oracle 触发器实现主键自增

drop table book;   

--创建表      

create table book(       

   bookId varchar2(4) primary key,   

   name varchar2(20)         

);   

--创建序列      

create sequence book_seq start with 1 increment by 1;    

  

--创建触发器      

create or replace trigger book_trigger       

before insert on book       

for each row       

begin       

select book_seq.nextval into :new.bookId from dual;      

end ;   

--添加数据      

insert into book(name)  values ('cc');    

insert into book(name)  values ('dd');   

  

commit;  

 



查询数据：select * from book; 

查询
select * from user_objects ubs where ubs.OBJECT_TYPE='SEQUENCE';