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';
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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);
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
平面立体的相贯线均为空间折线。( )
A. 对
B. 错