baoshi-was/database/migrations/2021_07_07_103716_change_warehouses_table.php

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

class ChangeWarehousesTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::table('warehouses', function (Blueprint $table) {
            $table->addColumn('bigInteger','province_id')->nullable();
            $table->addColumn('bigInteger','city_id')->nullable();
            $table->addColumn('bigInteger','county_id')->nullable();
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::table('warehouses', function (Blueprint $table) {
            //
        });
    }
}