数据库第三章作业

3．有两个关系S(A,B,C,D)和 T(C,D,E,F)，写出与下列查询等价的SQL表达式:

(1)${\sigma }_{A=10}(S)$
等价于从S表中选出A=10的元组

Select * From S
Where A = 10

(2) ${\Pi }_{A,B}(S)$
投影， 从S中选出A、B列

Select A, B From S

(3)$S\bowtie T$
S与T的自然连接，S与T的共同列是C与D，所以判断C，D是否相等即可

Select A, B, S.C, S.D, E, F
From S, T
Where S.C = T.C And S.D = T.D

(4)$S\underset{S.C=T.C}{\bowtie }T$
S与T的等值连接

Select *
From S, T
Where S.C = T.C

(5)$S\underset{A=E}{\bowtie }T$
S与T的非等值连接

Select *
From S, T
Where S.A=T.E

(6)${\Pi }_{C,D}(S)\times T$
从S中选出C、D列与T做笛卡尔积。

Select S.C,S.D,T.C,T.D,T.E,T.F
From S,T

4.用SQL语句建立第2章习题6中的4个表;针对建立的4个表用SQL完成第2章习题6中的查询。

建表代码如下：

 CREATE TABLE S(SNO CHAR(5), SNAME CHAR(5), STATUS INT, CITY CHAR(5));
 INSERT INTO S(SNO,SNAME,STATUS,CITY) VALUES ('S1','精益',20,'天津'); 
 INSERT INTO S(SNO,SNAME,STATUS,CITY) VALUES('S2','盛锡',10,'北京'); 
 INSERT INTO S(SNO,SNAME,STATUS,CITY) VALUES('S3','东方红',30,'北京'); 
 INSERT INTO S(SNO,SNAME,STATUS,CITY) VALUES('S4','丰泰盛',20,'天津'); 
 INSERT INTO S(SNO,SNAME,STATUS,CITY) VALUES('S5','为民','30','上海');
 CREATE TABLE P( PNO CHAR(5),PNAME CHAR(5), COLOR CHAR(5), WEIGHT INT);
 INSERT INTO P(PNO,PNAME,COLOR,WEIGHT) VALUES('P1','螺母','红',12);
 INSERT INTO P(PNO,PNAME,COLOR,WEIGHT) VALUES('P2','螺栓','绿',17);
 INSERT INTO P(PNO,PNAME,COLOR,WEIGHT) VALUES('P3','螺丝刀','蓝',14);
 INSERT INTO P(PNO,PNAME,COLOR,WEIGHT) VALUES('P4','螺丝刀','红',14); 
 INSERT INTO P(PNO,PNAME,COLOR,WEIGHT) VALUES('P5','凸轮','蓝',40);
 INSERT INTO P(PNO,PNAME,COLOR,WEIGHT) VALUES('P6','齿轮','红',30);
CREATE TABLE J( JNO CHAR(5),JNAME CHAR(10),CITY CHAR(5)); 
INSERT INTO J(JNO,JNAME,CITY) VALUES('J1','三建','北京'); 
INSERT INTO J(JNO,JNAME,CITY) VALUES('J2','一汽','长春'); 
INSERT INTO J(JNO,JNAME,CITY) VALUES('J3','弹簧厂','天津');
INSERT INTO J(JNO,JNAME,CITY) VALUES('J4','造船厂','天津');
INSERT INTO J(JNO,JNAME,CITY) VALUES('J5','机车厂','唐山'); 
INSERT INTO J(JNO,JNAME,CITY) VALUES('J6','无线电厂','常州'); 
INSERT INTO J(JNO,JNAME,CITY) VALUES('J7','半导体厂','南京');
CREATE TABLE SPJ( SNO CHAR(5), PNO CHAR(5), JNO CHAR(5),QTY SMALLINT); 
INSERT INTO SPJ(SNO,PNO,JNO,QTY) VALUES('S1','P1','J1',200); 
INSERT INTO SPJ(SNO,PNO,JNO,QTY) VALUES('S1','P1','J3',100);
INSERT INTO SPJ(SNO,PNO,JNO,QTY) VALUES('S1','P1','J4',700);  
INSERT INTO SPJ(SNO,PNO,JNO,QTY) VALUES('S1','P2','J2',100);
INSERT INTO SPJ(SNO,PNO,JNO,QTY) VALUES('S2','P3','J1',400); 
INSERT INTO SPJ(SNO,PNO,JNO,QTY) VALUES('S2','P3','J2',200);
INSERT INTO SPJ(SNO,PNO,JNO,QTY) VALUES('S2','P3','J4',500);
INSERT INTO SPJ(SNO,PNO,JNO,QTY) VALUES('S2','P3','J5',400);
INSERT INTO SPJ(SNO,PNO,JNO,QTY) VALUES('S2','P5','J1',400);
INSERT INTO SPJ(SNO,PNO,JNO,QTY) VALUES('S2','P5','J2',100);
INSERT INTO SPJ(SNO,PNO,JNO,QTY) VALUES('S3','P1','J1',200); 
INSERT INTO SPJ(SNO,PNO,JNO,QTY) VALUES('S3','P3','J1',200); 
INSERT INTO SPJ(SNO,PNO,JNO,QTY) VALUES('S4','P5','J1',100); 
INSERT INTO SPJ(SNO,PNO,JNO,QTY) VALUES('S4','P6','J3',300); 
INSERT INTO SPJ(SNO,PNO,JNO,QTY) VALUES('S4','P6','J4',200); 
INSERT INTO SPJ(SNO,PNO,JNO,QTY) VALUES('S5','P2','J4',100); 
INSERT INTO SPJ(SNO,PNO,JNO,QTY) VALUES('S5','P3','J1',200); 
INSERT INTO SPJ(SNO,PNO,JNO,QTY) VALUES('S5','P6','J2',200); 
INSERT INTO SPJ(SNO,PNO,JNO,QTY) VALUES('S5','P6','J4',500); 

