[{"_id":1,"item":"sweatshirt","price.usd":45.99,qty:300},{"_id":2,"item":"winter coat","price.usd":499.99,qty:200},{"_id":3,"item":"sun dress","price.usd":199.99,qty:250}]

db.collection.aggregate([{$project:{_id:0,item:0,qty:0}},])