MongoDB using Node.js - Part 2

var MongoClient = require('mongodb').MongoClient;

// Connect to the db
MongoClient.connect("mongodb://username:yourpassword@serveraddress:yourport/database", function(err, db) {

    if(err) { return console.dir(err); }

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

    var doc1 = {'_id':'doc1', 'city':'taipei', 'num' :25};
    var doc2 = {'_id':'doc2', 'city':'kaohsiung', 'num' :35};

    //insert
    collection.insert(doc1, {w:1}, function(err, result){});

    collection.insert(doc2, {w:1}, function(err, result) {
        console.log('insert');
        collection.update({city:'taipei'}, {$set:{num:55}}, {w:1}, function(err, result) {});
        
        collection.find().toArray(function(err, items) {});

        collection.find({city:'taipei'}).toArray(function(err, docs){
            console.log("retrieved records:");
            console.log(docs);
        });
    });
        
    var cursor = collection.find({city:'taipei'}).toArray(function(err, docs) {
          console.log("Printing docs from Array");
          docs.forEach(function(doc) {
                console.log("Doc from Array ");
                console.dir(doc);
                console.log(doc.city);
          });
    });
    //update
    collection.update({city:'taipei'}, {$inc:{num:25}}, {w:1}, function(err, result) {
        if(err)
        {
            console.log('fail update');
            return console.dir(err);
        }
        console.log('Successfully update');
    });
    //remove
    collection.remove({city:'kaohsiung'}, {w:1}, function(err, result) {});
});