Funny, that this can be translated literally. In German, too, there's a rare idiom "Alte Schule" which literally and idiomatic means old school. But nowadays, people rather use the Anglicism "oldschool"
I have seen DL make a big deal out of whether something is a sentence or not. Allow me to point out that this phrase does not start with a capital letter and does not end with a period. Therefore, it is not a sentence as described.