：修改student表中学号为2015001的学生的姓名为“张三”A:update student set sname=’ 张三’ where sid=’2015001’B:update student set sname=张三 where sid=’2015001’C:update student set sname=”张三” where sid=’2015001’D:alter table student alter sname=’ 张三’ where sid=’2015001答案: update student set sname=’ 张三’ where sid=’2015001’12、