Database

[{"name":"aa"},{"name":"a12a"},{"name":"a2a"},{"name":"a-a"},{"name":"a.-a"},{"name":"a/a"},{"name":1},{"name":"ß"},{"name":"ä"}]

Query

db.collection.find({"name":{"$regex":"[^a-zA-Z0-9ÄÖÜäöüß]"}})

Result