insert into course(cno, cname, period, credit, type) values('101', '网络数据库构建与维护', 96, 6, '必选课') insert into course(cno, cname, period, credit, type) values('102', '网页设计与制作, 60, 4, '必选课') update course set period=64 where cname='网页设计与制作' delete course where cno='101'