Synchronizing a one-to-many relationship in Laravel

Unfortunately there is no sync method for one-to-many relations. It’s pretty simple to do it by yourself. At least if you don’t have any foreign key referencing links. Because then you can simple delete the rows and insert them all again.

$links = array(
    new Link(),
    new Link()
);

$post->links()->delete();
$post->links()->saveMany($links);

If you really need to update existing one (for whatever reason) you need to do exactly what you described in your question.