exchange/database/seeds/RateTableSeeder.php

<?php

use Illuminate\Database\Seeder;

class RateTableSeeder extends Seeder
{
    /**
     * Run the database seeds.
     *
     * @return void
     */
    public function run()
    {
        DB::table('rates')->insert([
            'x1_cash' => 1.2,
            'x1_cheque' => 1.2,
            'x1_ba' => 1.2,
            'x2_cash' => 1.2,
            'x2_cheque' => 1.2,
            'x2_ba' => 1.2,
        ]);
    }
}