Oracle的ID自增长的设置。先编译上边，再编译下边即可。

创建自动增长序列

Create Sequence gygddj_cfjczb_Sequence
 Increment by 1     -- 每次加几个 
 start with 1       -- 从1开始计数     
 nomaxvalue         -- 不设置最大值,设置最大值：maxvalue 9999  
 nocycle            -- 一直累加，不循环    
 cache 10; 

创建触发器

 Create trigger gygddj_cfjczb_Sequence before 
 insert on gygddj_cfjczb for each row /*对每一行都检测是否触发*/
 begin
 select gygddj_cfjczb_Sequence.nextval into:New.AUTOID from dual;
 end;

create table t_user(
user_id number not null primary key,
user_name varchar2(30),
credits number,
user_password varchar2(32),
last_visit date,
last_ip varchar2(23)
)

create sequence T_USER_SEQ
minvalue 1
maxvalue 999999999999999999999999999
start with 21
increment by 1
cache 20;


create or replace trigger t_user_tr
before insert on t_user
for each row
begin
select t_user_seq.nextval into :new.user_id from dual;
end t_user_tr;


insert into t_user values(null,'xiaoming',123,'1114',sysdate,'192.168.37.132');
insert into t_user values(null,'xiaoming1',123,'1114',sysdate,'192.168.37.132');
insert into t_user values(null,'xiaoming1',123,'1114',sysdate,'192.168.37.132');
insert into t_user values(null,'xiaoming1',123,'1114',sysdate,'192.168.37.132');
insert into t_user values(null,'xiaoming2',123,'1114',sysdate,'192.168.37.132');
insert into t_user values(null,'xiaoming',123,'1114',sysdate,'192.168.37.132');
insert into t_user values(null,'xiaoming',123,'1114',sysdate,'192.168.37.132');
insert into t_user values(null,'xiaoming',123,'1114',sysdate,'192.168.37.132');
insert into t_user values(null,'xiaoming',123,'1114',sysdate,'192.168.37.132');
insert into t_user values(null,'xiaoming',123,'1114',sysdate,'192.168.37.132');


select * from t_user

第一步：
创建一张表

create table t_user(
user_id number not null primary key,
user_name varchar2(30),
credits number,
user_password varchar2(32),
last_visit date,
last_ip varchar2(23)
)

2. 为这个表创建序列

 create sequence T_USER_SEQ
minvalue 1 
maxvalue 999999999999999999999999999      -- 最大值  
start with 21           -- 从21开始  
increment by 1     -- 每次递增1  
cache 20;            --制定存入缓存（也就是内存）序列值的个数 默认20

3. 创建一个触发器
   t_user_tr:随意的名字，不要重复就行
   t_user:表名
   user_id ：自增的id

create or replace trigger t_user_tr
before insert on t_user
for each row
begin
select t_user_seq.nextval into :new.user_id from dual;
end t_user_tr;

4. 测试

insert into t_user values(null,'xiaoming',123,'1114',sysdate,'192.168.37.132');
insert into t_user values(null,'xiaoming1',123,'1114',sysdate,'192.168.37.132');
insert into t_user values(null,'xiaoming1',123,'1114',sysdate,'192.168.37.132');
insert into t_user values(null,'xiaoming1',123,'1114',sysdate,'192.168.37.132');
insert into t_user values(null,'xiaoming2',123,'1114',sysdate,'192.168.37.132');
insert into t_user values(null,'xiaoming',123,'1114',sysdate,'192.168.37.132');
insert into t_user values(null,'xiaoming',123,'1114',sysdate,'192.168.37.132');
insert into t_user values(null,'xiaoming',123,'1114',sysdate,'192.168.37.132');
insert into t_user values(null,'xiaoming',123,'1114',sysdate,'192.168.37.132');
insert into t_user values(null,'xiaoming',123,'1114',sysdate,'192.168.37.132');

5.查看结果

select * from t_user

这样就可以 本人亲试过；
oralce的自增id