——— rownum关键字：oracle对外提供的自动给查询结果编号的关键字，与每行的数据没有关系。 –注意：rownum关键字只能做< <=的判断，不能进行> >=的判断
select rownum ,e.* from so_delivery e where e.dr = 0; ———— 查询发货单的前5条数据 第一页数据 select rownum r,e.* from so_delivery e where rownum <=5; select * from (select rownum r,e.* from so_delivery e where rownum <=5) t where r>0;
———— 查询发货单的前6-10条数据 第二页数据 select * from (select rownum r,e.* from so_delivery e where rownum <=10) t where r>5;
–分页规律总结：每页显示m条数据，查询第n页数据 select * from (select rownum r,e. * from 要分页的表 e where rownum<=mn) t where r>mn-m ;
–要分页的表既可以是真实的表，也可以是一个查询语句 –分页查询员工信息按照工资排序 select * from (select rownum r,e.* from (select * from so_delivery order by creationtime desc) e where rownum <=10) t where r>5;
