PDO vs MySQLi

	PDO	MySQLi
Database support	12 different drivers	MySQL only
API	OOP	OOP + procedural
Connection	Easy	Easy
Named parameters	Yes	No
Object mapping	Yes	Yes
Prepared statements  (client side)	Yes	No
Performance	Fast	Fast
Stored procedures	Yes	Yes

Collection

// PDO
$pdo = new PDO("mysql:host=localhost;dbname=database", 'username', 'password');
 
// mysqli, procedural way
$mysqli = mysqli_connect('localhost','username','password','database');
 
// mysqli, object oriented way
$mysqli = new mysqli('localhost','username','password','database');

Named parameters

PDO

$params = array(':username' => 'test', ':email' => $mail, ':last_login' => time() - 3600);
     
$pdo->prepare('
    SELECT * FROM users
    WHERE username = :username
    AND email = :email
    AND last_login > :last_login');
     
$pdo->execute($params);

Mysqli

$query = $mysqli->prepare('
    SELECT * FROM users
    WHERE username = ?
    AND email = ?
    AND last_login > ?');
     
$query->bind_param('sss', 'test', $mail, time() - 3600);
$query->execute();

Object Mapping

class User {
    public $id;
    public $first_name;
    public $last_name;
     
    public function info()
    {
        return '#'.$this->id.': '.$this->first_name.' '.$this->last_name;
    }
}

$query = "SELECT id, first_name, last_name FROM users";
     
// PDO
$result = $pdo->query($query);
$result->setFetchMode(PDO::FETCH_CLASS, 'User');
 
while ($user = $result->fetch()) {
    echo $user->info()."\n";
}
// MySQLI, procedural way
if ($result = mysqli_query($mysqli, $query)) {
    while ($user = mysqli_fetch_object($result, 'User')) {
        echo $user->info()."\n";
    }
}
// MySQLi, object oriented way
if ($result = $mysqli->query($query)) {
    while ($user = $result->fetch_object('User')) {
        echo $user->info()."\n";
    }
}