Oracle建表[自增序列]

1 create table VACATIONSDAY
2 (
3   fldid    NUMBER(22) not null,
4   fldname  varchar2(200),
5   fldbegindata date,
6   fldenddata date,
7   fldselectid  number(10)
8 );

1 CREATE SEQUENCE vacationsday_Sequence
2 　　INCREMENT BY 1 -- 每次加几个 
3 　　START WITH 1 -- 从1开始计数 
4 　　NOMAXVALUE -- 不设置最大值 
5 　　NOCYCLE -- 一直累加，不循环 
6 　　CACHE 100; 

create or replace trigger vacationsday_trigger    
--users_trigger    触发器名称
before insert on vacationsday                  
--users是表名
for each row
declare
nextid number;
begin
IF :new.fldid IS NULL or :new.fldid=0 THEN                
 --userid是列名
select vacationsday_Sequence.nextval                                              
--user_Sequence 正是刚才创建的序列
into nextid
from sys.dual;
:new.fldid:=nextid;
end if;
end users_trigger ;