Node.js Mongoose Library find data in mongodb using promises



First, install the necessary packages with:

npm install express cors mongoose


Then, add dependencies to server.js, create the database schema and the name of the collection, create an Express.js server, and connect to MongoDB:

var express = require('express');
var cors = require('cors'); // We will use CORS to enable cross origin domain requests.
var mongoose = require('mongoose');
var Schema = mongoose.Schema;

var app = express();

var schemaName = new Schema({
    request: String,
    time: Number
}, {
    collection: 'collectionName'

var Model = mongoose.model('Model', schemaName);

var port = process.env.PORT || 8080;
app.listen(port, function() {
    console.log('Node.js listening on port ' + port);

app.use(function(err, req, res, next) {
  res.status(500).send('Something broke!');

app.use(function(req, res, next) {
  res.status(404).send('Sorry cant find that!');

Now add Express.js routes that we will use to query the data:

app.get('/find/:query', cors(), function(req, res, next) {
    var query = req.params.query;

        'request': query
    .exec() //remember to add exec, queries have a .then attribute but aren't promises
    .then(function(result) {
        if (result) {
        } else {
            next() //pass to 404 handler
    .catch(next) //pass to error handler

Assume that the following documents are in the collection in the model:

        "_id" : ObjectId("578abe97522ad414b8eeb55a"),
        "request" : "JavaScript is Awesome",
        "time" : 1468710551
        "_id" : ObjectId("578abe9b522ad414b8eeb55b"),
        "request" : "JavaScript is Awesome",
        "time" : 1468710555
        "_id" : ObjectId("578abea0522ad414b8eeb55c"),
        "request" : "JavaScript is Awesome",
        "time" : 1468710560

And the goal is to find and display all the documents containing "JavaScript is Awesome" under the "request" key.

For this, start MongoDB and run server.js with node server.js:


To use this to find data, go to the following URL in a browser:


Where <query> is the search query.




    _id: "578abe97522ad414b8eeb55a",
    request: "JavaScript is Awesome",
    time: 1468710551,
    __v: 0
    _id: "578abe9b522ad414b8eeb55b",
    request: "JavaScript is Awesome",
    time: 1468710555,
    __v: 0
    _id: "578abea0522ad414b8eeb55c",
    request: "JavaScript is Awesome",
    time: 1468710560,
    __v: 0