请问这道SQL题的答案应该是什么呀？

求一个第二题的答案！谢谢！

select count(distinct s.user_id)from (select user_id, count(distinct ORDER_CATEGORY) num from order where order_time >='2018-01-01'and order_time<'2018-02-01' group by user_id having num=2 ) s
inner join order r on s.user_id=r.user_id
where r.ORDER_CATEGORY in ('麻辣烫','汉堡')

手机一个个字母敲的，有写错字符，勿怪，你可以自己修正一下。