[TYPO3-mvc] Query mm-Relation by constraint in mm_table?

[Matthias Schröder]

Hi folks,

Abstract question:
How can I query a mm-Relation with constraint referring to a column in the mm_table?

Concrete question:
I use sys_category to categorize three kind of entities. I want to query all categories (ideally unique), that are assigned to one type of entity. For this, I have my own CategoryRepository, which extends the TYPO3-CategoryRepository. Same for model.
For example: Give me all cagetories that are assigned to articles.

I discovered the column 'tablenames' in sys_category_record_mm. But how to query? Is there any extbase-way without using SQL?

Thanks in advance,
Matthias