Do your clients realize that they are averaging averages?
I think the best solution would be to derive your grade percentage in your data set. If you can do that, then you can just do a avg(percentage) in your group footer.
سؤال
I'm a bit of a noobie working with SSRS 2008 and I'm having trouble trying to get the average of a sum of numbers. Here is how my report looks like (I couldn't put in a screen shot, hopefully the text table I created makes sense ):
Example |
ParentCode | ChildCode | Total Grade | A | B | A% | B%
P1
1234 5 1 4 20% 80%
Totals 5 1 4 20% 80%
P2
4567 6 3 3 50% 50%
5555 3 2 1 66.7% 33.3%
Totals 9 5 4 58.35% 41.65%
I am calculating the percentage of grades for each ChildCode (ie. code 5555 has 2 A's out of 3 grades total, so its A% = 66.67%). I am doing this by using scope descriptors:
=sum(Fields!grade.Value)/sum(Fields!grade.Value,"gradePercCol")
Where the first sum's scope is by the row grouping (ChildCode) and the second sum is by the grade percent column grouping.
For whatever reason, I need to get the average of these percentages. Ie:
For parent code P2, I need the average for column A%: (50% + 66.67%) / 2 = 58.35, as well as for the B% column and so on. The "Totals row" in my example would be an example of what I need.
I think I need to make a custom aggregate since the original percentages are calculated using the sum function and I can't get an average of an aggregate function. However, I'm having a lot of trouble understnding the documentation for custom aggregates.
http://technet.microsoft.com/en-us/library/bb934256(v=sql.100).aspx
Any help clarifying these links or pointing me in the right direction would be much appreciated. Thanks a lot!
المحلول
Do your clients realize that they are averaging averages?
I think the best solution would be to derive your grade percentage in your data set. If you can do that, then you can just do a avg(percentage) in your group footer.