index.js

const express = require('express')
const mongoose = require('mongoose')
const UserModel = require('./User')
var cors = require('cors')

const app = express()
const port = 3001
app.use(cors())

app.use(express.json())


mongoose.connect('mongodb://127.0.0.1/GaborniLE1', {
    useNewUrlParser: true, //optional to avoid display warning 
    useUnifiedTopology: true //optional to avoid display warning
})
.then(db => console.log('DB is connected'))
.catch(err => console.log(err));    

app.get('/', (req, res) => {
    UserModel.find()
        .then(users => res.json(users))
        .catch(err => res.json(err))
})

app.get('/get/:id', (req, res) => {
    const id = req.params.id
    UserModel.findById({ _id: id })
        .then(post => res.json(post))
        .catch(err => console.log(err))
})

app.post('/create', (req, res) => {
    UserModel.create(req.body)
      .then(user => res.json(user))
      .catch(err => res.json(err))
})

app.put('/update/:id', (req, res) => {
    const id = req.params.id;
    UserModel.findByIdAndUpdate({ _id: id }, {
        name: req.body.name,
        email: req.body.email,
        age: req.body.age
    }).then(user => res.json(user))
        .catch(err => res.json(err))
})

app.delete('/deleteuser/:id', (req, res) => {
    const id = req.params.id;
    UserModel.findByIdAndDelete({ _id: id })
      .then(response => res.json(response))
      .catch(err => res.json(err))    
})

app.listen(port, () => {
  console.log(`Example app listening on port ${port}`)
})