--创建sequence
create sequence seq_on_test
increment by 1
start with 1
nomaxvalue
nocycle
nocache;

--建表
drop table test;
create table test(
ID integer
,stu_name nvarchar2(4)
,stu_age number
);

--插入数据
insert into test values(seq_on_test.nextval,'Mary',15);
insert into test values(seq_on_test.nextval,'Tom',16);

select * from test;

--结果
/*
1 Mary 15
2 Tom 16
*/

--seq的两个方法
select seq_on_test.currval from dual;
select seq_on_test.nextval from dual;

--结果
/*
2
3
*/