数据库第三章练习题目

问题涉及到的题目见《数据库系统概论》不在赘述
3.
（1） $\sigma_{A=10}$(S)

select A
from S
where A=10

(2)
$\pi_{A,B}$(S)

select A ,B
from S

(3)
S $\Join$T

select A,B,S.C,S.D,E,F
from S,T
where S.C=T.C and S.D =T.D
--自然连接是去掉重复的列属性，在连接选择所有的相同的属性

(4)

S $\underset{S.C=T.C}\Join$T

select A,B S.C ,S.D ,T.C,T.D,E,F
from S,T
where S.C= T.C

(5)S $\underset{A<E}\Join$T

select *
from S,T
where A<E

(6) $\pi_{C,D}$x T

select S.C,S.D,E,F
from S,T

4

create table TEST.S(

Sno CHAR(9)PRIMARY KEY,
Sname CHAR(9) ,
Staus  smallint,
city char(9)
)

insert into TEST.S
values('s1','精益',20,'天津')

insert into TEST.S
values('s2','盛锡',10,'北京')

insert into TEST.S
values('s3','东方红',30,'北京')
insert into TEST.S
values('s4','丰盛泰',20,'天津')
insert into TEST.S
values('s5','为民',30,'上海')

--s表

create table TEST.P(

Pno CHAR(9)PRIMARY KEY,
Pname CHAR(9) ,
Color  char(9),
Weight smallint
)
insert into TEST.P
values('p1','螺母','红',12)
insert into TEST.P
values('p2','螺栓','绿',17)
insert into TEST.P
values('p3','螺丝刀','蓝',14)
insert into TEST.P
values('p4','螺丝刀','红','14')

insert into TEST.P
values('p5','凸轮','蓝',40)
insert into  TEST.P
values('p6','齿轮','红',30)
--p表



create table TEST.J(
Jno CHAR(9)PRIMARY KEY,
Jname CHAR(9) ,
city CHAR(9),

)
insert into TEST.J
values('j1','三建','北京')
insert into TEST.J
values('j2','一汽','长春')
insert into TEST.J
values('j3','弹簧厂','天津')
insert into TEST.J
values('j4','造船厂','天津')
insert into TEST.J
values('j5','机车厂','唐山')
insert  into TEST.J
values('j6','无线电','常州')
insert into TEST.J
values('j7','半导体','南京')
--J表
create table TEST.SPJ(
Sno CHAR(9),
Pno CHAR(9),
Jno char (9),
Qty smallint,
PRIMARY KEY (Sno,Pno,Jno),
FOREIGN KEY (Sno) REFERENCES TEST.S(Sno),
FOREIGN KEY (Pno) REFERENCES TEST.P(Pno),
FOREIGN KEY (Jno) REFERENCES TEST.J(Jno),
);

insert into TEST.SPJ
values('s1','p1','j1',200)
insert into TEST.SPJ
values('s1','p1','j3',100)
insert into TEST.SPJ values('s1','p1','j4',700)

insert into TEST.SPJ values('s1','p2','j2',100)
insert into TEST.SPJ values('s2','p3','j1',400)
insert into TEST.SPJ values('s2','p3','j2',200)
insert into TEST.SPJ values('s2','p3','j4',500)
insert into TEST.SPJ values('s2','p3','j5',400)
insert into TEST.SPJ values('s2','p5','j1',400)
insert into TEST.SPJ values('s2','p5','j2',100)
insert into TEST.SPJ values('s3','p1','j1',200)
insert into TEST.SPJ values('s3','p3','j1',200)
insert into TEST.SPJ values('s4','p5','j1',100)
insert into TEST.SPJ values('s4','p6','j3',300)
insert into TEST.SPJ values('s4','p6','j4',200)
insert into TEST.SPJ values('s5','p2','j4',100)
insert into TEST.SPJ values('s5','p3','j1',200)
insert into TEST.SPJ values('s5','p6','j2',200)
insert into TEST.SPJ values('s5','p6','j4',500)
--我真的是谁写的这个书

4.1
选择Sno

select distinct  Sno
from TEST.SPJ
where Jno='j1'

4.2选择Sno

select distinct Sno
from TEST.SPJ
where Jno='j1' and Pno='p1'

4.3选择为j1供应红色零件的 Sno

select Sno
from TEST.SPJ
where Jno='j1' and Pno in(
select Pno 
from TEST.P
where Color='红'
)

4.4

select SPJ.Jno
from TEST.SPJ

except
select  SPJ.Jno
from  TEST.SPJ
where  exists
(
select Sno
from (
select *
from TEST.P join TEST.S on  (city='天津' and Color='红')
)
as s_p
where SPJ.Sno=s_p.Sno and SPJ.Pno =s_p.Pno
)

(5)

select distinct Jno
from TEST.SPJ s1
where not exists
(
select *
from TEST.SPJ s2
where s2.Sno='s1' and not exists(
select *
from  TEST.SPJ s3
where s3.Jno=s1.Jno and s2.Pno=s3.Pno
)
)

5
（1）供货商姓名所在地

select Sname ,city
from TEST.S

（2）

select Color ,Weight,Pname
from TEST.P

（3）

select Jno
from TEST.SPJ
where Sno='s1'

（4）

select Pno,Qty
from TEST.SPJ
where Jno='j2'

（5）

select distinct Pno
from TEST.SPJ
where Sno in(
select Sno
from TEST.S
where city='上海'
)

（6）

select distinct Jno
from TEST.SPJ s1
 where s1.Pno in(
 select distinct Pno
from TEST.SPJ
where Sno in(
select Sno
from TEST.S
where city='上海'
)
 
 )
--第二种方法 使用exists 

Select distinct Jno
from TEST.SPJ s1
where exists(
select Pno
from (
select Pno 
from TEST.SPj s2
where Sno in (
select Sno
from TEST.S
where city='上海'
)
)
as spj_s
where  exists(
select Jno
from TEST.Spj s3
where s3.Jno=s1.Jno and spj_s.Pno=s3.Pno
)
)
--感觉还是不用好

（7）

 select distinct Jno
 from TEST.Spj

 except 
select  distinct Jno
from TEST.Spj
where Pno in (
select Pno 
from TEST.Spj
where Sno in(
select Sno 
from TEST.S
where city='天津'
)

)
---使用exists

select Jno 
from TEST.Spj s1
where not exists(
select Pno
from( 
select Pno 
from TEST.Spj s2
where Sno in(
select Sno 
from TEST.S
where  city='天津'
)
)
as spj_s
where  exists(
select *
from TEST.Spj  s3
where s3.Jno=s1.Jno and S3.Pno=spj_s.Pno
)

)

(8)

update TEST.P
set Color='蓝'
where Color='红'
---看反了

(9)

update TEST.Spj
set Sno='s3'
where Sno='s5' and Pno='p6' and Jno='j2' 

（10）

delete 
from TEST.Spj
where Sno ='s2'

delete 
from TEST.S
where Sno='s2'

(11)

insert into TEST.S
values('s2','盛',10,'北京')
insert into TEST.Spj
values('s2','p4','j6',200)

总结

一些语句还需要看之间写的博客才能想起来怎么用，看了同学的博客才想起来第七个还可以用not in。