检索选修了课程”C1”的学生中成绩最高的学生的学号，正确的SELECT语句为（ ） A: SELECT Sno FROM SC WHERE Cno=’C1’ AND GRADE >=ALL (SELECT Grade FROM SC WHERE Cno=’C1’); B: SELECT Sno FROM SC WHERE Cno=’C1’ AND GRADE IN (SELECT Grade FROM SC WHERE Cno=’C1’); C: SELECT Sno FROM SC WHERE Cno=’C1’ AND GRADE > ANY (SELECT Grade FROM SC WHERE Cno=’C1’); D: SELECT Sno FROM SC WHERE Cno=’C1’ AND GRADE >= (SELECT Grade FROM SC WHERE Cno=’C1’);

下面哪一条语句是正确的() A: select from b B: select sno from a where sno 2000 C: select * from a order by sno where age>20 D: select * from B group by cno where cno>1

查询选课门数大于3门的同学学号，姓名, 选课门数Select ______________from student s, scwhere s.sno=sc.sno group by __________having _____________ A: sno, sname, count(*) ; sno, sname; count(*)>3 B: sno, sname, count(*) ; sno; count(*)>3 C: sno, sname, count(cno) ; sno; count(cno)>3 D: sno, sname, count(sno) ; sno; count(sno)>3

在学生选课数据库中，将所有选了课程‘DB’且分数在60~70分之间的学生的成绩增加百分之十，SQL语句为（ ） A: UPDATE SC SET Grade=Grade*1.1 WHERE Cno=’DB’ AND Grade BETWEEN 60 AND 70; B: UPDATE SC SET Grade+=Grade*0.1 WHERE Cno=(Select Cno From Course WHERE Cname=’DB’) AND Grade >= 60 AND Grade <=70; C: UPDATE SC SET Grade=Grade*1.1 WHERE Cno=(Select Cno From Course WHERE Cname=’DB’) AND Grade <= 60 AND Grade >=70; D: UPDATE SC SET Grade=Grade*1.1 WHERE Cno IN (Select Cno From Course WHERE Cname=’DB’) AND Grade BETWEEN 60 AND 70;

没有选修c01课程同学的学号 SELECT<br/>sno FROM student WHERE<br/>_______________ A: cno&lt;&gt;'c01' B: cno!='c01' C: sno<br/>not in(SELECT sno FROM sc WHERE cno='c01') D: NOT<br/>EXISTS(SELECT * FROM sc WHERE cno='c01'AND student.sno=sno)

针对学生选课表sc（sno, cno, grade），其中sno为学号，cno为课程号，grade为成绩。以下（ ）语句可查询选修了两门以上成绩在90分以上课程的学生学号。 A: select sno from sc where grade&gt;90 group by sno having count(cno)&gt;2; B: select sno from sc where grade&gt;90 group by sno having count(*)&gt;2; C: select sno from sc where grade&gt;90 and count(*)&gt;2 group by sno; D: select sno from sc where grade&gt;90 group by sno having count(sno)&gt;2;

A．SELECT Cno, AVG(Score) FROM SCS GROUP BY Score ORDER BY 2, Cno Desc B．SELECT Cno, AVG(Score) FROM SCS GROUP BY Cno ORDER BY 2, Cno Desc C．SELECT Cno, AVG(Score) FROM SCS WHERE Cno, Desc GROUP BY Score D．SELECT Cno, AVG(Score) FROM SCS GROUP BY, AVG(Score) ORDER BY, Cno Desc

检索选课人数少于4人的课程号。正确的SQL语句是( ) A: SELECT CNO FROM SC WHERE COUNT(*)<;4 B: SELECT CNO FROM SC GROUP BY CNO HAVING COUNT(*)<;4 C: SELECT DISTINCT CNO FROM SC ORDER BY CNO D: SELECT CNO FROM SC WHERE COUNT(CNO)<;4

在“学生-选课-课程”数据库中的3个关系如下：S（SNO, SNAME, SEX, AGE）； C（CNO, CNAME, TEACHER）；SC（SNO, CNO, GRADE），查询既选修了“2”号又选修了“4”号课程的学生学号。若用关系代数表达式来表示为（ ）。 A: ПSNO (σCNO=’2’(SC) ∩ σCNO=’4’(SC) ) B: ПSNO (σCNO=’2’(SC)) ¥ ПSNO(σCNO=’4’(SC) ) C: ПSNO (σCNO=’2’(SC) ∪ σCNO=’4’(SC) ) D: σCNO=’2’(SC) ¥σCNO=’4’(SC)

在MySQL中,假设有学生选课表SC(sno,cno,score)。那么列出所有选修课程超过5门的学生学号以及选修课程数目,其正确的SQL语句为()。 A: select sno,count(cno)from scwhere count(cno)>=5; B: select sno,count(cno)from scgroup by sno where count(cno)>=5; C: select sno,count(cno)from scgroup by sno having count(cno)>=5; D: select sno,count(cno)from scgroup by cno having count(cno)>=5;