I am quite new to CiviCRM but I have programming skills with Drupal so I am looking for a best practice for our needs - and if programming is needed I would appreciate any links / information / hint how ro so that well in CiviCRM.
We have some custom fields on activities where we store some data like campaigns (this data is stored in three simple text fields where campaign names are saved - it has nothing to do with Civi) and for newsletter unsubscriptions we store the reasons why people unsubscribe (this is stored in Activity details field).
What we now need is a report showing us the sums of Activities gained by campaigns and unsubscription reasons. For that Civi need to sum up the Activities of the current month by the values in the fields.
In short: we need a list of the values stored in a period in a custom field of the activities with the sum of activities which have this value in the corresponding field.