title: Invalid schema, expected `mongodb` or `mongodb+srv`
body: <p>have a problem, one project simple node js app with adding and getting data from user and saving into mongo (use 3.. ver), everything OK (saving, getting etc), example is</p>
  
  <pre><code>var express = require('express');
  var router = express.Router();
  var mongo = require('mongodb').MongoClient;
  var objectID = require('mongodb').ObjectID;
  var assert = require('assert');
  
  const url = 'mongodb://localhost:27017';
  const dbName = 'ldex';
  const tblOffers = 'offers';
  
  router.post('/insert', function (req, res, next) {
      var order = {
          type: 'Sell',
          ..............
          max: req.body.max,
          protection: req.body.protection,
          comment: req.body.comment,
          date: new Date().toDateString()
      };
  
      mongo.connect(url, function (err, client) {
          assert.equal(null, err);
  
          const db = client.db(dbName);
  
          db.collection(tblOffers).insertOne(order, function (err, res) {
              assert.equal(null, err);
              console.log('Offer placed');
              client.close();
          })
      });
  
      res.redirect('/exchange')
  });
  </code></pre>
  
  <p>But here is another app, parser, that have the same mongo connection, it's adding some data in it from other web-site (when do not use mongo all ok, I recieve data well), here is the part of code:</p>
  
  <pre><code>...
  let assert = require('assert');
  let mongo = require('mongodb').MongoClient;
  let router = express.Router();
  
  const url = 'mongodb://localhost:27017/';
  const dbName = 'ceramo';
  const tblOffers = 'items';
  
  ...
  
  /*
   *  Get items from specific group
   */
  
  function getGroupItems(url, callback) {
      request({uri: url}, function (error, response, body) {
          let list = [];
          let $ = cheerio.load(body);
          $('#tovar').find('a.cat_item_disc_a').each(function(i, elem) {
              list[i] = 'https://plitkazavr.ru' + $(this).attr('href');
          });
          callback(list);
      });
  }
  
  /*
   *  Parse one item from specific link
   */
  
  function getItem(url) {
      request({uri: url}, function (error, response, body) {
          let list = {};
          let $ = cheerio.load(body);
          $('#item_border').find('&gt; #item_prop &gt; ul').find('li.item_list').each(function(i, elem) {
              list[$(this).find('.item_cell').first().text()] = $(this).find('div.item_cell.item_val').text();
          });
          list.price = (parseFloat($('#item_price').text()));
          list.img = ('https://plitkazavr.ru' + $('#item_img').attr('src'));
          list.meta = ($('#item_wrap').find('meta[itemprop="description"]').attr("content"));
  
          mongo.connect(url, function (err, client) {
              assert.equal(null, err);
  
              const db = client.db(dbName);
  
              db.collection(tblOffers).insertOne(order, function (err, res) {
                  assert.equal(null, err);
                  console.log('Offer placed');
                  client.close();
              })
          });
  
      });
  }
  
  router.get('/parse', function (req, res, next) {
  
      getGroupItems('https://plitkazavr.ru/Naxos/Clio', function (items) {
          items.forEach(function(item, i, arr) {
              setTimeout(function() {
                  getItem(item);
              }, 1000);
          });
      });
  
      res.end('ok');
  });
  </code></pre>
  
  <p>And it's down on connection and gives the</p>
  
  <pre><code>`Error: Invalid schema, expected `mongodb` or `mongodb+srv
  </code></pre>
  
  <p>Don't understand where is a problem, help please...</p>