLARE #T TABLE
(
RowID int IDENTITY,
id int,
StartDate date,
EndDate date,
tp int
);
INSERT INTO #T(Id, StartDate, EndDate, tp) VALUES
(1, '2012-02-18', '2012-03-18', 1),
(1, '2012-03-17', '2012-06-29', 1),
(1, '2012-06-27', '2012-09-27', 1),
(1, '2014-08-23', '2014-09-24', 3),
(1, '2014-09-23', '2014-10-24', 3),
(1, '2014-10-23', '2014-11-24', 3),
(2, '2015-07-04', '2015-08-06', 1),
(2, '2015-08-04', '2015-09-06', 1),
(3, '2013-11-01', '2013-12-01', 0),
(3, '2018-01-09', '2018-02-09', 0);
-- Make EndDate an opened interval, make it exclusive
-- [Start; End)
UPDATE #T
SET EndDate = DATEADD(day, 1, EndDate)
;
Recommended indexes
-- indexes to support solutions
CREATE UNIQUE INDEX idx_start_id ON T(id, tp, StartDate, RowID);
CREATE UNIQUE INDEX idx_end_id ON T(id, tp, EndDate, RowID);
Query
Read the Itzik's post to understand what is going on. He has nice illustrations there. In short, each timestamp (start or end) is treated as an event. Each event has a + or - type. Each time we encounter a + event (some interval starts) we increase the running counter. Each time we encounter a - event (some interval ends) we decrease the running counter. When the running counter is 0 it means that the streak of overlapping intervals is over.
I took Itzik's query as is and simply changed the column names to match your names.
WITH C1 AS
-- let e = end ordinals, let s = start ordinals
(
SELECT
RowID, id, tp, StartDate AS ts, +1 AS EventType,
NULL AS e,
ROW_NUMBER() OVER(PARTITION BY id, tp ORDER BY StartDate, RowID) AS s
FROM #T
UNION ALL
SELECT
RowID, id, tp, EndDate AS ts, -1 AS EventType,
ROW_NUMBER() OVER(PARTITION BY id, tp ORDER BY EndDate, RowID) AS e,
NULL AS s
FROM #T
),
C2 AS
-- let se = start or end ordinal, namely, how many events (start or end) happened so far
(
SELECT C1.*,
ROW_NUMBER() OVER(PARTITION BY id, tp ORDER BY ts, EventType DESC, RowID) AS se
FROM C1
),
C3 AS
-- For start events, the expression s - (se - s) - 1 represents how many sessions were active
-- just before the current (hence - 1)
--
-- For end events, the expression (se - e) - e represents how many sessions are active
-- right after this one
--
-- The above two expressions are 0 exactly when a group of packed intervals
-- either starts or ends, respectively
--
-- After filtering only events when a group of packed intervals either starts or ends,
-- group each pair of adjacent start/end events
(
SELECT id, tp, ts,
((ROW_NUMBER() OVER(PARTITION BY id, tp ORDER BY ts) - 1) / 2 + 1)
AS grpnum
FROM C2
WHERE COALESCE(s - (se - s) - 1, (se - e) - e) = 0
)
SELECT id, tp, MIN(ts) AS StartDate, DATEADD(day, -1, MAX(ts)) AS EndDate
FROM C3
GROUP BY id, tp, grpnum
ORDER BY id, tp, StartDate;
Result
+----+----+------------+------------+
| id | tp | StartDate | EndDate |
+----+----+------------+------------+
| 1 | 1 | 2012-02-18 | 2012-09-27 |
| 1 | 3 | 2014-08-23 | 2014-11-24 |
| 2 | 1 | 2015-07-04 | 2015-09-06 |
| 3 | 0 | 2013-11-01 | 2013-12-01 |
| 3 | 0 | 2018-01-09 | 2018-02-09 |
+----+----+------------+------------+
create table #table
(Id int,StartDate date, EndDate date, Type int)
insert into #table
values
