The ParaellePeriod function allows you to compare values โโbetween time points (how to compare sales compared to last year). I am doing something wrong in my use, but I have no idea what it could be.
Customization
I created a simple PowerPivot SQL Server 2008+ source query and named it Source. The query generates 168 lines: 6 identifiers (100-600) and 28 dates (first month from January 2010 to April 2012), all crossed are applied together.
; WITH SRC (groupKey, eventDate, value) AS
(
SELECT G.groupKey, D.eventDate, CAST(rand(G.groupKey * year(D.eventDate) * month(D.eventDate)) * 100 AS int)
FROM
(
SELECT 100
UNION ALL SELECT 200
UNION ALL SELECT 300
UNION ALL SELECT 400
UNION ALL SELECT 500
UNION ALL SELECT 600
) G (groupKey)
CROSS APPLY
(
SELECT CAST('2010-01-01' AS date)
UNION ALL SELECT CAST('2010-02-01' AS date)
UNION ALL SELECT CAST('2010-03-01' AS date)
UNION ALL SELECT CAST('2010-04-01' AS date)
UNION ALL SELECT CAST('2010-05-01' AS date)
UNION ALL SELECT CAST('2010-06-01' AS date)
UNION ALL SELECT CAST('2010-07-01' AS date)
UNION ALL SELECT CAST('2010-08-01' AS date)
UNION ALL SELECT CAST('2010-09-01' AS date)
UNION ALL SELECT CAST('2010-10-01' AS date)
UNION ALL SELECT CAST('2010-11-01' AS date)
UNION ALL SELECT CAST('2010-12-01' AS date)
UNION ALL SELECT CAST('2011-01-01' AS date)
UNION ALL SELECT CAST('2011-02-01' AS date)
UNION ALL SELECT CAST('2011-03-01' AS date)
UNION ALL SELECT CAST('2011-04-01' AS date)
UNION ALL SELECT CAST('2011-05-01' AS date)
UNION ALL SELECT CAST('2011-06-01' AS date)
UNION ALL SELECT CAST('2011-07-01' AS date)
UNION ALL SELECT CAST('2011-08-01' AS date)
UNION ALL SELECT CAST('2011-09-01' AS date)
UNION ALL SELECT CAST('2011-10-01' AS date)
UNION ALL SELECT CAST('2011-11-01' AS date)
UNION ALL SELECT CAST('2011-12-01' AS date)
UNION ALL SELECT CAST('2012-01-01' AS date)
UNION ALL SELECT CAST('2012-02-01' AS date)
UNION ALL SELECT CAST('2012-03-01' AS date)
UNION ALL SELECT CAST('2012-04-01' AS date)
) D (eventDate)
)
SELECT
*
FROM
SRC;
I added a derived column to PowerPivot using Formula I taken from MSDN
=CALCULATE(SUM(Source[value]), PARALLELPERIOD(Source[eventDate], -1, year))
No errors are displayed, but there has never been any calculated data. I tried different intervals (-1, +1) and periods (year, month), but to no avail.
