explanation wished: Two seamlesly same dax measures giving different results

[henkka]

Hi,

can anyone explain why these two different aproaches are giving different results ( first givin correct result)

Approach 1 - using three measures:

LatestAgreement =

 var latest = MAX ( 'WorkAgreement FACT'[Workagreement.id] )

 return

 latest

all latest agreement =

 CALCULATE ( [LatestAgreement] , ALL ( 'WorkAgreement FACT'[Workagreement.id] )

    )

Valid Agreements =

 VAR allagreements =

     VALUES ( 'WorkAgreement FACT'[Employee.id] )

 VAR agreementids =

     VALUES ( 'WorkAgreement FACT'[Workagreement.id] )

 RETURN

     COUNTX (

         allagreements,

         CALCULATE (

             COUNT ( 'WorkAgreement FACT'[Workagreement.id] ),

             FILTER ( agreementids, [LatestAgreement] = [all latest agreement] ),

             'WorkAgreement FACT'[Employee.id] <> BLANK (),

             StartDatesDim[Date] < TODAY () , 
             EndDatesDim[Date] > TODAY () || EndDatesDim[Date] = BLANK () )

     ) + 0

Approach number 2 (givin worng result):

 var latest = MAX ( 'WorkAgreement FACT'[Workagreement.id] ) + 0

 Var allLatest = CALCULATE ( latest, ALL ( 'WorkAgreement FACT'[Workagreement.id] ) )

 VAR allagreements =

     VALUES ( 'WorkAgreement FACT'[Employee.id] )

 VAR agreementids =

     VALUES ( 'WorkAgreement FACT'[Workagreement.id] )

     RETURN

     COUNTX (

         allagreements,

         CALCULATE (

             COUNT ( 'WorkAgreement FACT'[Workagreement.id] ),

              'WorkAgreement FACT'[Employee.id] <> BLANK (),

               FILTER ( agreementids, latest = allLatest ) ,

               StartDatesDim[Date] < TODAY (),

             EndDatesDim[Date] > TODAY () || EndDatesDim[Date] = BLANK ()          

         )

    ) + 0

[MFelix · Accepted solution]

Hi @henkka ,

Believe the main reason is the way you have the second calculation using variables, variables are calculated in the scope of the context so depedning on how you make use of them the calcuations changes.

When you use the 3 different metric approach you are making use of the Calculate argument even if not called directly so the calculation changes.

The context transiction is very tricky.

Check this blog post https://radacad.com/caution-when-using-variables-in-dax-and-power-bi

[henkka]

Hi, @MFelix and thanks for pointing out the reason behind that behaviour :)! I needed this understanding as I'm trying to create something a bit more efficient way to do this calculation 🙂

[henkka]

So the issue with the scenario 1 is that the variable is calculated and stored before the filtering and thus the filter is working as it should but the values for the filter are incorrect. The blog you linked was great!