学生成绩管理系统[网页版+数据库]

insert into user (username, password,type) values ('a','b','c') select * from user select * from user where username = 'a' and password = 'b' alter table student add column cc int(5) //add column alter table student drop column a //delete column delete from user where id = 1 update student set username = 'a',password = 'b' where id = 1