Nach verzweifelter Suche habe ich nun endlich die Lösung gefunden.
Fürs Archiv:
SELECT uploadcategorys.id catId,
uploadcategorys.categoryName catName,
uploadedfiles.id fId,
uploadedfiles.fileName fileName,
uploadedfiles.fileSize fileSize
FROM (SELECT id, categoryName
FROM uploadcategorys
ORDER BY id DESC
LIMIT ?, ?)
uploadcategorys
LEFT JOIN uploadedfiles
ON uploadcategorys.id = uploadedfiles.categoryId
ORDER BY uploadcategorys.id DESC, uploadedfiles.id
uff...
...und wieder zurück zu C++ :)
Grüße, Matze