MDX Dimension Navigation - ssas

I am on an MDX adventure and I'm at a point where I need to ask some questions.
I have a very basic dimension named Car. The attributes which comprise Car are as follows-
-Manufacturer
-Make
-Color
-Year
My fact table contains a sales measure ([Measures].[Sales]). I would like to know , without explicitly defining a user hierarchy, how to sum the sales from
a specific group in this hierarchy
For example, I want to sum the sales of all red Trucks made in 2002. My attempt errors out-
sum([Cars].[Make].[Make].&[Truck]&[Red]&[2002], [Measures].[Sales])
How can I navigate the attribute hierarchy in this way? I will be browsing the cube in excel
Thanks

If you open an mdx query in SSMS and drag a member from one of your attribute hierarchies into the query pain you will see the full name.
You definitely cannot chain hierarchies like this ...].&[Truck]&[Red]&[2002]
Each full name will likely be similar to what MrHappyHead has detailed but usually the attribute name is repeated e.g. for Make:
[Cars].[Make].[Make].&[Truck]
MrHappyHead have wrapped it all in the Sum function but this is not required - just wrap the coordinates in braces and a tuple is then formed which will point to the required area of the cube:
(
[Cars].[Make].[Make].&[Truck],
[Cars].[Color].[Color].&[Red],
[Cars].[Year].[Year].&[2002],
[Measures].[sales]
)
note: square brackets are pretty standard in mdx.

Is it something like:
Sum(
Cars.make.&[truck],
Cars.color.&[red],
Cars.year.[2002],
Measures.sales
)

Related

Showing measure values as "not applicable" which are not related to dimensions

I have a requirement where report should show measures as "not applicable" if one selects a attribute which is not linked to that measure Group.
1) unrelateddimesnion= 'false' is not solving my problem because i have few default members.
2) I could able to show measure value as "not applicable " by Writing this MDX statement
([Customer].[customer name].[customer name], [measures].[sales forecast]) = 'not applicable'
but with this i have to repeat the same line for each and every attribute present in the dimension ( and also for each and every measure present in the measure Group)
can someone help me Writing the MDX for entire dimension instead for individual attribute. Thanks in advance.
Kind Regards
Mah
Bad news! An MDX script on your cube can't reference such a sub-cube in a simple way. You may have seen the LEAVES(dimension) function for a scope statement but that won't work when one attribute in a dimension has the [All] level and another has a selection. (That is to say the function returns the leaves of the dimension's key attribute). What you can do is use nested scope statements with the outer one filtering down to the list of measures you want to affect. That will at least save you typing a formula num_attributes * num_measures times. The scope statement may even accept the MEASUREGROUPMEASURES function. (When I last used that it only returned visible measures but that's probably what you want anyway.)
It may be easier to link measure group and dimension and let your data sit on the UNKNOWN member. (Or an explicit dummy member.) Then filters against or slices to real customer hierarchy values will exclude your [Sales Forecast] rows and show it as null. That's not something I've done and it'll have ramifications for error processing and you'll have to allow users sight of the unknown or dummy member. So recommend you play with the idea before you rely on it.
I hope this helps some.

Calculated Members with multiple Attribute Hierarchy - MDX

I found this little code where it dynamically calculates TOTALs for all Dimension/Hierarchy I want.
This is close to what I need but will not work for Dimensions that have different number of Hierarchy Levels (Attribute Hierarchy). Current Code only works if there is only one Attribute Hierarchy because of CurrentMember.Parent. I could use CurrentMember.Parent.Parent for Dimension.Hierarchy that have two levels and so on but would not work for the the ones with only one Attribute Hierarchy (Level).
CALCULATE;
CREATE MEMBER CURRENTCUBE.[Measures].[Total On Hand Amount]
AS ([Measures].[On Hand Amount],Axis(1).Item(0).Item(0).Dimension.CurrentMember.Parent),
FORMAT_STRING = "#,#",
VISIBLE = 1 ;
I would like to make this MDX code work for any Dimension.Hierarchy regardless of number of Attribute Hierarchy (Level/s).
Any help is appreciated!!
You can use the ancestors function instead of parent. It takes a dimension parameter and a second parameter which shows how many levels you want to get (how deep in the tree to go). So if you know how many levels your dimension has you can use something like:
Ancestors(Axis(1).Item(0).Item(0).Dimension.CurrentMember, 5)
Instead of a number you can also add a dimension level as a second parameter. Then it will go as deep as the dimension level specified - so if you add the root dimension level it should get to there
(Axis(1).Item(0).Item(0).Dimension.Levels(0).Item(0), [Measures].[On Hand Amount])
Above gave me the correct answer, total for a measure for dynamic selection of any dimension but this MDX calculation would not work from PowerBI(DAX) report, which is merely PowerBI's limitation.
I got the TOTAL working now with this -
SCOPE(DESCENDANTS([Warehouses].[Warehouses],,AFTER));
[Measures].[Total On Hand Amount] = (ROOT([Warehouses]),[Measures].[On Hand Amount]);
END SCOPE;
I just have to repeat this SCOPE for each [Dimension].[Hierarchy] in the cube to make the TOTAL work for any selection including multiple dimensions from Power BI. It does not have dynamic functionality like Axis() did, but it yields the result I needed.
Hope this would help someone else too!!

