Question

我正在创建MERN堆栈应用程序，试图将我的应用程序与MongoDb数据库连接。我正在使用Mongoose库与`MongoDb连接。我在下面收到错误消息：< / p>

错误

TypeError：回调不是函数 ['server]位于$ initialConnection。$ initialConnection.then（H：\ React projects \ MyBlog \ node_modules \ mongoose \ lib \ connection.js：744：13） ['server]在process._tickCallback（internal / process / next_tick.js：68：7）

以下是我的代码：

server.js

const express = require('express');
const path = require('path');
const cors = require('cors');

const app = express();
app.use(cors());

app.use(require('./routes/saveData.js'));

const port = process.env.PORT || 5000;

app.listen(port,() => {

   console.log(`Server is running on ${port}.`);
});

saveData.js

const express = require('express');
const router = express.Router();
const bodyParser = require('body-parser');
const blogs = require('../models/blogPost');
const mongoose = require('mongoose');

router.use(bodyParser.json());
router.use(bodyParser.urlencoded({extended: true}));

const dburl = 'mongodb+srv://example:example@cluster1-5wp.mongodb.net/ExpDb?retryWrites=true'

router.post('/save',(req,res) => {

   const data = {

       title: req.body.title,
       detail: req.body.detail
     }

     const newBlog = new blogs(data);

    mongoose.connect(dburl, {useNewUrlParser: true,useUnifiedTopology:true}).then((resp) =>{

          resp.send("Connected");          
          console.log("connected");
        }).catch((err) => { 
            console.log("database error: ",err);
        });

  });

module.exports = router;

下面是猫鼬模式： blogPost.js

const mongoose = require('mongoose');
const Schema = mongoose.Schema;

const BlogPostSchema = new Schema({

  title:String,
  body:String,
  date:{
      type:String,
      dafault:Date.now()
    }
});

const BlogPost = mongoose.model('BlogPost',BlogPostSchema);

module.exports = BlogPost;

请让我知道我做错了。任何帮助将不胜感激。

谢谢

Answer 1

猫鼬返回的承诺值为resp。具有.send方法的服务器响应对象是res。请尝试以下：

router.post('/save', (req, res) => {
...
    mongoose.connect(dburl, {useNewUrlParser: true, useUnifiedTopology:true}).then((resp) =>{         
        // res not resp
        res.send("Connected");          
        console.log("connected");
    })

Answer 2

Documentation Reference

文档中的语法

  mongoose.connect(uri, options).then(
  () => { /** ready to use. The `mongoose.connect()` promise resolves to mongoose instance. */ },
  err => { /** handle initial connection error */ }
);

代码

router.post('/save',(req,res) => {

    mongoose.connect(dburl, {useNewUrlParser: true,useUnifiedTopology:true})
      .then(() =>{

              res.send("Connected");          
              console.log("connected");
            },(err)=> console.log("database error: ",err);)

      });

Answer 3

猫鼬连接没有回调

mongoose.connect(dburl, {useNewUrlParser: true},{useUnifiedTopology:true});

这应该有效。然后要更新，您应该在模型对象上使用猫鼬保存方法。

BlogPost.save();

无法使用nodeJS与MongoDb连接

3 个答案: