数据库对象

create SEQUENCE dept_deptno
                    increment by 1                                        //自增数
                    start with 10                                         //开始数
                    maxvalue  15                                          //最大值
                    minvalue 10                                           //最小值
                    nocache                                         
                    nocycle;                                              //不循环

insert into dept(deptno,dname,loc) VALUES (dept_deptno.nextval,‘marketing‘,‘beijing‘);

select dept_deptno.currval
  from dual;

ALTER SEQUENCE DEPT_DEPTNO
           MAXVALUE  20
           CYCLE;                      

drop sequence dept_deptno;