PHP - PDO Connect e prepared statements

pdo.php

/////////////////////
// Connect


try {
$host = "localhost";
$database = "learning_pdo";

$db = new PDO("mysql:host=$host;dbname=$database;charset=utf8","antonio","123");
}
catch(Exception $e){
	echo "Something went wrong";
}

/////////////////////
// Prepared statements

// MYSQL SELECT

$names = [ 'Maria', 'Andy' ];

$stmt = $db->prepare( "SELECT * FROM names WHERE firstname LIKE :firstname" );

forEach ( $names as $name ) {
	$stmt->bindParam( ':firstname', $name);
	$stmt->execute();

	while ( $row = $stmt->fetch( PDO::FETCH_ASSOC ) ) {
		echo htmlentities( $row['firstname'] ) . " " . htmlentities( $row['lastname'] ) . " " . htmlentities( $row['postcode'] ), "<br>";
		//var_dump($row);
	}
}

// close connections
$stmt = null;

// MYSQL UPDATE

$stmt = $db->prepare("UPDATE names SET postcode = :postcode WHERE firstname = :firstname");

$stmt->bindValue(':firstname','Joana');
$stmt->bindValue(':postcode','69XDAWM');
$stmt->execute();

// MYSQL INSERT

$stmt = $db->prepare("INSERT INTO names (firstname,lastname,postcode) VALUES (:firstname,:lastname,:postcode)");

$stmt->bindValue(':firstname','Joana');
$stmt->bindValue(':lastname','Albertina');
$stmt->bindValue(':postcode','DWAXD231');
$stmt->execute();