实验复杂查询
一、实验目的
掌握两个表以上的连接查询的应用,包括嵌套查询。
二、实验内容
(1)查询比“林红”年纪大的男学生信息。
select*from Student
where Sex='男'and
YEAR(Birth)-(select YEAR(Birth)
from Student where Sname='林红')<0
(2)检索所有学生的选课信息,包括学号、姓名、课号、课程名、成绩。select SC.Sno,Sname,Sex,Classno,Cname,Grade
from Student s,SC,Course c
where s.Sno=SC.Sno and https://www.wendangku.net/doc/2f17243663.html,o=https://www.wendangku.net/doc/2f17243663.html,o
(3)查询已选课学生的学号、姓名、课程名、成绩。
select SC.Sno,Sname,Cname,Grade
from Student s,course c,SC
where s.sno=SC.sno and https://www.wendangku.net/doc/2f17243663.html,o=https://www.wendangku.net/doc/2f17243663.html,o
(4)查询选修了“C语言程序设计”的学生的学号和姓名。
select sc.Sno,Sname
from Student s,course c,sc
where https://www.wendangku.net/doc/2f17243663.html,ame='C语言程序设计'and s.Sno=sc.Sno and https://www.wendangku.net/doc/2f17243663.html,o=https://www.wendangku.net/doc/2f17243663.html,o
(5)查询与“张虹”在同一个班级的学生学号、姓名、家庭住址。
a.用子查询
select Sno,Sname,Home_addr
from Student
where Classno='051' and Sname!='张虹'
b.用连接查询
select Sno,Sname,Home_addr
from Student
where Classno=(select Classno from Student where Sname='张虹') and Sname!='张虹'
(6)查询其他班级中比“051”班所有学生年龄大的学生的学号、姓名。
select Sno,Sname
from Student
where Classno<>'051'
and Birth where Classno='051') (7)(选作)查询选修了全部课程的学生姓名。 本题使用除运算的方法。 由题意可得另一种语言,没有一个选了课的学生没有选course表里的课程。那么,我们需要两个NOT EXISTS表示双重否定 select Sname from Student where not exists( select*from Course where not exists( select*from SC where Sno=Student.sno and cno=https://www.wendangku.net/doc/2f17243663.html,o)) (8)(选作)查询至少选修了学生“20110002”选修的全部课程的学生的学号,姓名。 select Sno,Sname from Student where Sno in( select distinct Sno from SC as SC1 where not exists( select*from SC as SC2 where SC2.Sno='20110002' and not exists( select*from SC as SC3 where SC3.Sno=SC1.Sno and https://www.wendangku.net/doc/2f17243663.html,o=https://www.wendangku.net/doc/2f17243663.html,o)) ) (9)检索学生的学号、姓名、学习课程名及课程成绩。select s.Sno,Sname,Cname,Grade from Student s,Course c,SC where s.Sno=sc.Sno and https://www.wendangku.net/doc/2f17243663.html,o=https://www.wendangku.net/doc/2f17243663.html,o (10)检索选修了“高数”课且成绩至少高于选修课程号为“002”课程的学生的学号、课程号、成绩,并按成绩从高到低次序排列。 由题意得,选修了高数课的学生的成绩要高于选修002课号课程的学生的成绩 select distinct Sno,Cno,Grade from SC where Cno in( select Cno from Course where Cname='高数') and Grade>(select MAX(Grade) from SC where cno='002') order by Grade desc (11)检索选修3门以上课程的学生的学号、总成绩(不统计不及格的课程),并要求按总成绩的降序排列出来。 select Sno,sum(grade)as总成绩 from SC where Sno in( select Sno from SC group by Sno having count(*)>3) and Grade>=60 group by Sno order by总成绩desc (12)检索多于3名学生选修的并以3结尾的课程号的平均成绩。 select avg(Grade)as平均成绩 from SC where Cno like'%3' group by Cno having count(Cno)>3 (13)检索最高分与最低分之差大于5分的学生的学号、姓名、最高分、最底分。select distinct SC.Sno学号,Sname姓名, max(grade)as最高分,min(grade)as最低分 from Student,SC where SC.Sno=Student.Sno group by SC.Sno,Sname having max(grade)-min(grade)>5 (14)外连接 对表Course和表SC做一个外连接查询,显示每门课程的课号、课名、选修该门课的学号、成绩,没有同学选修的课程(如Visual_Basic)也要在查询结果中。 select https://www.wendangku.net/doc/2f17243663.html,o课号,Cname课名,Sno学号,Grade成绩 from Course c left outer join SC on (https://www.wendangku.net/doc/2f17243663.html,o=https://www.wendangku.net/doc/2f17243663.html,o) (15)创建一个表Student_other,结构同Student,输入若干记录,部分记录和Student表中的相同。 创建过程: create table Student_other( Sno char(8)primary key, Sname varchar(8)not null, Sex char(2)not null, Birth smalldatetime not null, Classno char(3)not null, Entrance_date smalldatetime not null, Home_addr varchar(40), Sdept char(2)not null, Postcode char(6) ) 随意输入几条Student表中没有的信息,完成创建 a.查询同时出现在Student表和Student_other表中的记录select*from student_other so,Student s where so.Sno=s.Sno b. 查询Student表和Student_other表中的全部记录 select*from student union select*from student_other (16)(选作)创建一个数据库Student_info_other,参数自定。创建过程: 新建数据库 名称确定,参数自定义,然后“确定”即可 a.当前数据库为Student_info,将Student_info数据库中的Student_other复制到Student_info_other中。 select*into Student_info_other.dbo.Student_other from Student_info.dbo.Student_other b.查询同时出现在Student表和Student_info_other数据库Student_other表中的记录。select*from Student_info_other.dbo.student_other so, Student_info.dbo.Student s where so.sno=s.sno