test.php

<?php  
$options = array(
    PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
    PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
    PDO::ATTR_EMULATE_PREPARES => false,
    PDO::ATTR_STRINGIFY_FETCHES => false
);  

$db = new PDO('mysql:host=127.0.0.1;dbname=test', $user, $pass, $options);

$stmt = $db->prepare('SELECT * FROM foo');
$stmt->execute();

$results = $stmt->fetchAll();

var_dump($results);