如表10.6、表10.7和表10.8所示,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 IN (SELECT 课程号 FROM 选课 WHERE 成绩 IS NULL) ORDER BY 课程号
B、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
C、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
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)