Oracle 分页算法两则

-- Oracle 分页算法一
select * from (
       select page.*,rownum rn from (select * from help) page
       -- 20 = (currentPage-1) * pageSize + pageSize
       where rownum <= 20
)
-- 10 = (currentPage-1) * pageSize
where rn > 10;

-- Oralce 分页算法二
-- 20 = (currentPage-1) * pageSize + pageSize
select * from help where rownum<=20
minus
-- 10 = (currentPage-1) * pageSize
select * from help where rownum<=10;