java简单工作流程系统的设计与实现毕业设计英文文献翻译.doc

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1、毕业设计说明书英文文献及中文翻译学生姓名： 学号： 学 院： 专 业： 指导教师： 年 月DatabaseDevelopmentProcessBasedoninformationengineeringinformationsystemsplanningdatabaseisasourceofdevelopmentprojects.Thesenewdatabasedevelopmentprojectsisusuallyinordertomeetthestrategicneedsoforganizations,suchasimprovingcustomersupport,improveproduct

2、andinventorymanagement,oramoreaccuratesalesforecast.However,manymoredatabasedevelopmentprojectisthebottom -up approachemerging,suchasinformationsystemuserneedsspecificinformationtocompletetheirwork,thusbeginningaprojectrequest,andasotherinformationsystemsexpertsfoundthatorganizationsneedtoimprovedat

3、amanagementandbeginnewprojects.Bottom-upeveninthecircumstances,tosetupanenterprisedatamodelisalsonecessarytounderstandtheexistingdatabasecanprovidethenecessarydata,otherwise,thenewdatabase,dataentitiesandattributescanbeaddedtothecurrentdataresourcestotheorganization.Boththestrategicneedsoroperationa

4、linformationneedsofeachdatabasedevelopmentprojectsnormallyconcentratedinadatabase.Someprojectsonlyconcentratedinthedatabasedefinition,designandimplementationofadatabase,asafollow-uptothebasisofthedevelopmentofinformationsystems.However,inmostcases,thedatabaseandassociatedinformationprocessingfunctio

5、nasacompleteinformationsystemsdevelopmentprojectwaspartofthedevelopment.one.SystemDevelopmentLifeCycleGuidemanagementinformationsystemdevelopmentprojectsisthetraditionalprocessofsystemdevelopmentlifecycle(SDLC).Systemdevelopmentlifecycleisanorganizationofthedatabasedesignersandprogrammersinformation

6、systemcomposedofthePanelofExpertsdetaileddescription,development,maintenanceandreplacementoftheentireinformationsystemsteps.ThisprocessisbecauseWaterfallthanforeverystepintotheadjacentthenextstep,thatis,theinformationsystemisaspecificationdevelopedbyapieceofland,everypieceoftheoutputisunderaninput.H

7、owevershowninthefigure,thesestepsarenotpurelylinear,eachofthestepsoverlapintime(andthu-scanmanageparallelsteps),butwhentheneedtoreconsiderpreviousdecisions,butalsotorollbacksomestepsahead.(Andthereforewatercanbeputbackinthewaterfall!)Thesystemdevelopmentlifecycleincludingeachstageanddatabasedevelopm

8、ent-relatedactivities,therefore,thequestionofdatabasemanagementsystemsthroughouttheentiredevelopmentprocess.InFigure5werepeatofthesystemdevelopmentlifecyclestageoftheseven,andoutlinesthecommondatabaseateachstageofdevelopmentactivities.Pleasenotethatthesystemsdevelopmentlifecyclestagesanddatabasedeve

9、lopmentstepsexistsbetweentherelationshipbetweentheconceptofmodelingdatainbothsystemsdevelopmentlifecyclestagesbetween.1.1EnterpriseModelingDatabasedevelopmentprocessfromtheenterprisemodeling(systemdevelopme-ntlifecyclestageoftheprojectfeasibilitystudies,andtochooseapart) Organizationssetthescopeandg

10、eneraldatabasecontent.Enterprisemodelingininformationsystemsplanningandotheractivities,theseactivitiesdeterminewhichpartofinformationsystemsneedtochangeandstrengthentheentireorganizationandoutlinesthescopeofdata.Inthisstep,checkthecurrentdatabaseandinformationsystems,developmentoftheprojectasthemain

11、areasofthenatureofthebusiness,withaverygeneraldescriptionofeachterminthedevelopmentofinformationsystemswhenneededdata.Eachitemonlywhenitachievedtheexpectedgoalsoforganizationscanbewhenthenextstep.1.2ConceptualDataModelingOnehasalreadybegunontheInformationSystemproject,theconceptofdatamodelingphaseof

