数据库系统基础教程第二章答案解析VIP专享VIP免费

完美 WORD 格式 Exercise 2.2.1aFor relation Accounts, the attributes are:acctNo, type, balanceFor relation Customers, the attributes are:firstName, lastName, idNo, accountExercise 2.2.1bFor relation Accounts, the tuples are:(12345, savings, 12000),(23456, checking, 1000),(34567, savings, 25)For relation Customers, the tuples are:(Robbie, Banks, 901-222, 12345),(Lena, Hand, 805-333, 12345),(Lena, Hand, 805-333, 23456)Exercise 2.2.1cFor 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  idNo12345  accountExercise 2.2.1dFor relation Accounts, a relation schema is:Accounts(acctNo, type, balance)For relation Customers, a relation schema is:Customers(firstName, lastName, idNo, account)Exercise 2.2.1eAn example database schema is:Accounts (acctNo,type,balance)Customers (firstName,lastName, 专业整理分享 完美 WORD 格式 idNo,account)Exercise 2.2.1fA suitable domain for each attribute:acctNo  Integertype  Stringbalance  IntegerfirstName  StringlastName  StringidNo  String (because there is a hyphen we cannot use Integer)account  IntegerExercise 2.2.1gAnother equivalent way to present the Account relation:acctNobalancetype3456725savings234561000checking1234512000savingsAnother equivalent way to present the Customers relation:idNofirstNamelastNameaccount805-333LenaHand23456805-333LenaHand12345901-222RobbieBanks12345Exercise 2.2.2Examples of attributes that are created for primarily serving as keys in a relation:Universal Product Code (UPC) used widely in United States and Canada to track products in stores.Serial Numbers on a wide variety of products to allow the manufacturer to individually track each prod...