Over a million developers have joined DZone.
{{announcement.body}}
{{announcement.title}}

Geospatial Queries with MongoDB and Node.js

DZone's Guide to

Geospatial Queries with MongoDB and Node.js

· Java Zone
Free Resource

What every Java engineer should know about microservices: Reactive Microservices Architecture.  Brought to you in partnership with Lightbend.

 The following article was written by Javier Manzano

As I’m working on a new website on node.js with MongoDB (with mongoose), I’m just realizing how powerful is this combination. Just amazing.

In one of the new features I was developing I wanted to use geolocation on my searchs.

One of the first things you have to do is to tell mongoose (or MongoDB native driver) that one attribute is going to have a 2D index

var place = new Schema({
  ...
  creationDate: { type: Date, default: Date.now },
  userId: ObjectId,
  username: String,
  geo: {type: [Number], index: '2d'}
  ...
});
exports.PlaceService = mongoose.model('Place', place);

After that, we can include one method to find near places to the schema

place.methods.findNear = function(cb) {
  return this.model('Place').find({geo: { $nearSphere: this.geo, $maxDistance: 0.01} }, cb);
}

Now, if you’re using express.js, you can define a route in your app.js file (or whatever you call it and just add this function)

exports.nearPlaces = function(req, res) {
        //I'm just sending the geolocation points in a format like this 39.92,-23
        // but you can send it however you want
var coord = req.query.geo.split(',');
var Place = mongoose.model('Place');
var park = new Place({geo: coord});
place.findNear(
function(err,docs) {
if (!err) {
res.json(docs);
} else {
throw err;
}
});
};

As you can see, It’s incredible what you can achieve with just a bunch of lines of code.

I’m falling in love with Node.js!

See you later guys!!!! :)

Microservices for Java, explained. Revitalize your legacy systems (and your career) with Reactive Microservices Architecture, a free O'Reilly book. Brought to you in partnership with Lightbend.

Topics:

Published at DZone with permission of Will Soprano. See the original article here.

Opinions expressed by DZone contributors are their own.

THE DZONE NEWSLETTER

Dev Resources & Solutions Straight to Your Inbox

Thanks for subscribing!

Awesome! Check your inbox to verify your email so you can start receiving the latest in tech news and resources.

X

{{ parent.title || parent.header.title}}

{{ parent.tldr }}

{{ parent.urlSource.name }}