lachang/database/seeds/UpdateYeahMonthToUserWithdrawalsSeeder.php

<?php

use app\common\model\user\Withdraw;
use think\migration\Seeder;

class UpdateYeahMonthToUserWithdrawalsSeeder extends Seeder
{
    /**
     * Run Method.
     *
     * Write your database seeder using this method.
     *
     * More information on writing seeders is available here:
     * http://docs.phinx.org/en/latest/seeding.html
     */
    public function run()
    {
        $m = new Withdraw();
        $lists = $m->field('id,create_time')->select();
        if ($lists){
            foreach ($lists as $list){
                $ym = substr($list['create_time'],0,4).substr($list['create_time'],5,2);
                $m->where('id',$list['id'])->update(['year_month'=>intval($ym)]);
            }
        }
    }
}