MeanJS：MissingSchemaError当runnig服务器

我是MEANJS的新手：我正在用meanJS技术build立一个todolist。 我从服务器端开始。 当我运行我的server.js文件时出现以下错误：

node_modules\mongoose\lib\index.js:395 throw new mongoose.Error.MissingSchemaError(name); ^ MissingSchemaError: Schema hasn't been registered for model "Todo". Use mongoose.model(name, schema) at Mongoose.model (D:\meanjs\todolist\node_modules\mongoose\lib\index.js:395:13) at Object.<anonymous> (D:\meanjs\todolist\server\api\todo.js:5:23) at Module._compile (module.js:409:26) at Object.Module._extensions..js (module.js:416:10) at Module.load (module.js:343:32) at Function.Module._load (module.js:300:12) at Module.require (module.js:353:17) at require (internal/module.js:12:17) at Object.<anonymous> (D:\meanjs\todolist\server\api\index.js:3:21) at Module._compile (module.js:409:26) at Object.Module._extensions..js (module.js:416:10) at Module.load (module.js:343:32) at Function.Module._load (module.js:300:12) at Module.require (module.js:353:17) at require (internal/module.js:12:17) 

这是我的server.js文件：

 //Import dependencies const express = require('express'); const path = require('path'); const http = require('http'); const bodyParser = require('body-parser'); const mongoose = require('mongoose'); //Connect to mongoDB server mongoose.connect('mongodb://localhost/todoApp'); mongoose.set('debug', true); //Get our API routes const api = require('./server/api/'); //Require the models require('./server/models/task.model'); //HERE require('./server/models/todo.model'); //HERE //Init express const app = express(); //Set API routes app.use('/api', api); //Enable bodyParser app.use(bodyParser.json()); app.use(bodyParser.urlencoded({extended:false})); //Enable CORS app.use(function(req, res, next) { res.header("Access-Control-Allow-Origin", "*"); res.header("Access-Control-Allow-Methods", "GET, POST, DELETE, PUT"); res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept, Authorization"); next(); }); //Get environment port or use 3000 const port = process.env.PORT || '3000'; app.set('port', port); //Create HTTP server. const server = http.createServer(app); //Listen on port server.listen(port, () => console.log(`API running on localhost:${port}`)); 

我在server / api项目目录中有三个文件。 index.js

 var router = require('express').Router(); router.use('/todo', require('./todo')); router.use('/todo/task', require('./task')); module.exports = router; 

task.js

 "use strict"; const router = require('express').Router(); const mongoose = require('mongoose'); const Todo = mongoose.model('Todo'); const Task = mongoose.model('Task'); router.param('task', function (req, res, next, id) { if (!id.match(/^[0-9a-fA-F]{24}$/)) { return res.sendStatus(422); } Task.findById(id).then((task) => { if (!task) { return res.sendStatus(404); } req.task = task; return next(); }) }); router.post('/', (req, res) => { if (!req.body.todoId || !req.body.content) { res.sendStatus(422); } if (!req.body.todoId.match(/^[0-9a-fA-F]{24}$/)) { res.sendStatus(422); } Todo.findById(req.body.todoId).then((todo) => { if (!todo) { res.statusCode(404); } let task = new Task(); task.content = req.body.content; task.state = false; task.todo = todo; task.save().then(() => { todo.tasks.push(task); todo.save().then(() => { res.json(task.toDto()).statusCode(201); }); }); }); }); router.put('/', (req, res) => { if (req.body.state == undefined || !req.body.id) { res.sendStatus(422); } if (!req.body.id.match(/^[0-9a-fA-F]{24}$/)) { res.sendStatus(422); } Task.findById(req.body.id).then((task) => { task.state = req.body.state; task.save().then(() => { res.json(task.toDto()).statusCode(200); }) }) }); router.delete('/:task', (req, res) => { let task = req.task; task.remove().then(() => { res.sendStatus(200); }); }); 

todo.js

 "use strict"; const router = require('express').Router(); const mongoose = require('mongoose'); const Todo = mongoose.model('Todo'); const Task = mongoose.model('Task'); router.param('todo', function (req, res, next, id) { if (!id.match(/^[0-9a-fA-F]{24}$/)) { return res.sendStatus(422); } Todo.findById(id) .populate('tasks') .then(function (todo) { if (!todo) { return res.sendStatus(404); } req.todo = todo; return next(); }); }); router.get('/', (req, res) => { Todo.find() .populate('tasks') .then((todos) => { if (!todos) { return res.sendStatus(404); } return res.json({ todos: todos.map((todo) => { return todo.toDto(); }) }).statusCode(200); }); }); router.post('/', (req, res) => { if (!req.body.title) { res.sendStatus(422); } let todo = new Todo(); todo.title = req.body.title; todo.save().then(() => { res.json(todo.toDto()).statusCode(201); }) }); router.delete('/:todo', (req, res) => { req.todo.remove().then(function () { return res.sendStatus(200); }); }); 

我在服务器/模型中定义了每个模型的两个文件。 todo.model.js

 const mongoose = require('mongoose'); const Task = mongoose.model('Task','TaskSchema'); let TodoSchema = new mongoose.Schema({ title: { type: String, required: [true, "can't be blank"], index: true }, tasks: [{ type: mongoose.Schema.Types.ObjectId, ref: 'Task' }] }, { timestamps: true }); TodoSchema.pre('remove', (next) => { Task.remove({ todoId: this._id }).exec(); next(); }) TodoSchema.methods.toDto = function () { return { id: this._id, title: this.title, tasks: this.tasks.map((task) => { return task.toDto(); }) } } mongoose.model('Todo', TodoSchema); 

task.model.js

 const mongoose = require('mongoose'); let TaskSchema = new mongoose.Schema({ content: { type: String, maxlength: 200 }, state: { type: Boolean, default: false }, todo: { type: mongoose.Schema.Types.ObjectId, ref: 'Todo' } }, { timestamps: true }); TaskSchema.methods.toDto = function () { return { id: this._id, content: this.content, state: this.state } }; mongoose.model('Task', TaskSchema); 

请问我在哪里错了？

Answer 1

在server.js中

 //Get our API routes const api = require('./server/api/'); //Require the models require('./server/models/task.model'); //HERE require('./server/models/todo.model'); //HERE 

改变顺序

 //Require the models require('./server/models/task.model'); //HERE require('./server/models/todo.model'); //HERE //Get our API routes const api = require('./server/api/'); 

Answer 2

在Schema文件（task.model.js && todo.model.js）中，不会导出模型。 在这两个文件中，都需要添加以下内容：

 // models/todo.model.js module.exports = mongoose.model('Todo', TodoSchema); // models/task.model.js module.exports = mongoose.model('Task', TaskSchema); 

删除server.js中无关的要求：

 require('./server/models/task.model'); // GET RID OF THIS require('./server/models/todo.model'); // GET RID OF THIS 

另外在todo.js和task.js中，由于您现在正在导出模型，因此您必须像这样导入模型：

 const Todo = require('../models/task.model') const Task = require('../models/todo.model') 

注意：这是假设我有你的目录结构正确。

 -server -api -models