I have a database of music manuscripts that looks like the below diagram. A 'Source item' belongs to a certain manuscript (source). A source item is then categorized as EITHER a 'Section' of a 'Piece' OR an 'Extract' of a 'Section'. This categorization is done by filling in either the Section ID or Extract ID in respective fields in the Source item table.
My problem: I am creating a report in MS Access. I want to group the Source items which are Sections under a Section group, but then also group the Source items that are Extracts under the same group. At this moment I have only these levels:
Group on Piece title -> group on Section text_incipit -> group on Source item text incipit
I would like to do something like this:
Group on Piece title -> group on Section text_incipit -> group on Source item text incipit OR group on Extract text incipit.
Is there a way of grouping with an OR? Or can this be achieved some other way?
