CREATE TABLE IF NOT EXISTS `demo` (
   `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT '主键自增id',
   `created_at` bigint(20) unsigned NOT NULL COMMENT '创建时间',
   `updated_at` bigint(20) unsigned NOT NULL COMMENT '更新时间',
   PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='demo';