SELECT Cname 课程名,Credit 学分,SUM(Credit) AS 总学分From CourseWHERE Semester =2group by Cname ,Credit但是这样写会有问题,应该不是你要的 ,你需要的应该是这个SELECT Cname 课程名 ,SUM(Credit) AS 总学分From CourseWHERE Semester =2group by Cname