I am trying to create a query but it utilizes two different dimensions. I receive this error "Members, tuples, or sets must use the same hierarchies in the function." I've run this with/without the brackets in the row section and got the same error. How do I resolve this issue?
Error Message/MDX Query
You are using two different hierarchies of the same dimension [Dim Course] in the tuple which is not allowed.
You will have to change your query, something like this should work:
select {[Measures].[Dim Course Count],[Measures].[Dim Semester Count]} on 0,
{([Dim Course].[Course Code].[Course Code], [Dim Semester].[Academic Year].[Academic Year]) } on 1
from [CCSE-DM]
where [Dim Course].[Level1].[Level1]
Related
Problem: I'm trying to write a MDX query that will show the first date a member has measure values.
Data obstacles:
1. I don't have access to the data warehouse/source data
2. I can't request any physical calcs or CUBE changes
Looking for: I know this goes against what a CUBE should be doing, but is there any way to achieve this result. I'm running into locking conflicts and general run time issues.
Background: After some trial and error. I have a working query but sadly it's only is practical when filtered for <10 employees. I've tried some looping but there are ~60k employee ids in the cube with each one having 10-20 emp keys (one for each change in their employee info).
//must have values for measure 1 or 2
WITH
set NE_measures as
{
[Measures].[measure1] ,
[Measures].[measure2]
}
//first date with measure values for each unique emp key
MEMBER [Measures].[changedate] AS
Head
(
NonEmpty([Dim Date].[Date].[Date].allMEMBERS, NE_measures)
).Item(0).Member_Name
SELECT non empty {[Measures].[changedate]} ON COLUMNS,
non empty [Dim Employee].[Emp Key].[Emp Key].allmembers ON ROWS
FROM [Cube]
Try this:
MEMBER [Measures].[changedate] AS
Min(
[Dim Date].[Date].[Date].allMEMBERS,
IIF(
NOT(ISEMPTY([Measures].[measure1]))
OR NOT(ISEMPTY([Measures].[measure2])),
[Dim Date].[Date].CurrentMember.MemberValue,
NULL
)
);
I’m assuming the KeyColumn or ValueColumn is more likely to sort properly than the name. So if MemberValue doesn’t work then try Member_Key.
The most efficient way of accomplishing this would be to add a date column in the fact table with measure 1 and measure 2 then create a AggregateFunction=Min measure on it. But you said you couldn’t change the cube so I didn’t propose that superior option.
I am trying to learn MDX. I am an experienced SQL Developer.
I am trying to find an example of an MDX query that has more than two dimensions. Every single webpage that talks about MDX provides simple two dimensional examples link this:
select
{[Measures].[Sales Amount]} on columns,
Customer.fullname.members on rows
from [Adventure Works DW2012]
I am looking for examples that use the following aliases: PAGES (third dimension?), section (forth dimension?) and Chapter (fifth dimension?). I have tried this but I do not think it is correct:
select
{[Measures].[Sales Amount]} on columns,
Customer.fullname.members on rows,
customer.Location.[Customer Geography] as pages
from [Adventure Works DW2012]
I am trying to get this output using an MDX query (this is from AdventureWorks DW2012):
That's not a 3-dimensional resultset in your screenshot, unless there's something cropped from it.
Something like
SELECT [Geography].[Country].Members ON 0,
[Customer].[CustomerName].Members ON 1
FROM [whatever the cube is called]
WHERE [Measures].[Sales Amount]
(dimension/hierarchy/level names may not be exactly right)
would give a resultset like the one in your message.
The beyond 2nd-dimension dimensions and dimension names are not used in any client tool that I know. (Others may know different). They seem to be there in MDX so that MDX can hand >2-dimensional resultsets to clients that can handle them (e.g. an MDX subquery handing its results to the main query).
An often-used trick in MDX is to get the members of two dimensions onto one axis by cross-joining:
SELECT
{[Date].[Calendar Date].[Calendar Year].Members * [Geography].[Country].Members} ON 0,
[something else] ON 1
FROM [Cube]
How about the following - it does not send more than two dimensions back to a flat screen but it uses quite a few dimensions explicitly:
SELECT
[Measures].[Sales Amount] ON O,
[Customer].[fullname].MEMBERS ON 1
FROM
(
SELECT
[Date].[Calendar Month].[Calendar Month].&[February-2012] ON 0,
[Geography].[Country].[Country].&[Canada] ON 1,
[Product].[Product].&[Red Bike] ON 2,
[Customer].[Customer].&[foo bar] ON 3
FROM [Adventure Works DW2012]
)
I've made up the dimension | hierarchy | member combinations as I do not have access to the cube.
