You have to use SQL Server relational operator UNPIVOT/CROSS
APPLY to UnPivot data from Pivoted data.
·
For
single measure its simple to write unpivot query (tSql).
·
But
for multiple measures, unpivot operator should have to be used for multiple
times and a where clause required to relate each unpivor operator depends on
your chosen common dimension.
Example:
v Single
measure:
Ø Sample
Data - Table Name ([dbo].[TEST_PIVOT])
CITY
|
People
– 2001
|
People
– 2002
|
Dhaka
|
45623
|
524854
|
Dilly
|
456987
|
5478965
|
Ø Sample
Output
§ Here, CITY
is your provided dimension and People & 2001/2002 is your unpivotable measure & dimension (period).
CITY
|
Period
|
People
|
Dhaka
|
2001
|
45623
|
Dhaka
|
2002
|
524854
|
Dilly
|
2001
|
456987
|
Dilly
|
2002
|
5478965
|
Ø tSQL-
select CITY,
Period, People
from ( select
CITY, [People – 2001] as [2001], [People – 2002] as [2002] from [dbo].[TEST_PIVOT] ) Data
UNPIVOT (
People for Period IN ([2001], [ 2001])
) upvt
v Multi
Measures:
Ø Sample
Data
CITY
|
People
– 2001
|
People
– 2002
|
Home
– 2001
|
Home
- 2002
|
Dhaka
|
45623
|
524854
|
4000
|
50000
|
Dilly
|
456987
|
5478965
|
40000
|
5000000
|
Ø Sample
Output
§ Here, CITY
is your provided dimension and People & 2001/2002 is your unpivotable measure & dimension (period).
CITY
|
Period
|
People
|
Home
|
Dhaka
|
2001
|
45623
|
4000
|
Dhaka
|
2002
|
524854
|
50000
|
Dilly
|
2001
|
456987
|
40000
|
Dilly
|
2002
|
5478965
|
5000000
|
Ø tSQL
-
§ using
UNPIVOT operator-
select CITY,
PeriodPeople as Period, People, Home
from ( select
CITY, [People – 2001], [People – 2002], [Home – 2001], [Home – 2002] from [dbo].[TEST_PIVOT] ) Data
UNPIVOT (
People for PeriodPeople IN ([People – 2001], [People – 2002])
) upvtP
UNPIVOT (
Home for PeriodHome IN ([Home – 2001], [Home – 2002] )
) upvtH
WHERE RIGHT(upvtP.PeriodPeople,4) = RIGHT (upvtH.PeriodHome,4)
§ using
CROSS APPLY operator -
SELECT [CITY]
, [PERIOD]
, [People]
, [Home]
FROM [dbo].[TEST_PIVOT]
CROSS APPLY (
VALUES (
[People-2001]
, [Home-2001]
, right([People-2001], 4)
)
, (
[People-2002]
, [Home-2002]
, right([People-2002], 4)
)
) a([People], [Home], [PERIOD])
SELECT [CITY]
, [PERIOD]
, [People]
, [Home]
FROM [dbo].[TEST_PIVOT]
CROSS APPLY (
VALUES (
[People-2001]
, [Home-2001]
, right([People-2001], 4)
)
, (
[People-2002]
, [Home-2002]
, right([People-2002], 4)
)
) a([People], [Home], [PERIOD])
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