Fetching Previous Member while using order function in MDX - ssas

Question

I have a mdx query which returns "productCode" and "Product share of total Sales" as a result.Also i need that query be sorted on "Product share of total Sales" (Decs)
So I came up with following MDX Query
WITH MEMBER [Measures].[Contribution] AS
Format(
IIF(
IsEmpty([Measures].[Detail_Net_Sales]),
0,
[Measures].[Detail_Net_Sales]
)/
[Measures].[SumTotalPayable]
)
SELECT
{[Measures].[Contribution]}
ON COLUMNS,
Order(
[DIMProduct].[ProductCode].[ProductCode].AllMEMBERS,
[Measures].[Contribution],
BDESC
)
ON ROWS
FROM [Model] }
the problem is when i also want to have Previous Contribution for each productcode
i wrote down somthing like this :
WITH MEMBER [Measures].[Contribution] AS
Format(iif(IsEmpty([Measures].[Detail_Net_Sales]),0,[Measures] [Detail_Net_Sales])/[Measures].[SumTotalPayable] )
MEMBER [Measures].[test]
AS
([Measures].[Contribution], [DIMProduct].[ProductCode].CurrentMember.PrevMember)
SELECT { [Measures].[Contribution] ,[Measures].[test]} ON COLUMNS
, Order([DIMProduct].[ProductCode].[ProductCode].AllMEMBERS ,[Measures]. [Contribution],BDESC)ON ROWS
FROM [Model]
but the above code will return previous Contribution without desire order.
do you have any idea how can i fix this?
Edit :
I want to have the Contribution of the previous row base on my sort and also have the test measure base on my prior sort,like the below table:
ProductCode Contribution Test
----------- ------------ ----
123 17.56 null
332 17.30 17.56
245 16 17.30
656 15.90 16
but what i get is like this :
ProductCode Contribution Test
----------- ------------ ----
123 17.56 17.30
332 17.30 16
245 16 Null
656 15.90 17.30

Answer 1

WITH MEMBER [Measures].[Contribution] AS
Format(
IIF(
IsEmpty([Measures].[Detail_Net_Sales]),
0,
[Measures].[Detail_Net_Sales]
)/
[Measures].[SumTotalPayable]
)
SET SortedProducts AS
Order(
[DIMProduct].[ProductCode].[ProductCode].AllMEMBERS,
[Measures].[Contribution],
BDESC
)
MEMBER [Measures].[PrevContribution] AS
(SortedProducts.Item(
Rank([DIMProduct].[ProductCode].CurrentMember, SortedProducts) - 2)
.Item(0),
[Measures].[Contribution])
SELECT
{[Measures].[Contribution], [Measures].[PrevContribution]}
ON COLUMNS,
SortedProducts
ON ROWS
FROM [Model] }
Your definition of the test measure uses the order of members as defined in the cube (alphabetically, if you did not define a custom order). But you need the order by Contribution, so I defined that as a named set containing the members in this order. Then I mis-used the Rank function which gives you the position of a tuple in a set. As the rank of the first member is 1, and I use the Item function to get a tuple within the set - which starts numbering the tuples with zero -, and we have to go one member back, you need the - 2, and finally, we need another Item(0) to get a member from the tuple.