Also if we consider implicit dimensions then take the following:
SELECT
[Customer].[Location].[Customer Geography] ON 0,
[Customer].[fullname].[fullname].&[Aaron Flores] ON 1
FROM [Adventure Works DW2012]
WHERE
(
[Measures].[Sales Amount]
);
On the slicer I've used braces (..) which indicate a tuple, but this is actually shorthand for the following:
SELECT
[Customer].[Location].[Customer Geography] ON 0,
[Customer].[fullname].[fullname].&[Aaron Flores] ON 1
FROM [Adventure Works DW2012]
WHERE
(
[Measures].[Sales Amount]
,[Date].[Calendar Month].[Calendar Month].[All],
,[Geography].[Country].[Country].[All],
,[Product].[Product].[All]
,...
,...
....
);
The All member from every dimension in the cube could be included in this slicer without affecting the result.
So the whole nature of mdx is multi-dimensional - yes you do not get more than a 2 dimensional table returned to your screen but the way you get to that cellset could well involve many dimensions.
I understand how to use the MDX Aggregate() and Sum() functions, and the differences between them.
(One interesting one is that the Sum of a measure defined at a higher level in a hierarchy over that level's Children multiplies the measure by the number of children - whereas Aggregate "correctly" returns just the value defined at the higher level).
The documented syntax on MSDN is:
Aggregate(Set_Expression [ ,Numeric_Expression ])
I've always used it with both arguments. But what does Aggregate do when only the set_expression argument is provided? The documentation (again from MSDN) is pretty obscure:
If a numeric expression is not provided, this function aggregates each measure within the current query context by using the default aggregation operator that is specified for each measure.
I tried it in an MDX query like this:
WITH MEMBER WeekSummedTotal AS
Aggregate([Days].[WeeksAndDays].CurrentMember.Children)
SELECT
{Measures.ThingoCount,Measures.WeekTotal,Measures.WeekSummedTotal} ON 0,
[Days].[WeeksAndDays].[WeekName] ON 1
FROM DateGRoupingTest
What would this do? Would Aggregate aggregate the cube's default measure over the set? Or the set Measures.Members? Or the set of other measures specified on the 0 axis?
None of these! The query runs and returns results, but the calcd measure WeekSumTotal shows #Error, with a completely nonsensical error:
Aggregate functions cannot be used on calculated members in the measures dimension
Now this is true, but completely irrelevant. None of the other measures in the query is calculated, and in fact the cube doesn't have any calculated members. So what is Aggregate() actually trying to do here? Is this error message (again, in MDX!) completely misleading?
ADDITION: #whytheq in the answer below suggested creating the calculated measure using Aggregate, but creating it on a spare dimension hierarchy rather than in the Measures dimension. This works, but only if the cross-join with the [All] member of the selected "any old..." dimension is included.
Creating the measure there also makes it impossible to put the two (base) measures and the calculated measure on the same axis. If I try to do this:
{Measures.ThingoCount,Measures.WeekTotal,[Ages].[Age Key].WeekSummedTotal} ON 0,
I get the deeply-unhelpful error message:
Members, tuples or sets must use the same hierarchies in the function.
which, I think, translates to "I can't make a set using the , (UNION) function between members of Measures and members of [Ages].[Age Key] because they're members of different dimensions".
My conclusion, thanks to your informative answers, is that Aggregate() with a single argument is a tricky beast; I wonder why it was designed with the second argument optional?
I've also noted that trying to create my calculated member on my Ages dimension (only one hierarchy, only one attribute) gives me the misleading error message:
The 'Ages' dimension contains more than one hierarchy, therefore
the hierarchy must be explicitly specified.
unless I explicitly specify the hierarchy. MDX has so much potential, but the learning curve would be that much gentler if MS had put more effort into making it feed back errors properly.
What would this do? Would Aggregate aggregate the cube's default
measure over the set? Or the set Measures.Members? Or the set of other
measures specified on the 0 axis?
Aggregate function aggregates the set over the current measure for Measures dimension. And a measure is "current" if it is in scope. If a measure is not in scope, the default member from measures dimension is considered for aggregation.
A measure can be added to scope in many ways like
Having the measure on axes
with member [Customer].[Customer].abc as
aggregate([Customer].[Customer].members)
select [Customer].[Customer].abc on 0,
{[Measures].[Internet Sales Amount],[Measures].[Reseller Sales Amount]} on 1
from [Adventure Works]
In the above example the member abc was calcualted twice, once for each measure.
Using Subcube
with member [Customer].[Customer].abc as
aggregate([Customer].[Customer].members)
select [Customer].[Customer].abc on 0
from (select {[Measures].[Internet Sales Amount] } on 0 from [Adventure Works])
Having the measure in definition
with member [Customer].[Customer].abc as
aggregate([Customer].[Customer].members, [Measures].[Internet Sales Amount])
select [Customer].[Customer].abc on 0
from [Adventure Works]
In Where clause
with member [Customer].[Customer].abc as
aggregate([Customer].[Customer].members)
select [Customer].[Customer].abc on 0
from [Adventure Works]
where [Measures].[Internet Sales Amount]
As suggested by whytheq, have the member on some other dimension-hierarchy combo. Otherwise, the aggregate function would probably lead to the calculated member self-referencing itself.