12、theinformationsystemsneedsofallthedata.Itisdividedintotwostages.First,itbegantheprojectintheplanningstage.Atthesametimeoutliningtheestablishmentofotherdocumentstotheexistingdatabasewithoutconsideringthecircumstancesspecificdevelopmentprojectsinthescopeoftherequireddata.Thiscategoryonlyincludeshigh-l

13、eveldata(entities),andmaincontact.Theninthesystemdev-elopmentlife-cycleanalysisstagemusthaveamanagementinformationsystemsettheentireorganizationDetailsofthedatamodeldefinitionofalldataattributes,listingalldatatypesthatalldatainter-entitybusinesslinkages,definingdescriptionofthefulldataintegrityrules

14、.Intheanalysisphase,butalsotheconceptofinspectiondatamodel(alsocalledtheconceptbehindthemodel)andthegoalofinformationsystemsusedtoexplainotheraspectsofthemodelofconsistencycategories,suchasprocessingsteps,rulesanddataprocessingtimeoftiming.However,eveniftheconceptissuchdetaileddatamodelisonlyprelimi

15、nary,becausefollow-upinformationsystemlifecycleactivitiesinthedesignofservices,statements,displayandinquiriesmayfindthatmissingelementormistakes.Therefore,theconceptofdataoftensaidthatmodelingisatop-downmanner,itsareasofoperationfromthegeneralunderstandingofthedriver,ratherthanthespecificinformation

16、processingactivitiesbythedriver.1.3LogicalDatabaseDesignLogicaldatabasedesignfromtwoperspectivesdatabasedevelopment.First,theconceptofdatamodeltransformintorelationaldatabasetheorybasedonthecriteriathatmeans-between.Then,asthedesignofinformationsystems,everycomputerprocedures(includingproceduresfort

17、heinputandoutputformat),databasesupportservices,statements,andinquiriesrevealedthatadetailedexamination.Inthisso-calledBottom-upanalysis,accurateverificationoftheneedtomaintainthedatabaseandthedataineachaffairs,statementsandsoontheneedsofthoseinthenatureofthedata.Foreachseparatestatements,services,a

18、ndsoontheanalysismusttakeintoaccountaspecific,limitedbutcompletedatabaseview.Whenstatements,services,andotheranalysismightbenecessarytochangetheconceptofdatamodel.Especiallyinlarge-scaleprojects,thedifferentanalyticalsystemsdevelopmentstaffandtheteamcanworkindependentlyindifferentproceduresorinacent

19、ralized,thedetailsoftheirworkuntilallthelogicdesignstagemaybedisplayed.Inthesecircumstances,logicdatabasedesignstagemustbetheoriginalconceptofdatamodelanduserviewtheseindependentormergedintoacomprehensivedesign.Inlogicdesigninformationsystemsalsoidentifyadditionalinformationprocessingneedsofthesenew

20、demandsatthistimemustbeintegratedintothelogicofearlieridentifiedinthedatabasedesign.Logicaldatabasedesignisbasedonthefinalstepfortheformationofgooddataspecificationsanddeterminetherules,thecombination,thedataafterconsultationspecificationsorconvertedintobasicatomicelement.Mostoftodaysdatabase,theser

21、ulesfromtherelationaldatabasetheoryandtheprocessknownasstandardization,#.Thisstepistheresultofmanagementofthesedatahavenotcitedanydatabasemanagementsystemforacompletedescriptionofthedatabasemap.Logicaldatabasedesigncompleted,webegantoidentifyindetailthelogicofthecomputerprogramandmaintenance,therepo

22、rtcontentsofthedatabaseforinquiries.1.4PhysicaldatabasedesignanddefinitionPhysicaldatabasedesignanddefinitionphasedecisionscomputermemory(usuallydisk)databaseintheorganization,definitionofAccordingtothelibrarymanagementsystemforphysicalstructure,theproceduresoutlinedprocessingservices,producethedesi

23、redmanagementinformationanddecisionsupportstatements.Theobjectiveofthisstageistodesignaneffectiveandsafemanagementofalldata-processingdatabase,thephysicaldatabasedesigntocloselyintegratetheinformationsystemsofotherphysicalaspectsofthedesign,includingprocedures,computerhardware,operatingsystemsanddat

24、acommunicationsnetworks.1.5DatabaseImplementationThedatabasepreparedbytherealizationstage,testingandinstallationproceduresforhandlingdatabases.Designerscanusethestandardprogramminglanguage(suchasCOBOL,CorVisualBasic),thededicateddatabaseprocessinglanguages(suchasSQL),ortheprocessofthenon-exclusivela

