显示'db.get不是函数'NodeJs，MongoDB

Question

制作一个投票应用程序，该应用程序由以下两个模型用户和投票以及由两个集合用户和民意调查组成的数据库组成。

user.js的

'use strict'; 

var mongoose = require('mongoose'); 
var Schema = mongoose.Schema; 
var User = new Schema({ 
    github: { 
     id: String, 
     displayName: String, 
     username: String, 
     publicRepos: Number 
    }, 
    nbrClicks: { 
     clicks: Number 
    } 
}); 
module.exports = mongoose.model('User', User); 

Poll.js

'use strict'; 

var mongoose = require('mongoose'); 
var Schema = mongoose.Schema; 
var Poll = new mongoose.Schema({ 
    title: { type: String, required: true }, 
    creator: String, 
    choices: [String], 
    votes: [Number] 
}); 
module.exports = mongoose.model('Poll', Poll); 

，这是路由部分

'use strict'; 
require('dotenv').load(); 
var path = process.cwd(); 
var ClickHandler = require(path + '/app/controllers/clickHandler.server.js'); 
var mongo = require('mongodb'); 
var mongoose = require('mongoose'); 
var db = mongoose.createConnection(process.env.MONGO_URI); 

module.exports = function (app, passport) { 
    function isLoggedIn (req, res, next) { 
     if (req.isAuthenticated()) { 
      return next(); 
     } else { 
      res.redirect('/login'); 
     } 
    } 

    var clickHandler = new ClickHandler(); 
    app.route('/').get(isLoggedIn, function (req, res) { 
     //console.log(display-name.profile-value); 
     res.render(path + '/public/index.jade'); 
    }); 
    app.route('/polls').get(function(req, res) { 
     var polls = db.get('polls'); 
     console.log(polls); 
     res.render(path + '/public/polls.jade'); 
    }) 

这是错误被抛出

TypeError: db.get is not a function 
at /home/ubuntu/workspace/app/routes/index.js:39:22 
at Layer.handle [as handle_request] (/home/ubuntu/workspace/node_modules/express/lib/router/layer.js:95:5) 
at next (/home/ubuntu/workspace/node_modules/express/lib/router/route.js:131:13) 
at Route.dispatch (/home/ubuntu/workspace/node_modules/express/lib/router/route.js:112:3) 
at Layer.handle [as handle_request] (/home/ubuntu/workspace/node_modules/express/lib/router/layer.js:95:5) 
at /home/ubuntu/workspace/node_modules/express/lib/router/index.js:277:22 
at Function.process_params (/home/ubuntu/workspace/node_modules/express/lib/router/index.js:330:12) 
at next (/home/ubuntu/workspace/node_modules/express/lib/router/index.js:271:10) 
at SessionStrategy.strategy.pass (/home/ubuntu/workspace/node_modules/passport/lib/middleware/authenticate.js:325:9) 
at SessionStrategy.authenticate (/home/ubuntu/workspace/node_modules/passport/lib/strategies/session.js:71:10) 
at attempt (/home/ubuntu/workspace/node_modules/passport/lib/middleware/authenticate.js:348:16) 
at authenticate (/home/ubuntu/workspace/node_modules/passport/lib/middleware/authenticate.js:349:7) 
at Layer.handle [as handle_request] (/home/ubuntu/workspace/node_modules/express/lib/router/layer.js:95:5) 
at trim_prefix (/home/ubuntu/workspace/node_modules/express/lib/router/index.js:312:13) 
at /home/ubuntu/workspace/node_modules/express/lib/router/index.js:280:7 
at Function.process_params (/home/ubuntu/workspace/node_modules/express/lib/router/index.js:330:12) 
at next (/home/ubuntu/workspace/node_modules/express/lib/router/index.js:271:10) 
at initialize (/home/ubuntu/workspace/node_modules/passport/lib/middleware/initialize.js:53:5) 
at Layer.handle [as handle_request] (/home/ubuntu/workspace/node_modules/express/lib/router/layer.js:95:5) 
at trim_prefix (/home/ubuntu/workspace/node_modules/express/lib/router/index.js:312:13) 
at /home/ubuntu/workspace/node_modules/express/lib/router/index.js:280:7 
at Function.process_params (/home/ubuntu/workspace/node_modules/express/lib/router/index.js:330:12) 

Answer 1

首先，您需要将Poll导入路由文件。

var Poll = require('./PATH_TO_POLL/Poll'); 

然后为@ numbers1311407形容，如果你想返回所有已保存的文件投票尝试：

Poll.find(function (err, polls) { 
    if (err) return console.error(err); 
    console.log(polls); 
}) 

编辑：

上module.exports的更多信息，可以发现here