Mysql题目

练习题目

• • 第一章
  • 第二章
  • 第三章

第一章

第二章

第三章

3
【单选题】
查询所有未达60分的选课记录，要求显示出该学生的姓名、该门课程的名称和分数，不正确的查询语句是：（ ）

A、

SELECT Student.Sname, Course.Cname, SC.Grade

FROM SC, Student, Course

WHERE SC.Sno = Student.Sno

AND SC.Cno = Course.Cno

AND SC.Grade < 60;



 

B.



SELECT Student.Sname, Course.Cname, SC.Grade

FROM Student

LEFT JOIN SC

ON SC.Sno = Student.Sno

LEFT JOIN Course

ON SC.Cno = Course.Cno

WHERE SC.Grade < 60;

B、
SELECT Student.Sname, Course.Cname, SC.Grade

FROM SC

LEFT JOIN Student

ON SC.Sno = Student.Sno

LEFT JOIN Course

ON SC.Cno = Course.Cno

WHERE SC.Grade < 60;

C、
SELECT Student.Sname, Course.Cname, SC.Grade

FROM Student

LEFT JOIN SC

ON SC.Sno = Student.Sno

LEFT JOIN Course

ON SC.Cno = Course.Cno

WHERE SC.Grade < 60;

D、
SELECT Student.Sname, Course.Cname, SC.Grade

FROM Course

LEFT JOIN SC

ON SC.Cno = Course.Cno

LEFT JOIN Student

ON SC.Sno = Student.Sno

AND SC.Grade < 60;

正确答案： D 我的答案：D

3
【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 Sname

FROM Student S1

WHERE NOT EXISTS (

   SELECT *

   FROM Student S2

   WHERE S2.Sdept = 'CS'

   AND S1.Sage < S2.Sage

)

AND Sdept != 'CS';



B、
SELECT Sname

FROM Student S1

WHERE EXISTS (

   SELECT *

   FROM Student S2

   WHERE S2.Sdept = 'CS'

   AND S1.Sage >= S2.Sage

)

AND Sdept != 'CS';



C、
SELECT Sname

FROM Student

WHERE Sage >= (

   SELECT MIN(Sage)

    FROMStudent

   WHERE Sdept = 'CS'

)

AND Sdept != 'CS';



D、
SELECT Sname

FROM Student

WHERE Sage >= ANY (

   SELECT Sage

   FROM Student

   WHERE Sdept = 'CS'

)

AND Sdept != 'CS';



正确答案： A 我的答案：B