mongouniversity-hw-2.2.js

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

MongoClient.connect('mongodb://localhost:27017/weather', function(err, db) {
	if(err) throw err;

	var cursor = db.collection('data').find().sort({'State': 1, 'Temperature': -1}).batchSize(5000);

	var prevState = '';
	cursor.each(function(err, doc) {
        	if(err) throw err;

        	if(doc == null) {
        	    return db.close();
        	}

		if (prevState != doc.State) {
			console.log(prevState, doc.State);
			db.collection('data').update({_id: doc._id}, {$set: {month_high: true}});
			console.log(doc);
		}
		prevState = doc.State;
	});
});