How to insert a post with multi category and with multi column deferent category in laravel?

Hello all I am a new laravel, I have problem with my project. I have 2 table:

posts: id title category_id
category: id name(PHP, Laravel, Ruby)

Ex: I am insert a post into posts database title=Jonh and chosse two category name(PHP,Laravel), and the result will two column like posts(id=1 title(jonh) category_id(1), id=2 title(jonh) category_id(2)) but it still not work I try to find in google and youtube follow and it not work, and here is my code:

View(create.blade.php)
{!!Form::open(array('route' => 'store', 'method' => 'POST'))!!}

<br>

@foreach($category as $categories)


@endforeach
<br>

{!!Form::close()!!}

Controller(PostsController.php)
public function create()
    {
        $category = Category::all();
        return view('create',compact('category'));
    }
    public function store(Request $request)
    {
       $post = new Posts;
       $post->title = $request['title'];
       $post->category_id = $request['category_id'];
       $post->save();
    }

Help pls

via Chebli Mohamed