How create a new array field with the aggregate framework

Question

I\'m starting to use mongoDb and I\'m stuck with a simple use case.

Let\'s say I\'ve got a collection \'aCollection\' with entries such as this:

Answer 1

It looks like MongoDB 3.2 provides fairly simple and elegant way to create GeoJSON points using aggregation framework.

We had to perform the transformation on approximately 2 Million records two times a day, so aggregation framework was the fastest and probably most reliable approach.

Below is a Mongoose example of how to transform geolocation data from collection with longitude/latitude into a collection with GeoJSON points.

Locations
    .aggregate([
        {
            $project : {
                _id: 0,
                "location": {
                    "type": { $literal: "Point" }, 
                    "coordinates": ["$longitude", "$latitude"]
                }
            }
        },
        {
            $out : 'test_1'
        }])
    .exec(function(err,data) {
        if (err) {
            console.error(err);
        } else {
            console.log("Done transforming.");
        }
    });