Javascript MongoError:拓扑被破坏（查找文档时），实例池被破坏（插入文档时）

我正在尝试用Node.js、Express和Mongodb构建RESTAPI。我使用mongodb npm包连接到数据库，下面是我的sever.js文件代码

var express = require("express");
var app = express();
var bodyParser = require("body-parser");
var port = process.env.PORT || 8080;
var mongo = require("mongodb");
var Server = mongo.Server;
var Db = mongo.Db;
var ObjectID = mongo.ObjectID;
try{    
    var config = require('./configure.js');
}catch(e){
    console.log("configuration file is hidden on github for security");
    config = null;
}
var usersCollection = config.usersCollection;
var login = require('./routes/login/index.js');
var signup = require('./routes/signup/index.js');
var Database = new Db(process.env.DBNAME || config.DBNAME , new Server(process.env.DBHOST || config.DBHOST, process.env.DBPORT || config.DBPORT, {'native_parser': true}));


Database.open(function (err, mongoclient) {
        if(err){
            console.log("Failed to connect to the database. Please Check the connection");
            throw err;
        }else{
            Database.authenticate(process.env.DBUSER || config.DBUSER, process.env.DBPASS || config.DBPASS, function(err, res) {
                if (err) {
                    console.log("Authentication Failed"); 
                    throw err; 
                }else{
                    console.log("Connected to the database Successfully");
                    app.use(bodyParser.urlencoded({ extended: true }));
                    app.use(bodyParser.json());
                    var users = Database.collection(usersCollection);
                    login(app,users);
                    signup(app,users);

                    Database.close();
                }
            });
        }
    });

app.listen(port,function(){
    console.log("Server Started Listening to port : "+port);
});

路由/login/index.js

module.exports = function(app,users){
app.route('/login')
   .post(function(req,res){
        var username = req.body.username;
        var password = req.body.password;
        var query = {'FirstName':username};

        users.find().toArray(function(err,docs){
            if(err){
                throw err;
            }else{
                console.log("no err");
                if(doc.LastName == password){
                    res.send({status : true});
                }else{
                    res.send({status : false});
                }
            }
        });
   });

}

和routes/signup/index.js

module.exports = function(app,users){
app.route('/signup')
   .post(function(req,res){
        var doc = { EmpNo:"1",
                    FirstName:"Andrew",
                    LastName:"Neil",
                    Age:"30",
                    Gender:"Male",
                    Skill:"MongoDB",
                    Phone:"408-1234567",
                    Email:"Andrew.Neil@gmail.com",
                    Salary:"80000"
        };

        users.insert(doc,function(err,info){
            if(err){
                throw err;
            }else{
                console.log('Successfully inserted ' + JSON.stringify(info));
                res.send({result: 'done'});
            }
        });
    });

}

当我尝试在server.js中插入文档时，我能够成功地插入它们，但是通过routes/signup/index.js，我得到的实例池也被破坏了，如果我尝试在server.js中查找文档，没有错误，但是如果我尝试从routes/login/index.js中进行插入，那么当拓扑被破坏时，我会得到错误

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需要帮助来解决它

＞P>这些错误如果在过程中间被某种方式切断，就会被抛出。

---

因为

users.find（）

和

users.insert（）

函数都是异步的，所以您的server.js文件会到达

数据库.close（）函数，并在完成过程之前关闭与数据库的连接，从而给出错误。
我明白了，我删除了Database.close（）语句，它工作正常。非常感谢。