用oracle列实现sqlserver的自增列

create sequence User_ID increment by 1 start with 1 nomaxvalue nocycle              实现按1自增的序列

create table  Accounts_Users  (
   User_ID          int                      not null,
   UserName          varchar(50)              not null,
   Password          varchar(20)             not null
 )                                 创建表

create or replace trigger Trigger_Accounts_Users                 创建触发器
  before insert on Accounts_Users for each row  
begin  
 select User_ID.nextval into :new.User_ID from dual;      将序列的值传入到表Accounts_Users的User_ID列   实现自增列的效果
end;