Oracle自增ID实现

CREATE TABLE example(

ID Number(4) NOT NULL PRIMARY KEY,

NAME VARCHAR(25));

CREATE SEQUENCE example_sequence

INCREMENT BY 1 -- 步长，每次增加几个

START WITH 1 -- 从1开始计数

NOMAXVALUE -- 不设置最大值

NOCYCLE -- 一直累加，不循环

NOCACHE -- 不建缓冲区

CREATE TRIGGER example_triger BEFORE

INSERT ON example FOR EACH ROW WHEN (new.id is null)--只有在id为空时，启动该触发器生成id号

begin

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

end;

insert into example(name) values('张三');

insert into example(id, name) values(111,'李四');

select t.* from EXAMPLE t