我的回调函数不起作用

Question

I am do a nodeJS application, in which there is a call back function to persist the value to the database( MongoDB ). The callback function as below:

exports.add = function(student, cb) {
    var collection = db.get().collection('students');
    collection.insert(student, function(err) {
        if (err) {
           throw err;
        }
        console.log("Record added");
    });
}

The above call back function is called from the another fuction as below:

router.post("/add", function(req,res){
    var student = req.body;
    Students.add(student, function(err) {
        if (err) {
            throw err;
        }
        var respOut = JSON.stringify({id:student.id});
        console.log("respOut");
        res.send(respOut);
    });
});

The call back function is called from the above bolded(Students.add) section. Currently I am able to persist the data on to the DB. But not getting any output on the console( given console out as -> console.log("respOut"); or any response in the UI(from above code). Is there any problem with my call back function? or I am missing anything?

Answer 1

You're not using cb in your Students.add method.

The easiest would be to just pass the callback through to collection.insert :

exports.add = function(student, cb) {
    var collection = db.get().collection('students');
    collection.insert(student, cb);
}