oracle中的主键自动增长

1、建用户数据表

create table t_user(

userid number primary key,

name varchar2(20),

sex varchar2(3)

);

2、创建自动增长序列

create sequence SEQ_ID_T_USER

minvalue 1

maxvalue 99999999

start with 1

increment by 1

cache 20;

3、创建触发器

create or replace trigger tri_id_t_user

before insert on t_user

for each row

begin

select SEQ_ID_T_USER.nextval into :new.userid from dual;

end;

4、提交

insert into t_user(name,sex) values ('wang','女');

commit;