查询所有非计算机系学生的信息,不正确的SQL语句是:( )
A: SELECT * FROM Student WHERE Sdept != 'CS';
B: SELECT * FROM Student WHERE NOT Sdept = 'CS';
C: SELECT * FROM Student WHERE Sdept IN ('MA', 'IS');
D: SELECT * FROM Student WHERE NOT Sdept IN ('CS');
A: SELECT * FROM Student WHERE Sdept != 'CS';
B: SELECT * FROM Student WHERE NOT Sdept = 'CS';
C: SELECT * FROM Student WHERE Sdept IN ('MA', 'IS');
D: SELECT * FROM Student WHERE NOT Sdept IN ('CS');
举一反三
- 使用教学(STC)数据库,与如下查询语句等价的是( )。 SELECT *FROM Student WHERE Sdept = 'CS' EXCEPT SELECT * FROM Student WHERE Sage <= 19; A: SELECT * FROM Student WHERE Sdept = 'CS' AND Sage > 19 B: SELECT * FROM Student WHERE Sdept = 'CS' AND Sage <= 19 C: SELECT * FROM Student WHERE Sdept = 'CS' OR Sage <= 19 D: SELECT * FROM Student WHERE Sdept = 'CS' OR Sage > 19
- 在所有学生中查询比计算机系学生平均年龄大的学生姓名,可以使用的查询语句是: A: SELECT Sname FROM Student WHERE Sage > ( SELECT AVG(Sage) FROM Student ); WHERE Sdept = 'CS' B: SELECT Sname FROM Student WHERE Sage > AVG( SELECT Sage FROM Student WHERE Sdept = 'CS' ); C: SELECT Sname FROM Student WHERE Sage > ( SELECT AVG(Sage) FROM Student WHERE Sdept = 'CS' ); D: SELECT Sname FROM Student WHERE AVG(Sage) > ( SELECT Sage FROM Student WHERE Sdept = 'CS' );
- 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,正确的查询语句是___________________。 A: SELECT Sname FROM Student WHERE Sage > ( SELECT MAX(Sage) FROM Student WHERE Sdept = 'CS'); B: SELECT Sname FROM Student WHERE Sage > ALL ( SELECT Sage FROM Student WHERE Sdept = 'CS'); C: SELECT Sname FROM Student S1 WHERE EXISTS ( SELECT Sage FROM Student S2 WHERE Sdept = 'CS' AND S1.Sage > S2.Sage); D: SELECT Sname FROM Student S1 WHERE NOT EXISTS ( SELECT * FROM Student S2 WHERE Sdept = 'CS' AND S1.Sage <= S2.Sage);
- 对教材79页学生表的查询,若描述条件‘年龄大于计算机系某个学生的年龄’,可以表示为: A: WHERE sage>ANY(SELECT sage FROM student WHERE sdept='CS') B: WHERE sage>SOME(SELECT sage FROM student WHERE sdept='CS') C: WHERE sage>ALL(SELECT sage FROM student WHERE sdept='CS') D: WHERE sage>(SELECT MIN(sage) FROM student WHERE sdept='CS'))
- S_T数据库关系图如下:[img=332x128]17e448fc85e997f.jpg[/img]查询与“刘晨”在同一个系学习的学生,要求显示学生学号(Sno)、姓名(Sname)及系别(Sdept)。下列SQL语句正确的是()。 A: SELECT Sno, Sname, Sdept FROM Student WHERE Sdept = (SELECT Sdept FROM Student WHERE Sname = '刘晨'); B: SELECT S1.Sno, S1.Sname , S1.Sdept FROM Student S1 , Student S2 WHERE S1.Sdept = S2.Sdept AND S2.Sname = '刘晨'; C: SELECT Sno, Sname, Sdept FROM Student WHERE Sdept IN (SELECT Sdept FROM Student WHERE Sname = '刘晨'); D: SELECT Sno, Sname, Sdept FROM Student WHERE Sdept LIKE (SELECT Sdept FROM Student WHERE Sname = '刘晨');