How to insert an excel sheet into mysql with Laravel-Excel?

I am using Laravel 5.4,
I want to import an excel sheet into mysql,
I use Laravel-Excel package to do this,
I read the docs but I don't know how to insert the excel file's content into mysql after loading it.

docs:http://www.maatwebsite.nl/laravel-excel/docs/import

For example:

There is an article table in mysql database,it has these columns:

id  title content created_at updated_at

And there is an excel file article.xls,it has the same columns as article table.

id title     content            created_at           updated_at
1  example1  example1's content 2017-04-02 00:00:00  2017-04-02 00:00:00
2  example2  example2's content 2017-04-02 00:00:00  2017-04-02 00:00:00

I use Laravel-Excel to load this excel file:

Excel::load('article.xlsx', function($reader) {

   //...
});

Question:
How to insert the excel file's content into article table?

UPDATE:

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use Maatwebsite\Excel\Facades\Excel;
use App\Article;



class ExcelController extends Controller
{
    public function uploadJobs()
    {
      Excel::load('D:/test/article.xlsx', function($reader) {
         foreach ($reader->toArray() as $row) {
           Article::firstOrCreate($row);
         }
      });
    }
}

I try this but it doesn't work.why is it?

via zwl1619