Understanding the Cube display in SQL Studio Manager

I have built a small data warehouse using the Adventure works database. I have deployed it to SQL Studio Manager. I have written my first MDX query
select
customer.[full name].members on rows,
order (measures.[sales amount],asc) on columns
from [Adventure Works DW2012]
Please see the screenshot below:
I understand that the top level of the hierarchy are dimensions i.e. Customer, Date, Due Date, Interne Sales, Order Date, Product and Ship Date. I understand that dimensions have attributes. For example: Model Name, Product Line, Product Name are attributes of the Product dimension and Product Model Lines is a hierarchy of the Product dimension.
What is meant by: Financial; History and Stocking?
You've come up against something I think is a genuinely confusing and ill-designed aspect of SSAS.
You're correct that Model Name, Product Line and Product Name are attributes of the Product dimension. But what you're seeing here (in your screenshot) is hierarchies called Model Name, Product Line and Product Name.
These are not "hierarchies" in the sense that most people use the term (a structure with more than one level). They're the "attribute hierarchies" based on the attributes of the same name. They only have one level two levels. (EDIT: as whytheq pointed out, they have one leaf level, and almost always also have an "All" level).
(EDIT) Product Model Lines is a "real" (aka "user") hierarchy, with multiple levels apart from the All and leaf levels, based on multiple attributes.
Financial, History and Stocking are "folders". They get "created" by the setting of any AttributeHierarchyDisplayFolder property of any Attribute in the Dimension design (or the DisplayFolder property of any "real" hierarchy). They have nothing to do with any dimension structure - they're just for display convenience. Probably necessary because, as becomes clearer the more I try to explain it, the structure of Dimensions in SSAS is really unnecessarily complicated.
You can hide the "attribute hierarchies" from client applications (e.g. Excel) by setting the AttributeHierarchyVisible property of the attribute to False. But they'll still show up in the MDX "helper" screen you're looking at.

SSAS Dimension attribute as Calculated Measure

I am having some issues trying to implement an average of a dimension attribute.
The basic structure is:
Booking Header Dimension
Fact Table (multiple rows per Booking Header
entry)
On the booking header dimension I have a numerical attribute called Booking Window, and I want to be able to create a calculated measure that averages this value.
We are using SQL Server 2012 standard edition.
Any help would be greatly appreciated.
The best approach would be to create a measure group from the dimension table (in BIDS, go to cube designer, tab "Cube Structure", right-click the cube object in the Measures list, and select "New Measure Group", select your dimension table). BIDS will generate some measures, and you can remove all but two: the one based on your numeric attribute (I will call it "YourSummedAttrib" to have a name to refer to below), and the count measure. The aggregate function for the measure "YourSummedAttrib" will probably be "sum", leave that as it is.
Then, create a calculated measure which divides "YourSummedAttrib" by the count measure, which gives the average. Finally, if you have tested everything, make the two measures "YourSummedAttrib" and the count measure invisible before you give the cube to the users, as they only need to see the average, which is the calculated measure.
You can try this which should give you the average of that attribute across all members.
WITH MEMBER [Measures].[Booking Window Value] AS
[Booking Header].[Booking Window].CURRENTMEMBER.MEMBER_VALUE
MEMBER [Measures].[Avg Booking Window Value] AS
AVG([Booking Header].[Booking Window].[Booking Window].MEMBERS,[Measures].[Booking Window Value])
SELECT
[Measures].[Avg Booking Window Value] ON COLUMNS
FROM
[YourCube]
Hope that helps and apologies for any confusion on my part.
Ash
I tried to use the same idea, but without success. The solution I found was create a view with the calculated average and include a new group of measures.

How to get the name of invisible attributes and user defined Hierarchies using MDX?

I have a cube with some dimensions. There I have a dimension 'Product' which has some attributes and user defined hierarchies hidden. I do not know which attributes are hidden.
Is there a way to write an MDX to get the invisible attributes and user defined hierarchies?
I can get the name by other ways. But I want to know the way to get using MDX.
http://msdn.microsoft.com/en-us/library/ms145613.aspx gives an example query that reveals a member property:
WITH MEMBER [Measures].[Product List Price] AS
[Product].[Product].CurrentMember.Properties("List Price")
SELECT
[Measures].[Product List Price] on COLUMNS,
[Product].[Product].MEMBERS ON Rows
FROM [Adventure Works]
I cannot test it myself right now, but I assume that you could also write .Properties(0) or .Properties(1) to refer to properties by index, since you don't know the names. I'm not sure if there is a way to then discover the property name from the resulting cellset or not, sorry.
I'd start with looking into the DMVs for this, as you're really after metadata, not data.
http://dwbi1.wordpress.com/2010/01/01/ssas-dmv-dynamic-management-view/
They look like SQL, but run in the MDX window of SQL Management Studio, so will also run in an MSOLAP connection.
SELECT * FROM $system.mdschema_properties
That looks to be the query, a full list of members and a column identifying which are visible.
See how that works out for you.