超星 - 3.5 数据查询——嵌套查询（续）

单选题

查询计算机系任意学生选修过的课程号，不正确的查询语句是：

A. SELECT DISTINCT CnoFROM SCWHERE NOT EXISTS (SELECT SnoFROM StudentWHERE Sdept = 'CS'AND SC.Sno = Student.Sno);
B. SELECT DISTINCT CnoFROM SCWHERE EXISTS (SELECT SnoFROM StudentWHERE Sdept = 'CS'AND SC.Sno = Student.Sno);
C. SELECT DISTINCT CnoFROM SCWHERE Sno IN (SELECT SnoFROM StudentWHERE Sdept = 'CS');
D. SELECT DISTINCT CnoFROM SCLEFT JOIN StudentON SC.Sno = Student.SnoWHERE Sdept = 'CS';

查看答案

单选题

查询学号为201215121的同学选修过的所有课程的名字，不正确的查询语句是：

A. SELECT CnameFROM CourseLEFT JOIN SCON Course.Cno = SC.CnoWHERE Sno = '201215121';
B. SELECT CnameFROM CourseWHERE Cno IN (SELECT CnoFROM SCWHERE Sno = '201215121');
C. SELECT CnameFROM CourseWHERE EXISTS (SELECT *FROM SCWHERE SC.Cno = Course.CnoAND Sno = '201215121');
D. SELECT CnameFROM CourseWHERE NOT EXISTS (SELECT *FROM SCWHERE SC.Cno = Course.CnoAND Sno = '201215121');

查看答案

单选题

查询非计算机系中比计算机系中年龄最小者年龄大或相等的学生姓名，不正确的查询语句是：

A. SELECT SnameFROM Student S1WHERE NOT EXISTS (SELECT *FROM Student S2WHERE S2.Sdept = 'CS'AND S1.Sage < S2.Sage)AND Sdept != 'CS';
B. SELECT SnameFROM Student S1WHERE EXISTS (SELECT *FROM Student S2WHERE S2.Sdept = 'CS'AND S1.Sage >= S2.Sage)AND Sdept != 'CS';
C. SELECT SnameFROM StudentWHERE Sage >= (SELECT MIN(Sage) FROMStudentWHERE Sdept = 'CS')AND Sdept != 'CS';
D. SELECT SnameFROM StudentWHERE Sage >= ANY (SELECT SageFROM StudentWHERE Sdept = 'CS')AND Sdept != 'CS';

查看答案

单选题

在所有学生中查询比计算机系所有学生年龄都要大的学生姓名，不正确的查询语句是：

A. SELECT SnameFROM StudentWHERE Sage > (SELECT MAX(Sage)FROM StudentWHERE Sdept = 'CS');
B. SELECT SnameFROM StudentWHERE Sage > ALL (SELECT SageFROM StudentWHERE Sdept = 'CS');
C. SELECT SnameFROM Student S1WHERE EXISTS (SELECT SageFROM Student S2WHERE Sdept = 'CS'AND S1.Sage > S2.Sage);
D. SELECT SnameFROM Student S1WHERE NOT EXISTS (SELECT SageFROM Student S2WHERE Sdept = 'CS'AND S1.Sage <= S2.Sage);

查看答案

判断题

所有带 IN 谓词、比较运算符、ANY 和 ALL 谓词的子查询都能用带 EXISTS 谓词的子查询等价替换。

A. 对
B. 错

查看答案