In MDX, we can CROSS JOIN two members, a measure and a member but not two measures. Why is this so? What does it imply?
SELECT
[Measures].[xyz] * [DimTable1].[SomeHierarchy].[Level] on 0,
[DimTable2].[SomeOtherHierarchy].&[Value] on 1
FROM [MyCube]
// WORKS
SELECT
[Measures].[xyz] on 0,
[DimTable2].[SomeOtherHierarchy].&[Value] * [DimTable1].[SomeHierarchy].[Level] on 1
FROM [MyCube]
// OF COURSE IT WORKS
SELECT
[Measures].[xyz] * [Measures].[ABC] on 0,
[DimTable1].[SomeHierarchy].&[Value] on 1
FROM [MyCube]
// DOES NOT WORK!!
I believe you forgot:
SELECT
[dd].[hh].[mm1] * [dd].[hh].[mm2] on 0,
[DimTable1].[SomeHierarchy].&[Value] on 1 FROM [MyCube]
did not work neither. [Measures] is not different than [dd] in my example. In MDX you cannot define a tuple with _ several members _ of the _ same hierarchy _. Have a look to this gentle introduction explaining the main concepts.
EDIT
Your third query, that does not work, looks like this:
The yellow area is empty so it is understandable that it is not happy.
EDIT
Following is an analogy using Excel pivot tables which use OLAP technology
If you put a crossjoin of measures A and B on rows you get something like this:
Then if we add a very small level (with 4 members) onto columns we get the following:
So what will go into the main body of this table?
A count is possible and probably is, in MDX, if you create a custom measure (don't have a server to test this statement on). Excel will default to a count but the result is pretty pointless?
Related
I'm completely new to SSAS cubes and terminologies (members, hierarchies, e.t.c) and MDX queries but i have started my journey to learn this stuff, so apologies if my question is very clear.
SELECT NON EMPTY { } ON COLUMNS, {
[Suggestions].[Parent_id].[Parent_id] *--.ALLMEMBERS *
[Suggestions].[id].[id] * --.ALLMEMBERS *
[Suggestions].[Sugg - #].[Sugg - #] *-- .ALLMEMBERS *
[Suggestions].[Sugg - Assigned].[Sugg - Assigned] * --.ALLMEMBERS *
[Suggestions].[Sugg - Assigned to].[Sugg - Assigned to]* --.ALLMEMBERS *
[Suggestions].[Sugg - Status].[Sugg - Status] *--.ALLMEMBERS
--[Parent_Details].[Unit_Name].[Unit_Name] --.ALLMEMBERS
}
DIMENSION PROPERTIES MEMBER_CAPTION,
MEMBER_UNIQUE_NAME ON ROWS
FROM ( SELECT ( { [Suggestions].[Sugg - Assigned to].&[UNIT] } ) ON COLUMNS
FROM ( SELECT ( STRTOSET('SG123', CONSTRAINED) ) ON COLUMNS
FROM ( SELECT ( { [Suggestions].[Sugg - Status].&[Pending Inputt] } ) ON COLUMNS
FROM [BOI_Tracker-Stats])))
CELL PROPERTIES VALUE
I have the above MDX query that executing. I generated the query from the MDX query designer tool in SSMS and have only simple modifications by hand.
In the query, if i comment out the line [Parent_Details].[Unit_Name].[Unit_Name] --.ALLMEMBERS, i get the correct number of rows.
Main Question.
If i un-comment it so that i return the Unit_Name column, my rows are duplicated. The original 100 correct rows now because thousands of rows with duplicate values all over. Any body know what i should look out for that is causing this. Looks a wrong join is being applied.
Other things i would like to understand.
1. The query designer generated the query in the format
[Suggestions].[Parent_id].[Parent_id].ALLMEMBERS * . If i comment out .ALLMEMBERS * such that the query is just [Suggestions].[Parent_id].[Parent_id] with out .ALLMEMBERS * the results are the same. So what is the use of .ALLMEMBERS *
2. I also notice that the column i want to select is repeated twice like
Suggestions].[Parent_id].[Parent_id], why is this so?, why can't it just be generated as Suggestions].[Parent_id]
If you select from different dimensions like that you basically multiply the results. If you think about it that's the correct behavior. In your case you have [Suggestions] and [Parent_Details] . These are different dimensions. In your query you want results having both so it does:
For each member of [Suggestion] get all members of [Parent Details] and add them to the result. So the result set becomes:
[Suggestion-1][Parent_Details-1][Measures...]
[Suggestion-1][Parent_Details-2][Measures...]
[Suggestion-2][Parent_Details-1][Measures...]
[Suggestion-2][Parent_Details-2][Measures...]
[Suggestion-3][Parent_Details-1][Measures...]
etc.
( having different levels from the [Suggestions] dimension doesn't multiply the measures )
This is a correct behavior when you think about it because if you add these two dimensions you probably want to know something like "What are the measures for that suggestion and for these parent details?" And that exact row will be correct in the result set. It all depends on what result do you want to get (What do you ask for).
