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lbendlin's avatar
lbendlin
Icon for Super User rankSuper User
6 years ago
Solved

value = BLANK() versus ISBLANK(value)

This is a followup from https://community.powerbi.com/t5/DAX-Commands-and-Tips/seaching-for-keywords-in-text-for-use-as-index-seach-function/m-p/1152135   Why does this work? but this doesnt...
  • lbendlin's avatar
    lbendlin
    6 years ago

    Mystery solved. CONCATENATEX never returns blank. At the minimum it returns an empty string.  So there seems to be a bug in DAX that allows the comparison of an empty string to BLANK() to be true.

     

     

lbendlin's avatar
lbendlin
Icon for Super User rankSuper User
6 years ago

Mystery solved. CONCATENATEX never returns blank. At the minimum it returns an empty string.  So there seems to be a bug in DAX that allows the comparison of an empty string to BLANK() to be true.

 

 

lbendlin's avatar
lbendlin
Icon for Super User rankSuper User
6 years ago

marcorusso  I ran this in DAX studio.  Is there a good explanation for this?

 

evaluate row(
"Test1",ISBLANK(""),
"Test2",""=BLANK()
)

    • lbendlin's avatar
      lbendlin
      Icon for Super User rankSuper User
      6 years ago

      Thank you Marco.  Would be nice if the article could also mention the "=="  operator.

      • marcorusso's avatar
        marcorusso
        Icon for Most Valuable Professional rankMost Valuable Professional
        6 years ago

        Good suggestion, I just added an example of == in that article. Thanks!

    • lbendlin's avatar
      lbendlin
      Icon for Super User rankSuper User
      6 years ago

      Anonymous  Thank you. I am not ashamed to admit that I was not aware of the equality operator ("==") being available in DAX.  That makes more sense now.  Single equal sign does a type transformation.  Thanks again!