How to build a dynamic MDX formula for a calculated member? - dynamic

Question

I am trying to create a Calculated Member to get a sum up to last week.
No problem to get the week value (I need it to be two digits i.e. '05', so adding 100-1 )
with
Member [Measures].Week as
'right(str(int(99+datepart ( ''ww'', Now()))),2)'
-- That works as expected
member [Measures].SalesUpToWeek as
'strtomember(
"aggregate(periodstodate([Dim].[2015],[Dim].[2015].[" + ([Measures].Week) + "]),[Measures].[Sales])")'
I get the literal value
aggregate(
periodstodate([Dim].[2015],[Dim].[2015].[25])
,[Measures].[Sales]
)
What I need is the value of this MDX calculation.
All other attempts end up with a syntax error. Just as an example
member [Measures].SumToWeek as
'aggregate(
periodstodate(
[Dim].[2015],[Dim].[2015].[' + strtomember([Measures].Week) + '])
,[Measures].[Sales])'
Error
Lexical error at line 2, column 0. Encountered: after : "[\n"
Any idea?

Answer 1

[Measures].Week is already a string entity. You don't need to put StrToMember around it. Instead you should have it outside the string you dynamically defined.
with
Member [Measures].Week as
"right(str(int(99+datepart ( ''ww'', Now()))),2)"
member [Measures].SumToWeek as
aggregate(
periodstodate(
[Dim].[2015],
StrToMember("[Dim].[2015].[" + [Measures].Week + "]")
)
,
[Measures].[Sales]
)

Answer 2

This is your error:
strtomember([Measures].Week)
Let us say that [Measures].Week is equal to 15 then you are trying to do this:
strtomember(15)
So there are two errors in the above:
You're feeding a numeric into a functions that converts Strings to Memebers
You need to feed in the full string representation of the member i.e."[Dim].[2015].[15]"
Maybe try putting the strToMember function around the string that is the representation of the member:
MEMBER[Measures].SumToWeek AS
'aggregate(
periodstodate(
[Dim].[2015],
strtomember('[Dim].[2015].[' + [Measures].Week + ']', constrained)
)
,[Measures].[Sales])'
Here is the MSDN reference for the function strtomember:
https://msdn.microsoft.com/en-us/library/ms146022.aspx?f=255&MSPPError=-2147217396
Edit
Looking at this previous post: (StrToMember does not accept calculated measure (mdx))
...you need to create the member before feeding it into the new measure, so:
WITH
MEMBER [Measures].[Week] AS
Right
(
Str(Int(99 + Datepart('ww',Now())))
,2
)
MEMBER [Dim].[2015].[TargetWeek] AS
StrToMember
(
'[Dim].[2015].[' + [Measures].Week + ']'
,constrained
)
MEMBER [Measures].SumToWeek AS
Aggregate
(
PeriodsToDate
(
[Dim].[2015]
,[Dim].[2015].[TargetWeek]
)
,[Measures].[Sales]
)
Edit2
Ok if you wish to use PeriodsToDate then we need to use StrToSet and then use the member in this set inside the function. This is because custom members lose their family ties and are therefore useless inside some mdx functions.
Here is a working script in AdvWrks illustrating the approach I'm suggesting:
WITH
MEMBER [Measures].[Wk] AS
Right
(
Str(Int(99 + Datepart('ww',Now())))
,2
)
SET [TargetWeek] AS
StrToSet
(
'[Date].[Calendar Weeks].[Calendar Week].[Week ' + cstr([Measures].[Wk]) + ' CY 2007]'
)
MEMBER [Measures].[SumToWeek] AS
Aggregate
(
PeriodsToDate
(
[Date].[Calendar Weeks].[Calendar Year]
,[TargetWeek].item(0).item(0)
)
,([Measures].[Internet Sales Amount])
)
SELECT
{[Measures].[SumToWeek]} ON 0,
[Product].[Product Categories].[All] ON 1
FROM [Adventure Works];

Answer 3

I got an interesting suggestion on Pentaho forums that pointed me to a nice blog post which allowed to write an elegant solution:
http://diethardsteiner.blogspot.com.es/2009/10/current-date-function-on-mondrian.html
with
member [Measures].sm as aggregate(
periodstodate(
currentdatemember([Dim],'["Dim"]\.[yyyy]'), -- current year
currentdatemember([Dim],'["Dim"]\.[yyyy]\.[ww]').lag(1) -- previous week
),
[Measures].[Sales])
Thks