('1','2012-02-18','2012-03-18','1'),('1','2012-03-19','2012-06-19','1'),
('1','2012-06-27','2012-09-27','1'),('1','2014-08-23','2014-09-24','3'),
('1','2014-09-23','2014-10-24','3'),('1','2014-10-23','2014-11-24','3'),
('2','2015-07-04','2015-08-06','1'),('2','2015-08-04','2015-09-06','1'),
('3','2013-11-01','2013-12-01','0'),('3','2018-01-09','2018-02-09','0')
select ID,MIN(startdate)sd,MAX(EndDate)ed,type from #table
group by ID,TYPE,YEAR(startdate),YEAR(EndDate)
this can be easily achieved by using some window-functions and CTE's. Here is the solution
DECLARE #table TABLE
(id INT,
StartDate DATE,
EndDate DATE,
[Type] INT
);
INSERT INTO #table(Id, StartDate, EndDate, [Type]) VALUES
(1, '2012-02-18', '2012-03-18', 1),
(1, '2012-03-17', '2012-06-29', 1),
(1, '2012-06-27', '2012-09-27', 1),
(1, '2014-08-23', '2014-09-24', 3),
(1, '2014-09-23', '2014-10-24', 3),
(1, '2014-10-23', '2014-11-24', 3),
(2, '2015-07-04', '2015-08-06', 1),
(2, '2015-08-04', '2015-09-06', 1),
(3, '2013-11-01', '2013-12-01', 0),
(3, '2018-01-09', '2018-02-09', 0);
WITH C1 AS
(
SELECT *,
MAX(EndDate) OVER(PARTITION BY Id, [Type]
ORDER BY StartDate, EndDate
ROWS BETWEEN UNBOUNDED PRECEDING AND 1 PRECEDING) AS PrevEnd
FROM #table
),
C2 AS
(
SELECT *,
SUM(StartFlag) OVER(PARTITION BY Id, [Type]
ORDER BY StartDate, EndDate
ROWS UNBOUNDED PRECEDING) AS GroupID
FROM C1
CROSS APPLY ( VALUES(CASE WHEN StartDate <= PrevEnd THEN NULL ELSE 1 END) ) AS A(StartFlag)
)
SELECT Id, [Type], MIN(StartDate) AS StartDate, MAX(EndDate) AS EndDate
FROM C2
GROUP BY Id, [Type], GroupID;

Get all overlapping date ranges when all overlap at the same time

I'm struggling with this for a few days... trying to write an SQL query to get all date ranges when all units overlap at the same time. It's better to see it graphically.
Here is the simplified table with the image for reference:
UnitId Start End
====== ========== ==========
1 05/01/2018 09/01/2018
1 10/01/2018 13/01/2018
2 04/01/2018 15/01/2018
2 19/01/2018 23/01/2018
3 06/01/2018 12/01/2018
3 14/01/2018 22/01/2018
Expected result:
Start End
====== ==========
06/01/2018 09/01/2018
10/01/2018 12/01/2018
What I currently have:
DECLARE #sourceTable TABLE (UnitId int, StartDate datetime, EndDate datetime);
INSERT INTO #sourceTable VALUES
(1, '2018-01-05', '2018-01-09')
,(1, '2018-01-10', '2018-01-13')
,(2, '2018-01-04', '2018-01-15')
,(2, '2018-01-19', '2018-01-23')
,(3, '2018-01-06', '2018-01-12')
,(3, '2018-01-14', '2018-01-22');
SELECT DISTINCT
(SELECT max(v) FROM (values(A.StartDate), (B.StartDate)) as value(v)) StartDate
,(SELECT min(v) FROM (values(A.EndDate), (B.EndDate)) as value(v)) EndDate
FROM #sourceTable A
JOIN #sourceTable B
ON A.startDate <= B.endDate AND A.endDate >= B.startDate AND A.UnitId != B.UnitId
I believe it is "count number of overlapping intervals" problem (this picture should help). Here is one solution to it:
DECLARE #t TABLE (UnitId INT, [Start] DATE, [End] DATE);
INSERT INTO #t VALUES
(1, '2018-01-05', '2018-01-09'),
(1, '2018-01-10', '2018-01-13'),
(2, '2018-01-04', '2018-01-15'),
(2, '2018-01-19', '2018-01-23'),
(3, '2018-01-06', '2018-01-12'),
(3, '2018-01-14', '2018-01-22');
