Async node-postgres sample code

server.js

/*
import express from 'express';
import db from './core/db';

const app = express();
const port = process.env.PORT || 3000;

app.get('/visits', (req, res, next) => {
  db.connect(async ({ query } => {
    await query('INSERT INTO visit (date) VALUES ($1)', new Date());
    const result = await query('SELECT COUNT(date) AS count FROM visit');
    res.send(`You are visitor number ${result.rows[0].count}.`);
  }).catch(next);
});

app.listen(port);
*/

// callback version, just for demo purposes
const express = require('express');
const db = require('./core/db');
const errTo = require('errto');

const app = express();
const port = process.env.PORT || 3000;

app.get('/visits', (req, res, next) => {
  db.connect(errTo(next, (query) => {
    query('INSERT INTO visit (date) VALUES ($1)', new Date(), errTo(next, (result) => {
      res.send(`You are visitor number ${result.rows[0].count}.`);
    }));
  }));
});

app.listen(port);