Counting Sub-summary Rows

[parallax]

I'm running into a problem reporting sales by month and counting the months with sales. The report has a sub-summary part that totals invoice detail rows using a month(invoice_date) break field. The 'body' is the invoice details, which we actually hide on the report. Some customers purchase only a few times each year and the challenge is to count the number of months (we want to use that count in various calculations, like avg-sales-per-month for that customer). The 'count' function only counts the records in the body (the invoice detail rows). So how the heck do I count the resulting months?

The report breaks each month, then breaks again for a new customer.

Customer A

Jan 200 units

Apr 100 units

Jun 300 units

==============

avg sales = 200 units /month

Customer B

Feb 100 units

May 200 units

==============

avg sales = 150 units /month

etc.

I've seen this discussed on this forum before but I can't find the topic. Any help would be greatly appreciated.

[comment]

See here, for example:

http://fmforums.com/forum/showtopic.php?tid/196703/post/297056/#297056

[parallax]

Thanks! That was the post I was trying to find. Much appreciated.

[efen]

I seem to have been beaten to reply to this while making this sample file - but I will include it anyway in case it's of some help ...

subsummary.zip

[parallax]

efen,

i appreciate the sample file, but your example doesn't work. it counts the number of detail records which only results in the correct count *if* there is only one detail per month.

i'm trying to count the number of months w/ data, not the number of records. if there are sales on jan 1, jan 2, jan 3, jan 4 and no others, i want to see "1" month, not "4".

[efen]

I'm running into a problem reporting sales by month and counting the months with sales. ... Some customers purchase only a few times each year and the challenge is to count the number of months ...

.

That is how I read your problem