laravel comprobar existe un registro
$user = User::where('email', '=', Input::get('email'))->first();
if ($user === null) {
// user doesn't exist
}
laravel db existe
if (DB::table('orders')->where('finalized', 1)->exists()) {
// ...
}
if (DB::table('orders')->where('finalized', 1)->doesntExist()) {
// ...
}