使用 node.js 向 mongodb 添加数据时出错

Question

控制台：

弃用警告：当前的服务器发现和监控引擎已弃用，并将在未来版本中删除。要使用新的服务器发现和监控引擎，请将选项 { useUnifiedTopology: true } 传递给 MongoClient constructor。服务器盯着端口 7777 mongodb连接成功

events.js:200

  throw er; // Unhandled 'error' event
  ^

ReferenceError: res is not defined
    at D:\java script\React\hello\database\server.js:26:9
    at D:\java script\React\hello\database\node_modules\mongoose\lib\model.js:4883:16
    at D:\java script\React\hello\database\node_modules\mongoose\lib\model.js:4883:16
    at D:\java script\React\hello\database\node_modules\mongoose\lib\helpers\promiseOrCallback.js:24:16
    at D:\java script\React\hello\database\node_modules\mongoose\lib\model.js:4906:21
    at D:\java script\React\hello\database\node_modules\mongoose\lib\query.js:4390:11
    at D:\java script\React\hello\database\node_modules\kareem\index.js:135:16
    at processTicksAndRejections (internal/process/task_queues.js:76:11)
Emitted 'error' event on Function instance at:
    at D:\java script\React\hello\database\node_modules\mongoose\lib\model.js:4885:13
    at D:\java scr

ipt\React\hello\database\node_modules\mongoose\lib\helpers\promiseOrCallback.js:24:16
        [... lines matching original stack trace ...]
        at processTicksAndRejections (internal/process/task_queues.js:76:11)
    npm ERR! code ELIFECYCLE
    npm ERR! errno 1
    npm ERR! Database@1.0.0 start: `node server.js "--port" "7777"`
    npm ERR! Exit status 1
    npm ERR!
    npm ERR! Failed at the Database@1.0.0 start script.
    npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

    npm ERR! A complete log of this run can be found in:
    npm ERR!     C:\Users\HP\AppData\Roaming\npm-cache\_logs20-06-11T07_56_43_613Z-debug.log

我的代码是：他是我的server.js档案。我在其中尝试将 post 数据转换为 mongodb.

const express =require("express")
const app=express();
const path=require('path');
const bodyParser=require('body-parser');
const cors =require('cors');
app.use(cors());
app.use(bodyParser.json());
const structRoute=express.Router();
let Struct=require('./query.model');


const mongooes=require('mongoose');
mongooes.connect('mongodb://127.0.0.1:27017/query',{ useNewUrlParser: true });
const connection=mongooes.connection;
connection.once("open",function(){
  console.log("mongodb connection is successfull");
})


structRoute.route('/').get(function(){
  Struct.find(function(err,query){
    if(err){
      console.log("error");
      }
      else{
        res.json(query);
      }
  });
});

structRoute.route('/:id').get(function(req,res){
  let id=req.params.id;
  Struct.findById(id,function(err,query){
    res.json(query);

  });

});

structRoute.route('/add').post(function(req,res){
    let query=new Struct(req.body);
    query.save()
    .then(query=>{
        res.status(200).json({'query':"added successfully"})
    })
    .catch(
      err=>{res.status(400).send("adding failed");}
    );
});

app.use('/Struct',structRoute);

    enter code here

app.listen(7777,()=>{
    console.log("server stared at port 7777")

})

Answer 1

您忘记将 req 和 res 添加到此函数。

structRoute.route("/").get((req, res) => {
  Struct.find((err, query) => {
    if (err) {
      console.log("error");
    } else {
      res.json(query);
    }
  });
});

使用 node.js 向 mongodb 添加数据时出错

Error while adding data to mongodb using node.js

mongodb

node.js

express

mern