【简答题】以下MySQL语句中,已知关系模式stu_course(Sno,Cno,Term,Grade),查询成绩良好的人数记录,正确的是( )。A. SELECT COUNT(grade) AS 成绩良好的人数 FROM stu_course WHERE grade BETWEEN 80 AND 89; B. SELECT COUNT(*) FROM stu_course WH...
【简答题】以下MySQL语句中,已知关系模式stu_course(Sno,Cno,Term,Grade),在stu_course表中排序记录,正确的是( )。A. SELECT * FROM stu_course ORDER BY grade ASC; B. SELECT cno,grade FROM stu_course grade DESC; C. SELECT * ...
【简答题】以下MySQL语句中,已知关系模式stu_course(Sno,Cno,Term,Grade),查询统计总成绩和平均成绩的记录,正确的是( )。A. SELECT SUM(grade) AS ‘总成绩’,AVG(grade) AS ‘成绩平均值’ FROM stu_course; B. SELECT grade AS “总成绩” FROM stu_course; C. SE...
【简答题】以下MySQL语句中,已知关系模式stu_course(Sno,Cno,Term,Grade),查询成绩最大值和成绩最小值的记录,正确的是( )。A. SELECT grade AS 成绩最大值 FROM stu_course; B. SELECT MAX(grade) AS 成绩最大值,MIN(grade) AS 成绩最小值 FROM stu_course; C. S...