1、ORACLE没有类似SQL SERVER的自增长字段; 2、在ORACLE中,使用触发器实现字段的自增长; 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');
new.bookId from dual什么意思
一般用序列吧....触发器什么的太麻烦..create sequence seq_t_student minvalue 1 maxvalue 999999999 start with 1 increment by 1 nocache;用的话可以 select seq_t_student.nextval from dual; 就能取到下一个值了...实在懒...也可以 select max(id)+1 from t_student; 不过这个不保险噢...
2、在ORACLE中,使用触发器实现字段的自增长;
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');
minvalue 1
maxvalue 999999999
start with 1
increment by 1
nocache;用的话可以
select seq_t_student.nextval from dual;
就能取到下一个值了...实在懒...也可以
select max(id)+1 from t_student;
不过这个不保险噢...