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.