如下几个表所示学生、课程和选课关系,用SQL语言实现下列操作。试列出计算机系所开课程(CS标志)的最高成绩、最低成绩和平均成绩。如果某门课程的成绩不全(即“成绩”中有NULL出现),则该课程不予统计,结果按“课程号”升序排列。正确的SQL语句是_____。
A.SELECT 课程号,MAX(成绩),MIN(成绩),AVG(成绩) FROM 选课 WHERE 课程号 Like ‘CS%’ GROUP BY 课程号 HAVING 课程号 NOT IN (SELECT 课程号 FROM 选课 WHERE 成绩 IS NULL) ORDER BY 课程号;
B.SELECT 课程号,MAX(成绩),MIN(成绩),AVG(成绩) FROM 选课 WHERE 课程号 Like ‘CS%’ GROUP BY 课程号 HAVING 课程号 IN (SELECT 课程号 FROM 选课 WHERE 成绩 IS NULL) ORDER BY 课程号;
C.SELECT MAX(成绩),MIN(成绩),AVG(成绩) FROM 选课 WHERE 课程号= ‘CS%’ GROUP BY 课程号 HAVING 课程号 NOT IN (SELECT 课程号 FROM 选课 WHERE 成绩 IS NULL) ORDER BY 课程号;
D.SELECT 课程号,MAX(成绩),MIN(成绩),AVG(成绩) FROM 选课 WHERE 课程号 Like ‘CS%’ GROUP BY 课程号 HAVING 课程号 NOT IN (SELECT 课程号 FROM 选课 WHERE 成绩 IS NULL)
- · 有1位网友选择 C,占比100%