分页查询

1.无ORDER BY排序的写法。(效率最高)

SELECT *
  FROM (SELECT ROWNUM AS rowno, t.*
          FROM emp t
         WHERE hire_date BETWEEN TO_DATE ('20060501', 'yyyymmdd')
                             AND TO_DATE ('20060731', 'yyyymmdd')
           AND ROWNUM <= 20) table_alias
 WHERE table_alias.rowno >= 10;

2.有ORDER BY排序的写法。(效率较高)

SELECT *
  FROM (SELECT tt.*, ROWNUM AS rowno
          FROM (  SELECT t.*
                    FROM emp t
                   WHERE hire_date BETWEEN TO_DATE ('20060501', 'yyyymmdd')
                                       AND TO_DATE ('20060731', 'yyyymmdd')
                ORDER BY create_time DESC, emp_no) tt
         WHERE ROWNUM <= 20) table_alias
 WHERE table_alias.rowno >= 10;

参考链接

• https://blog.csdn.net/use_admin/article/details/83622414