Synchronizing a one-to-many relationship in Laravel

Question

If I have a many-to-many relationship it\'s super easy to update the relationship with its sync method.

But what would I use to synchronize a one-to-many re

Answer 1

I did like this, and it is optimized for minimal query and minimal updates:

first, put link ids to sync in an array: $linkIds and the post model in its own variable: $post

Link::where('post_id','=',$post->id)->whereNotIn('id',$linkIds)//only remove unmatching
    ->update(['post_id'=>null]);
if($linkIds){//If links are empty the second query is useless
    Link::whereRaw('(post_id is null OR post_id<>'.$post->id.')')//Don't update already matching, I am using Raw to avoid a nested or, you can use nested OR
        ->whereIn('id',$linkIds)->update(['post_id'=>$post->id]);
}