2 Replies Latest reply on Jan 21, 2010 9:25 AM by michel_1

    Subtracting subsummary Min from subsummary Max

    michel_1

      Title

      Subtracting subsummary Min from subsummary Max

      Post

      I am rusty with databases and need some help.  I have a file with student test scores and want to know the range (in the sense of the difference between the maximum and minimum scores) when sorting by teacher.  I created a subsummary and when I sort by teacher can see the maximum and minimum.  Great.  But how do I subtract them from each other in the subsummary? 

       

      I thought I could do this with GetSummary(Max;Class)-GetSummary(Min;Class).  This worked in a smaller simpler file, but not in my real file.  I just get a blank field in the summary.  The only difference that I can see between the two is that my sort field "class" is coming from a related table.  I set up a "class" field in the student table with a calculation to see if this would solve the problem, but still it is blank.

       

      Is there something I am missing?  Is there an easier way? I apologize if this is obviously simple, but I am stumped.  THANKS!