How to query data from mongoDB with moongoose in nodejs - node.js

Question

I only want to check if the key exist in the databse but when i try to query it I only get NULL.
This is my invite.js
var mongoose = require('mongoose');
mongoose.createConnection('mongodb://localhost/invitation');
var db2 = mongoose.createConnection;
// User Schema
var InvitationSchema = mongoose.Schema({
key: {
type: String,
index: true
},
used: {
type: String
}
});
var Invitation = module.exports = mongoose.model('Invitation', InvitationSchema);
module.exports.getUsedByKey = function(id, callback){
var query = {used: key};
Invitation.findById(query, callback);
};
module.exports.getInvitationByKey = function(key, callback){
var query = {key: key};
Invitation.findOne(query, callback);
console.log('keythingy ' + callback);
};
And this is how I try to use that function:
function checkKey(key, res) {
Invitation.getInvitationByKey(key, function(err, key2) {
//console.log('key: ' + key + '\nkey2: ' + key2.key)
if (err) throw err;
if (key2 !=null) {
return key2.key;
} else {
return false;
}
})
}

Answer 1

Use the below best way for write code in NodeJS. Mongoose.
Make one JavaScript class for connection with mongodb like --> db.js
var mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/invitation');
var Schema = mongoose.Schema;
// User Schema
var InvitationSchema = mongoose.Schema({
key: {
type: String,
index: true
},
used: {
type: String
}
}, {
collection: 'Invitation'
});
module.exports.Invitation = mongoose.model('Invitation', InvitationSchema);
Make another fetch data from collection JavaScript class --> invitation.js
var db = require('db.js');
module.exports.Initation = {
getInvitationByKey : function(key, callback) {
var query = {key: key};
db.Invitation.findOne(query, function(err, result){
console.log("Result : ", result, ", Error : ", err);
callback(err, result);
});
}
}
Make route JavaScript class --> invitation_route.js
var express = require('express');
var router = express.Router();
var invitation = require('invitation.js').Initation;
router.get('/get/:key', function(req, res, next) {
invitation.getInvitationByKey(req.params.key, function(err, result){
if (err) {
console.log(' Error : ', err);
res.body(err);
} else {
console.log(' Result : ' + JSON.stringify(result));
res.send(result);
};
});
});