(1)求供应工程J1零件的供应商号码SNO;

Select SNO From SPJ Where Jno = 'J1'

结果如下：

(2）求供应工程J零件P1的供应商号码SNO:

Select SNO From SPJ Where Pno = 'P1'

结果如下：

(3)求供应工程J1零件为红色的供应商号码SNO;

SELECT SNO
FROM SPJ,P
WHERE P.PNO=SPJ.PNO AND JNO='J1' AND COLOR='红';

结果如下：

(4）求没有使用天津供应商生产的红色零件的工程号JNO;

先求出天津商生产的红色零件的Jno，然后在SPJ表中查询即可

Select Jno From Spj Where Jno Not in(
Select Jno From SPJ,P,S
WHERE S.CITY='天津' AND COLOR='红' AND S.SNO=SPJ.SNO AND P.PNO=SPJ.PNO)
)

结果如下：

(5)求至少用了供应商S1所供应的全部零件的工程号JNO。

这意味着工程y不存在一个零件x，S1拥有零件x而y没有拥有

Select Distinct Jno From Spj SpjX Where Not Exists(
  Select Pno From SPj SpjY  Where Sno='S1' And Not Exists(
  Select Pno From SPj SpjZ Where SpjX.Jno=SpjZ.Jno And SpjY.Pno = SpjZ.Pno
)
)

查询结果如下：

5．针对习题4中的4个表试用SQL完成以下各项操作:（1)找出所有供应商的姓名和所在城市;

(1)找出所有供应商的姓名和所在城市;

Select Sname,City
From S;

(2)找出所有零件的名称、颜色、重量;

select Pno,Color,Weight from P;

(3)找出使用供应商S1所供应零件的工程号码;

select jno 
from SPJ
where sno='S1';

(4)找出工程项目J2使用的各种零件的名称及其数量;

select pname,qty
from SPJ,P
where jno='J2' and P.pno=SPJ.pno;

(5)找出上海厂商供应的所有零件号码;

select pno 
from SPJ,S
where city='上海'and S.sno=SPJ.sno;

(6)找出使用上海产的零件的工程名称;

select jname 
from SPJ,S,J
where S.city='上海'and S.sno=SPJ.sno and J.jno=SPJ.jno;

(7)找出没有使用天津产的零件的工程号码;

select jno
from SPJ
where jno not in(
				select jno
				from SPJ,S
				where S.sno=SPJ.sno and S.city='天津');

(8)把全部红色零件的颜色改成蓝色;

update P set color='红'
where color='蓝';
Select Color From P

(9)由S5供给4的零件P6改为由S3供应，请作必要的修改;Viorel2阿PW(10）从供应商关系中删除S2的记录，并从供应情况关系中删除相应的记录;

update SPJ set sno='S3'
where sno='S5' and jno='J4' and pno='P6';
Select * From Spj 

(10)从供应商关系中删除S2的记录，并从供应情况关系中删除相应的记录;

delete from S where sno='S2';
delete from SPJ where sno='S2';

(11)请将(S2,J6,P4,200)插入供应情况关系。

insert into SPJ values('S2','P4','J6',200);

9.请为三建工程项目建立一个供应情况的视图，包括供应商代码(SNO)、零件代码（PNO)、供应数量（QTY）。针对该视图完成下列查询:

视图创建如下：

create view v_SPJ as
select sno,pno,qty
from SPJ
where jno=(select jno
			from J
			where jname='三建');

(1）找出三建工程项目使用的各种零件代码及其数量:

select pno,qty from v_SPJ;

(2）找出供应商S1的供应情况。

select * from v_SPJ where sno='S1';

作业好多， 我人晕了