Import the Sequelize module into your Node project

npm i sequelize

Add the specific database driver to coincides with the SQL DBMS that you are using:

npm i --save pg pg-hstore   

Connect to the database in your Node application

Option 1: Passing a connection URI

const sequelize = new Sequelize('postgres://user:pass@example.com:5432/dbname') 

module.exports = sequelize;

Option 2: Passing parameters separately (other dialects)

const sequelize = new Sequelize('database', 'username', 'password', {    
   host: 'localhost', 
   dialect: 'postgres'
});

module.exports = sequelize;

Test the connection

try { 
   await sequelize.authenticate(); 
   console.log('Connection has been established successfully.'); 
} catch (error) { 
   console.error('Unable to connect to the database:', error); 
}

Create a new model

The db variable is imported from the Sequelize connection above (Opt 1 or 2) which we are assuming is in a separate file.

const Sequelize = require('sequelize');
const db = require('../config/database');

const Person = db.define('gig', {
   name: {
      type: Sequelize.STRING
   },
   age: {
      type: Sequelize.INTEGER
   },
   description: {
      type: Sequelize.STRING
   }
});

module.exports = Person;

Start making Sequelize queries in server routes

The beauty of Sequelize is that it allows you to use object-oriented syntax to make queries to relational/SQL databases.

app.get('/', (req, res) =>
   Person.findAll()
      .then(people => console.log(people))
      .catch(err => console.log(err)));