ulthon_admin/database/migrations/20261012000002_system_admin_email.php

<?php

use think\migration\Migrator;
use think\migration\db\Column;

/**
 * system_admin 追加电子邮箱字段（幂等，已存在则跳过）.
 */
class SystemAdminEmail extends Migrator
{
    public function change()
    {
        $table = $this->table('system_admin');

        if(!$table->hasColumn('email')){
            $table->addColumn(Column::char('email', 100)->setDefault('')->setComment('电子邮箱'));
            $table->update();
        }
    }
}