怎样在查询中,限制反回的行数?请高手指教.
tableName : goods
goodsno goods_name price
1001 显示器 1200
1002 主板 1800
1003 硬盘 1500
1004 硬盘 1200
1005 中央处理器 1200
怎样在查询中,限制反回的行数?
降序排列后 我只想要前两条记录.
请指教,谢谢!
问题点数：20、回复次数：9Top
1 楼yjdn（人形机器）回复于 2005-06-04 14:48:03 得分 10
select * from (select * from goods order by price desc) a where rownum<3Top
2 楼libin_ftsafe（子陌红尘：TS for Banking Card）回复于 2005-06-04 16:03:45 得分 10
通过rownum限制:
select * from (select * from goods order by price desc) where rownum<=2Top
3 楼nicholasgunn（阿东子）回复于 2005-06-04 16:10:59 得分 0
rownum<=2 的效率比较高。Top
4 楼yjdn（人形机器）回复于 2005-06-04 16:55:42 得分 0
libin_ftsafe(子陌红尘)
--你也两版都混，呵呵Top
5 楼cchhbbggn（斌宏程）回复于 2005-06-04 18:57:40 得分 0
select top 2 * from (select * from goods order by price desc)Top
6 楼zsfww1205（努力学习oracle）回复于 2005-06-04 20:56:06 得分 0
select * from (select t.* ,row_number()over (order by price desc) seq from goods )
where seq <=2Top
7 楼bluecocoqd（小骗骗）回复于 2005-06-04 21:51:02 得分 0
select * from (select * from goods order by price desc) where rownum<=2;
select * from (select * from goods order by price desc) a where rownum<3;
select * from (select t.* ,row_number()over (order by price desc) seq from goods )
where seq <=2;
学习ing
Top
8 楼vondon（冯唐）回复于 2005-06-06 14:03:13 得分 0
select * from dqbm f where f.bm like '15____' AND rownum <3Top
9 楼heyixiang（子豚の愛人）回复于 2005-06-07 09:42:01 得分 0
PL/SQL中没有top 只能用rownum
不知道
select * from (select t.* ,row_number()over (order by price desc) seq from goods) a
where seq <=2
和
select * from (select * from goods order by price desc) a where rownum<=2
到底谁效率高？Top
