基于这样的3个表,即学生表S、课程表C和学生选课表SC,它们的关系模式如下:S(S,SN,SEX,AGE,DEPT)(学号,姓名,性别,年龄,系别)C(C,CN)(课程号,课程名称)SC(S,C,GRADE)(学号,课程号,成绩).检索4门以上课程的学生总成绩,并要求按总成绩的降序排列出来。正确的SELECT语句是()
A.SELECT S#,SUM(GRAGE) FROM SC WHERE GRADE>=60 GROUP BY S# ORDER BY S# HAVING COUNT(*)>=4 B.SELECT S#,SUM(GRADE) FROM SC WHERE GRADE>=60 GROUP BY S# HAVING COUNT(*)>=4 ORDER BY 2 DESC C.SELECT S#,SUM(GRADE) FROM SC WHERE GRADE>=60 HAVING COUNT(*)<=4 GROUP BY S# ORDER BY 2 DESC D.SELECT S#,SUM(GRADE) FROM SC WHERE GRADE>=60 HAVING COUNT(*)>=4 GROUP BY S# ORDER BY 2