The multiplication of the names depends on your cube design. First row is a level and second a member. If you create a hierarchy for example it will not look like that.
This query gives me sales of one store:
select
[measures].[sales] on 0
from [MyCube]
where [store].[store].[042]
However, if I move the slicer to inside of the subquery, it gives me sales of all stores.
select
[measures].[sales] on 0
from (select
from [MyCube]
where [store].[store].[042]
)
How to understand the mechanisms behind this difference?
This is also noted in this article, but without much explanation.
----EDIT----:
I tried various things and read around for a while. I'd like to add a question: is there a scenario in which the where clause in sub-select does filter the result?
This query gives me sales of all stores in state MI (store [042] belongs to MI):
select
[measures].[sales] on 0
from (select
[store].[state].[MI] on 0
from [myCube]
where [store].[store].[042]
)
Thinking of 'inner query only filters if the filtered dimension is returned on an axis', the theory is proved wrong if I do this:
select
[measures].[sales] on 0
from (select
[store].[state].members on 0
from [myCube]
where [store].[store].[042]
)
The sub-select still returns one state MI, but the outer query returns sales of all stores (of all states).
----EDIT 4/13----:
Re-phrasing the question in AdventureWorks cube with screenshot.
Query 1: sales of one store
Query 2: it returns sales of all stores if where clause is in the sub-select.
Query 3: the two answers I got suggested that we select the dimension in an axis - here is the result - we get all cities.
select
[measures].[sales] on 0
from (select
from [MyCube]
where [store].[store].[042]
)
The above query reduces the scope of stores just to the member [042]. Make note that sub-select is executed before the actual select. So, when it comes to the select, the engine just sees a cube which has all the members in all the dimensions; but only the member [store].[store].[042] in the store dimension. It's as if the cube has been kept intact every where else but sliced off on the Store dimension.
If you go a step ahead and add the store on to one of the axes, like
select
[measures].[sales] on 0,
[store].[store].members on 1
from (select
from [MyCube]
where [store].[store].[042]
)
you would see that although the member [All] appears in the output, it actually is just comprised of only one store.
In essence, the [All] is a special member which is calculated with respect to scope of the cube. It reflects the combined effect of all the members in the cube.
In SQL terms, it is similar to:
select sales, store as [All] from
(select sales, store from tbl where store = '042') tbl
Even though you see Sales----All, it is but a reflection of sales for store [042]
Here are some other good references concerning sub-select and slicer debate:
http://bisherryli.com/2013/02/08/mdx-25-slicer-or-sub-cube/
https://cwebbbi.wordpress.com/2014/04/07/free-video-on-subselects-in-mdx/
Chris Webb's video being located here:
https://projectbotticelli.com/knowledge/what-is-a-subselect-mdx-video-tutorial?pk_campaign=tt2014cwb
This should still leave an All member:
SELECT
[measures].[sales] ON 0
FROM
(
SELECT
FROM [MyCube]
WHERE
[store].[store].[042]
);
...but the member [All] of the Store hierarchy will only now be made up of [store].[store].[042].
You can see this by adding the Store hierarchy onto ROWS:
SELECT
[measures].[sales] ON 0,
[store].MEMBERS ON 1
FROM
(
SELECT
FROM [MyCube]
WHERE
[store].[store].[042]
);
This is the AdvWorks version similar to the reference in your question:
SELECT
{[Measures].[Order Count]} ON 0
,[Subcategory].MEMBERS ON 1
FROM
(
SELECT
{
[Subcategory].[Subcategory].&[22]
} ON 0
FROM [Adventure Works]
);
It returns the member from the sub-select and the All member adjusted to take account of the subselect:
In the references article why is the [All] less than the sum of the other two - this is not down to the subselect but is in connection with the measure that he has chosen [Measures].[Order Count] which is a distinct count. If you take away the subselect you see exactly the same behaviour of the All member being less than the sum of the other subcategory members (I've marked the point at which the total of the parts becomes higher than the All member):
SELECT
{[Measures].[Order Count]} ON 0
,Order
(
[Subcategory].MEMBERS
,[Measures].[Order Count]
,bdesc
) ON 1
FROM [Adventure Works];
Order Count: on 1 order there might be several Product Subcategories - hence this behaviour.
Edit
This query of yours:
select
[measures].[sales] on 0
from (select
[store].[state].members on 0
from TestCube //<< added this!
where [store].[store].[042]
)
This inner script is not valid? Using the same dimension on an axes and the WHERE clause is not valid:
select
[store].[state].members on 0
from TestCube
where [store].[store].[042]
Edit2
An mdx script returns a cube, which may be sliced or not sliced, but nevertheless it returns a cube. The WHERE clause is used to slice the cube that is returned. If we were using a third party tool then the dimension added to the WHERE clause would go into a combobox - with say Cliffside selected. BUT the user could effectively select Ballard from that combobox - it is just a slicer. The WHERE clause is not changing the cube that is returned by the mdx script, it is just affecting what is displayed in the cellset.
