SQL学习之连接符，数值运算，函数

create table bookitem
(
bookname varchar(80) not null,
book_price Decimal(5,2) not null,
quantity int not null
)
 
insert into bookitem values('Image Processing',34.95,8)
insert into bookitem values('Signal Processing',51.75,6)
insert into bookitem values('Singal And System',48.5,10)
insert into bookitem values('Digital Signal Processing',45.0,12)
insert into bookitem values('The Logic Circuit',28.65,10)
insert into bookitem values('SQL Techniques',65.50,10)
insert into bookitem values('A Firest Course in Database Systems',52.80,9)
 
 
-------Teacher
create table teacher
(
TNO int not null,
TNAME char(10) not null,
CNO int not null,
SAL int,
DNAME char(10) not null,
TSEX char(2) not null,
AGE int not null
)
 
insert into teacher values(1,'王军',4,800,'数学','男',32)
insert into teacher values(2,'李彤',5,1200,'生物','女',54)
insert into teacher values(3,'王永军',1,900,'计算机','男',40)
insert into teacher values(4,'刘小静',2,1200,'计算机','女',39)
insert into teacher values(5,'高伟',8,2100,'电子工程','男',39)
insert into teacher values(6,'李伟',7,1200,'机械工程','男',29)
insert into teacher values(3,'王永军',1,900,'计算机','男',40)
 
 
---Course
create table course
(
CNO int not null,
CNAME char(30) not null,
CTIME int not null,
SCOUNT int not null,
CTEST smalldatetime not null
)
 
insert into course values(4,'应用数学基础',48,120,2006-7-10)
insert into course values(5,'生物工程概论',32,80,2006-7-8)
insert into course values(1,'计算机软件基础',32,70,2006-7-8)
insert into course values(2,'计算机硬件基础',28,90,2006-7-10)
insert into course values(8,'模拟电路设计',48,120,2006-7-10)
insert into course values(3,'生物化学',32,40,2006-7-2)
insert into course values(9,'数据库设计',16,80,2006-7-1)
insert into course values(6,'设计理论',28,45,2006-6-30)
 
 
create table student
(
SNO char(4) not null,
sname char(10) not null,
dname char(10) not null,
sex char(2),
CNO i