问一个mysql子查询的问题

[什么都不能]

SELECT aID,sid,subject,postdate FROM duoxun_subject WHERE sid<> (select sid from duoxun_sort where name='讲师新闻') order by postdate desc limit 1,8
这个该怎么写?

[klan]

SELECT aID,sid,subject,postdate FROM duoxun_subject WHERE sid not in (select sid from duoxun_sort where name='讲师新闻') order by postdate desc limit 1,8

[XqYuan]

SELECT aID,sid,subject,postdate From duoxun_subject left join duoxun_sort on
duoxun_subject.sid=duoxun_sort.sid where duoxun_sort.sid is null order by postdate
desc limit 1,8