JAVASCRIPT

mongoose connection nodejs

const mongoose = require('mongoose');

const connectDB = async () => {
    mongoose
        .connect('mongodb://localhost:27017/playground', {
            useCreateIndex: true,
            useNewUrlParser: true,
            useUnifiedTopology: true,
            useFindAndModify: false
        })
        .then(() => console.log('Connected Successfully'))
        .catch((err) => console.error('Not Connected'));
}

module.exports = connectDB;

mongoose connection

const mongoose = require("mongoose");

//  database connection with mongoose
mongoose.connect("mongodb://localhost/todos", {
        useNewUrlParser: true,
        useUnifiedTopology: true
    })
    .then(() => console.log("connection successful"))
    .catch((err) => console.log(err));

connecting mongoose with express js

const mongoose = require('mongoose');
mongoose.connect('mongodb://localhost:27017/test', {useNewUrlParser: true, useUnifiedTopology: true});

mongoose connection in express

//config/db.js
const mongoose = require('mongoose');

const connect = async () => {
  try {
    await mongoose.connect(process.env.MONGODB);
    console.log('database connect');
  } catch (error) {
    console.log(error.message);
  }
};

module.exports = connect;

//index.js 
require('dotenv').config();
const connect = require('./config/db');

connect();