How to manipulate data returned from mongo db using mongoose

Question

I've created a local database using mongo (using this tutorial actually)

It has a db named 'simple' and collection named 'people'. Then I import json with each element as

{
    "id": 1,
    "guid": "1581cfde-f2fc-44f8-8953-511331e943ab",
    "isActive": true,
    "firstName": "Ilene",
    "lastName": "Kent",
    "email": "[email protected]"
  }

I then create the schema and Person model in my node app

var express = require('express');
var path = require('path');
var mongoose = require('mongoose');

var app = express();

app.set('port', (process.env.PORT || 5000));

mongoose.connect('mongodb://localhost/simple')

var personSchema = {
  firstname: String,
  lastname: String,
  email: String
}

var Person = mongoose.model('Person', personSchema, 'people')

app.get('/users', function(req,res){
  Person.find(function(err, doc){
    var x = doc[0]
    console.log(x)
    console.log(Object.keys(x))
    res.send(200);
  });
});

On calling find() on the Person model I get logged (for console.log(doc[0])) - the first item in the doc returned:

{ _id: 548e41afa0bad91d53f34cce,
  id: 0,
  guid: 'af6a931d-1801-4662-9d52-c95dc97bac22',
  isActive: false,
  firstName: 'Janna',
  lastName: 'Shelton',
  email: '[email protected]' }

But my problem is that when I look for the property firstName on doc[0] (i.e. doc[0].firstName) I get an undefined.

I've tried diagnosing this and Object.keys(doc[0]) gives me:

[ '$__',
  'isNew',
  'errors',
  '_maxListeners',
  '_doc',
  '_pres',
  '_posts',
  'save',
  '_events' ]

meaning I suspect there must be some special methods for mongoose when you want to access the data from your returned elements - but I can't find the answer in documentation or here.

Thanks

Answer 1

You receive an array of Documents. Mongoose API

doc[0].get('firstName')

Answer 2

When you just want a plain JavaScript representation of the documents that you can freely manipulate, add lean() to your Mongoose query chain:

app.get('/users', function(req,res){
  Person.find().lean().exec(function(err, docs){
    var x = docs[0]
    console.log(x)
    console.log(Object.keys(x))
    res.send(200);
  });
});