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相关试题
- 1.下列哪些语句是统计CS系的学生人数选项： A:SELECT COUNT(Sno) FROM Student GROUP BY Sdept B:SELECT COUNT(Sno) FROM Student WHERE Sdept ="CS" C:SELECT COUNT(*) FROM Student WHERE Sdept ="CS" D:SELECT MAX(Sno) FROM Student WHERE Sdept ="CS"
- 2.针对表Student（sno, sname, ssex, sage, sdept），其中sno为学号，sname为姓名，ssex为性别，sage为年龄，sdept为系别。查询女生平均年龄超过20岁的系别以及女生平均年龄。选项： A:select sdept ,avg(sage) from student group by sdept having avg(sage) >20; B:select sdept ,avg(sage) from student where ssex='女' and avg(sage) >20 group by sdept ; C:select sdept ,avg(sage) from student where ssex='女' group by sdept; D:select sdept ,avg(sage) from student where ssex='女' group by sdept having avg(sage) >20
- 3.针对表Student（sno, sname, ssex, sage, sdept），其中sno为学号，sname为姓名，ssex为性别，sage为年龄，sdept为系别。查询女生平均年龄超过20岁的系别以及女生平均年龄。 选项： A、select sdept ,avg(sage) from student where ssex='女' and avg(sage) >20 group by sdept B、select sdept ,avg(sage) from student where ssex='女' group by sdept having avg(sage) >20 C、select sdept ,avg(sage) from student where ssex='女' group by sdept D、select sdept ,avg(sage) from student group by sdept having avg(sage) >20
- 4.针对表Student(sno, sname, ssex, sage, sdept),其中sno为学号,sname为姓名,ssex为性别,sage为年龄,sdept为系别。查询女生平均年龄超过20岁的系别以及女生平均年龄。 选项： A、select sdept ,avg(sage) from student group by sdept having avg(sage) >20 B、select sdept ,avg(sage) from student where ssex='女' group by sdept C、select sdept ,avg(sage) from student where ssex='女' group by sdept having avg(sage) >20 D、select sdept ,avg(sage) from student where ssex='女' and avg(sage) >20 group by sdept
- 5.在学生选课数据库中有学生表student(sno,sname,ssex,sage,sdept)，课程表course(cno,cname)及学生选课表sc(sno,cno,grade)，其中sno是学号，sname是姓名，ssex是性别，sage是年龄，sdept是系别，cno是课程号，cname是课程名，grade是成绩。以下（ ）SQL语句可以实现查询“CS”系并且年龄超过20岁的学生姓名。选项： A:select sname from student where sdept=’CS‘exceptselect sname from student where sage<=20; B:select sname from student where sdept=’CS‘intersectselect sname from student where sage>20; C:select sname from student where sdept=’CS‘ and sage>20; D:select sname from student where sdept=’CS‘unionselect sname from student where sage>20
- 6.在学生选课数据库中有学生表student(sno,sname,ssex,sage,sdept)，课程表course(cno,cname)及学生选课表sc(sno,cno,grade)，其中sno是学号，sname是姓名，ssex是性别，sage是年龄，sdept是系别，cno是课程号，cname是课程名，grade是成绩。以下（ ）SQL语句可以实现查询“CS”系并且年龄超过20岁的学生姓名。选项： A:select sname from student where sdept=’CS‘ and sage>20; B:select sname from student where sdept=’CS‘intersectselect sname from student where sage>20; C:select sname from student where sdept=’CS‘exceptselect sname from student where sage<=20; D:select sname from student where sdept=’CS‘unionselect sname from student where sage>20
- 7.针对表Student（sno, sname, ssex, sage, sdept），其中sno为学号，sname为姓名，ssex为性别，sage为年龄，sdept为系别。查询女生平均年龄超过20岁的系别以及女生平均年龄。 选项： A、select sdept ,avg(sage) from student group by sdept having ssex='女' and avg(sage) >20 B、select sdept ,avg(sage) from student where ssex='女' group by sdept having avg(sage) >20 C、select sdept ,avg(sage) from student where ssex='女' group by sdept D、select sdept ,avg(sage) from student group by sdept having avg(sage) >20
- 8.在学生选课数据库中有学生表student(sno,sname,ssex,sage,sdept)，课程表course(cno,cname)及学生选课表sc(sno,cno,grade)，其中sno是学号，sname是姓名，ssex是性别，sage是年龄，sdept是系别，cno是课程号，cname是课程名，grade是成绩。以下（ ）SQL语句可以实现查询“CS”系并且年龄超过20岁的学生姓名。 选项： A、select sname from student where sdept=’CS‘ and sage>20 B、select sname from student where sdept=’CS‘intersectselect sname from student where sage>20 C、select sname from student where sdept=’CS‘exceptselect sname from student where sage<=20 D、select sname from student where sdept=’CS‘unionselect sname from student where sage>20
- 9.查询表student（sno,sname,sage,ssex,sphone,cno）中男生的相关信息的SQL语句为（ ）选项： A:select * from student where ssex='男' ; B:select sno,sname,sage,ssex,sphone,cno from student order by ssex='男' ; C:select sno,sname,sage,ssex,sphone,cno from student having ssex='男' ; D: SELECT* FROM student Group By ssex='男‘
