useset.js

var mongoose = require('./mongoose')
mongoose.connect('localhost', 'testing_487');

var Schema = mongoose.Schema;

var db = mongoose.connection;


var S = new Schema({a: String, b: String});
var A = db.model('A', S);

var a = new A({a:"hi",b:"bye"});
a.save(function (err) {
  if (err) return console.error(err.stack||err);
  A.find({}, function (err) {
    if (err) return console.error(err.stack||err);
    A.update({a:"hi"}, { $set: { b: "goooooobye" }}, function (err) {
      if (err) return console.error(err.stack||err);
      A.find({}, function (err, docs) {
        if (err) return console.error(err.stack||err);
        console.error('done. found', docs);
        mongoose.connection.db.dropDatabase(function () {
          mongoose.connection.close();
        });
      })
    })
  })
})