Add mongoose to node and express

.env

MONGO_PROD_URI=mongodb+srv://admin:<password>@cluster.mongodb.net/<dbname>?retryWrites=true&w=majority
MONGO_DEV_URI=mongodb://127.0.0.1:27017/<dbname>

index.js

require("dotenv").config()

const express = require("express")
const app = express()

const mongoose = require("mongoose")

mongoose
	.connect(process.env.MONGO_LOCAL_URI, {
	  useNewUrlParser: true,
	  useUnifiedTopology: true,
	  useCreateIndex: true
	})
	.then(() => console.log("Database connected!"))
	.catch((err) => console.log(err))

app.get("/", (req, res) => res.send("Server is up and running"))

const UserSchema = new mongoose.Schema({
  name: String,
  age: Number,
  isAdult: Boolean,
  joined: {
    type: Date,
    default: Date.now
  },
})

const User = mongoose.model("users", UserSchema)

const newUser = new User({
  name: "Elliot Alderson",
  age: 23,
  isAdult: true,
})

newUser.save().then(() => console.log("Saved new user"))

const PORT = process.env.PORT || 4444

app.listen(PORT, () => console.log(`Server is running on port ${PORT}`))

Comment here, if you have any issues regarding the code part. Refer to the whole blog here.