hemall.terabimsoft.com.cn/database/migrations/2019_08_14_183505_add_yz_goods_table.php

<?php

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

class AddYzGoodsTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        if (Schema::hasTable('yz_goods')) {
            if (!Schema::hasColumn('yz_goods', 'old_id')) {
                Schema::table('yz_goods', function (Blueprint $table) {
                    $table->integer('old_id')->nullable();
                });
            }
        }
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        //
    }
}