【单选题】【消耗次数:1】
下列删除计算机系学生(在student表中)的修课记录(在SC表中)的语句,正确的是( )。
DELETEFROM SC JOIN Student b ON S.Sno = b.Sno   WHERE Sdept = 计算机系
DELETE FROM SC FROM SC JOIN Student b ON SC.Sno = b.Sno   WHERE Sdept = 计算机系
DELETE FROM StudentWHERE Sdept = 计算机系
DELETE FROM SC WHERE Sdept = 计算机系
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相关题目
【单选题】 删除计算机系学生(在student表中)的修课记录(在SC表中)的语句,正确的是( )。
①  DELETE FROM SC JOIN Student b ON S.Sno = b.Sno WHERE Sdept = 计算机系
②  DELETE FROM SC FROM SC JOIN Student b ON SC.Sno = b.Sno WHERE Sdept = 计算机系
③  DELETE FROM Student WHERE Sdept = 计算机系
④  DELETE FROM SC WHERE Sdept = 计算机系
【判断题】 SELECT * FROM Student INNER JOINSC ON Student.Sno = SC.Sno语句可将Student与 SC连接起来。
①  正确
②  错误
【单选题】 查询计算机系选修了5门以上课程的学生姓名。下面SQL语句中正确的是( )。
①  SELECT 姓名 FROM 选课单 WHERE 系=’计算机’AND COUNT(*)>5
②  SELECT 姓名 FROM 选课单 WHERE 系=’计算机’AND COUNT(*)>5 GROUP BY 姓名
③  SELECT 姓名 FROM 选课单 WHERE 系=’计算机’GROUP BY 姓名 HAVING COUNT(*)>5
④  SELECT 姓名 FROM 选课单 WHERE系=’计算机’GROUP BY 姓名 HAVING系=’计算机’AND COUNT(*)>5
【单选题】 对于关系表Student(Sno,Sname,Ssex,Sdept,Sage),以下SQL语句中语法正确的是( )。
①  A.Select Sname From Student Where Sdept=’MA’
②  B.Insert Into Student Values(‘20170001’,’liming’,’男’)
③  C.Delete Sdept From Student Where Sno=’20170002’
④  D.Create View Birthyear_Student as Select Sno,Sname,2019-Sage From Student
【单选题】 设数据库中已有教材中的Student(Sno,Sname,Ssex,Sage,Sdept)、Course(Cno,Cname,Credit,Semster)和SC(Sno,Cno,Grade)表。现要查询学生选的第2学期开设课程的情况,只需列出学号、姓名、所在系和所选的课程号。该查询涉及到的表是( )。
①  仅Student表
②  仅Student和SC表
③  仅Student和Course表
④  Student、SC和Course表
【单选题】 计算机系统应该包括()
①  主机、键盘、显示器
②  计算机和它的外围设备
③  系统软件和应用软件
④  计算机硬件系统和软件系统
【多选题】 设有一个学生选课数据库,其包括学生表S、课程表C和学生选课表SC三个关系: S(SNO, SNAME, SAGE, SSEX, SDEP); C(CNO, CNAME); SC(SNO, CNO, GRADE),其中SNO是学生号,SNAME是学生姓名,SAGE是年龄,SDEP是学生所在系,CNO是课程号,CNAME是课程名称,那么“查询计算机科学系年龄大于19岁的学生”的SQL语句为( )。
①  A.SELECT* FROM S WHERE SDEP = ‘CS’ EXCEPT SELECT* FROM S WHERE SAGE
②  B.SELECT* FROM S WHERE SDEP = CS AND SAGE
③  C.SELECT* FROM S WHERE SDEP = CS AND SAGE
④  D.SELECT* FROM S WHERE SDEP != CS AND SAGE
【单选题】 用脱机外围设备操作技术的计算机系统中,计算机系统中至少需要()台计算机。
①  1
②  2
③  3
④  4
【单选题】 采用脱机外围设备操作技术的计算机系统中,计算机系统中至少需要()台计算机。
①  1
②  2
③  3
④  4
【判断题】 SELECT COUNT(DISTINCT Sno) FROM SC 语句用于统计学生的总人数。
①  正确
②  错误
随机题目
【单选题】 — As we all know, the invention of the Internet was a great breakthrough in human history. ___________?— Yes, of course.
①  What is your opinion
②  Do you know the reason
③  Do you think so
④  what do you think?
【单选题】 The caregivers hope the elderly people will soon.(考点:recover)
①  regain
②  restore
③  recover
④  refeel
【单选题】 —Do you have much experience with caring for babies?— .
①  Yes, I do. I am responsible, loving, warm girl, and often take care of kids in my free time.
②  No, you are freshmen. You should work hard.
③  Yes, they are. They are very cute.
【单选题】 —Linda, what’s wrong with your grandmother?— .
①  She is not retired
②  She hurt her leg.
③  She got a new house.
④  She got a new book.
【单选题】 The better the elderly people are known, they are.
①  the happier
②  the happy
③  so happy
④  very happy
【单选题】 —Ken did badly in his math test. Im terribly worried about the result.— .
①  I am so happy he is very healthy.
②  Well, it is hard to see.
③  Come on. it isn’t the end of the world.
【单选题】 She chose to be a teacher, but personally I’d to be a caregiver.
①  fancy
②  prefer
③  love
④  hate
【单选题】 _________ we’ve no money, we can’t buy it.
①  Since
②  Because of
③  Therefore
④  Why
【单选题】 We often compare children ______ flowers.
①  with
②  . to
③  in
【单选题】 Translation: Apple has entered the textbook market.
①  苹果公司已经开发了市场学教材。
②  苹果公司已经进入了教材市场。
③  苹果已经在市场上销售了。
④  苹果已经在市场了。