WITH cte1(date, val) AS (
SELECT [Start], 1 FROM #t AS t
UNION ALL
SELECT [End], 0 FROM #t AS t
UNION ALL
SELECT DATEADD(DAY, 1, [End]), -1 FROM #t AS t
), cte2 AS (
SELECT date, SUM(val) OVER (ORDER BY date, val) AS usage
FROM cte1
)
SELECT date, MAX(usage) AS usage
FROM cte2
GROUP BY date
It will give you a list of all dates at which the use count (possibly) changed:
date usage
2018-01-04 1
2018-01-05 2
2018-01-06 3
2018-01-09 3
2018-01-10 3
2018-01-12 3
2018-01-13 2
2018-01-14 2
2018-01-15 2
2018-01-16 1
2018-01-19 2
2018-01-22 2
2018-01-23 1
2018-01-24 0
With this approach you do not need a calendar table or rCTE to build missing dates. Converting the above to ranges (2018-01-05 ... 2018-01-15, 2018-01-19 ... 2018-01-22 etc) is not very difficult.
DECLARE #t TABLE (UnitId INT, [Start] DATE, [End] DATE);
INSERT INTO #t VALUES
(1, '2018-01-05', '2018-01-09'),
(1, '2018-01-10', '2018-01-13'),
(2, '2018-01-04', '2018-01-15'),
(2, '2018-01-19', '2018-01-23'),
(3, '2018-01-06', '2018-01-12'),
(3, '2018-01-14', '2018-01-22');
WITH cte1(date, val) AS (
SELECT [Start], 1 FROM #t AS t -- starting date increments counter
UNION ALL
SELECT [End], 0 FROM #t AS t -- we need all edges in the result
UNION ALL
SELECT DATEADD(DAY, 1, [End]), -1 FROM #t AS t -- end date + 1 decrements counter
), cte2 AS (
SELECT date, SUM(val) OVER (ORDER BY date, val) AS usage -- running sum for counter
FROM cte1
), cte3 AS (
SELECT date, MAX(usage) AS usage -- group multiple events on same date together
FROM cte2
GROUP BY date
), cte4 AS (
SELECT date, usage, CASE
WHEN usage > 1 AND LAG(usage) OVER (ORDER BY date) > 1 THEN 0
WHEN usage < 2 AND LAG(usage) OVER (ORDER BY date) < 2 THEN 0
ELSE 1
END AS chg -- start new group if prev and curr usage are on opposite side of 1
FROM cte3
), cte5 AS (
SELECT date, usage, SUM(chg) OVER (ORDER BY date) AS grp -- number groups for each change
FROM cte4
)
SELECT MIN(date) date1, MAX(date) date2
FROM cte5
GROUP BY grp
HAVING MIN(usage) > 1
Result:
date1 date2
2018-01-05 2018-01-15
2018-01-19 2018-01-22
You are looking for date ranges where all units overlap. So look for start dates where all units exist and end dates where all units exist and then join the two.
I'm using ROW_NUMBER to join the first start date with the first end date, the second start date with the second end date and so on.
select s.startdate, e.enddate
from
(
select startdate, row_number() over (order by startdate) as rn
from #sourceTable s1
where
(
select count(*)
from #sourceTable s2
where s1.startdate between s2.startdate and s2.enddate
) = (select count(distinct unitid) from #sourceTable)
) s
join
(
select enddate, row_number() over (order by startdate) as rn
from #sourceTable s1
where
(
select count(*)
from #sourceTable s2
where s1.enddate between s2.startdate and s2.enddate
) = (select count(distinct unitid) from #sourceTable)
) e on e.rn = s.rn
order by s.startdate;
There may be more elegant ways to solve this, but I guess this query is at least easy to understand :-)
Rextester demo: https://rextester.com/GRRSW89045

How to aggregate (counting distinct items) over a sliding window in SQL Server?

