我需要拆分重叠的日期范围。我有一个主表（我在本例中将其称为“就业”），我需要从此表中返回一个人的所有Begin-End日期范围。我也有多个子表（由Car和Food表示），我想在主表中给出的时间内返回子表中活动的值。这将涉及在子表项更改时拆分主表日期范围。
我不想返回不在主表中的日期的子表信息。
DECLARE @Employment TABLE
( Person_ID INT, Employment VARCHAR(50), Begin_Date DATE, End_Date DATE )
DECLARE @Car TABLE
( Person_ID INT, Car VARCHAR(50), Begin_Date DATE, End_Date DATE )
DECLARE @Food TABLE
( Person_ID INT, Food VARCHAR(50), Begin_Date DATE, End_Date DATE )
INSERT INTO @Employment ( [Person_ID], [Employment], [Begin_Date], [End_Date] )
VALUES ( 123 , 'ACME' , '1986-01-01' , '1990-12-31' )
, ( 123 , 'Office Corp' , '1995-05-15' , '1998-10-03' )
, ( 123 , 'Job 3' , '1998-10-04' , '2999-12-31' )
INSERT INTO @Car ( [Person_ID] , [Car] , [Begin_Date] , [End_Date] )
VALUES ( 123, 'Red Car', '1986-05-01', '1997-06-23' )
, ( 123, 'Blue Car', '1997-07-03', '2999-12-31' )
INSERT INTO @Food ( [Person_ID], [Food], [Begin_Date], [End_Date] )
VALUES ( 123, 'Eggs', '1997-01-01', '1997-03-09' )
, ( 123, 'Donuts', '2001-02-23', '2001-02-25' )
对于上述数据，结果应为：
Person_ID Employment Food Car Begin_Date End_Date
123 ACME 1986-01-01 1986-04-30
123 ACME Red Car 1986-05-01 1990-12-31
123 Office Corp Red Car 1995-05-15 1996-12-31
123 Office Corp Eggs Red Car 1997-01-01 1997-03-09
123 Office Corp Red Car 1997-03-10 1997-06-23
123 Office Corp 1997-06-24 1997-07-02
123 Office Corp Blue Car 1997-07-03 1998-10-03
123 Job 3 Blue Car 1998-10-04 2001-02-22
123 Job 3 Donuts Blue Car 2001-02-23 2001-02-25
123 Job 3 Blue Car 2001-02-26 2999-12-31
第一排是他在ACME工作的时间，在那里他没有汽车或奇怪的食物痴迷。在第二排，他购买了一辆汽车，仍然在ACME工作。在第三排，他将工作换成了Office Corp，但仍然拥有红色汽车。请注意，即使他有红色汽车，我们在失业期间也不会返回数据。我们只想知道就业表中有值的时候汽车和食品表中的内容。
我找到了一个使用LEAD / LAG功能来实现这一目标的SQL Server 2012解决方案，但我仍然坚持使用2008 R2。
答案 0 :(得分：1)
要将2012年的解决方案从该博客更改为使用2008，您需要在以下内容中替换LEAD
with
ValidDates as …
,
ValidDateRanges1 as
(
select EmployeeNo, Date as ValidFrom, lead(Date,1) over (partition by EmployeeNo order by Date) ValidTo
from ValidDates
)
有很多方法可以做到这一点，但是一个例子是自相连到同一个表+ 1行（这实际上是一个领导者）。一种方法是通过添加另一个中间CTE（例如ValidDatesWithRowno）将rownumber放在上一个表上（因此很容易找到下一行）。然后对该表执行左外连接，其中EmployeeNo相同且rowno = rowno + 1，并使用该值替换潜在客户。如果你想要一个领先2，你会加入到rowno + 2等等。所以2008版本看起来像
with
ValidDates as …
,
ValidDatesWithRowno as --This is the ValidDates + a RowNo for easy self joining below
(
select EmployeeNo, Date, ROW_NUMBER() OVER (ORDER BY EmployeeNo, Date) as RowNo from ValidDates
)
,
ValidDateRanges1 as
(
select VD.EmployeeNo, VD.Date as ValidFrom, VDLead1.Date as ValidTo
from ValidDatesWithRowno VD
left outer join ValidDatesWithRowno VDLead1 on VDLead1.EmployeeNo = VD.EmployeeNo
and VDLead1.RowNo = VD.RowNo + 1
)
所描述的解决方案的其余部分看起来像是你想要的2008年。
答案 1 :(得分：0)
这是我想出的答案。它有效，但它不是很漂亮。
它是两波，首先拆分任何重叠的就业/汽车日期，然后再次运行相同的SQL添加食物日期并再次拆分任何重叠。
DECLARE @Employment TABLE
( Person_ID INT, Employment VARCHAR(50), Begin_Date DATE, End_Date DATE )
DECLARE @Car TABLE
( Person_ID INT, Car VARCHAR(50), Begin_Date DATE, End_Date DATE )
DECLARE @Food TABLE
