store-geospatial-data.md

• Store geospatial data with Mongoose

Store geospatial data with Mongoose

MongoDB can store geospatial information and perform queries on it. In order to do so, you should store information as GeoJSON objects.

The format of a GeoJSON point is as follows:

{
  "type": "Point",
  "coordinates": [ -73.856077, 40.848447 ]
}

The two numbers are the longitude and latitude. A third optional number may be included to indicate the altitude.

This is an example of how to define a location property with this format in a Mongoose schema:

const geolocatedSchema = new Schema({
  location: {
    type: {
      type: String,
      required: true,
      enum: [ 'Point' ]
    },
    coordinates: {
      type: [ Number ],
      required: true,
      validate: {
        validator: validateGeoJsonCoordinates,
        message: '{VALUE} is not a valid longitude/latitude(/altitude) coordinates array'
      }
    }
  }
});

// Create a geospatial index on the location property.
geolocatedSchema.index({ location: '2dsphere' });

// Validate a GeoJSON coordinates array (longitude, latitude and optional altitude).
function validateGeoJsonCoordinates(value) {
  return Array.isArray(value) && value.length >= 2 && value.length <= 3 && isLongitude(value[0]) && isLatitude(value[1]);
}

function isLatitude(value) {
  return value >= -90 && value <= 90;
}

function isLongitude(value) {
  return value >= -180 && value <= 180;
}