1 Reply Latest reply on Mar 28, 2014 7:19 AM by Noah Salvaterra

    Filter out rows from a table

    Thomas Beaulieu

      Hello - I have the following table that looks almost the way I need.





      I want to filter out the rows where either the Long Lead category is blank or the Short lead category is blank or both are blank.  In the above example, this would mean Null ans A00253 are filtered, A00254 is kept, A00277 is filtered and so on.  I know this has to be easy but its just not coming to me.  Any advice?  I tried making a set with Long Lead data and another set with short lead data and then creating a third set that filters on items shared between both the long and short lead sets but it did not work, everything got filtered away.




      Tom B.

        • 1. Re: Filter out rows from a table
          Noah Salvaterra

          This touches near an area I've struggled through known as data densification. If you apply isnull directly to one of your aggregated measures you won't see any nulls. That is because there is no data there. OK, so in theory, you could use size to compute how many different categories are represented in each row. The surprising result to this is 2 across the board. Tableau has actually created a place to hang these 2s, so an even more surprising result is that isnull now works as expected. The trick is the table calculation, and the behavior actually depends on how things are laid out on your worksheet! Try moving category to the level of detail on the size sheet and the result of this calculation will change. Note, I wrapped this in an if statement to get a 1 if it is null and a zero if it isn't. Since this calculation is now working as desired I can take a window_max to get an indicator if there is a null anywhere in the row. Since window_max is also a table calculation I no longer need to include size, once I have the window_max as a filter I can clean up the the view removing things that are no longer needed.


          If you find this confusing, you're not alone. Hopefully this helps, and I didn't add too much to that confusion. At his point densification isn't something that has been documented very well, but there are smart people thinking about it.