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

Another manual sync process :

Add Model

class Post extends Model
{
    protected $fillable = ["name"];

    function links()
    {
        return $this->hasMany("App\Link");
    }
}

class Link extends Model
{
    protected $fillable = ["name", "post_id"];

    function post()
    {
        return $this->belongsTo("App\Post");
    }
}

class PostLink extends Model
{
    protected $fillable = ["post_id", "link_id"];

    function post()
    {
        return $this->belongsTo("App\Post");
    }

    function link()
    {
        return $this->belongsTo("App\Link");
    }
}

Here we go

// list ids from request
$linkIds = $request->input("link");
if (!empty($linkIds))
{
    // delete removed id from list in database
    PostLink::where('post_id','=', $post->id)->whereNotIn('post_id', $linkIds)->delete();
    // list remain id in database
    $postLinkIds = $post->links()->pluck('post_id')->toArray();
    // remove ids that already on db
    $linkIds = array_diff($linkIds, $postLinkIds);
    // check if still have id that must be save
    if (!empty($linkIds))
    {
        foreach ($linkIds as $id)
        {
            // save id to post
            $post->links()->create(['post_id' => $id]);
        }
    }
}