Oracle 创建主键自增表示例代码

create table tb_student

(

   id         NUMBER(10)      not null ,

   createtime     DATE          not null ,

   constraint PK_tb_student primary key (id)

);

comment on table "tb_student" is

'学生表' ;

comment on column "tb_student" . "id" is

'主键id' ;

comment on column "tb_student" . "createtime" is

'创建时间' ;

--创建序列

create sequence seq_tb_student

minvalue 1

nomaxvalue

start with 1

increment by 1

nocycle  --一直累加，不循环

nocache;

--创建触发器，如果insert语句不指定ID自动插入增长值

CREATE OR REPLACE TRIGGER tr_tb_student

BEFORE INSERT ON tb_student FOR EACH ROW WHEN (new.id is null )

begin

select seq_tb_student.nextval into :new.id from dual;

end ;