数据库实验《实验6》

1、实验名称实验6实验地点8-318实验类型设计实验学时1实验日期2018-6-14 撰写注意：版面格式已设置好（不得更改），填入内容即可。一、 实验目的1. 掌握系统数据类型的特点和功能。2. 掌握创建、修改表结构的方法。3. 掌握插入、更新和删除表数据的方法。二、 实验内容1.查询所有班级的期末成绩平均分，并按照平均分降序排序。2.查询教师基本信息和教授课程信息，其中包括未分配课程的教师信息。3.查询160501班级中选修了“韩晋升”老师讲授的课程的学生学号、姓名、课程号和期末成绩。4.查询每门课程的课程号、课程名和选修该课程的学生人数，并按所选人数升序排序。5.查询两门及以上课程的期末成绩超

2、过80分的学生姓名及平均成绩。6.查询入学考试成绩最高的学生学号、姓名和入学成绩。7.查询同时教授c05127号和c05109号课程的教师信息。8.查询至少选修了姓名为“韩吟秋”的学生所选修课程中一门课程的学生学号和姓名。9.查询所有教授c05127号课程的教师信息。10.查询没有被任何学生选修的课程编号、课程名称和学分。11.查询“C语言”课程期末成绩比“电子技术”课程期末成绩高的所有学生的学号和姓名。12查询所有班级期末平均成绩的最高分，并将其赋值给变量，通过PRINT语句输出。13.使用游标输出学生姓名、选修课程名称和期末考试成绩。14.使用游标统计每个学院教师所开设课程的选修率。15.

3、使用游标计算学生期末成绩的等级，并更新level列。三、 实验环境1. 操作系统：Windows XP2. 开发软件：SQL Server 2008四、 提交文档提交本实验报告（电子版），文件名命名：学号 姓名实验X：XXXXXXX.doc教师将批阅后（有分数）的全体学生实验报告刻入一张光盘存档，保证光盘可读。五、 附：源代码1.select studentno,AVG(final) as 平均分 from score group by studentno order by AVG(final)2.select * from teacherselect * from studentselect

4、 * from courseinsert into course(courseno,cname,ctype,period,credit)values('c05103','高等数学','必修',64,4.0) select * from scoreinsert into score(studentno,courseno,usually,final)values('16122210009','c05103',87.00,82.00)insert into teacher(teacherno,tname,major,pr

5、of,department)values('t05001','韩晋升','软件工程','教授','计算机学院')select * from classinsert into class(classno,classname,department,monitor)values('160501','计算机','计算机学院','张三')select * from teach_classinsert into teach_class(teacherno,clas

6、sno,courseno)values('t05001','160501','c05103')select * from teacherselect * from courseselect * from scoreselect classno,AVG(final) as 平均分 from student join scoreon student.studentno=score.studentno group by classnoorder by AVG(final) descselect teacher.*,cname from teacher

7、left join teach_classon teacher.teacherno=teach_class.teachernoleft join course on teach_class.classno=course.courseno3.select student.studentno,sname,cname,final from studentjoin score on student.studentno=score.studentnojoin course on course.courseno=score.coursenowhere score.courseno in(select co

8、urseno from teach_class join teacher on teach_class.teacherno=teacher.teachernowhere tname='韩晋升')and classno='090501'4.select course.courseno,cname,COUNT(studentno) fromscore join course on score.courseno=course.coursenogroup by course.courseno,cnameorder by COUNT(studentno) desc5.se

9、lect sname,AVG(final) from score join student on score.studentno=student.studentnowhere final>=80group by student.studentno,snamehaving COUNT(courseno)>=26.select studentno,sname,point from student wherestudentno=(select top 1 studentno from student order by point)7.select teacher.teacherno,tn

10、ame,major ,prof,department from teacher join teach_class on teacher.teacherno=teach_class.teachernowhere courseno='c05127'8.select distinct student.studentno,sname from scorejoin student on score.studentno=student.studentnowhere courseno in(select courseno from score join student onscore.stu

11、dentno=student.studentnowhere sname='韩吟秋')and sname!='韩吟秋'9.select * from teacher where teacherno in(select teacherno from teach_class wherecourseno='c05127')10.select courseno,cname,credit from course where not exists(select * from score where score.courseno=course.courseno)

12、11.select student.studentno,sname from score sc1 join studenton (sc1.studentno=student.studentno) join course c1 on(sc1.courseno=c1.courseno)where ame='c语言' and exists(select * from score sc2 join course c2 on(sc2.courseno=c2.courseno)where ame='电子技术' and sc1.studentno=sc2.studentnoa

13、nd sc1.final>sc2.final)12.declare max numeric(6,2)select max=MAX(平均分) from (select classno as 班级号,AVG(final) as 平均分 from scorejoin student on (score.studentno=student.studentno)join course on (course.courseno=score.courseno)where final is not nullgroup by classno) tprint '所有班级期末平均成绩的最高分:'

14、+cast(max as varchar(6)13.declare sname nchar(8),cname nchar(10),final numeric(6,2)declare sc_cursor cursor forselect sname,cname,finalfrom score join student on(score.studentno=student.studentno)join course on(score.courseno=course.courseno)open sc_cursorfetch next from sc_cursor into sname,cname,f

15、inalprint '学生姓名 课程名称 期末成绩'print '-'while FETCH_STATUS=0beginprint sname+cname+cast(final as nchar(6)fetch next from sc_cursor into sname,cname,finalendclose sc_cursordeallocate sc_cursor14.declare department nchar(30),num int,avg floatdeclare cur cursor staticfor select department,co

16、unt(*) as '选修课数' from classwhere class.classno in(select student.classno from student group by classno)group by departmentopen curfetch curinto department,numset avg=num/(select COUNT(*) from class where department=department)print departmentprint avgwhile FETCH_STATUS=0beginfetch next from

17、curinto department,numset avg=num/(select COUNT(*) from class where department=department)print departmentprint avgendclose curdeallocate cur15.declare sname nchar(30),cname nchar(30),final floatdeclare stu cursor staticforselect sname,final,cnamefrom student,score,coursewhere student.studentno=scor

18、e.studentno and course.courseno=score.coursenoopen stufetch stuinto sname,final,cnameif final>=90print N'优'+sname+cnameelse if final>=80 and final<90print N'良'+sname+cnameelse if final>=70 and final<80print N'中'+sname+cnameelse if final>=60 and final<70print N'及'+sname+cnameelse if final<60print N'差'+sname+cnamewhile FETCH_STATUS=0beginfetch next from stuinto sname,final,cnameif final>=90print N'