Counting unique groups of records
I have asked this beofre but it turns out my calc was faulty so will ask again in a more simple fashion. I am attempting to cound how many orders are placed in a month by counting the job numbers in a given month. I have the script working that can do the find but am not sure about how to create a count field to use as the search criterie.
The table that is to be used for this is an invoice table. Seeing as one job number can have many invoices (different numbers) then I want to count the number of unique job numbers in a month. How do I do this?
I have a job_no field as well as a field that creates a month name from the invoice date as this will be used inthe search..