Calculating previous month in active reports

[Ivan V]

Hello All!

The situation is very simple at first glance.

I have an active report, which contains a data drop-down list with months and a column visualization linked to this drop-down list.

The visualization should show a comparison of the month selected in the drop-down list to the previous month. (Total two columns)

And the problem is in the calculating of previous month. I cannot calculate it because (as I guess) I cannot use active variables in my query.

The question whether it is possible to do this? May be some workaround?

Thank you!

Regards,
Ivan V