1、有兩個關係S(A,B,C,D)和T(C,D,E,F),寫出與下列查詢等價的SQL表達式:
(1)
//選擇
select *
from S
where A=10;
(2)
//投影
select A,B
from S;
(3)
//自然連接
select S.*,T.*
from S,T;
(4)
//等值連接
select S.*,T.*
from S,T
where S.C=T.C;
(5)
//非等值連接
select S.*,T.*
from S,T
where A<E;
(6)
//S在cd上的投影與T的笛卡爾積
//方法一:
select C,D
from S
union
select *
from T;
//方法二:
select S.C,S.D,T.*
from S,T
2、用SQL語句建立以下的4個表;針對建立的4個表用SQL完成第二章習題6中的查詢。
S表:
create table S(sno char(10),
sname char(10),
status smallint,
city char(10)
);
insert into S
values('s1','精益',20,'天津');
insert into S
values('s2','盛錫',10,'北京');
insert into S
values('s3','東方紅',30,'北京');
insert into S
values('s4','豐泰盛',20,'天津');
insert into S
values('s5','爲民',30,'上海');
P表:
create table P(pno char(10),
pname char(10),
color char(10),
weight smallint
);
insert into P
values('P1','螺母','紅',12);
insert into P
values('P2','螺栓','綠',17);
insert into P
values('P3','螺絲刀','藍',14);
insert into P
values('P4','螺絲刀','紅',14);
insert into P
values('P5','凸輪','藍',40);
insert into P
values('P6','齒輪','紅',30);
J表:
create table J(jno char(10),
jname char(10),
city char(10)
);
insert into J
values('J1','三建','北京');
insert into J
values('J2','一汽','長春');
insert into J
values('J3','彈簧廠','天津');
insert into J
values('J4','造船廠','天津');
insert into J
values('J5','機車廠','唐山');
insert into J
values('J6','無線電廠','常州');
insert into J
values('J7','半導體廠','南京');
SPJ:
CREATE TABLE SPJ(SNO CHAR(4),
PNO CHAR(4),
JNO CHAR(4),
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);
最終結果:
(1)求供應工程J1零件的供應商號碼SNO;
select sno
from spj
where jno='j1'
(2)求供應工程J1零件P1的供應商號碼SNO;
select sno
from spj
where jno='j1' and pno='p1';
(3)求供應工程J1零件爲紅色的供應商號碼SNO;
select sno
from spj,p
where jno='j1' and p.pno=spj.pno and color='紅';
(4)求沒有使用天津供應商生產的紅色零件的工程號JNO;
select jno
from j
where not exists(
select *
from spj,s,p
where s.city='天津' and p.color='紅'
and spj.jno=j.jno and spj.pno=p.pno);
(5)求至少用了供應商S1所供應的全部零件的工程號JNO。
select distinct jno
from spj x
where not exists(
select *
from spj y
where y.sno='s1'
and not exists(
select *
from spj z
where z.pno=y.pno
and z.jno= x.jno)
);
3、針對習題4中的4個表使用SQL完成以下各項操作:
(1)找出所有供應商的姓名和所在城市;
select jname,city
from j;
(2)找出所有零件的名稱、顏色、重量;
select pname,color,weight
from p;
(3)找出使用供應商S1所供應零件的工程號碼;
select jno
from spj
where sno='s1';
(4)找出工程項目J2使用的各種零件的名稱及其數量;
select pname,qty
from spj,p
where jno='j2' and spj.pno=p.pno;
(5)找出上海廠商供應的所有零件號碼;
select distinct pno
from spj,s
where city='上海' and spj.sno=s.sno;
(6)找出使用上海產的零件的工程項目;
select distinct jname
from spj,s,j
where s.sno=spj.sno
and s.city='上海'
and j.jno=spj.jno;
(7)找出沒有使用天津產的零件的工程號碼;
select jno
from j
where not exists(
select *
from spj,s
where spj.jno=j.jno
and spj.sno=s.sno
and s.city='天津');
(8)把全部紅色零件的顏色改成藍色;
update p
set color='藍'
where color='紅';
(9)由S5供給J4的零件P6改爲由S3供應,請作必要的修改;
update spj
set sno='s3'
where sno='s5'
and jno='j4'
and pno='p6';
(10)從供應商關係中刪除S2的記錄,並從供應情況關係中刪除相應的記錄;
delete
from spj
where sno='s2'
delete
from s
where sno='s2';
(11)請將(S2,J6,P4,200)插入供應情況關係;
insert into spj
values('s2','p4','j6',200);
4、請爲三建工程項目建立一個供應情況的視圖,包括供應商代碼(SNO)、零件代碼(PNO)、供應商數量(QTY)。針對該視圖完成下列查詢:
create view view_s
as
select sno,pno,qty
from spj
where jno=(select jno
from j
where jname='三建');
(1)找出三建工程項目使用的各種零件代碼及其數量;
select pno,qty
from view_s
(2)找出供應商S1的供應情況;
select *
from view_s
where sno='s1'