// Database
var MongoClient = require('mongodb').MongoClient;
var db;

// Initialize connection once
MongoClient.connect("mongodb://localhost:27017/maindb", function(err, database) {
  if(err) return console.error(err);

  db = database;
  console.error("Connected to db");
});

// Insert
var item = [{"Item" : "val"} { "Item" : "val" }];
db.collection('orders').insert(item, function(err, request) {
    console.log('Inserted.');
});