require database code example

Example: require database

const express = require('express');
const cors = require('cors');
const superagent = require('superagent');
const pg = require('pg');
require('dotenv').config();
const app = express();
app.use(cors());
app.use(express.static('public'));
app.set('view engine', 'ejs');
app.use(express.urlencoded({extended: true}));
const PORT = process.env.PORT;
const DATABASE_URL = process.env.DATABASE_URL;
const client = new pg.Client(DATABASE_URL);
//----------------------------------------------