I'll try to explain. Property can be (then 1 in table field in DB) or can not be (than 0 in table field in DB). How can I output names of only those properties where 1 in table field?
If it's not a relation, but individual columns, there's no other option then to do it by hand. There's nothing to loop over.
If you have a lot of these properties, you might want to look at an EAV container, which is more flexible when it comes to recording different properties or attributes of an object.