How to mimic SQL subtraction of results from two different queries in mdx - mdx

Question

I wanted to do the trend analysis between the dates. For an instance current date- 30 days
30-60 days and so on.Below is the snippet of comparable sql query but same I wanted to do in MDX.
SQL
SELECT
ROUND
(
(
(
(
SELECT
SUM(del_pri_impr)
FROM
reporting.so_sli_calc_val a,
reporting.user_group_tenant b,
reporting.salesorder c
WHERE
created_on BETWEEN DATE(now()-30) AND DATE(now())
)
-
(
SELECT
SUM(del_pri_impr)
FROM
reporting.so_sli_calc_val a,
reporting.user_group_tenant b,
reporting.salesorder c
WHERE
created_on BETWEEN DATE(now()-60) AND DATE(now()-30)
)
)
/
(
SELECT
SUM(del_pri_impr)
FROM
reporting.so_sli_calc_val a,
reporting.user_group_tenant b,
reporting.salesorder c
WHERE
created_on BETWEEN DATE(now()-60) AND DATE(now()-30)
) *100
)
,
0
) AS trend
MDX:
WITH
SET [~FILTER] AS
{[Created_Date.Created_Hir].[Created_On].[2014-04-01]:[Created_Date.Created_Hir].[Created_On].[2014-04-30]}
SET [~ROWS] AS
{[Sales Order Attributes SO.Sales_order].[Sales Order ID].Members}
SELECT
NON EMPTY {[Measures].[CONT_AMT_GROSS], [Measures].[CONT_AMT_NET]} ON COLUMNS,
NON EMPTY [~ROWS] ON ROWS
FROM [SALES_ORDER]
WHERE [~FILTER]
As of now I have hard coded the dates, that will come from parameters.
I am facing difficulty in creating the second set and how to do subtraction between two sets in MDX.

Answer 1

You already have the logic on how to obtain sets of date corresponding to "last 30 days from now" and "last 60 to last 30 days from now". So, I am going to skip that part.
NOTE - You would have to use the parameter values while building these sets.
What you want to do here is first find the values corresponding to these sets of dates and then perform operations on them.
You can proceed like this -
WITH
SET [~FILTER] AS
{[Created_Date.Created_Hir].[Created_On].[2014-04-01]:[Created_Date.Created_Hir].[Created_On].[2014-04-30]}
SET [~ROWS] AS
{[Sales Order Attributes SO.Sales_order].[Sales Order ID].Members}
SET [Last30Days] AS
...
SET [Last60ToLast30Days] AS
...
MEMBER [~Last30Days - Now] AS
Aggregate
(
[Last30Days],
[Measures].[SomeMeasure]
)
MEMBER [~Last60Days - Last30Days] AS
Aggregate
(
[Last60ToLast30Days],
[Measures].[SomeMeasure]
)
MEMBER [~Measure] AS
([~Last30Days - Now]-[~Last60Days - Last30Days] )/([~Last60Days - Last30Days] * 100), format_string = '#,##0'
SELECT
NON EMPTY {
[Measures].[CONT_AMT_GROSS],
[Measures].[CONT_AMT_NET],
[~Measure]
} ON COLUMNS,
NON EMPTY [~ROWS] ON ROWS
FROM [SALES_ORDER]
Format_String takes care of rounding.

Answer 2

Not sure if I totally agree with Sourav's answer as I think some form of aggregation will be needed; creating tuples with sets in them may raise an exception.
Here is a simple model, against AdvWrks, that is tested and will do a subtraction for you:
WITH
SET [Set1] AS
[Date].[Calendar].[Date].&[20060301]
:
[Date].[Calendar].[Date].&[20070308]
SET [Set2] AS
[Date].[Calendar].[Date].&[20070308]
:
[Date].[Calendar].[Date].&[20080315]
MEMBER [Date].[Calendar].[All].[Set1Agg] AS
aggregate([Set1])
MEMBER [Date].[Calendar].[All].[Set2Agg] AS
aggregate([Set2])
MEMBER [Date].[Calendar].[All].[x] AS
(
[Date].[Calendar].[All].[Set1Agg]
,[Measures].[Internet Sales Amount]
)
MEMBER [Date].[Calendar].[All].[y] AS
(
[Date].[Calendar].[All].[Set2Agg]
,[Measures].[Internet Sales Amount]
)
MEMBER [Date].[Calendar].[All].[x-y] AS
[Date].[Calendar].[All].[x] - [Date].[Calendar].[All].[y]
SELECT
{
[Date].[Calendar].[All].[x]
,[Date].[Calendar].[All].[y]
,[Date].[Calendar].[All].[x-y]
} ON 0
,[Product].[Category].[Category] ON 1
FROM [Adventure Works];
Reflecting against your code maybe something like the following:
WITH
SET [Set1] AS
[Created_Date.Created_Hir].[Created_On].[2014-04-01]
:
[Created_Date.Created_Hir].[Created_On].[2014-04-30]
SET [Set2] AS
[Created_Date.Created_Hir].[Created_On].[2014-03-01]
:
[Created_Date.Created_Hir].[Created_On].[2014-03-31]
MEMBER [Created_Date.Created_Hir].[All].[Set1Agg] AS
Aggregate([Set1])
MEMBER [Created_Date.Created_Hir].[All].[Set2Agg] AS
Aggregate([Set2])
MEMBER [Measures].[~Last30Days - Now] AS
(
[Created_Date.Created_Hir].[All].[Set1Agg]
,[Measures].[SomeMeasure]
)
MEMBER [Measures].[~Last60Days - Last30Days] AS
(
[Created_Date.Created_Hir].[All].[Set2Agg]
,[Measures].[SomeMeasure]
)
MEMBER [Measures].[~Measure] AS
([Measures].[~Last30Days - Now] - [Measures].[~Last60Days - Last30Days])
/
[Measures].[~Last60Days - Last30Days]
* 100
,format_string = '#,##0'
SET [~ROWS] AS
{
[Sales Order Attributes SO.Sales_order].[Sales Order ID].MEMBERS
}
SELECT
NON EMPTY
{
[Measures].[CONT_AMT_GROSS]
,[Measures].[CONT_AMT_NET]
,[Measures].[~Measure]
} ON COLUMNS
,NON EMPTY
[~ROWS] ON ROWS
FROM [SALES_ORDER]
WHERE
[~FILTER];