I am currently using this query (in SQL Server) to count the number of unique item each day:
SELECT Date, COUNT(DISTINCT item)
FROM myTable
GROUP BY Date
ORDER BY Date
How can I transform this to get for each date the number of unique item over the past 3 days (including the current day)?
The output should be a table with 2 columns:
one columns with all dates in the original table. On the second column, we have the number of unique item per date.
for instance if original table is:
Date Item
01/01/2018 A
01/01/2018 B
02/01/2018 C
03/01/2018 C
04/01/2018 C
With my query above I currently get the unique count for each day:
Date count
01/01/2018 2
02/01/2018 1
03/01/2018 1
04/01/2018 1
and I am looking to get as result the unique count over 3 days rolling window:
Date count
01/01/2018 2
02/01/2018 3 (because items ABC on 1st and 2nd Jan)
03/01/2018 3 (because items ABC on 1st,2nd,3rd Jan)
04/01/2018 1 (because only item C on 2nd,3rd,4th Jan)
Using an apply provides a convenient way to form sliding windows
CREATE TABLE myTable
([DateCol] datetime, [Item] varchar(1))
;
INSERT INTO myTable
([DateCol], [Item])
VALUES
('2018-01-01 00:00:00', 'A'),
('2018-01-01 00:00:00', 'B'),
('2018-01-02 00:00:00', 'C'),
('2018-01-03 00:00:00', 'C'),
('2018-01-04 00:00:00', 'C')
;
CREATE NONCLUSTERED INDEX IX_DateCol
ON MyTable([Date])
;
Query:
select distinct
t1.dateCol
, oa.ItemCount
from myTable t1
outer apply (
select count(distinct t2.item) as ItemCount
from myTable t2
where t2.DateCol between dateadd(day,-2,t1.DateCol) and t1.DateCol
) oa
order by t1.dateCol ASC
Results:
| dateCol | ItemCount |
|----------------------|-----------|
| 2018-01-01T00:00:00Z | 2 |
| 2018-01-02T00:00:00Z | 3 |
| 2018-01-03T00:00:00Z | 3 |
| 2018-01-04T00:00:00Z | 1 |
There may be some performance gains by reducing the date column prior to using the apply, like so:
select
d.date
, oa.ItemCount
from (
select distinct t1.date
from myTable t1
) d
outer apply (
select count(distinct t2.item) as ItemCount
from myTable t2
where t2.Date between dateadd(day,-2,d.Date) and d.Date
) oa
order by d.date ASC
;
Instead of using select distinct in that subquery you could use group by instead but the execution plan will remain the same.
Demo at SQL Fiddle
The most straight forward solution is to join the table with itself based on dates:
SELECT t1.DateCol, COUNT(DISTINCT t2.Item) AS C
FROM testdata AS t1
LEFT JOIN testdata AS t2 ON t2.DateCol BETWEEN DATEADD(dd, -2, t1.DateCol) AND t1.DateCol
GROUP BY t1.DateCol
ORDER BY t1.DateCol
Output:
| DateCol | C |
|-------------------------|---|
| 2018-01-01 00:00:00.000 | 2 |
| 2018-01-02 00:00:00.000 | 3 |
| 2018-01-03 00:00:00.000 | 3 |
| 2018-01-04 00:00:00.000 | 1 |
GROUP BY should be faster then DISTINCT (make sure to have an index on your Date column)
DECLARE #tbl TABLE([Date] DATE, [Item] VARCHAR(100))
;
INSERT INTO #tbl VALUES
('2018-01-01 00:00:00', 'A'),
('2018-01-01 00:00:00', 'B'),
('2018-01-02 00:00:00', 'C'),
('2018-01-03 00:00:00', 'C'),
('2018-01-04 00:00:00', 'C');
SELECT t.[Date]
--Just for control. You can take this part away
,(SELECT DISTINCT t2.[Item] AS [*]
FROM #tbl AS t2
WHERE t2.[Date]<=t.[Date]
AND t2.[Date]>=DATEADD(DAY,-2,t.[Date]) FOR XML PATH('')) AS CountedItems
--This sub-select comes back with your counts
,(SELECT COUNT(DISTINCT t2.[Item])
FROM #tbl AS t2
WHERE t2.[Date]<=t.[Date]
AND t2.[Date]>=DATEADD(DAY,-2,t.[Date])) AS ItemCount
FROM #tbl AS t
GROUP BY t.[Date];
The result
Date CountedItems ItemCount
2018-01-01 AB 2
2018-01-02 ABC 3
2018-01-03 ABC 3
2018-01-04 C 1
This solution is different from other solutions. Can you check performance of this query on real data with comparison to other answers?
