I've read a few guides on how to use Mongo with Node, and they all seem to connect to databases differently. One particular way that worked well for me was:

```
MongoClient.connect("mongodb://localhost:27017/exampleDb", function(err, db) {
  if(err) { return console.dir(err); }

  db.createCollection('users', function(err, collection) {});

  //Do all server/database operations in here

});

```

However, this seems inefficient/odd to me, I would have to reconnect to the database every time there is an `app.get()`, like for making a new user or retrieving information. 

Another way that seems better suited to me is

```
var mongoose = require("mongoose")
var db = mongoose.connect("localhost:27107/users");

db.createCollection('users', function(err, collection) {});

```

I've seen several sites do something along these lines, but I personally can't get the above to work. I keep getting the error `TypeError: db.createCollection is not a function` server-side. So, my question is why the above code doesn't work, if the first code is a good alternative, and if there are any other ways to do this.