1import mongoose from 'mongoose'
2
3export const connectDb = async () => {
4  try {
5    await mongoose.connect('mongodb://localhost:27017/test', {
6      useNewUrlParser: true,
7      useUnifiedTopology: true,
8      useCreateIndex: true,
9    })
10  } catch (error) {
11    console.log(error.message)
12  }
13}

1//Import the mongoose module
2var mongoose = require('mongoose');
3
4//Set up default mongoose connection
5var mongoDB = 'mongodb://127.0.0.1/my_database';
6mongoose.connect(mongoDB, {useNewUrlParser: true, useUnifiedTopology: true});
7
8//Get the default connection
9var db = mongoose.connection;
10
11//Bind connection to error event (to get notification of connection errors)
12db.on('error', console.error.bind(console, 'MongoDB connection error:'));

1const mongoose = require('mongoose');
2
3const connectDB = async () => {
4    mongoose
5        .connect('mongodb://localhost:27017/playground', {
6            useCreateIndex: true,
7            useNewUrlParser: true,
8            useUnifiedTopology: true,
9            useFindAndModify: false
10        })
11        .then(() => console.log('Connected Successfully'))
12        .catch((err) => console.error('Not Connected'));
13}
14
15module.exports = connectDB;

1const mongoURI =
2  "mongodb+srv://userTest:<password>@cluster0.hgkll.mongodb.net/myFirstDatabase?authSource=admin&replicaSet=atlas-eu2ek5-shard-0&w=majority&readPreference=primary&appname=MongoDB%20Compass&retryWrites=true&ssl=true";
3mongoose
4  .connect(mongoURI, {
5    useNewUrlParser: true,
6    useUnifiedTopology: true,
7  })
8  .then(() => {
9    // eslint-disable-next-line
10    console.log("Database Connection Established...!");
11  })
12  .catch((err) => {
13    // eslint-disable-next-line
14    console.log("Error: Database connection can not be established...!", err);
15  });
16

1mongoose.connect('mongodb://localhost:27017/test', {
2  useMongoClient: true,
3  connectTimeoutMS: 1000
4})

1mongoose.connect('mongodb://username:password@host:port/database?options...', {useNewUrlParser: true});