这种方法对大数据量查询的效率影响大不大 ? 如 select * from tbname where rownum<10009 minus select * from tbname where rownum<10005;
select * from ( select rownum as rowcount ,table.* from table) where rowcount between 5 and 9
minus效率当然太低~举个例子 =============================================== SQL> select id from aa; ID ---------- 1 2 3 4 5 66 rows selected.SQL> select * from (select rownum aa 2 from (select id from aa group by id)) 3 where aa between 2 and 4 ; AA ---------- 2 3 4
如
select * from tbname where rownum<10009
minus
select * from tbname where rownum<10005;
select * from (
select rownum as rowcount ,table.* from table)
where rowcount between 5 and 9
===============================================
SQL> select id from aa; ID
----------
1
2
3
4
5
66 rows selected.SQL> select * from (select rownum aa
2 from (select id from aa group by id))
3 where aa between 2 and 4 ; AA
----------
2
3
4
BTW,相同问题提过N遍了,
能否在FAQ中寻找答案?
刚刚找到
http://expert.csdn.net/Expert/topic/2268/2268228.xml?temp=.942547