Node JS and Express cannot read data from Mongo DB

Question

I want to get my data from Mongo DB with Node JS and Express JS. I Already made a mongoose schema and exported the module. But when I'm running the function, I just get an empty JSON object.. here is some code:

This is my exports function:

var Buchung = module.exports = mongoose.model('Buchung', buchungSchema);

//Get Buchungen
module.exports.getBuchungen = function (callback) {
    Buchung.find(callback);
};

And here's my function to actually get the data:

Buchung = require('../DB/models/buchung_mitarbeiter');

router.get('/buchungen', function(req,res){
    Buchung.getBuchungen(function (err, buchung) {
        if(err){
            throw err;
        }
    console.log(buchung);
    res.json(buchung);

    });
});

and finally my Schema:

var buchungSchema = mongoose.Schema({
    user:{
          type: String,
          required: true
      },
    tor:{
        type: Number,
        required: true
    },
    datum:{
        type: String,
        required: true
    },
    sendungsstruktur:{
        type: String,
        required: true
    }

});

I'm greatful for any help!

Answer 1

I have updated the code below. please try and let me know if still facing the issue. I have marked with * so remove * before using.

Buchung = require('../DB/models/buchung_mitarbeiter');

    router.get('/buchungen', function(req,res){
        Buchung.getBuchungen(function (err, buchung) {
            if(err){
                throw err;
            }
        console.log(buchung);
        res.json(buchung);
        **res.send(buchung)**
        });
    });

Answer 2

Export your Schema.

module.exports = mongoose.model('Buchung', buchungSchema);
Buchung = require('../DB/models/buchung_mitarbeiter');

router.get('/buchungen', (req,res) => {
   Buchung.find().then(buchungs => {
     res.json(buchungs);
   }).catch(err => res.json({err})) 
});
`

Answer 3

var Buchung = module.exports = mongoose.model('Buchung', buchungSchema);
module.exports.getBuchungen = function (callback) {
    Buchung.find()
    .then(response => {
    return response; 
    })
    .catch(error => {
    return error;
});
};