The basic idea is that each row can participate in the window for its own date, the day after, or the day after that. So this first expands the row out into three rows with those different dates attached and then it can just use a regular COUNT(DISTINCT) aggregating on the computed date. The HAVING clause is just to avoid returning results for dates that were solely computed and not present in the base data.
with cte(Date, Item) as (
select cast(a as datetime), b
from (values
('01/01/2018','A')
,('01/01/2018','B')
,('02/01/2018','C')
,('03/01/2018','C')
,('04/01/2018','C')) t(a,b)
)
select
[Date] = dateadd(dd, n, Date), [Count] = count(distinct Item)
from
cte
cross join (values (0),(1),(2)) t(n)
group by dateadd(dd, n, Date)
having max(iif(n = 0, 1, 0)) = 1
option (force order)
Output:
| Date | Count |
|-------------------------|-------|
| 2018-01-01 00:00:00.000 | 2 |
| 2018-01-02 00:00:00.000 | 3 |
| 2018-01-03 00:00:00.000 | 3 |
| 2018-01-04 00:00:00.000 | 1 |
It might be faster if you have many duplicate rows:
select
[Date] = dateadd(dd, n, Date), [Count] = count(distinct Item)
from
(select distinct Date, Item from cte) c
cross join (values (0),(1),(2)) t(n)
group by dateadd(dd, n, Date)
having max(iif(n = 0, 1, 0)) = 1
option (force order)
Use GETDATE() function to get current date, and DATEADD() to get the last 3 days
SELECT Date, count(DISTINCT item)
FROM myTable
WHERE [Date] >= DATEADD(day,-3, GETDATE())
GROUP BY Date
ORDER BY Date
SQL
SELECT DISTINCT Date,
(SELECT COUNT(DISTINCT item)
FROM myTable t2
WHERE t2.Date BETWEEN DATEADD(day, -2, t1.Date) AND t1.Date) AS count
FROM myTable t1
ORDER BY Date;
Demo
Rextester demo: http://rextester.com/ZRDQ22190
Since COUNT(DISTINCT item) OVER (PARTITION BY [Date]) is not supported you can use dense_rank to emulate that:
SELECT Date, dense_rank() over (partition by [Date] order by [item])
+ dense_rank() over (partition by [Date] order by [item] desc)
- 1 as count_distinct_item
FROM myTable
One thing to note is that dense_rank will count null as whereas COUNT will not.
Refer this post for more details.
