The result set paging sql

--对结果集a分页

--  pageSize        pageIndex           内层条件                外层条件
--    10                1               rownum rn <= 1*10       rn > 0*10
--    10                2               rownum rn <= 2*10       rn > 1*10
--    ...               ...             ...                     ...
--    s                 i               rownum rn <= i*s        rn > (i-1)*s

select b.* from (select rownum rn, a.* from a where rownum <= 1*10) b where rn > (1-1)*10
select b.* from (select rownum rn, a.* from a where rownum <= 2*10) b where rn > (2-1)*10

select b.* from (select rownum rn, a.* from a where rownum <= i*s) b where rn > (i-1)*s