- 10.单选题]针对表Student(sno, sname, ssex, sage, sdept),其中sno为学号,sname为姓名,ssex为性别,sage为年龄,sdept为系别。查询女生平均年龄超过20岁的系别以及女生平均年龄。 选项： A:select sdept ,avg(sage) from student group by sdept having avg(sage) >20 B:select sdept ,avg(sage) from student where ssex='女' group by sdept C:select sdept ,avg(sage) from student where ssex='女' group by sdept having avg(sage) >20 D:select sdept ,avg(sage) from student where ssex='女' and avg(sage) >20 group by sdept
- 11.单选题 （2分）针对表Student(sno, sname, ssex, sage, sdept)，其中sno为学号，sname为姓名，ssex为性别，sage为年龄，sdept为系别。查询女生平均年龄超过20岁的系别以及女生平均年龄( )。 选项： A:select sdept ,avg(sage) from student group by sdept having ssex='女' and avg(sage) >20 B:select sdept ,avg(sage) from student where ssex='女' group by sdept having avg(sage) >20 C:select sdept ,avg(sage) from student where ssex='女' group by sdept D:select sdept ,avg(sage) from student group by sdept having avg(sage) >20
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12.针对表 Student(sno, sname, ssex, sage, sdept)，其中 sno 为学号，sname 为姓名，ssex 为性别，sage 为年龄，sdept 为系别。查询女生平均年龄超过 20 岁的系别以及女生平均年龄( )。 选项： A:
select sdept ,avg(sage) from student group by sdept having ssex='女' and avg(sage) >20
B:select sdept ,avg(sage) from student where ssex='女' group by sdept having avg(sag e) >20
C:select sdept ,avg(sage) from student where ssex='女' group by sdept
D:select sdept ,avg(sage) from student group by sdept having avg(sage) >20
- 13.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; 选项： 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
- 14.针对数据库S_T，有学生表student(sno,sname,ssex,sage,sdept)，课程表course(cno,cname,cpno,ccredit)，选课表sc(sno,cno,grade)。以下创建视图的命令不正确的是（ ）。（3.0分） 选项： A:create view view1 as select sno,avg(grade) from sc group by sno; B:create view view3 as select sno,sage+20 from student where ssex='女'; C:create view view4 as select student.sno,sname,sc.sno,cno,grade from sc,student where sc.sno=student.sno and cno='1'; D:create view view2 as select sno,sname,sdept from student where sdept='CS';
- 15.针对学生表student（sno,sname,ssex,sage,sdept），其中sno为学号，sname为姓名，ssex为性别，sage为年龄，sdept为系别。查询学生的姓名sname，系别sdept和年龄sage，显示时按系别升序排列，系别相同的再按年龄降序排列。（ ）选项： A:select sname, sdept, sage from student order by sdept desc , sage; B:select * from student order by sdept , sage; C:select sname, sdept, sage from student order by sdept , sage desc; D:select * from student order by sdept desc, sage
- 16.针对学生表student(sno,sname,ssex,sage,sdept),其中sno为学号,sname为姓名,ssex为性别,sage为年龄,sdept为系别。查询学生的姓名sname,系别sdept和年龄sage,显示时按系别升序排列,系别相同的再按年龄降序排列。( )A．select sname, sdept, sage from student order by sdept , sage descB．select * from student order by sdept , sageC．select * from student order by sdept desc, sageD．select sname, sdept, sage from student order by sdept desc , sage
- 17.针对学生表student（sno,sname,ssex,sage,sdept），其中sno为学号，sname为姓名，ssex为性别，sage为年龄，sdept为系别。查询学生的姓名sname，系别sdept和年龄sage，显示时按系别升序排列，系别相同的再按年龄降序排列。（ ）选项： A:select * from student order by sdept , sage; B:select sname, sdept, sage from student order by sdept , sage desc; C:select sname, sdept, sage from student order by sdept desc , sage; D:select * from student order by sdept desc, sage
- 18.在关系stu（sno，sname，sage，ssex，sdept），查询所有女生的学号和姓名，SQL语句为（）选项： A:select 学号，姓名 from stu B:select 姓名，学号 from stu where ssex='女' C:select sno,sname where ssex='女' D:select sno,sname from stu where ssex='女'
- 19.以下（ ）操作实现了student表与sc之间的自然连接。选项： A:select student.* , sc.* from student , sc where student.sno=sc.sno; B:select student.* , cno, grade from student , sc where student.sno=sc.sno; C:select student.sno, sname,ssex,sage,sdept , cno, grade from student , sc where student.sno=sc.sno; D:select student.* , cno, grade from student join sc on student.sno=sc.sno
