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al-0543's avatar
al-0543
Frequent Visitor
3 years ago

DAX weirdness - nested condition changes behaviour based on output string value

I have the following query for a calculated column, which uses variables set by filtering down tables to a single value.  These two variables are then used in a two part conditional statement to set ...
al-0543's avatar
al-0543
Frequent Visitor
3 years ago

I still am struggling to understand how equivalence in the output values (due to case insensitivity) can cause the nested condition to be evaluated before the condition that contains it.  I'm also not sure why this behaviour would be seen when the variables Condition1 and Condition1 are set in the way shown but not when the variables are set by simple assignment of a value.

 

Regarding evaluation according to row, this behavious only bites on rows where the returned value should be set by the first conditional.  All other rows in the table were returned correctly - following the logic in the second conditional.

johnt75's avatar
johnt75
Super User
3 years ago

You can't tell from the results which branch of the condition is being returned, because the text will be converted to the same case as the first row to be evaluated. For an example, create 2 tables like

Tmp 1 = { "Ha", "ha" }

Tmp 2 = { "ha", "Ha" }

Both rows of the tables will show the same values, with the case depending on which was evaluated first.

  • al-0543's avatar
    al-0543
    Frequent Visitor
    3 years ago

    So why does this issue go away if I assign values to the variables rather than getting them from the two queries?  If it was simply to do with the the first row on which the expression is evaluated, shouldn't that then carry through into the simpler situation where the variables are simply assigned?

    • johnt75's avatar
      johnt75
      Super User
      3 years ago

      From your original post it seemed that the behaviour only changed when you changed the strings which the condition returned ?