DB2和Oracle创建序列和查询的区别

DB7.2以后才有sequence这个对象，创建的时候和oralce一样。

CREATE SEQUENCE seq_name AS INT

START WITH 1

INCREMENT BY 1

MINVALUE 1

NO MAXVALUE

NO CYCLE

NO CACHE

ORDER

在使用的过程中有些不同

DB2中：nextval for sequencename ，prevval for sequencename

select nextval for seq_name from sysibm.sysdummy1;

select prevval for seq_name from sysibm.sysdummy1;

oracle中：sequencename.nextval，sequencename.currval

select seq_name.nextval from dual;

select seq_name.currval from dual;

sysibm.sysdummy1是DB2内存中的一个特殊的表。

 

 

 

 

 

 

 

 

from: http://blog.csdn.net/woaizhoulichao1/article/details/6128614