期末试题-数据库技术与应用

1北京邮电大学2007——2008学年第一学期《数据库技术与应用》期末考试试题考试注意事项一、学生参加考试须带学生证或学院证明，未带者不准进入考场。学生必须按照监考教师指定座位就坐。二、书本、参考资料、书包等与考试无关的东西一律放到考场指定位置。三、学生不得另行携带、使用稿纸，要遵守《北京邮电大学考场规则》，有考场违纪或作弊行为者，按相应规定严肃处理。四、学生必须将答题内容做在专用答题纸上，做在试卷、草稿纸上一律无效。考试课程数据库技术与应用考试时间年月日题号一二三四五六七八总分满分2030103010得分阅卷教师True-FalseQuestions（20）题号12345678910答案题号11121314151617181920答案班级：学号：姓名：2MultipleChoiceQuestions（30）题号12345678910答案题号11121314151617181920答案题号21222324252627282930答案FillintheBlankQuestions（10）题号答案12345678910EssayQuestions（30）1323445Giveyoursuggestionaboutthiscourse（10）5True-FalseQuestions（1point*20）1.Thepurposeofadatabaseistohelppeoplekeeptrackofthings.2.Therelationalmodelwasfirstproposedin1970byE.F.CoddatIBM.3.Arelationisathree-dimensionaltable.4.Anasterisk(*)followingtheSELECTverbmeansthatallcolumnsaretobeobtained.5.TheSQLkeywordGROUPBYinstructstheDBMStogrouptogetherthoserowsthathavethesamevalueinacolumn.6.InanE-Rmodel,thethreetypesofmaximumcardinalityare1:1,1:NandN:M.7.Anullvalueisanattributevaluethathasbeensettozero.8.Adataconstraintisalimitationondatavalues.9.Inarelationaldatabasedesign,allrelationshipsareexpressedbycreatingaforeignkey.10.Atransactionisagroupofalternativedatabaseactionsfromwhichthedatabasecanchoosetoperformonlyoneofthem.11.Two-phasedlockinghasagrowingphaseandashrinkingphase.12.RepeatableReadsisolationisthemostrestrictivelevelofisolation.13.Adatabasesaveisusedtomarktheendofatransaction.14.ToaddaNULLcolumntoatable,wesimplyusetheMODIFYTABLEstatement.15.Deletingtablesandrelationshipsisbasicallyamatterofdroppingforeignkeyconstraintsandthendroppingthetables.16.TheSQLkeywordDELETEisusedtodeleteatable'sstructure.17.Joinsthatshowonlymatchingrowsfromthejoinedtablesintheirresultsarecalledinnerjoins.18.AnSQLvirtualtableiscalledaview.19.SQLtriggersareusedforprovidingdefaultvalues,validitychecking,updatingviews,andperformingreferentialintegrityactions.20.Storedprocedureshavetheadvantageofgreatersecurity,decreasednetworktraffic,SQLoptimizedbytheDBMScompiler,andcodesharing.6MultipleChoiceQuestions（1point*30）1.Adatabasestores:a.)data.b.)relationships.c.)metadata.d.)aandbe.)a,bandc2.Aprogramwhosejobistocreate,processandadministerdatabasesiscalledthe______.a.)DatabaseModelingSystemb.)DatabaseManagementSystemc.)DataBusinessModelSystemd.)RelationalModelManagere.)DataBusinessManagementService3.Adatabaseisconsideredself-describingbecause____________________________.a.)alltheusers'dataisinoneplaceb.)itreducesdataduplicationc.)itcontainsadescriptionofitsownstructured.)itcontainsalistingofalltheprogramsthatuseite.)Alloftheabove.4.Averypopulardevelopmenttechniqueusedbydatabaseprofessionalsfordatabasedesignisknownas_______________________.a.)datamartsb.)normalizationc.)datamodelsd.)entity-relationshipdatamodelinge.)datamigration5.InanSQLquery,whichSQLkeywordisusedtostatetheconditionthatspecifieswhichrowsaretobeselected?a.)EXISTSb.)FROMc.)SELECTd.)SETe.)WHERE6.InanSQLquery,whichofthefollowingsymbolsisusedbyANSISQLtorepresentasingleunspecifiedcharacter?a.)(underscore)b.)?(questionmark)c.)*(asterisk)d.)%(percent)e.)#(pound)7.Givenatablewiththestructure:EMPLOYEE(EmpNo,Name,Salary,HireDate),whichofthefollowingwouldfindallemployeeswhosenamebeginswiththeletterSusingstandardSQL?7a.)SELECT*FROMEMPLOYEEWHERENameIN['S'];b.)SELECTEmpNoFROMEMPLOYEEWHERENameLIKE'S';c.)SELECT*FROMNameWHEREEMPLOYEELIKE'S*';d.)SELECT*FROMEMPLOYEEWHERENameLIKE'S%';e.)Noneoftheabove.8.Givenatablewiththestructure:EMPLOYEE(EmpNo,Name,Salary,HireDate),whichofthefollowingisnotavalidANSISQLcommand?a.)SELECT*FROMEMPLOYEEWHERENameLIKE'Ja%';b.)SELECTCOUNT(*)FROMEMPLOYEEWHERESalary30000;c.)SELECTCOUNT(EmpNo)FROMEMPLOYEE;d.)SELECTHireDate,COUNT(*)FROMEMPLOYEEWHERESalary30000;e.)SELECTHireDate,COUNT(*)FROMEMPLOYEEGROUPBYHireDate;9.Arelation__________________________.a.)hasrowscontainingdataaboutanentityb.)hascolumnscontainingdataaboutattributesoftheentityc.)hascellsthatholdonlyasinglevalued.)hasnotwoidenticalrowse.)Alloftheabove.10.WhichofthefollowingistrueaboutthefunctionaldependencyA(X,Y)?a.)XisfunctionallydependentonA.b.)AdeterminesY.c.)Aisadeterminant.d.)XandYarefunctionallydependentonA.e.)Alloftheabove.11.ArelationisinfourthnormalformifitisinBCNFandithasno_________________.a.)transitivedependenciesb.)multivalueddependenciesc.)partialdependenciesd.)deletiondependencies8e.)referentialintegrityconflicts12.Theadvantagesofnormalizationinclude________________.a.)theeliminationofmodificationanomaliesb.)theeliminationofduplicateddatac.)morecomplexSQLformultitablesubqueriesandjoinsd.)aandbe.)a,bandc13.Tocheckfornullvaluesinacolumninatable,usetheSQLphrase________________.a.)ISb.)ISNOTc.)ISNULLd.)COUNT(ISNOT)e.)COUNT(ISNULL)14.Acompositeattributeisanattributethat__________________________.a.)ismultivaluedb.)describesacharacteristicoftherelationshipc.)consistsofagroupofattributesd.)iscalculatedatrun-timee.)isanidentifier15.Maximumcardinalityrefersto______________________________.a.)themostinstancesofoneentityclassthatcanbeinvolvedinarelationshipinstancewithanotherentityclassb.)theminimumnumberofentityclassesinv