Unexpected Excel Pivot behaviour with SQL Server Tabular model (v2)

Question

We use Excel from Office 365 with a SQL Server 2019 Tabular model

I have a "strange" behaviour of Excel Pivot regarding the level at which calculations are requested from DAX.

I create 3 simple (SQL Server) tables, MyDim, DimColour and MyFact

There is an implicit hierachy (not enforced) between the BrandName and ItemName in the MyDim table.

I could not enforce this because nothing says that an Item can only belong to one brand.

I create a very basic measure to aggregate the fact although I don't really need it here

FactTotal := SUM(MyFact[FactValue])

And I also create 2 additional measures that are more interesting

LowestLevel :=
SWITCH (
    TRUE (),
    ISFILTERED ( 'MyDim'[ItemName] ), "Item",
    ISFILTERED ( 'MyDim'[BrandName] ), "Brand",
    "Neither Brand nor Item"
)

Lowest Level ALWAYS return a value, regardless of whether there are rows in the fact table.

LowestLevelButItem :=
SWITCH (
    TRUE (),
    ISFILTERED ( 'MyDim'[ItemName] ), BLANK (),
    ISFILTERED ( 'MyDim'[BrandName] ), "Brand",
    "Neither Brand nor Item"
)

LowestLevelButItem returns a value as long as we are not filtering on ItemName

Now, this is the behaviour which bothers us...

Open the cube in an Excel Pivot table, filter on colours Blue and Yellow

Result 1, ok

This is the right result. No problem here.

Add the measure LowestLevelButItem...

Result 2, unexpected

Now, this is not the result we would like... I would not expect to see "Brand A" at all in this result

It shows that the measure displayed in D4 has been evaluated at a different level than D5 & D6.

D5 & D6 are evaluated at the Item level, as expected while D4 is evaluated at a higher level because there is no matching row at Item level...

Now, add the measure LowestLevel

Result 3, ok

Now, I understand this result.

Because LowestLevel ALWAYS returns a value, it makes Brand A / Item 1 visible, which forces evaluation of the measure LowestLevelButItem at the Item level, hence blank().

The problem I have is with the second result...

Question

How could I force the Pivot table to NOT return the Brand if there is no suitable Item underneath?

SSMS Behaviour

If I browse my cube in SSMS, I get the results I would expect, which is that my measures are always evaluated at the leaf level only and rows are not returned unless they have leaf level members.

SSMS Result 1, same

SSMS Result 2

SSMS did not return a row for "Brand A" with no Item member

SSMS Result 3

SQL Script to reproduce

CREATE TABLE MyDim(MyDimId      INT NOT NULL PRIMARY KEY
                  ,BrandName    VARCHAR(100) NOT NULL
                  ,ItemName     VARCHAR(100) NOT NULL
                  );

GO

-- TRUNCATE TABLE MyDim;
INSERT INTO MyDim(MyDimId, BrandName, ItemName)
  VALUES(1, 'Brand A', 'Item 1')
       ,(2, 'Brand B', 'Item 2')
       ,(3, 'Brand B', 'Item 3');
GO

CREATE TABLE DimColour(Colour VARCHAR(100) NOT NULL PRIMARY KEY);
GO

INSERT INTO DimColour(Colour)
  VALUES('Red')
      , ('Blue')
      , ('Yellow');

CREATE TABLE MyFact(MyDimId   INT NOT NULL
                   ,Colour    VARCHAR(100) NOT NULL
                   ,FactValue INT NOT NULL
                   ,PRIMARY KEY(MyDimId, Colour)
                   );
GO

-- TRUNCATE TABLE MyFact;
INSERT INTO MyFact(MyDimId, Colour, FactValue)
  VALUES(1, 'Red',    1)
      , (2, 'Blue',   2)
      , (3, 'Blue',   4)
      , (3, 'Yellow', 8);

MDX generated for Result 2 queries

• By SSMS (producing the result I want)

• Excel MDX

Answer 1

Just add the following IF clause to your measure:

LowestLevelButItem :=
IF(
  NOT(ISBLANK([FactTotal])),
  SWITCH (
    TRUE (),
    ISFILTERED ( 'MyDim'[ItemName] ), BLANK (),
    ISFILTERED ( 'MyDim'[BrandName] ), "Brand",
    "Neither Brand nor Item"
  )
)