如何在一个语句中实现“限制”和“反向”

[rosen]

select * from phpbb_topics limit 0,5 order by topic_id DESC;

这一句报错：Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in c:\test\index.php on line 141

[shuixin13]

select * from phpbb_topics order by topic_id DESC limit 0,5;

[rosen]

奇怪，我刚才也有这么写，但是错了。
可是现在却对了，你凶。