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1、完美WORD格式Exercise2.2.1aForrelationAccounts,theattributesare:acctNo,type,balanceForrelationCustomers,theattributesare:firstName,lastName,idNo,accountExercise2.2.1bForrelationAccounts,thetuplesare:(12345,savings,12000),(23456,checking,1000),(34567,savings,25)Forrelatio
2、nCustomers,thetuplesare:(Robbie,Banks,901-222,12345),(Lena,Hand,805-333,12345),(Lena,Hand,805-333,23456)Exercise2.2.1cForrelationAccountsandthefirsttuple,thecomponentsare:123456àacctNosavingsàtype12000àbalanceForrelationCustomersandthefirsttuple,thecomponentsare:Rob
3、bieàfirstNameBanksàlastName901-222àidNo12345àaccountExercise2.2.1dForrelationAccounts,arelationschemais:Accounts(acctNo,type,balance)ForrelationCustomers,arelationschemais:Customers(firstName,lastName,idNo,account)Exercise2.2.1eAnexampledatabaseschemais:Accounts(acc
4、tNo,type,balance)Customers(firstName,lastName,idNo,account)Exercise2.2.1fAsuitabledomainforeachattribute:acctNoàIntegertypeàStringbalanceàIntegerfirstNameàStringlastNameàString专业整理分享完美WORD格式idNoàString(becausethereisahyphenwecannotuseInteger)accountàIntegerExercise2
5、.2.1gAnotherequivalentwaytopresenttheAccountrelation:acctNobalancetype3456725savings234561000checking1234512000savingsAnotherequivalentwaytopresenttheCustomersrelation:idNofirstNamelastNameaccount805-333LenaHand23456805-333LenaHand12345901-222RobbieBanks12345Exercis
6、e2.2.2Examplesofattributesthatarecreatedforprimarilyservingaskeysinarelation:UniversalProductCode(UPC)usedwidelyinUnitedStatesandCanadatotrackproductsinstores.SerialNumbersonawidevarietyofproductstoallowthemanufacturertoindividuallytrackeachproduct.VehicleIdentifica
7、tionNumbers(VIN),auniqueserialnumberusedbytheautomotiveindustrytoidentifyvehicles.Exercise2.2.3aWecanorderthethreetuplesinanyof3!=6ways.Also,thecolumnscanbeorderedinanyof3!=6ways.Thus,thenumberofpresentationsis6*6=36.Exercise2.2.3bWecanorderthethreetuplesinanyof5!=1
8、20ways.Also,thecolumnscanbeorderedinanyof4!=24ways.Thus,thenumberofpresentationsis120*24=2880Exercise2.2.3cWecanorderthethreetuplesinanyof
