将‘CS’系的全体学生的成绩置零一共有多少种方法
我只知道两种，大神看看对不对
update SC
set Grade=0
where Sno in(select Sno
fron Student
where Sdept ='CS')
update SC
set Grade=0
from Student,SC
where SC.Sno=Student.Sno and Sdept ='CS'