( Person_ID INT, Food VARCHAR(50), Begin_Date DATE, End_Date DATE )
INSERT INTO @Employment ( [Person_ID], [Employment], [Begin_Date], [End_Date] )
VALUES ( 123 , 'ACME' , '1986-01-01' , '1990-12-31' )
, ( 123 , 'Office Corp' , '1995-05-15' , '1998-10-03' )
, ( 123 , 'Job 3' , '1998-10-04' , '2999-12-31' )
INSERT INTO @Car ( [Person_ID] , [Car] , [Begin_Date] , [End_Date] )
VALUES ( 123, 'Red Car', '1986-05-01', '1997-06-23' )
, ( 123, 'Blue Car', '1997-07-03', '2999-12-31' )
INSERT INTO @Food ( [Person_ID], [Food], [Begin_Date], [End_Date] )
VALUES ( 123, 'Eggs', '1997-01-01', '1997-03-09' )
, ( 123, 'Donuts', '2001-02-23', '2001-02-25' )
DECLARE @Person_ID INT = 123;
--A table to hold date ranges that need to be merged together
DECLARE @DatesToMerge TABLE
(
ID INT,
Person_ID INT,
Date_Type VARCHAR(10),
Begin_Date DATETIME,
End_Date DATETIME
)
INSERT INTO @DatesToMerge
SELECT ROW_NUMBER() OVER(ORDER BY [Car])
, Person_ID
, 'Car'
, Begin_Date
, End_Date
FROM @Car
WHERE Person_ID = @Person_ID
INSERT INTO @DatesToMerge
SELECT ROW_NUMBER() OVER(ORDER BY [Employment])
, Person_ID
, 'Employment'
, Begin_Date
, End_Date
FROM @Employment
WHERE Person_ID = @Person_ID;
--A table to hold the merged @Employment and Car records
DECLARE @EmploymentAndCar TABLE
(
RowNumber INT,
Person_ID INT,
Begin_Date DATETIME,
End_Date DATETIME
)
;
WITH CarCTE AS
(--This CTE grabs just the Car rows so we can compare and split dates from them
SELECT ID,
Person_ID,
Date_Type,
Begin_Date,
End_Date
FROM @DatesToMerge
WHERE Date_Type = 'Car'
),
NewRowsCTE AS
( --This CTE creates just new rows starting after the Car dates for each @Employment date range
SELECT a.ID,
a.Person_ID,
a.Date_Type,
DATEADD(DAY,1,b.End_Date) AS Begin_Date,
a.End_Date
FROM @DatesToMerge a
INNER JOIN CarCTE b
ON a.Begin_Date <= b.Begin_Date
AND a.End_Date > b.Begin_Date
AND a.End_Date > b.End_Date -- This is needed because if both the Car and @Employment end on the same date, there is split row after
),
UnionCTE AS
( -- This CTE merges the new rows with the existing ones
SELECT ID,
Person_ID,
Date_Type,
Begin_Date,
End_Date
FROM @DatesToMerge
UNION ALL
SELECT ID,
Person_ID,
Date_Type,
Begin_Date,
End_Date
FROM NewRowsCTE
),
FixEndDateCTE AS
(
SELECT CONVERT (CHAR,c.ID)+CONVERT (CHAR,c.Begin_Date) AS FixID,
MIN(d.Begin_Date) AS Begin_Date
FROM UnionCTE c
LEFT OUTER JOIN CarCTE d
ON c.Begin_Date < d.Begin_Date
AND c.End_Date >= d.Begin_Date
WHERE c.Date_Type <> 'Car'
GROUP BY CONVERT (CHAR,c.ID)+CONVERT (CHAR,c.Begin_Date)
),
Finalize AS
(
SELECT ROW_NUMBER() OVER (ORDER BY e.Begin_Date) AS RowNumber,
e.Person_ID,
e.Begin_Date,
CASE WHEN f.Begin_Date IS NULL THEN e.End_Date
ELSE DATEADD (DAY,-1,f.Begin_Date)
END AS EndDate
FROM UnionCTE e
LEFT OUTER JOIN FixEndDateCTE f
ON (CONVERT (CHAR,e.ID)+CONVERT (CHAR,e.Begin_Date)) = f.FixID
)
INSERT INTO @EmploymentAndCar ( RowNumber, Person_ID, Begin_Date, End_Date )
