php - How to use pagination with laravel DB::select query

Question

I am working on a project in Laravel and using DB facade to run raw queries of sql. In my case I am using DB::select, problem is that pagination method is not working with this DB raw query and showing this error

Call to a member function paginate() on array

I just want how to implement laravel pagination with DB raw queries here is my code:

<?php

namespace AppHttpControllers;

use IlluminateHttpRequest;
use AppNotice;
use IlluminateSupportFacadesDB;
use IlluminatePaginationPaginator;
use IlluminatePaginationLengthAwarePaginator;

class NoticeController extends Controller
{

public function index(){

    $notices = DB::select('select 
notices.id,notices.title,notices.body,notices.created_at,notices.updated_at,
    users.name,departments.department_name
    FROM notices
    INNER JOIN users ON notices.user_id = users.id
    INNER JOIN departments on users.dpt_id = departments.id
    ORDER BY users.id DESC')->paginate(20);

    $result = new Paginator($notices,2,1,[]);

    return view('welcome')->with('allNotices', $notices);
 }
}

Answer 1

public function index(Request $request){

$notices = DB::select('select notices.id,notices.title,notices.body,notices.created_at,notices.updated_at,
users.name,departments.department_name
FROM notices
INNER JOIN users ON notices.user_id = users.id
INNER JOIN departments on users.dpt_id = departments.id
ORDER BY users.id DESC');

$notices = $this->arrayPaginator($notices, $request);

return view('welcome')->with('allNotices', $notices);

}

public function arrayPaginator($array, $request)
{
    $page = Input::get('page', 1);
    $perPage = 10;
    $offset = ($page * $perPage) - $perPage;

    return new LengthAwarePaginator(array_slice($array, $offset, $perPage, true), count($array), $perPage, $page,
        ['path' => $request->url(), 'query' => $request->query()]);
}