Error while adding data to mongodb using node.js - node.js

Question

Console:
DeprecationWarning: current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to the MongoClient constructor.
server stared at port 7777
mongodb connection is successfull
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\_logs\2020-06-11T07_56_43_613Z-debug.log
My code is: He is my server.js file. In which I an trying to post data into 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

You forget add req and res to this function.
structRoute.route("/").get((req, res) => {
Struct.find((err, query) => {
if (err) {
console.log("error");
} else {
res.json(query);
}
});
});