<?php

$user = 'root';
$pass = 'root';

$sql = "SELECT * FROM reste_a_faire LEFT JOIN heure_journlieres ON reste_a_faire .id = heure_journlieres .fk_id";
$bdd = new PDO('mysql:host=localhost;dbname=test', $user, $pass);

$query = $bdd->query($sql);
$resultats = $query->fetchAll();

var_dump($resultat);