How to Create a query using multiple periods?

Umknix

I want to create a query where I can use more than one period in a row.
For example: I want to show Item Ledger Entries for each item per month. If I add an other Dataitem the query doesn't work correctly. Can someone
give me a hint?

What my customer expects:
Item No. - Description - Qty January - Qty February - etc.

Actually I work with a report but it's very slow (20 Minutes).
The real requirement works with 2 different tables, both of them were customerspecific tables.