laravel обновит, если существует, или создаст
$flight = App\Flight::updateOrCreate(
['departure' => 'Oakland', 'destination' => 'San Diego'],
['price' => 99]
);
laravel как проверить, существуют ли записи
//User:: User is going to be what model you use.
//$user can be what ever you need it to be
$user = User::where('email', '=', Input::get('email'))->first();
if ($user != null) {
// Record does exist
}