pl/sql有关问题

pl/sql问题
一张dept表怎么取前五个？

[解决办法]
rownum <=5
[解决办法]
需要按照某条件排序不？

不需要，则：
select * from dept where rownum<=5;

需要，则：
select * from (select select t.*, ROWNUM rn from dept order by xxx asc|desc)
where rn<=5
[解决办法]
select * from dept where rowid<6
[解决办法]

SQL code

select * from dept where rownum <=5;
[解决办法]
探讨


需要，则：
select * from (select select t.*, ROWNUM rn from dept order by xxx asc|desc)
where rn <=5