, , MSDN, , . , . 2010-01-01 2012-06-01 (1096 )
DECLARE
@start int = 20100101
, @stop int = 20120601;
WITH L0 AS
(
SELECT
0 AS C
UNION ALL
SELECT
0
)
, L1 AS
(
SELECT
0 AS c
FROM
L0 AS A
CROSS JOIN L0 AS B
)
, L2 AS
(
SELECT
0 AS c
FROM
L1 AS A
CROSS JOIN L1 AS B
)
, L3 AS
(
SELECT
0 AS c
FROM
L2 AS A
CROSS JOIN L2 AS B
)
, L4 AS
(
SELECT
0 AS c
FROM
L3 AS A
CROSS JOIN L3 AS B
)
, L5 AS
(
SELECT
0 AS c
FROM
L4 AS A
CROSS JOIN L4 AS B
)
, NUMS AS
(
SELECT
ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) AS number
FROM
L5
)
, YEARS AS
(
SELECT
Y.number
FROM
NUMS Y
WHERE
Y.number BETWEEN @start / 10000 AND @stop / 10000
)
, MONTHS AS
(
SELECT
Y.number
FROM
NUMS Y
WHERE
Y.number BETWEEN 1 and 12
)
, DAYS AS
(
SELECT
Y.number
FROM
NUMS Y
WHERE
Y.number BETWEEN 1 and 31
)
, CANDIDATES_0 AS
(
SELECT
Y.number * 10000 + M.number * 100 + D.number AS SurrogateKey
, CAST(Y.number * 10000 + M.number * 100 + D.number AS char(8)) AS DateValue
FROM
YEARS Y
CROSS APPLY
MONTHS M
CROSS APPLY
DAYS D
)
, HC AS
(
SELECT
Y.number * 10000 + M.number * 100 + D.number AS SurrogateKey
, CAST(Y.number * 10000 + M.number * 100 + D.number AS char(8)) AS DateValue
FROM
YEARS Y
CROSS APPLY
MONTHS M
CROSS APPLY
DAYS D
WHERE
D.number < 31
AND M.number IN (4,6,9,11)
UNION ALL
SELECT
Y.number * 10000 + M.number * 100 + D.number AS SurrogateKey
, CAST(Y.number * 10000 + M.number * 100 + D.number AS char(8)) AS DateValue
FROM
YEARS Y
CROSS APPLY
MONTHS M
CROSS APPLY
DAYS D
WHERE
D.number < 32
AND M.number IN (1,3,5,7,8,10,12)
UNION ALL
SELECT
Y.number * 10000 + M.number * 100 + D.number AS SurrogateKey
, CAST(Y.number * 10000 + M.number * 100 + D.number AS char(8)) AS DateValue
FROM
YEARS Y
CROSS APPLY
MONTHS M
CROSS APPLY
DAYS D
WHERE
D.number < 29
AND M.number = 2
AND
(
Y.number % 4 > 0
OR Y.number % 100 = 0 AND Y.number % 400 > 0
)
UNION ALL
SELECT
Y.number * 10000 + M.number * 100 + D.number AS SurrogateKey
, CAST(Y.number * 10000 + M.number * 100 + D.number AS char(8)) AS DateValue
FROM
YEARS Y
CROSS APPLY
MONTHS M
CROSS APPLY
DAYS D
WHERE
D.number < 30
AND M.number = 2
AND
(
Y.number % 4 = 0
OR Y.number % 100 = 0 AND Y.number % 400 = 0
)
)
, CANDIDATES AS
(
SELECT
C.SurrogateKey
, CAST(C.DateValue as date) As DateValue
FROM
HC C
WHERE
ISDATE(c.DateValue) = 1
)
, PARTS
(
DateKey
, FullDateAlternateKey
, DayNumberOfWeek
, EnglishDayNameOfWeek
, DayNumberOfMonth
, DayNumberOfYear
, WeekNumberOfYear
, EnglishMonthName
, MonthNumberOfYear
, CalendarQuarter
, CalendarYear
, CalendarSemester
) AS
(
SELECT
CAST(C.SurrogateKey AS int)
, C.DateValue
, DATEPART(WEEKDAY, C.DateValue)
, DATENAME(WEEKDAY, C.DateValue)
, DATEPART(DAY, C.DateValue)
, DATEPART(DAYOFYEAR, C.DateValue)
, DATEPART(WEEK, C.DateValue)
, DATENAME(MONTH, C.DateValue)
, DATEPART(MONTH, C.DateValue)
, DATEPART(QUARTER, C.DateValue)
, DATEPART(YEAR, C.DateValue)
, DATEPART(WEEK, C.DateValue)
FROM
CANDIDATES C
WHERE
C.DateValue IS NOT NULL
)
SELECT
P.*
FROM
PARTS P
ORDER BY 1;
Source Dates
=CALCULATE(SUM(Source[value]), PARALLELPERIOD(Dates[FullDateAlternateKey], -1, year))
PowerPivot
, ?