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
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