WHERE is valid within a subselect. It is part of the definition:
https://msdn.microsoft.com/en-us/library/ff487138.aspx
I've never found a use case for a subselect's WHERE clause.
Edit3
This link will explain things:
https://social.msdn.microsoft.com/Forums/sqlserver/en-US/ccb66ac3-0f9a-4261-8ccc-b6ecc51b6f07/is-where-clause-pointless-inside-a-subselect?forum=sqlanalysisservices
As Darren gosbell says in the answer to this question:
https://msdn.microsoft.com/en-us/library/ff487138.aspx it says that:
The WHERE clause does not filter the subspace.
I am new to MDX Querying and am trying to create a query that utilizes Except. I currently have one that works when i do a filter with a bunch of OR's but it is very slow.
What i want to do is count the distinct back order lines (where that doesn't equal 0) except when 2 aging codes are set. (050 and 060).
This query seems to work but is extremely slow (not using except)
DISTINCTCOUNT(filter([Product].[Segment - Line - Types].[Product].members,
(([Measures].[BackOrderLineCount], [Aging].[AgingCode].[Aging].&[005] ) OR
([Measures].[BackOrderLineCount], [Aging].[AgingCode].[Aging].&[010] )OR
([Measures].[BackOrderLineCount], [Aging].[AgingCode].[Aging].&[020] )OR
([Measures].[BackOrderLineCount], [Aging].[AgingCode].[Aging].&[030] )OR
([Measures].[BackOrderLineCount], [Aging].[AgingCode].[Aging].&[040] ))))
I was hoping if i switched it to "EXCEPT" it would speed it up...
Any help would be appreciated i've been searching all day for this.
You don't really need to use a FILTER function for this requirement. Also, the minus operator is as good as EXCEPT while being more handy.
You should be looking at obtaining tuples of products and aging code which have a value for back order line.
DISTINCTCOUNT([Product].[Segment - Line - Types].[Product].members *
NonEmpty(
([Aging].[AgingCode].[Aging].CHILDREN - {[Aging].[AgingCode].[Aging].&[50], [Aging].[AgingCode].[Aging].&[60]}),
[Measures].[BackOrderLineCount])
)
The NonEmpty function returns those aging codes which have back order lines.
If you had to use EXCEPT, the code would look like below:
EXCEPT
(
[Aging].[AgingCode].[Aging].CHILDREN, {[Aging].[AgingCode].[Aging].&[50], [Aging].[AgingCode].[Aging].&[60]}
)
I have an MDX query as follows:
WITH
MEMBER [MatCode] AS [Product].[Material]
SELECT
([MatCode]) on 0,
([Activity].[ActivityCode].[T-50051151]) ON 1
FROM
[Cube]
This returns a value such as:
MatCode
T-50051151 Null
Which tells me it is not joining the activity code to the description when I know they match up
How can I correct my MDX query to join activity code to material?
thanks
Why not try something like the following to look for areas of the cube with data? You'll can use the WHERE clause to slice by a specific measure in your cube.
SELECT
{[Activity].[ActivityCode].[T-50051151]} ON 0,
//NON EMPTY //<<include to hide nulls
{[Product].[Material].members} on 1
FROM
[Cube]
WHERE
([Measures].[someMeasure])
Your query returns the _ default _ value / cell for the tuple :
( [Activity].[ActivityCode].[T-50051151], [Product].[Material].defaultMember )
as well as the .defaultMember for every other dimension not mentionned in your query. There is nothing wrong with it.
I've just started to learn MDX and i want to do a query like that:
filter data by the cost ( i've already made that query but without the sum) like that:
SELECT [Measures].[SumOfSelled] ON 0,
FILTER ([From].[From].[City].members, [Measures].[SumOfSelled]>7000) ON 1
FROM [BI-Avia]
It's working
and it is OK
BUT!!!
I need also to show the sum of filtered elements under this filtered result by cities
I know how to find it separately:
with member [Measures].FilteredSum as sum(filter([From].From].City].members,Measures].SunOfSelled]>7000),Measures].[SumOfSelled])
select{SumOfSelled} on 0
from [BI-AVIA]
But i have to show this together!! The SUM under Filtered! two in one! I need youe help! I think it's very clear for you!!!
Just define the calculated member on the [From].[From] hierarchy and then combine both queries, using a union of sets (abbreviated with + in MDX):
with member [From].[From].FilteredSum as
sum(filter([From].[From].City].members, Measures].SumOfSelled]>7000))
SELECT [Measures].[SumOfSelled]
ON 0,
FILTER ([From].[From].[City].members, [Measures].[SumOfSelled]>7000)
+
{ [From].[From].FilteredSum }
ON 1
FROM [BI-Avia]
You could possibly define the filter as a set in the WITH clause, which would avoid that Analysis Services evaluates it twice.