var mongo = require('mongodb');
var host = "localhost";
var port = mongo.Connection.DEFAULT_PORT;
//创建MongoDB数据库所在服务器的Server对象
var server = new mongo.Server(host, port, {auto_reconnect:true});
//创建MongoDB数据库
var db = new mongo.Db('node-mongo-example', server, {saft:true});
//数据库连接操作
db.open(function(err, db){
  if(err) {
    console.log('连接数据库发生错误');
    throw err;}
  else{
    console.log("成功建立数据库连接");
    db.close();
  }
});
db.on('close',function(err,db){
  if (err) {throw err;}
  else{
    console.log("成功关闭数据库");
  }
});

2015-12-13T00:49:12.195+0600 I STORAGE [initandlisten] exception in initAndListen: 28663 Cannot start server. The default storage engine 'wiredTiger' is not available with this build of mongod. Please specify a different storage engine explicitly, e.g. --storageEngine=mmapv1., terminating 2015-12-13T00:49:12.195+0600 I CONTROL [initandlisten] dbexit: rc: 100

D:\MongoDB\bin mongod --storageEngine=mmapv1 --dbpath [your-path]