A brief description of various ways one can fetch data in PHP using PDO

pdo_fetch_types.php

<?php
include_once('../../db.php');

// SET 1
$sql = 'SELECT * FROM users';
$stmt = $userConn->query($sql);
$users = $stmt->fetch(); // by default, the argument in the bracket is PDO:FETCH_BOTH

echo '<pre>',print_r($users),'</pre>';


// =============================================

// SET 2 (fetch as numeric array)
$sql = 'SELECT * FROM users';
$stmt = $userConn->query($sql);
$users = $stmt->fetch(PDO::FETCH_NUM);

echo '<pre>',print_r($users),'</pre>';

// =============================================

// SET 3 (fetch as assoociative array)
$sql = 'SELECT * FROM users';
$stmt = $userConn->query($sql);
$users = $stmt->fetch(PDO::FETCH_ASSOC);

echo '<pre>',print_r($users),'</pre>';

// =============================================

// SET 4 (fetch as anonymous object)
$sql = 'SELECT * FROM users';
$stmt = $userConn->query($sql);

// either
$users = $stmt->fetch(PDO::FETCH_OBJ);
echo '<pre>',print_r($users),'</pre>';

// or 
/* while($users = $stmt->fetch(PDO::FETCH_OBJ)) {
    echo $users->username, '<br>';
} */

// =============================================

// SET 5 (fetch using Class)
class UserRecord {
    public $email, $username, $entry;

    public function __construct()
    {
        $this->entry = "{$this->username} has email: {$this->email}";
    }
}
$sql = 'SELECT * FROM users';
$stmt = $userConn->query($sql);
$stmt->setFetchMode(PDO::FETCH_CLASS, 'UserRecord');
while($users = $stmt->fetch()){
    echo $users->entry.'<br>';
}

// =============================================

// SET 6 (fetch all as assoociative arrays)
$sql = 'SELECT * FROM users';
$stmt = $userConn->query($sql);
$users = $stmt->fetchAll(PDO::FETCH_ASSOC);

echo '<pre>',print_r($users),'</pre>';
?>