String sql = "select t2.* from (select t1.*, rownum rn from (select * from tb_courseinfo order by rownum  desc )t1 where rownum <= "+(curpage+1)*page_record+" )t2 where rn > "+curpage*page_record;

方法一

1.建立测试数据表
CREATE TABLE TEST
(
 ID NUMBER,
 NAME VARCHAR2(20),
 PRIMARY KEY(ID)
);

2.创建序列
CREATE SEQUENCE SEQ_TEST;

3.创建触发器
CREATE OR REPLACE TRIGGER AUTOINCREMENT
BEFORE INSERT ON TEST
FOR EACH ROW
WHEN (NEW.ID IS NULL)
BEGIN
SELECT SEQ_TEST.NEXTVAL INTO :NEW.ID FROM DUAL;
END;
/

4.插入数据
INSERT INTO TEST(NAME) VALUES('NAME1');

5.查看插入结果
SELECT * FROM TEST;

方法二


SQL   Server,Sybase:  
  有个identity属性可以让系统自动增1  
  create   table   a  
  (  
  a1   int   identity(1,1),  
  a2   varchar(6)  
  )   
  然后在insert时:  
  insert   into   a   values('hello!'); --不用管a1,系统会自动增1  
   
  Oracle:  
  使用SEQUENCE(序列)可以达到要求  
  create   table   a  
  (  
  a1   int   ,  
  a2   varchar2(6)  
  );  
   
  create   SEQUENCE   seq_a     INCREMENT   BY   1;   
    
  然后在insert时:  
  insert   into   a   values(seq_a.nextval,'hello!'); --seq_a.nextval是该序列的下个值