Here is a simple solution that uses myTable itself as the source of grouping dates (edited for SQLServer dateadd). Note that this query assumes there will be at least one record in myTable for every date; if any date is absent, it will not appear in the query results, even if there are records for the 2 days prior:
select
date,
(select
count(distinct item)
from (select distinct date, item from myTable) as d2
where
d2.date between dateadd(day,-2,d.date) and d.date
) as count
from (select distinct date from myTable) as d
I solve this question with Math.
z (any day) = 3x + y (y is mode 3 value)
I need from 3 * (x - 1) + y + 1 to 3 * (x - 1) + y + 3
3 * (x- 1) + y + 1 = 3* (z / 3 - 1) + z % 3 + 1
In that case; I can use group by (between 3* (z / 3 - 1) + z % 3 + 1 and z)
SELECT iif(OrderDate between 3 * (cast(OrderDate as int) / 3 - 1) + (cast(OrderDate as int) % 3) + 1
and orderdate, Orderdate, 0)
, count(sh.SalesOrderID) FROM Sales.SalesOrderDetail shd
JOIN Sales.SalesOrderHeader sh on sh.SalesOrderID = shd.SalesOrderID
group by iif(OrderDate between 3 * (cast(OrderDate as int) / 3 - 1) + (cast(OrderDate as int) % 3) + 1
and orderdate, Orderdate, 0)
order by iif(OrderDate between 3 * (cast(OrderDate as int) / 3 - 1) + (cast(OrderDate as int) % 3) + 1
and orderdate, Orderdate, 0)
If you need else day group, you can use;
declare #n int = 4 (another day count)
SELECT iif(OrderDate between #n * (cast(OrderDate as int) / #n - 1) + (cast(OrderDate as int) % #n) + 1
and orderdate, Orderdate, 0)
, count(sh.SalesOrderID) FROM Sales.SalesOrderDetail shd
JOIN Sales.SalesOrderHeader sh on sh.SalesOrderID = shd.SalesOrderID
group by iif(OrderDate between #n * (cast(OrderDate as int) / #n - 1) + (cast(OrderDate as int) % #n) + 1
and orderdate, Orderdate, 0)
order by iif(OrderDate between #n * (cast(OrderDate as int) / #n - 1) + (cast(OrderDate as int) % #n) + 1
and orderdate, Orderdate, 0)

T-SQL Calculate duration in months between different years of ranges

I have a table in SQL Server which contains the duration of a user working for different jobs. I need to calculate the total number of experience for user.
Declare #temp table(Id int, FromDate DATETIME, ToDate DATETIME)
INSERT INTO #temp ( Id ,FromDate ,ToDate )
VALUES ( 1 , '2003-1-08 06:55:56' , '2005-5-08 06:55:56'),
( 2 , '2000-10-08 06:55:56' , '2008-7-08 06:55:56'),
( 3 , '2013-6-08 06:55:56' , '2015-1-08 06:55:56'),
( 4 , '2006-4-08 06:55:56' , '2011-3-08 06:55:56' )
SELECT * FROM #temp
I want to calculate the total number of experience;
Id FromDate ToDate Difference IN Months
===================================================
1 2003-01-08 2005-05-08 28
2 2000-10-08 2008-07-08 93
3 2013-06-08 2015-01-08 19
4 2006-04-08 2011-03-08 59
after removing the years overlapping like 2003-2005 covers up in 2000-2008;
I got something like this:
Id FromDate ToDate Difference IN Months
===================================================
1 2000-10-08 2011-03-08 125
2 2013-06-08 2015-01-08 19
So the answer would be 125+19 = 144 Months.
Please help me to find a solution.
