mongodb - Find documents with unique field -

i have collection of addresses geo field (lng/lat). want documents unique geo lng/lat pairs populate google map instance pins. naturally don't want multiple pins sitting in top of each other, need unique lng/lat pairs only.

var mongoose = require("mongoose"),     schema = mongoose.schema;  var venueschema = new schema({     name: string,     street: string,     streetnumber: string,     postcode: string,     suburb: string,     state: string,     geo: array, // [lng, lat] });  var venue = mongoose.model('venue', venueschema); 

using distinct operator, can unique lng/lat. unfortunately query returns array of lng/lat geo points , not documents fields. have no idea business name belongs geo point.

keystone.list('venue').model.find().distinct('geo')     .exec(function(err, venues){          if(err){             throw err;         }          console.log(venues); // array of lat/lng pairs }); 

how construct query actual documents fields no 2 geo locations same?

you can use aggregate pipeline uses $group provide distinct-like behavior more flexibility:

keystone.list('venue').model.aggregate([     // group docs geo field, taking first doc each unique geo     {$group: {         _id: '$geo',         doc: { $first: '$$root' }     }} ], callback); 

$$root system variable contains input document of pipeline stage. gives first document of each unique geo value.