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Segment distance between segments in SQL

I have a SQL Server 2005 database that contains a Memberships table.

Table layout:

PersonID int, Surname nvarchar(30), FirstName nvarchar(30), Description nvarchar(100), StartDate datetime, EndDate datetime

I am currently working on a grid function that shows a breakdown of membership from a person. One of the requirements is the separation of membership rows, where there is the intersection of date ranges. The intersection should be connected with the surname and first name FirstName, i.e. Splits occur only with membership records of the same surname and first name.

Example table data:

18 Smith John Poker Club 01/01/2009 NULL
18 Smith John Library 01/05/2009 01/18/2009
18 Smith John Gym 01/10/2009 01/28/2009
26 Adams Jane Pilates 01/03/2009 02/16/2009

Expected Result:

18 Smith John Poker Club 01/01/2009 01/04/2009
18 Smith John Poker Club / Library 01/05/2009 01/09/2009
18 Smith John Poker Club / Library / Gym 01/10/2009 01/18/2009
18 Smith John Poker Club / Gym 01/19/2009 01/28/2009
18 Smith John Poker Club 01/29/2009 NULL
26 Adams Jane Pilates 01/03/2009 02/16/2009

Does anyone know how I can write a stored procedure that will return a result set that has the breakdown described above.

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3 answers

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ROW_NUMBER, , .

/*
SET DATEFORMAT dmy
USE tempdb;
GO
CREATE TABLE Schedule
( PersonID int, 
 Surname nvarchar(30), 
 FirstName nvarchar(30), 
 Description nvarchar(100), 
 StartDate datetime, 
 EndDate datetime)
GO
INSERT INTO Schedule VALUES (18, 'Smith', 'John', 'Poker Club', '01/01/2009', NULL)
INSERT INTO Schedule VALUES (18, 'Smith', 'John', 'Library', '05/01/2009', '18/01/2009')
INSERT INTO Schedule VALUES (18, 'Smith', 'John', 'Gym', '10/01/2009', '28/01/2009')
INSERT INTO Schedule VALUES (26, 'Adams', 'Jane', 'Pilates', '03/01/2009', '16/02/2009')
GO

*/

SELECT 
 PersonID, 
 Description, 
 theDate
INTO #SplitRanges
FROM Schedule, (SELECT DATEADD(dd, number, '01/01/2008') AS theDate
    FROM master..spt_values
    WHERE type = N'P') AS DayTab
WHERE theDate >= StartDate 
  AND theDate <= isnull(EndDate, '31/12/2012')

SELECT 
 ROW_NUMBER() OVER (ORDER BY PersonID, theDate) AS rowid,
 PersonID, 
 theDate, 
 STUFF((
  SELECT '/' + Description
  FROM #SplitRanges AS s
  WHERE s.PersonID = sr.PersonID 
    AND s.theDate = sr.theDate
  FOR XML PATH('')
  ), 1, 1,'') AS Descriptions
INTO #MergedDescriptions
FROM #SplitRanges AS sr
GROUP BY PersonID, theDate


SELECT 
 ROW_NUMBER() OVER (ORDER BY PersonID, theDate) AS ID, 
 *
INTO #InterimResults
FROM
(
 SELECT * 
 FROM #MergedDescriptions AS t1
 WHERE NOT EXISTS 
  (SELECT 1 
   FROM #MergedDescriptions AS t2 
   WHERE t1.PersonID = t2.PersonID 
     AND t1.RowID - 1 = t2.RowID 
     AND t1.Descriptions = t2.Descriptions)
UNION ALL
 SELECT * 
 FROM #MergedDescriptions AS t1
 WHERE NOT EXISTS 
  (SELECT 1 
   FROM #MergedDescriptions AS t2 
   WHERE t1.PersonID = t2.PersonID 
     AND t1.RowID = t2.RowID - 1
     AND t1.Descriptions = t2.Descriptions)
) AS t

SELECT DISTINCT 
 PersonID, 
 Surname, 
 FirstName
INTO #DistinctPerson
FROM Schedule

SELECT 
 t1.PersonID, 
 dp.Surname, 
 dp.FirstName, 
 t1.Descriptions, 
 t1.theDate AS StartDate, 
 CASE 
  WHEN t2.theDate = '31/12/2012' THEN NULL 
  ELSE t2.theDate 
 END AS EndDate
FROM #DistinctPerson AS dp
JOIN #InterimResults AS t1 
 ON t1.PersonID = dp.PersonID
JOIN #InterimResults AS t2 
 ON t2.PersonID = t1.PersonID 
  AND t1.ID + 1 = t2.ID 
  AND t1.Descriptions = t2.Descriptions

DROP TABLE #SplitRanges
DROP TABLE #MergedDescriptions
DROP TABLE #DistinctPerson
DROP TABLE #InterimResults

/*

DROP TABLE Schedule

*/

, , PersonID 18, :

INSERT INTO Schedule VALUES (18, 'Smith', 'John', 'Gym', '10/02/2009', '28/02/2009')

. , , , . , SELECT DISTINCT, JOIN.