The syntax here is finding all FromDate that doesn't have an overlapping FromDate and ToDate interval and all ToDates that doesn't have an overlapping FromDate and ToDate interval. Giving them a rownumber according to the date value and matching them on that rownumber:
;WITH CTE as
(
SELECT min(Id) Id ,FromDate, row_number() over (ORDER BY FromDate) rn
FROM #temp x
WHERE
not exists
(SELECT * FROM #temp WHERE x.FromDate > FromDate and x.FromDate <= Todate)
GROUP BY FromDate
), CTE2 as
(
SELECT Max(Id) Id ,ToDate, row_number() over (ORDER BY ToDate) rn
FROM #temp x
WHERE
not exists
(SELECT * FROM #temp WHERE x.ToDate >= FromDate and x.ToDate < Todate)
GROUP BY ToDate
)
SELECT SUM(DateDiff(month, CTE.FromDate, CTE2.ToDate))
FROM CTE
JOIN CTE2
ON CTE.rn = CTE2.rn
Result:
144
You can try this
SELECT Set1.FromDate,MIN(List1.ToDate) AS ToDate, DATEDIFF(MONTH,Set1.FromDate,MIN(List1.ToDate))
FROM #temp Set1
INNER JOIN #temp List1 ON Set1.FromDate <= List1.ToDate
AND NOT EXISTS(SELECT * FROM #temp List2
WHERE List1.ToDate >= List2.FromDate AND List1.ToDate < List2.ToDate)
WHERE NOT EXISTS(SELECT * FROM #temp Set2
WHERE Set1.FromDate > Set2.FromDate AND Set1.FromDate <= Set2.ToDate)
GROUP BY Set1.FromDate
ORDER BY Set1.FromDate
You can try this code:
DECLARE #temp TABLE (ID INT, FromDate DATETIME, ToDate DATETIME)
INSERT INTO #temp (ID, FromDate, ToDate)
VALUES ( 1 , '2003-1-08 06:55:56' , '2005-5-08 06:55:56'),
( 2 , '2000-10-08 06:55:56' , '2008-7-08 06:55:56'),
( 3 , '2013-6-08 06:55:56' , '2015-1-08 06:55:56'),
( 4 , '2006-4-08 06:55:56' , '2011-3-08 06:55:56' )
SELECT
ID,
CONVERT(DATE, FromDate) AS FromDate,
CONVERT(DATE, ToDate) AS ToDate,
DATEDIFF(MONTH, FromDate, ToDate) AS [Difference IN Months]
INTO #tmp
FROM #temp
SELECT T1.ID AS ID1, T2.ID AS ID2, T2.ToDate, T1.[Difference IN Months] + T2.[Difference IN Months] AS [Difference IN Months]
INTO #tmp2
FROM #tmp T1
INNER JOIN #tmp T2
ON CAST(T1.ToDate AS DATE) = CAST(T2.FromDate AS DATE)
OR (YEAR(T1.ToDate) = YEAR(T2.FromDate) AND CAST(T1.ToDate AS DATE) < CAST(T2.FromDate AS DATE))
OR YEAR(T1.ToDate) = YEAR(T2.FromDate) - 1
DELETE #tmp WHERE ID IN (SELECT ID2 FROM #tmp2)
UPDATE #tmp
SET ToDate = (SELECT ToDate FROM #tmp2 WHERE #tmp.ID = ID1),
[Difference IN Months] = (SELECT [Difference IN Months] FROM #tmp2 WHERE #tmp.ID = ID1)
WHERE ID IN (SELECT ID1 FROM #tmp2)
SELECT
*,
ROW_NUMBER() OVER(ORDER BY FromDate) AS RF
INTO #tmp3
FROM #tmp
SELECT T1.ID AS ID1, T2.ID AS ID2, T1.ToDate
INTO #tmp4
FROM #tmp3 T1
INNER JOIN #tmp3 T2 ON T1.RF = T2.RF + 1
WHERE CAST(T1.FromDate AS DATE) < CAST(T2.ToDate AS DATE)
UPDATE #tmp
SET ToDate = (SELECT ToDate FROM #tmp4 WHERE #tmp.ID = ID2)
WHERE ID IN (SELECT ID2 FROM #tmp4)
DELETE #tmp WHERE ID IN (SELECT ID1 FROM #tmp4)
UPDATE #tmp
SET[Difference IN Months] = DATEDIFF(MONTH, FromDate, ToDate)
SELECT
ROW_NUMBER() OVER(ORDER BY FromDate) AS ID,
FromDate, ToDate, [Difference IN Months]
FROM #tmp
DROP TABLE #tmp
DROP TABLE #tmp2
DROP TABLE #tmp3
DROP TABLE #tmp4
Result:
ID FromDate ToDate Difference IN Months
===================================================
1 2000-10-08 2011-03-08 125
2 2013-06-08 2015-01-08 19