In order to connect to PostgreSQL with Node.js it is necessary to use the pg module. To make that possible, you have to add it to the dependency file called package.json. The following is just a code sample to help you understand the concept:
"dependencies": { "pg": "0.10.2", "express": "latest" }
Then use the pg module to connect to PostgreSQL through the DATABASE_URL environment variable in your code:
var pg = require('pg'); pg.connect(process.env.DATABASE_URL, function(err, client, done) { if(err) { return console.error('Client error.', err); } client.query('SELECT * FROM doctors', function(err, result) { done(); if(err) { return console.error('Query error.', err); } console.log(result.rows); }); });