exchange/database/seeds/CreditTableSeeder.php

<?php

use Illuminate\Database\Seeder;
use Carbon\Carbon;

class CreditTableSeeder extends Seeder
{
    /**
     * Run the database seeds.
     *
     * @return void
     */
    public function run()
    {
        DB::table('setting_credits')->insert([
            'rmb_credit_limit' => 20000,
            'usd_credit_limit' => 20000,
            'created_at' => Carbon::now()->format('Y-m-d H:i:s'),
            'updated_at' => Carbon::now()->format('Y-m-d H:i:s'),
        ]);
    }
}