猫鼬架构尚未注册模型

我正在学习的平均堆，当我尝试使用来启动服务器

npm start

我得到一个异常说：

schema hasn't been registered for model 'Post'. Use mongoose.model(name, schema)

这里是我的内/​​models/Posts.js代码

var mongoose = require('mongoose');

var PostSchema = new mongoose.Schema({
    title: String,
    link: String, 
    upvotes: { type: Number, default: 0 },
    comments: [{ type: mongoose.Schema.Types.ObjectId, ref: 'Comment' }]
});

mongoose.model('Post', PostSchema);

我所看到的架构应注册为模型“邮政”，但什么能可能导致的异常被抛出？

提前致谢。

编辑：这里的异常错误

/home/arash/Documents/projects/personal/flapper-news/node_modules/mongoose/lib/index.js:323
  throw new mongoose.Error.MissingSchemaError(name);
        ^
MissingSchemaError: Schema hasn't been registered for model "Post".
Use mongoose.model(name, schema)

这里是一个与猫鼬初始化app.js代码：

var mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/news');
require('./models/Posts');
require('./models/Comments');

前行：

app.use('/', routes);

这不是与模型出口的问题。我遇到过同样的问题。

真正的问题是，需要为模特的语句

var mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/news');
require('./models/Posts');
require('./models/Comments');

低于该航线的依赖。只需将上面的路线依赖MongoDB的依赖关系。这是它应该是什么样子：

// MongoDB
var mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/news');
require('./models/Posts');
require('./models/Comments');

var routes = require('./routes/index');
var users = require('./routes/users');

var app = express();