摘要：
1、建用户数据表drop table dectuser;create table dectuser(userid integer primary key， /*主键*/name varchar2(20)，sex varchar2(2));2、创建自动增长序列drop sequence seq_dectuser;create sequence seq_dectuser minvalue 1 maxvalue 99999999increment by 1start with 1; /*步长为1*/3、创建触发器create or replace trigger tri_dectuserbefore 阅读全文