我有一个SQL Server 2005数据库，其中包含一个名为Memberships的表。
表架构是：
PersonID int, Surname nvarchar(30), FirstName nvarchar(30), Description nvarchar(100), StartDate datetime, EndDate datetime我目前正在制作网格功能，该功能显示了按人员分列的会员资格。其中一个要求是在存在日期范围交集的位置拆分成员资格行。交集必须由Surname和FirstName绑定，即拆分仅与同一姓氏和FirstName的成员资格记录一起发生。
示例表数据：
18 Smith John Poker Club 01/01/2009 NULL 18 Smith John Library 05/01/2009 18/01/2009 18 Smith John Gym 10/01/2009 28/01/2009 26 Adams Jane Pilates 03/01/2009 16/02/2009
预期结果集：
18 Smith John Poker Club 01/01/2009 04/01/2009 18 Smith John Poker Club / Library 05/01/2009 09/01/2009 18 Smith John Poker Club / Library / Gym 10/01/2009 18/01/2009 18 Smith John Poker Club / Gym 19/01/2009 28/01/2009 18 Smith John Poker Club 29/01/2009 NULL 26 Adams Jane Pilates 03/01/2009 16/02/2009
有没有人知道如何编写一个存储过程，它将返回一个具有上述细分的结果集。
答案 0 :(得分：2)
您将遇到的问题是，随着数据集的增长，使用TSQL解决问题的解决方案将无法很好地扩展。下面使用一系列临时表来解决问题。它使用数字表将每个日期范围条目分成各自的日期。这是它无法扩展的地方，主要是由于您的开放范围NULL值似乎是无限的，因此您必须交换远期的固定日期，将转换范围限制为可行的时间长度。您可以通过构建天数表或日历表来获得更好的性能，并使用适当的索引来优化每天的渲染。
分割范围后，将使用XML PATH合并描述，以便范围系列中的每一天都具有为其列出的所有描述。按PersonID和Date进行行编号允许使用两个NOT EXISTS检查找到每个范围的第一行和最后一行，以查找匹配的PersonID和描述集不存在前一行的实例，或者下一行没有的情况t存在匹配的PersonID和Description集。
然后使用ROW_NUMBER重新编号此结果集，以便它们可以配对以构建最终结果。
/*
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
*/
上述解决方案也将处理其他描述之间的差距，因此如果您要为PersonID 18添加另一个描述，留下空白：
INSERT INTO Schedule VALUES (18, 'Smith', 'John', 'Gym', '10/02/2009', '28/02/2009')
它将适当填补空白。正如评论中所指出的，你不应该在这个表中有名称信息，它应该被标准化为可以在最终结果中加入的人员表。我使用SELECT DISTINCT模拟了另一个表，以构建一个临时表来创建JOIN。
答案 1 :(得分：1)
试试这个
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)
答案 2 :(得分：0)
[仅仅很多年以后。]
我创建了一个存储过程，它将通过单个表中的分区对齐和中断段，然后您可以使用这些对齐的中断使用子查询和XML PATH将描述转换为不规则列。
看看以下帮助：
例如，您的通话可能如下所示：
EXEC dbo.DateSegments_AlignWithinTable
@tableName = 'tableName',
@keyFieldList = 'PersonID',
@nonKeyFieldList = 'Description',
@effectivveDateFieldName = 'StartDate',
@terminationDateFieldName = 'EndDate'
您需要将结果（这是一个表）捕获到另一个表或临时表中（假设在下面的示例中将其称为“AlignedDataTable”）。然后，您可以使用子查询进行透视。
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