mongoInsert.js

var http = require('http');
var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/testdb";

var companies = [{'name' : 'Sun Pharma', 'medicine' : [1, 2]},
                {'name' : 'Hello Pharma', 'medicine' : [3, 4]},
                {'name' : 'Sayan Pharma Ltd.', 'medicine' : [5]}];

MongoClient.connect(url, (err, db) => {
  if (err) {
    console.log (err);
  } else {
    db.createCollection ('company', (err, collection) => {
      var index = 0;
      companies.forEach ((company) => {
          collection.insert (company, () => {
            if (index++ === companies.length-1)
            {
              collection.find ().toArray ((err, result) => {
                db.close (() => {
                  console.log (result);
                });
              });
            };
          });
      });
    });
  };
});