orcle中触发器的使用

orcle中触发器的使用

通过触发器和sequence实现id的自动增加

一，创建表格

create table user_test(
 id number not null,
 age number,
 name varchar2(30)
);

 

二，建立sequence

create sequence user_seq
minValue 100
maxValue 999999
start with 100
increment by 1
cache 20;

 

三，创建触发器

create or replace trigger user_trigger
before insert on user_test for each row
begin
 select user_seq.nextval into:new.id from dual;
end user_trigger; 

   注意：new.id的id为user_test表格中的列，dual;和user_trigger;中的;必须有

 

四，测试

insert into user_test(age,name) values(28,'Jack');
insert into user_test(age,name) values(27,'Tom');
insert into user_test(age,name) values(29,'Rose');

 

select * from user_teset

五，测试结束

drop sequence user_seq;

drop trigger user_trigger;

drop table user_test;