节点 js mongodb 数据库连接错误无法连接到服务器

Question

C：\mynodeprojects\test>node app 在 300 上服务器启动失败，连接失败 到服务器 [本地主机：27017] 在第一次连接 [MongoError： geta ddrinfo 本地主机：27017]

包：-

{
  "name": "test",
  "version": "1.0.0",
  "description": "simple test app",
  "main": "app.js",
  "scripts": {
    "test": "echo "Error: no test specified" && exit 1"
  },
  "author": "hukam thakur",
  "license": "ISC",
  "dependencies": {
    "express": "^4.16.2",
    "mongodb": "^2.2.33",
    "mongoose": "^4.10.8",
    "sudo": "^1.0.3"
  }
}

这里的数据库连接： -

var mongoose = require('mongoose');
var mongoURI = "mongodb://localhost:27017/test";
var MongoDB = mongoose.connect(mongoURI).connection;
MongoDB.on('error', function(err) { console.log(err.message); });
MongoDB.once('open', function() {
  console.log("mongodb connection open");
}); 

Answer 1

请尝试此代码，它对我有用：

var database,
ObjectId = require('mongodb').ObjectID,
MongoClient = require('mongodb').MongoClient,
url = 'mongodb://localhost:27017/test',
connection=MongoClient.connect(url, function(err, db) {  
  if (err) throw err;
  database=db;
});

然后编写查询，例如查找uniqueId(-

database.collection("users").findOne({_id:new ObjectId(userId)}, function(err, res) { 
 if (err) console.log(err);
   console.log(res);
});