SELECT F.RowNumber
, F.Person_ID
, F.Begin_Date
, F.EndDate
FROM Finalize F
INNER JOIN @Employment Employment
ON F.Begin_Date BETWEEN Employment.Begin_Date AND Employment.End_Date AND Employment.Person_ID = @Person_ID
ORDER BY F.Begin_Date
--------------------------------------------------------------------------------------------------
--Now that the Employment and Car dates have been merged, empty the DatesToMerge table
DELETE FROM @DatesToMerge;
--Reload the DatesToMerge table with the newly-merged Employment and Car records,
--and the Food records that still need to be merged
INSERT INTO @DatesToMerge
SELECT RowNumber
, Person_ID
, 'PtBCar'
, Begin_Date
, End_Date
FROM @EmploymentAndCar
WHERE Person_ID = @Person_ID
INSERT INTO @DatesToMerge
SELECT ROW_NUMBER() OVER(ORDER BY [Food])
, Person_ID
, 'Food'
, Begin_Date
, End_Date
FROM @Food
WHERE Person_ID = @Person_ID
;
WITH CarCTE AS
(--This CTE grabs just the Food rows so we can compare and split dates from them
SELECT ID,
Person_ID,
Date_Type,
Begin_Date,
End_Date
FROM @DatesToMerge
WHERE Date_Type = 'Food'
),
NewRowsCTE AS
( --This CTE creates just new rows starting after the Food dates for each Employment date range
SELECT a.ID,
a.Person_ID,
a.Date_Type,
DATEADD(DAY,1,b.End_Date) AS Begin_Date,
a.End_Date
FROM @DatesToMerge a
INNER JOIN CarCTE b
ON a.Begin_Date <= b.Begin_Date
AND a.End_Date > b.Begin_Date
AND a.End_Date > b.End_Date -- This is needed because if both the Food and Car/Employment end on the same date, there is split row after
),
UnionCTE AS
( -- This CTE merges the new rows with the existing ones
SELECT ID,
Person_ID,
Date_Type,
Begin_Date,
End_Date
FROM @DatesToMerge
UNION ALL
SELECT ID,
Person_ID,
Date_Type,
Begin_Date,
End_Date
FROM NewRowsCTE
),
FixEndDateCTE AS
(
SELECT CONVERT (CHAR,c.ID)+CONVERT (CHAR,c.Begin_Date) AS FixID,
MIN(d.Begin_Date) AS Begin_Date
FROM UnionCTE c
LEFT OUTER JOIN CarCTE d
ON c.Begin_Date < d.Begin_Date
AND c.End_Date >= d.Begin_Date
WHERE c.Date_Type <> 'Food'
GROUP BY CONVERT (CHAR,c.ID)+CONVERT (CHAR,c.Begin_Date)
),
Finalize AS
(
SELECT ROW_NUMBER() OVER (ORDER BY e.Begin_Date) AS RowNumber,
e.Person_ID,
e.Begin_Date,
CASE WHEN f.Begin_Date IS NULL THEN e.End_Date
ELSE DATEADD (DAY,-1,f.Begin_Date)
END AS EndDate
FROM UnionCTE e
LEFT OUTER JOIN FixEndDateCTE f
ON (CONVERT (CHAR,e.ID)+CONVERT (CHAR,e.Begin_Date)) = f.FixID
)
SELECT DISTINCT
F.Person_ID
, Employment
, Car
, Food
, F.Begin_Date
, F.EndDate
FROM Finalize F
INNER JOIN @Employment Employment
ON F.Begin_Date BETWEEN Employment.Begin_Date AND Employment.End_Date AND Employment.Person_ID = @Person_ID
LEFT JOIN @Car Car
ON Car.[Begin_Date] <= F.Begin_Date
AND Car.[End_Date] >= F.[EndDate]
AND Car.Person_ID = @Person_ID
LEFT JOIN @Food Food
ON Food.[Begin_Date] <= F.[Begin_Date]
AND Food.[End_Date] >= F.[EndDate]
AND Food.Person_ID = @Person_ID
ORDER BY F.Begin_Date
如果有人有更优雅的解决方案，我很乐意接受他们的回答。