Taking this section of the MSDN definition:
...this function aggregates each measure within the current query
context ...
each measure in the context of your script is the following:
{Measures.ThingoCount,Measures.WeekTotal,Measures.WeekSummedTotal}
Now Measures.WeekSummedTotal is a calculated members in the measures dimension - hence the error.
I'd imagine something like the following would function ok, where you use Aggregate to create a member in a dimension other than Measures?:
WITH
MEMBER [SomeSpareDim].[SomeSpareHier].WeekSummedTotal AS
Aggregate
(
[Days].[WeeksAndDays].CurrentMember.Children * [SomeDim].[SomeHier].[All]
)
SELECT
[SomeSpareDim].[SomeSpareHier].WeekSummedTotal ON 0
,[Days].[WeeksAndDays].[WeekName] ON 1
FROM DateGRoupingTest;
The above can be changed to show Aggregate being very useful:
WITH
MEMBER [Days].[WeeksAndDays].[Last3Weeks] AS
Aggregate
(
{
[Days].[WeeksAndDays].[Weekx]
,[Days].[WeeksAndDays].[Weeky]
,[Days].[WeeksAndDays].[Weekz]
}
)
SELECT
{Measures.ThingoCount,Measures.WeekTotal} ON 0
,{
//<< the following custom aggregated member will work for any measure, that is ON 0, via Aggregate
//it can be mixed up with the normal members of the same hierarchy like the following
[Days].[WeeksAndDays].[Last3Weeks]
,[Days].[WeeksAndDays].[WeekName].members
} ON 1
FROM DateGRoupingTest;
I'm trying to run this query:
select [Dim Date].[Date] on ROWS,
{[Measures].[Available Time Net],[Measures].[Logged On Time Net]} on columns
from [OTS Agent Time Net Data]
where {[Dim Date].[Date].&[08/01/2014]:[Dim Date].[Date].&[12/31/2014]}
I want to get the measures that exist in the where clause, but I also want to show the dates on the rows. I keep getting an error.
Why not just add the set directly to the ROWS ?
SELECT
NON EMPTY
{
[Dim Date].[Date].&[08/01/2014] : [Dim Date].[Date].&[12/31/2014]
} ON ROWS
,{
[Measures].[Available Time Net]
,[Measures].[Logged On Time Net]
} ON COLUMNS
FROM [OTS Agent Time Net Data];
You cannot use the same hierarchy ([Dim Date].[Date]) both on one axis and in the slicer (MDX tutorial); I guess using a sub-query would be fine for your example:
select
[Dim Date].[Date] on ROWS,
{[Measures].[Available Time Net],[Measures].[Logged On Time Net]} on columns
from (
select {[Dim Date].[Date].&[08/01/2014]:[Dim Date].[Date].&[12/31/2014]} on 0
from [OTS Agent Time Net Data]
)
Hope that helps.
(edit: using a named-set or using the slicer content right in the axis - see other responses - is a bit different because the request is filtering on a range of days but select [Dim Date].[Date] does not necessarily displays days; that could for example be the 'All' of the hierarchy of [Dim Date].[Date])
I agree with Marc's answer and that's probably the best way to do it. But there is one more way to do it, which doesn't need subselect, by making use of named sets.
with set DateRange AS
{[Dim Date].[Date].&[08/01/2014]:[Dim Date].[Date].&[12/31/2014]}
select NON EMPTY DateRange on ROWS,
{[Measures].[Available Time Net],[Measures].[Logged On Time Net]} on COLUMNS
from [OTS Agent Time Net Data]
EDIT
As per your request, if you want to additionally filter by time, here's one way to proceed. Replace the defenition of set DateRange with the below:
with set DateRange AS
EXISTS({[Dim Date].[Date].&[08/01/2014]:[Dim Date].[Date].&[12/31/2014]}
,[Dim Time].[Time].&[1930]
, "Time Net"
)
Few things which you need to fill in here..
Assuming time dimension's hierarchy to be [Dim Time].[Time]. Please replace with the actual name along with the member's format(Assumed it to be &[1930]
Also, Time Net is the measure group name to which the measures [Measures].[Available Time Net] and [Measures].[Logged On Time Net] belong to. Again, replace with original name.
Here is the query that I am using:
SELECT
NON EMPTY { [Dim Date].[Week].[Week].Members } ON COLUMNS,
[Dim Source].[Source Name].[Source Name].Members ON ROWS
FROM [Some Cube];
The things is, right now, I have many measures.
But as I am using dimension members on COLUMNS, I cannot indicate the measure anymore.
So this query results in a default measure.
My question is how can I indicate the measure instead of using the default in mdx query?
Or is there any other way that I can do this query (dimension in both row and columns is required for reading result logic in C# in possible) ?
You can do it in two ways:
Either on the SELECT statement, as
{ [Dim Date].[Week].[Week].Members } * { [Measures].[My Measure] } ON COLUMNS,
or on the WHERE slicer by adding
WHERE [Measures].[My Measure]
at the end.