oracle建表

alter table T_POOR_USER_INFO_TMP modify   PEOPLE_YEAR_INCOME   DEFAULT '0';

你首先要有CREATE SEQUENCE或者CREATE ANY SEQUENCE权限，
CREATE SEQUENCE emp_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
NOCYCLE – 一直累加，不循环
CACHE 10; --设置缓存cache个序列，如果系统down掉了或者其它情况将会导致序列不连续，也可以设置为---------NOCACHE

例如：

create sequence 序列名

minvalue 1

maxvalue 999999999999999999999999999999

start with 1

increment by 1

nocache;

创建触发器

create or replace trigger 触发器名

before insert on 表明

for each row when (new.id is=0) ------when触发的条件

begin

select 序列名.nextval into :new.id from dual;

end;

—将序列的下一个值赋给new.id，如果你的主键不是id,如stu_id,则设置成new.stu_id

两者结合即可

示例：

–创建测试表

create table test_table(
stu_id number(32) not null primary key ,
MER_NO varchar(16)
)

–创建序列

create sequence SEQ_HXTC_CUSTOMER_ID
minvalue 1
maxvalue 999999999999999999999999999999
start with 1
increment by 1
nocache;

–创建 stu_id自增的触发器，触发条件没有
create or replace trigger test_trigger
before insert on test_table
for each row
begin
select SEQ_HXTC_CUSTOMER_ID.nextval into :new.stu_id from dual;
end;

–测试一下

insert into test_table (MER_NO) values (1)
SELECT t.* ,t.rowid FROM test_table t

CREATE TRIGGER "SCOTT"."TG_T_VERIFICATION_CODE" BEFORE INSERT ON "SCOTT"."T_VERIFICATION_CODE" REFERENCING OLD AS "OLD" NEW AS "NEW" FOR EACH ROW BEGIN SELECT SEQ_T_VERIFICATION_CODE.NEXTVAL INTO :NEW.ID FROM DUAL; END TG_T_VERIFICATION_CODE ;