baoshi-was/database/seeds/UnitsSeeder.php

<?php

use Illuminate\Database\Seeder;

class UnitsSeeder extends Seeder
{
    /**
     * Run the database seeds.
     *
     * @return void
     */
    public function run()
    {
        \App\Unit::create([
            'name'=>'kg'
        ]);
    }
}