关系SC(Sno，Cno，Grade)表示学号，课程号，成绩。现要查询平均分在90分以上的学生的学号和平均成绩，正确的语句是______。
A: SELECT Sno，AVG(Grad FROM SC WHERE AVG(Grad＞=90 GROUP BY Sno
B: SELECT Sno，AVG(Grad FROM SC GROUP BY Sno HAVING AVG(Grad＞=90
C: SELECT Sno，AVG(Grad FROM SC WHERE AVG(Grad＞=90 ORDER BY Sno
D: SELECT Sno，AVG(Grad FROM SC GROUP BY Cno HAVING AVG(Grad＞=90
A: SELECT Sno，AVG(Grad FROM SC WHERE AVG(Grad＞=90 GROUP BY Sno
B: SELECT Sno，AVG(Grad FROM SC GROUP BY Sno HAVING AVG(Grad＞=90
C: SELECT Sno，AVG(Grad FROM SC WHERE AVG(Grad＞=90 ORDER BY Sno
D: SELECT Sno，AVG(Grad FROM SC GROUP BY Cno HAVING AVG(Grad＞=90
举一反三
- 在学生选课数据库中，查询平均成绩大于等于60分的同学，SQL语句为（ ） A: SELECT Sno, AVG(Grade) FROM SC GROUP BY Sno HAVING AVG(Grade)>=60; B: SELECT Sno FROM SC WHERE Grade>=60 GROUP BY Sno; C: SELECT Sno, Grade FROM SC GROUP BY Sno HAVING AVG(Grade)>=60; D: SELECT Sno FROM SC GROUP BY Sno HAVING Grade >=60;
- 查询最低成绩大于85分的学生学号和平均成绩,可以使用的查询语句是: 。 A: SELECT Sno, AVG(Grade) FROM SC HAVING MIN(Grade) > 85 GROUP BY Sno; B: SELECT Sno, AVG(Grade) FROM SC GROUP BY Sno HAVING MIN(Grade) > 85; C: SELECT Sno, AVG(Grade) FROM SC WHERE MIN(Grade) > 85 GROUP BY Sno; D: SELECT Sno, AVG(Grade) FROM SC GROUP BY Sno WHERE MIN(Grade) > 85;
- 表sc中存放了多个学生的多门课程的成绩，sno为学号，cno为课程号，grade为成绩。要查询平均分最高的学生学号和平均分，下列（）语句可以实现。 A: SELECT top 1 sno,avg(grade) FROM sc group by sno order by avg(grade) desc B: SELECT sno,max(avg(grade)) FROM sc group by sno C: SELECT sno,max(grade), avg(grade) FROM sc group by sno D: SELECT sno,max(grade) FROM sc group by sno
- 在学生选课数据库中，查询平均成绩大于等于60分的同学，SQL语句为（ ） A: SELECT Sno, AVG(Grade) FROM SC GROUP BY Sno HAVING AVG(Grade)>=60; B: SELECT Sno FROM SC WHERE Grade>=60 GROUP BY Sno; C: SELECT Sno, Grade FROM SC GROUP BY Sno HAVING AVG(Grade)>=60; D: SELECT Sno FROM SC GROUP BY Sno HAVING Grade >=60;
- 已知关系模式：sc(sno,sname,grade)，各属性含义依次为学号、课程名、分数。要查找“数据库”课分数最高的学生的学号，正确的SQL语句是( )。 A: SELECT sno FROM sc WHERE sname="数据库"AND grade=MAX(grad B: SELECT sno FROM sc FOR sname="数据库"OR grade＞=MAX(grad C: SELECT sno FROM sc WHERE sname="数据库"AND grade=(SELECT MAX(grad FROM s D: SELECT sno FROM sc FOR sname="数据库"OR grade=(SELECT MAX(grad FROM s