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1、ExerciseFor relation Accounts, the attributes are:acctNo, type, balanceFor relation Customers, the attributes are:firstName, lastName, idNo, accountExerciseFor relation Accounts, the tuples are:(12345, savings, 12000),(23456, checking, 1000),(34567, savings, 25)For relation Customers, the tuples are
2、:(Robbie, Banks, 901-222, 12345),(Lena, Hand, 805-333, 12345),(Lena, Hand, 805-333, 23456)ExerciseFor relation Accounts and the first tuple, the components are:123456 acctNosavings type12000 balanceFor relation Customers and the first tuple, the components are:Robbie firstNameBanks lastName901-222 i
3、dNo12345 accountExerciseFor relation Accounts, a relation schema is:Accounts(acctNo, type, balance)For relation Customers, a relation schema is:Customers(firstName, lastName, idNo, account)ExerciseAn example database schema is:Accounts (acctNo,type,balance)Customers (firstName,lastName,idNo,account)
4、ExerciseA suitable domain for each attribute:acctNo Integertype Stringbalance IntegerfirstName StringlastName StringidNo String (because there is a hyphen we cannot use Integer)account IntegerExerciseAnother equivalent way to present the Account relation:acctNobalancetype3456725savings234561000check
5、ing1234512000savingsAnother equivalent way to present the Customers relation:idNofirstNamelastNameaccount805-333LenaHand23456805-333LenaHand12345901-222RobbieBanks12345Examples of attributes that are created for primarily serving as keys in a relation:Universal Product Code (UPC) used widely in Unit
6、ed States and Canada to track products in stores.Serial Numbers on a wide variety of products to allow the manufacturer to individually track each product.Vehicle Identification Numbers (VIN), a unique serial number used by the automotive industry to identify vehicles.We can order the three tuples i
7、n any of 3! = 6 ways. Also, the columns can be ordered in any of 3! = 6 ways. Thus, the number of presentations is 6*6 = 36.We can order the three tuples in any of 5! = 120 ways. Also, the columns can be ordered in any of 4! = 24 ways. Thus, the number of presentations is 120*24 = 2880We can order t
8、he three tuples in any of m! ways. Also, the columns can be ordered in any of n! ways. Thus, the number of presentations is n!m!CREATE TABLE Product (makerCHAR(30),modelCHAR(10) PRIMARY KEY,type CHAR(15);CREATE TABLE PC (model CHAR(30),speed DECIMAL(4,2),ram INTEGER,hd INTEGER,price DECIMAL(7,2);CRE
9、ATE TABLE Laptop (model CHAR(30),speed DECIMAL(4,2),ram INTEGER,hd INTEGER,screen DECIMAL(3,1),price DECIMAL(7,2);CREATE TABLE Printer (model CHAR(30),color BOOLEAN,type CHAR (10),price DECIMAL(7,2);ALTER TABLE Printer DROP color;ALTER TABLE Laptop ADD od CHAR (10) DEFAULT none;CREATE TABLE Classes
10、(class CHAR(20),type CHAR(5),country CHAR(20),numGuns INTEGER,bore DECIMAL(3,1),displacement INTEGER);CREATE TABLE Ships (name CHAR(30),class CHAR(20),launched INTEGER);CREATE TABLE Battles (name CHAR(30),date DATE);CREATE TABLE Outcomes (ship CHAR(30),battle CHAR(30),result CHAR(10);ALTER TABLE Cla
11、sses DROP bore;ALTER TABLE Ships ADD yard CHAR(30);R1 := speed 3.00 (PC)R2 := model(R1)model100510061013R1 := hd 100 (Laptop)R2 := Product (R1)R3 := maker (R2)makerEABFGR1 := maker=B (Product PC)R2 := maker=B (Product Laptop)R3 := maker=B (Product Printer)R4 := model,price (R1)R5 := model,price (R2)
12、R6: = model,price (R3)R7 := R4 R5 R6modelprice100464910056301006104920071429R1 := color = true AND type = laser (Printer)R2 := model (R1)model30033007R1 := type=laptop (Product)R2 := type=PC(Product)R3 := maker(R1)R4 := maker(R2)R5 := R3 R4makerFGR1 := PC1(PC)R2 := PC2(PC)R3 := R1 (PC1.hd = PC2.hd A
13、ND PC1.model PC2.model) R2R4 := hd(R3)hd25080160R1 := PC1(PC)R2 := PC2(PC)R3 := R1 (PC1.speed = PC2.speed AND PC1.ram = PC2.ram AND PC1.model PC2.model) R2R4 := PC1.model,PC2.model(R3)PC1.modelPC2.model10041012R1 := model(speed 2.80(PC) model(speed 2.80(Laptop)R2 := maker,model(R1 Product)R3 := R3(maker2,model2)(R2)R4 := R2 (maker = maker2 AND model model2) R3R5 := maker(R4)makerBER1 := model,speed(PC)R2 := model,speed(Laptop)R3 := R1 R2R4 := R4(model2,speed2)(R3)R5 := model,sp
