以下试题基于这样的三个表即学生表S、课程表C和学生选课表SC,它们的结构如下 S(S#, SN, SEX, AGE, DEPT) C(C#, CN) SC(S#, C#, GRADE) 其中:S#为学号,SN为姓名,SEX为性别,AGE为年龄,DEPT为系别,C#为课程号,CN为课程名, GRADE为成绩 检索选修4门以上课程的学生总成绩(不统计不及格的课)并按总成绩降序排列出来。正确的 SELECT语句是
A.
SELECT S#, SUM(GRADE) FROM SC WHERE GRADE>=60 GROUP BY S# ORDER BY 2 DESC 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 ORDER BY 2 DESC GROUP BY S# HAVING COUNT(*)>=4