ORACLE几种分页查询SQL语句
作者:互联网
一、效率高的写法
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 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)
(经过测试,此方法随着查询范围的扩大,速度也会越来越慢)
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;
二、效率垃圾但又似乎很常用的分页写法
SELECT * FROM (SELECT ROWNUM AS rowno, t.* FROM k_task t WHERE flight_date BETWEEN TO_DATE ('20060501', 'yyyymmdd') AND TO_DATE ('20060731', 'yyyymmdd')) table_alias WHERE table_alias.rowno <= 20 AND table_alias.rowno >= 10; --TABLE_ALIAS.ROWNO between 10 and 100;
标签:语句,rowno,DATE,yyyymmdd,SQL,ORACLE,ROWNUM,WHERE,SELECT 来源: https://www.cnblogs.com/pypua/p/12896984.html