app.get("/students/:snumber", function (req, res, next) {
console.log('student number =', req.params.snumber)
next() },

function (req, res, next) {
var query = { student_number: req.params.snumber };

MongoClient.connect('mongodb://localhost:27017/uni', function (err, client) {
if (err) throw err
    var db = client.db('uni')
    db.collection('students').find(query).toArray(function (err, result) {
    if (err) throw err
console.log(result)
res.send(result)
})
})
});