16 Replies Latest reply: Mar 3, 2018 2:26 PM by Rob Wunderlich RSS

    Inconsistent expression results for isnull

    Samuel Brown

      Hi,

       

      I'm fairly new to qlik, so I apologise if this is a simple problem. What I'm trying to do is an isnull expression to populate a field based on two fields from different tables. My expression is:

       

      =if(isnull(AltAccountName), AccountName, AltAccountName)
      
      

       

      ColAccountNameAltAccountName

      Expression

      (as dimension)

      1

      DickinsonDickinsonDickinson
      2-PannellPannell
      3-Owen-
      4Buzzacott-Buzzacott

       

      For rows 1, 2 and 4 it's working just as I want. But I can't figure out why row 3 is producing a different result to row 2 when on the surface it looks exactly the same. Can anyone suggest as to what could be causing this or is there a workaround I could try?

       

      I don't know if this is a clue, but if I write the exact same expression down as a measure rather than dimension, it works perfectly . But unfortunately I'm looking to filter these results in the app.

      Doing an =len on both field returns either the length or a null value. So using len=0 does thes same as the above.

       

      Many thanks in advance

       

      Sam