建表
CREATE TABLE TF_TF3
(
  CODE  NUMBER      NOT NULL  PRIMARY KEY
)

创建一个序列，由1开始取值，递增1，最大值为10000
create sequence sq_code 
increment by 1 start with 1 maxvalue 10000 cycle;


insert into TF_TF2 values(sq_code.nextval);

create table postino
(
    code number primary key not null
)

select * from postino

insert into postino(code) values(20)

update postino set code=code+1