We don't seem to have this feature on the database activity yet.

Some user stories:

• As a user, I want to mark items in a database activity as favourites, so that I can easily refer to them in the future.
• As a user, I want to see a list of my favourite items in a database list, so that I can get an organised view of my favourites.
• As a user, I want to my favourite items in a database activity are exported or deleted appropriately, so that I can have peace of mind that my personal data is being handled by Moodle properly.