Oracle自动增长

1.创建表

   create table userInfo

 (

    userId number(5) primary key ,

    userName varchar2(20)

  );

2.创建序列

  create sequence seq_user

  nocache;

3.创建触发器

  create or replace trigger user_tg

  before insert on userInfo

  for each row

  declare

    --local variables here

  begin

    select seq_user.nextval into :new.userId from userInfo dual;

  end user_tg;

 /