4 Replies Latest reply on Sep 18, 2018 2:17 PM by Shinichiro Murakami

    Creating a Gantt chart when connected to Access database

    Chris Broughton

      I have successfully created a desired Gantt view from data in an Excel spreadsheet using a Fixed LOD in the calculation for time between dates.

      P1=

      {FIXED [Company],[Project]:MIN(IF[Milestone]='Mlstn 2' THEN [Milestone date] END)}

      -

      {FIXED [Company],[Project]:MIN(IF[Milestone]='Mlstn 1' THEN [Milestone date] END}

       

      I then aggregate my 3 time spans with

      Project timeline=

      CASE [Milestone] WHEN 'Mlstn 1' THEN [P1] WHEN 'Mlstn 2' THEN [P2] WHEN 'Mlstn 3' THEN [P3-L] END

       

      Using the Project timeline calculation as size and Milestone dimension as color I create this view.

       

      Gantt.PNG

       

      However, I need to create this view using data from an Access database connection, which does not support use of the Fixed LOD.  I have tried using the same time span calculation as above without the Fixed LOD, which returns no result.  I can generate a timespan using this calculation:

      P1-2=

      DATEDIFF('day',MIN(IF [Milestone]='Mlstn 1' THEN DATE(Milestone date)END), MIN(IF [Milestone]='Mlstn 2' THEN DATE([Milstone date]) END))

       

      But when I try to aggregate the 3 time spans using this calculation:

      Project timeline-2=

      CAST ATTR([Milestone]) WHEN 'Mlstn 1' THEN [P1-2] WHEN 'Mlstn 2' THEN [P2-2] WHEN 'Mlstn 3' THEN [P3-L-2] END

       

      It produces no result.  Is there a different way to aggregate these duration calculations?  Or a different way to calculation the durations, without the Fixed LOD, that will aggregate?

       

      I am using Tableau desktop ver. 10.5, workbook attached below.

       

      Chris Broughton