How to access members of a object in node.js

I'm really new to node.js and having a bit of a problem with objects. Lets say I have two files, one called printer.js and another called database.js. printer.js prints the results database returns. printer.js looks like this:

var db = require("./database")

db.getStations(dbReturn);

function dbReturn(stations) {
    for(var i = 0; i < stations.length; i++) {
        console.log('id: ' + stations.id);
    }
}

and my database.js looks like this:

function getStations(callback){
    var listOfStations = [];

    for(var index = 0; index < 10; index++) {
        var station = new Station(index);
        listOfStations[index] = station;
    }
    callback(listOfStations);
}

function Station(id){
    this.id = id;
}

exports.getStations = getStations;

I would just like to mention that Station class has a lot more members than that. But the problem here is that I cannot access the members from the Station objects I created in database.js from printer.js. I am having quite a bit of trouble figuring out how to do this. I have learned how to create a new object of Station in printer.js by exporting Station, but I still can't access the members of an object I created somewhere else! It just spits out 10 x "id: undefined"

I have been suggested to do something similar to this:

database.prototype.getStations = function(callback) {
    //...
}

database.prototype.Station = function(id) {
    //...
}

module.exports = database;

But this does not seem to work since it just tells me that database is undefined. What am I doing wrong here?