Oracle的分页sql

–1:无ORDER BY排序的写法。(效率最高)
–(经过测试，此方法成本最低，只嵌套一层，速度最快！即使查询的数据量再大，也几乎不受影响，速度依然！)

SELECT *
  FROM (SELECT ROWNUM AS rowno, t.*
          FROM emp t
         WHERE ROWNUM <= 20) table_alias
 WHERE table_alias.rowno >= 10;

–2:有ORDER BY排序的写法。(效率最高)
–(经过测试，此方法随着查询范围的扩大，速度也会越来越慢哦！)

SELECT *
  FROM (SELECT tt.*, ROWNUM AS rowno
          FROM (  SELECT t.*
                    FROM emp t
                   WHERE   ORDER BY create_time DESC, emp_no) tt
         WHERE ROWNUM <= 20) table_alias
 WHERE table_alias.rowno >= 10;