【转】Oracle实现插入记录ID自增长

create table users
(
 userid integer primary key,
 username varchar2(10) ,
 address varchar2(20),
 phone  varchar2(13),
 loginname varchar2(20),
 loginpwd varchar2(20)
)
create sequence user_sq;
--触发器实现id自增长
create or replace trigger tri_users
       before insert on users
       for each row
declare
       nextid number;
begin
       if
       :new.userid is null or :new.userid='' or :new.userid=0 then
       select user_sq.nextval into nextid from dual;
       
       :new.userid:=nextid;
       
       end if;
end tri_users;
insert into users(username,address,phone,loginname,loginpwd) values('wenshuo','深圳','13632699421','wenshuo','123');