Oracle中varchar2类型的id为自动增长

Question

Oracle中id的类型为varchar2（10）主键，怎样创建自动增长的id

Answer 1

可以的，使用序列

创建序列

create sequence SEQ_CEID
minvalue 1
maxvalue 9999999999
start with 41
increment by 1
cache 20;
创建表，插入，查询
create table table_f (
id varchar(10) primary key,
name varchar(20)
)
insert into table_f values(SEQ_CEID.NEXTVAL,'wef')

或者加上触发器

2.--创建表

3.create table book(

1. bookId varchar2(4) primary key,
   
2. name varchar2(20)
   6.);
   7.--创建序列
   8.create sequence book_seq start with 1 increment by 1;
   
3. 10.--创建触发器
   11.create or replace trigger book_trigger
   12.before insert on book
   13.for each row
   14.begin
   15.select book_seq.nextval into :new.bookId from dual;
   16.end ;
   17.--添加数据
   18.insert into book(name) values ('cc');
   19.insert into book(name) values ('dd');