Query return value in case of Select with no matching rows in MySQLi

?php
$mysqli = new mysqli("localhost", "username", "password", "database");

if ($mysqli->connect_errno) {
    echo "Failed to connect to MySQL: " . $mysqli->connect_error;
    exit();
}

$sql = "SELECT * FROM mytable WHERE id = 123";
$result = $mysqli->query($sql);

if (!$result) {
    echo "Error executing query: " . $mysqli->error;
    exit();
}

if ($result->num_rows == 0) {
    echo "No rows found.";
    exit();
}

// Process results here
while ($row = $result->fetch_assoc()) {
    // Do something with $row
}

$result->free();
$mysqli->close();
?>