node-mongo.js

var MongoClient = require('mongodb').MongoClient
    , format = require('util').format;    

MongoClient.connect('mongodb://127.0.0.1:27017/ricardo-crawler-2', function(err, db) {
    if(err) throw err;

    var items = db.collection('items');


      items.count(function(err, count) {
        console.log(format("%s items", count));
      });
      
      items.find({sold: true}).count(function(err, count) {
        console.log(format("%s items sold", count));
      });
      
      items.find({sold: false}).count(function(err, count) {
        console.log(format("%s unsold", count));
      });

      
  });