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1、Part3:QuestionsAnswers1.Considerthefollowingrelationalschema:student(studentno_rstnamelastname)book(isbntitleauthspublisheryear)loan(studentnoisbncheckoutdateduration)UseSQLtowritethefollowingqueries:A.Createthetablefthe
2、booktableappropriatedomainrequiredcontraints.B.Changethedatatypeofthecheckoutdateattributeoftheloantabletodate.C.Addaconstraintintotheloantabletomakesuretheloandurationisnomethan180days.D.GrantArvilAmyupdateauthrizationo
3、nthebooktable.2.Whatare6basicoperatsofrelationalalgebra3.Explainhownaturaljoinoperationcanbeaccomplishedbybasicrelationalalgebraoperations4.Explainhowthedivisionoperationcanbeaccomplishedbybasicrelationalalgebraoperation
4、s5.Thedatabaseofaresearchcentercontainsthefollowingthreetablesaboutemployeesprojectsthetimespentbytheemployeesontheprojects.Employee(ssn:intname:stringjobTitle:string)Project(pid:intname:stringspons:stringstartYear:inten
5、dYear:int)WkedOn(ssn:intpid:intyear:intmonth:intnoHours:int).ThetableEmployeelistsalltheemployeesofthecentre.ThetableProjectlistsalltheprojectsofthecentrewiththeirsponsthestartendyearoftheproject.ThetableWkedOnrecdshowma
6、nyhourstheemployeeshavespentonwhichprojectinwhichmonth.Feachtabletheattributesthatmakeuptheprimarykeyareunderlined.Expresseachofthefollowingqueriesinrelationalalgebra.A.Returnthenamesoftheprojectsthatwereactivein2008.B.R
7、eturnthenamesofthoseprogrammerswhoinsomemonthspentmethan60hoursonaprojectsponsedbytheEU.C.ReturnthenamesofthoseprogrammerswhoneverwkedonaprojectsponsedbytheEU.6.ConsidertherelationalschemaofQuestion5.WriteSQLqueriesovert
8、hisschemathatanswerthefollowingquestions.A.Howmanyprojectsthatwereactivein2008weresponsedbytheEUB.Feachprojectyearmonthhowmanyhoursofwkhavebeenspent(Returnonlydatafaprojectyearmonthifsometimehasbeenspent.)C.Howmanyprogra
9、mmersaretherewhohaveexperienceinwkingonaprojectsponsedbytheEU(Notethataprogrammerwhowkedontwomeprojectsshouldbecountedonlyonce.)D.ReturnthenamesoftheprogrammerswhowkedonnomethantwoprojectssponsedbytheEU.(Notethatthisincl
10、udestheprogrammerswhoneverwkedonanyprojectsponsedbytheEU.)E.Whichprogrammer(s)spentthemaximaltotalnumberofhoursonEUprojects10.Considerthefollowingemployeedatabasewheretheprimarykeysareunderlined.Employee(ename:stringstre
11、et:stringcity:string)Wks(employee:stringcompany:stringsalary:real)Company(cname:stringcity:string)Manages(employee:stringmanagername:string)GiveasingleSQLstatementfeachofthefollowingqueries:A.Findthenamesstreetaddressesc
12、itiesofresidenceofallemployeeswhowkf“FirstBankCpation“earnmethan$40000.B.Findthenamesofallemployeesinthedatabasewholiveinthesamecitiesasthecompaniesfwhichtheywk.C.GiveallmanagersofFirstBankCpation“a10percentsalaryraise.D
13、.Findthenamesofallemployeesinthedatabasewhoearnmethananyemployeeof“SmallBankCpation“.E.Assumethatthecompaniesmaybelocatedinseveralcities.FindthenamesofallcompanieslocatedineverycityinwhichSmallBankCpation“islocated.F.Fin
14、dthenameofthecompanythathasthemostemployees.G.Findthosecompanieswhoseemployeesearnahighersalaryonaveragethantheaveragesalaryat“FirstBankCpation“displaythosecompaniesnamesinendingder.11.Considerthefollowing(simplified)rel
15、ationalschemafuniversitystudy:Student(id:integerfamily:stringgiven:stringdegree:stringenrolled:date)Course(id:integercode:stringsession:stringtitle:stringsyllabus:string)Enrolment(student:integercourse:stringmark:realgra
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