+2

SET DATEFORMAT dmy
DECLARE @Membership TABLE( 
    PersonID    int, 
    Surname     nvarchar(16), 
    FirstName   nvarchar(16), 
    Description nvarchar(16), 
    StartDate   datetime, 
    EndDate     datetime)   
INSERT INTO @Membership VALUES (18, 'Smith', 'John', 'Poker Club', '01/01/2009', NULL)
INSERT INTO @Membership VALUES (18, 'Smith', 'John','Library', '05/01/2009', '18/01/2009')
INSERT INTO @Membership VALUES (18, 'Smith', 'John','Gym', '10/01/2009', '28/01/2009')
INSERT INTO @Membership VALUES (26, 'Adams', 'Jane','Pilates', '03/01/2009', '16/02/2009')

--Program Starts
declare @enddate datetime
--Measuring extreme condition when all the enddates are null(i.e. all the memberships for all members are in progress)
-- in such a case taking any arbitary date e.g. '31/12/2009' here else add 1 more day to the highest enddate
select @enddate =  case when max(enddate) is null then '31/12/2009' else max(enddate) + 1 end from @Membership

--Fill the null enddates
; with fillNullEndDates_cte as
(
    select
            row_number() over(partition by PersonId order by PersonId) RowNum
            ,PersonId
            ,Surname
            ,FirstName
            ,Description
            ,StartDate
            ,isnull(EndDate,@enddate) EndDate
    from @Membership
)
--Generate a date calender
, generateCalender_cte as
(
    select 
        1 as CalenderRows
        ,min(startdate) DateValue
    from @Membership
       union all
        select 
            CalenderRows+1
            ,DateValue + 1
        from    generateCalender_cte   
        where   DateValue + 1 <= @enddate
)
--Generate Missing Dates based on Membership
,datesBasedOnMemberships_cte as
 (
    select 
            t.RowNum
            ,t.PersonId
            ,t.Surname
            ,t.FirstName
            ,t.Description          
            , d.DateValue
            ,d.CalenderRows
    from generateCalender_cte d 
    join fillNullEndDates_cte t ON d.DateValue between t.startdate and t.enddate
)
--Generate Dscription Based On Membership Dates
, descriptionBasedOnMembershipDates_cte as
(
    select    
        PersonID
        ,Surname
        ,FirstName
        ,stuff((
            select '/' + Description
            from datesBasedOnMemberships_cte d1
            where d1.PersonID = d2.PersonID 
            and d1.DateValue = d2.DateValue
            for xml path('')
        ), 1, 1,'') as Description
        , DateValue
        ,CalenderRows
    from datesBasedOnMemberships_cte d2
    group by PersonID, Surname,FirstName,DateValue,CalenderRows
)
--Grouping based on membership dates
,groupByMembershipDates_cte as
(
    select d.*,
    CalenderRows - row_number() over(partition by Description order by PersonID, DateValue) AS  [Group]
    from descriptionBasedOnMembershipDates_cte d
)
select PersonId
,Surname
,FirstName
,Description
,convert(varchar(10), convert(datetime, min(DateValue)), 103) as StartDate
,case when max(DateValue)= @enddate then null else convert(varchar(10), convert(datetime, max(DateValue)), 103) end as EndDate
from groupByMembershipDates_cte 
group by [Group],PersonId,Surname,FirstName,Description
order by PersonId,StartDate
option(maxrecursion 0)
+1

[ , .]

, , XML PATH.

, :

, :

EXEC dbo.DateSegments_AlignWithinTable
@tableName = 'tableName',
@keyFieldList = 'PersonID',
@nonKeyFieldList = 'Description',
@effectivveDateFieldName = 'StartDate',
@terminationDateFieldName = 'EndDate'

( ) ( , "AlignedDataTable" ). , .

SELECT 
    PersonID, StartDate, EndDate,

    SUBSTRING ((SELECT ',' + [Description] FROM AlignedDataTable AS innerTable 
        WHERE 
            innerTable.PersonID = AlignedDataTable.PersonID
            AND (innerTable.StartDate = AlignedDataTable.StartDate) 
            AND (innerTable.EndDate = AlignedDataTable.EndDate)
        ORDER BY id
        FOR XML PATH ('')), 2, 999999999999999) AS IdList

 FROM AlignedDataTable
 GROUP BY PersonID, StartDate, EndDate 
 ORDER BY PersonID, StartDate
0

Source: https://habr.com/ru/post/1717218/

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