题目呢？没有题怎么回答。 补充回答update course set 学分 =3 where 课程号=3select * from student where 年龄>18 order by 学号 descselect s.学号,s.姓名，s.性别 from student s inner join sc on sc.学号= s.学号 inner join course c on sc.课程号 on c.课程号 where c.学分=3 and sc.成绩>30group by s.学号,s.姓名，s.性别这个查询会比用in查询快一些。create trigger my_trig on studen
1.update sc set 成绩=3 where 课程号=32.select * from student where 年龄>18 order by 学号3.select 学号,姓名,性别 from student,course,sc where student.学号=sc.学号 and course.课程号=sc.课程号 and 学分=3 an
1. update course set 学分=3 where 课程号=32. select * from student where 年龄>18 order by 学号 desc3. select 学号、姓名,性别 from student join sc on student.学号=sc.学号 where 成绩>80 and 课程号 in (se
