练习-----查询

 1 create table student   #学生表
 2 (
 3   Sno varchar(20) primary key,  #学号，主键
 4   Sname varchar(20) not null,    #学生姓名
 5   Ssex varchar(20) not null,     #学生性别
 6    Sbirthday datetime,       #学生出生日期
 7    Class varchar(20)     #学生所在班级
 8 );
 9 
10 create table Teacher     #教师表
11 (
12    Tno varchar(20) primary key ,    #教职工编号,主键
13     Tnam varchar(20) not null,   #教职工姓名
14     Tsex varchar(20) not null,  #教职工性别
15     Tbirthday datetime,    # 教职工出生年月
16      Prof varchar (20),      #职称
17      Depart varchar(20)not null    #教职工所在部门
18 );
19 
20 create table Course   #课程表
21 (
22    Con varchar(20) primary key,  #课程号，主键
23     Cname varchar(20) not null,   #课程名称
24     Tno varchar(20) not null,   #教职工
25     foreign key(Tno)references Teacher(Tno)    #教工编号，外键
26 ); 
27 #           从表的列名                      主表的列名
28 
29 
30 create table Score   #成绩表
31 (
32    Sno varchar(20) not null,
33    foreign key(Sno) references Student(Sno) , #学号，外键
34    Con varchar(20) not null,  #组合主键  
35    Degree Decimal(4,1) ,      #Degree  成绩   
36    foreign key(Con) references Course(Con) ,   #课程号，外键
37    primary key (Sno,Con)       #成绩
38 );
39 #values  值的意思
40 
41 
42 
43 
44 #Student表
45 insert into Student values(‘108‘,‘曾华‘,‘男‘,‘1977-09-01‘,‘95033‘);  
46 insert into Student values(‘105‘,‘匡明‘,‘男‘,‘1975-10-02‘,‘95031‘);
47 insert into Student values(‘107‘,‘王丽‘,‘女‘,‘1976-01-23‘,‘95033‘);
48 insert into Student values(‘101‘,‘李军‘,‘男‘,‘1976-02-20‘,‘95033‘);
49 insert into Student values(‘109‘,‘王芳‘,‘女‘,‘1975-02-10‘,‘95031‘);
50 insert into Student values(‘103‘,‘陆君‘,‘男‘,‘1974-06-03‘,‘95031‘);
51 
52 
53 
54 
55  #Teacher表
56 insert into Teacher values(‘804‘,‘李诚‘,‘男‘,‘1958-12-02‘,‘副教授‘,‘计算机系‘);
57 insert into Teacher values(‘856‘,‘张旭‘,‘男‘,‘1969-03-12‘,‘讲师‘,‘电子工程系‘);
58 insert into Teacher values(‘825‘,‘王萍‘,‘女‘,‘1972-05-05‘,‘助教‘,‘计算机系‘);
59 insert into Teacher values(‘831‘,‘刘冰‘,‘女‘,‘1977-08-14‘,‘助教‘,‘电子工程系‘);
60 
61 
62 
63 #Course    课程表
64 insert into Course values(‘3-105‘,‘计算机导论‘,‘825‘);
65 insert into Course values(‘3-245‘,‘操作系统‘,‘804‘);
66 insert into Course values(‘6-166‘,‘数字电路‘,‘856‘);
67 insert into Course values(‘9-888‘,‘高等数学‘,‘831‘);
68  
69 
70 
71 #Score    成绩表
72 insert into Score values(‘103‘,‘3-245‘,‘86‘);
73 insert into Score values(‘105‘,‘3-245‘,‘75‘);
74 insert into Score values(‘109‘,‘3-245‘,‘68‘);
75 insert into Score values(‘103‘,‘3-105‘,‘92‘);
76 insert into Score values(‘105‘,‘3-105‘,‘88‘);
77 insert into Score values(‘109‘,‘3-105‘,‘76‘);
78 insert into Score values(‘101‘,‘3-105‘,‘64‘);
79 insert into Score values(‘107‘,‘3-105‘,‘91‘);
80 insert into Score values(‘108‘,‘3-105‘,‘78‘);
81 insert into Score values(‘101‘,‘6-166‘,‘85‘);
82 insert into Score values(‘107‘,‘6-166‘,‘79‘);
83 insert into Score values(‘108‘,‘6-166‘,‘81‘);

 select Sname,Ssex,Class from Student

 select distinct Depart from Teacher 

select * from Student

select * from Score where Degree between 60 and 80

select * from Score where Degree in (85,86,88)

 select * from Student where Class=‘95031‘ and Ssex=‘女‘ 

select * from Student order by Class desc 

 select * from Score order by Cno asc , Degree desc