unable to find index for $geoNear query

Question

I am writing an application using node and mongodb and i can't make any geolocation query. I'm sending by post this query :

{  
    "geometry": {
          "type": "Point",
          "coordinates" : [-8.139530, -79.032231 ]
    }
}

and this is the output from my server :

    { MongoError: Unable to execute query: error processing query: ns=dblocations.locations limit=1000 skip=0                                     
Tree: GEONEAR  field=geometry maxdist=0.00125569 isNearSphere=0                                                                               
Sort: {}                                                                                                                                      
Proj: {}                                                                                                                                      
 planner returned error: unable to find index for $geoNear query                                                                              
    at Function.MongoError.create (/Users/giuseppemarotta/Documents/Mockinghi/node_modules/mongodb-core/lib/error.js:31:11)                   
    at queryCallback (/Users/giuseppemarotta/Documents/Mockinghi/node_modules/mongodb-core/lib/cursor.js:198:34)                              
    at /Users/giuseppemarotta/Documents/Mockinghi/node_modules/mongodb-core/lib/connection/pool.js:436:18                                     
    at _combinedTickCallback (internal/process/next_tick.js:67:7)                                                                             
    at process._tickCallback (internal/process/next_tick.js:98:9)                                                                             
  name: 'MongoError',                                                                                                                         
  message: 'Unable to execute query: error processing query: ns=dblocations.locations limit=1000 skip=0\nTree: GEONEAR  field=geometry maxdist
=0.00125569 isNearSphere=0\nSort: {}\nProj: {}\n planner returned error: unable to find index for $geoNear query',                            
  '$err': 'Unable to execute query: error processing query: ns=dblocations.locations limit=1000 skip=0\nTree: GEONEAR  field=geometry maxdist=
0.00125569 isNearSphere=0\nSort: {}\nProj: {}\n planner returned error: unable to find index for $geoNear query',                             
  code: 17007 } 

I have tried to use the native mongoshell/mongoose query and i cant make it work.

This is my location schema:

var mongoose     = require('mongoose');
var Schema       = mongoose.Schema;


var LocationSchema = new mongoose.Schema({

  name: String,
  geometry: {
        coordinates: { type: [Number], required:true }
    },
  created_by : { type: String, required: true},
    category: String,
    description: String,
    rating: Number,
  created_at: Date,
  updated_at: Date
});

// on every save, add the date
LocationSchema.pre('save', function(next) {
  // get the current date
  var currentDate = new Date();
  rating = 0 ;
  // change the updated_at field to current date
  this.updated_at = currentDate;

  // if created_at doesn't exist, add to that field
  if (!this.created_at)
    this.created_at = currentDate;

  next();
});

LocationSchema.index({ geometry: '2dsphere' });

module.exports=mongoose.model('Location', LocationSchema);

This is my server.js:

       //lets require/import the mongodb native drivers.
var mongoose = require('mongoose');
//We need to work with "MongoClient" interface in order to connect to a mongodb server.


// Connection URL. This is where your mongodb server is running.
var url = 'mongodb://--------:[email protected]:21895/dblocations';
var Location = require('./models/location');
var User = require('./models/user');

//lets require/import the mongodb native drivers.
var mongodb = require('mongodb');

//We need to work with "MongoClient" interface in order to connect to a mongodb server.
var MongoClient = mongodb.MongoClient;

mongoose.connect(url);

// server.js

// BASE SETUP
// =============================================================================

// call the packages we need
var express    = require('express');        // call express
var app        = express();                 // define our app using express
var bodyParser = require('body-parser');


router.route('/query')
// create a location (accessed at POST http://localhost:8080/mockinghi/register)
    .post(function(req, res) {

    var limit = req.query.limit || 10;
    limit=10;
    // get the max distance or set it to 8 kilometers
    var maxDistance = req.query.distance || 8;
    var minDistance = 0;
    // we need to convert the distance to radians
    // the raduis of Earth is approximately 6371 kilometers
    maxDistance /= 6371;

    // get coordinates [ <longitude> , <latitude> ]
    var coords = [];
    console.log(req);
    coords = req.body.geometry.coordinates;

    console.log("coords = "+coords);    
    console.log("MAxDistance = "+maxDistance);
/*
    // Use connect method to connect to the Server
    MongoClient.connect(url, function (err, db) {
    if (err) {
        console.log('Unable to connect to the mongoDB server. Error:', err);
    } else {
        //HURRAY!! We are connected. :)
        console.log('Connection established to', url);
        var locations_col = db.collection('locations');
        // do some work here with the database.

        locations_col.createIndex({ "geometry": "2d" });

        locations_col.createIndex({ "geometry.coordinates": "2d" });
        locations_col.ensureIndex({ "geometry" : "2dsphere" });
        locations_col.ensureIndex({ "geometry.coordinates" : "2dsphere" });


        locations_col.find(
            {
                geometry: {         
                $near :
                    {
                        $geometry: { type: "Point", 
                                    coordinates:[ coords[0],
                                                coords[1] ] },
                        $maxDistance: maxDistance
                    },
                }
            }
        ).toArray(function (err, result) {
                if (err) {
                    console.log(err);
                } else if (result.length) {
                    console.log('Found:', result);
                } else {
                    console.log('No document(s) found with defined "find" criteria!');
                }
            }
        );



        //Close connection
        db.close();

    }
    }); 


*/

    // find a location
    Location.find({
      loc: {        
        $near :
              {
                $geometry: { type: "2d", 
                             coordinates:[ coords[0],
                                           coords[1] ] },
                $maxDistance: maxDistance
              },
      }
    }).limit(limit).exec(function(err, locations) {
      if (err) {
        return res.json(500, err);
      }
    //console.log(locations);
    res.json(200, locations);
    });


    });

Answer 1

You need to create index for your entries like as the error clearly specifies there is no index for $geoNear.

db.collection_name.createIndex({"geometry.coordinates": "2dsphere"}))

Answer 2

It needs to be a geojson object and the type is a string, but default it to a point. There are several other things like polygon, line, etc, but you're just storing points. Remember the coordinates are [longitude, latitude]

geometry: {
    type: {
        type: String,
        default: "Point"
    },
    coordinates: {
        type: [Number]
    },
    index: '2dsphere'
}

you could also put the index else where

LocationSchema.index({geometry: '2dsphere'});