MongoDB – client.open()返回“未在函数中定义”

这是我有:

var express = require('express'); var MongoClient = require('mongodb').MongoClient; var Server = require('mongodb').Server; var app = express(); var client = new MongoClient(new Server('localhost', 27017, {}), {}); client.open(function(err, client){ //callback }); 

而当我运行它时,它指向打开方法的行,并说“未定义不是一个函数”。 我究竟做错了什么?

从mongo文档 :

 var MongoClient = require('mongodb').MongoClient // Connection URL var url = 'mongodb://localhost:27017/myproject'; // Use connect method to connect to the Server MongoClient.connect(url, function(err, db) { console.log("Connected correctly to server"); db.close(); });