25、nguageprogramminginordertoproduceastatementofthefixedformat,theresultwillbedisplayed,andmayalsoincludecharts.Inachievingstage,butalsothecompletionofallthedatabasefiles,trainingusersforinformationsystems(database)usersetupprogram.Thefinalstepistouseexistingsourcesofinformation(documentslegacyapplicat

26、ionsanddatabasesandnowneedsnewdata)loadingdata.Loadingdataisoftenthefirststepindatafromexistingfilesanddatabasestoanintermediateformat(suchasbinaryortextfiles)andthentoturnintermediateloadingdatatoanewdatabase.Finally,runningdatabasesandrelatedapplicationsfortheactualusermaintenanceandretrievalofdat

27、a.Inoperation,theregularbackupdatabaseandthedatabasewhendamagedoraffectedresumedatabase.1.6DatabasemaintenanceDuringthedatabaseintheprogressivedevelopmentofdatabasemaintenance.Inthisstep,inordertomeetchangingbusinessconditions,inordertocorrecttheerroneousdatabasedesign,databaseapplicationsorprocessi

28、ngspeedincrease,deleteorchangethestructureofthedatabase.Whenaprocedureorfailureofthecomputerdatabaseaffectordamagethedatabasemayalsobereconstruction.Thisstepusuallyisthelongestinthedatabasedevelopmentprocessstep,asitcontinuedtodatabasesandrelatedapplicationsthroughoutthelifecycle,thedevelopmentofeac

29、hdatabasecanbeseenasabriefdatabasedevelopmentprocessanddatamodelingconceptsarise,logicalandphysicaldatabasedesignanddatabasetoachievedealingwiththechanges.two.InformationSystemdevelopedbyothermeansSystemDevelopmentLifeCycleminorchangesinlaworitsvariantoftheoftenusedtoguideinformationsystemsanddataba

30、sedevelopment.InformationSystemisalife-cyclemethodology,itishighlystructuredapproach,whichincludesmanychecksandbalancestoensurethateverystepofproduceaccurateresults,andneworalternativeinformationsystemanditmustcommunicationsordatadefinitionsconsistentexistingsystemneedsconsistency.Systemdevelopmentl

31、ifecyclebecauseoftheregularneedtohaveaworkingsystemforalongtimebeencriticizedbecauseonlyworkinthesystemuntiltheendofthewholeprocessgenerated.Moreandmoreorganizationsnowuserapidapplicationdevelopmentmethod,itisaincludesanalysis,designandimplementationofstepstorepeattherapiditerativeprocessuntilconver

32、gencetousersthesystemsofar.RapidApplicationDevelopmentActrequiredthedatabasehasbeeninexistence,andenhancesystemismainlytotheapplicationofdataretrievalapplication,butnottothosewhogenerateandmodifydatabaseapplications.Themostwidelyusedmethodofrapidapplicationdevelopmentisoneoftheprototype.Theprototype

33、systemisamethodofiterativedevelopmentprocess,analystsandusersthroughcloseco-operation,continuingtorevisethesystemwilleventuallyconvertalltheneedsofaworkingsystem.Inthisdiagramwecontainsnotes,brieflydescribeseachstageoftheprototypeofthedatabasedevelopmentactivities.Normally,wheninformationsystemsprob

34、lemswereidentified,triedonlyaroughconceptofdatamodeling.Inthedevelopmentoftheinitialprototype,thedesignoftheuserwantstodisplayandstatements,andthatanynewdatabaseneedsanddefineatermprototypedatabase.Thisisusuallyanewdatabase,copythepartoftheexistingsystem,butmightalsoaddedsomenewcontent.Whentheneedfo

35、rnewcontent,theseelementsareusuallyfromexternaldatasources,suchasmarketresearchdata,thegeneraleconomicindicatorsorindustrystandards.Whenaprototypeofanewversiontorepeattheachievementandmaintenanceofdatabaseactivities.Usuallyonlyaminimumlevelofsecurityandintegritycontrol,becauseatthistimethefocusisass

36、oonaspossibletoproduceaprototypeversioncanbeused.Butdocumentmanagementprojectalsodeferredtothefinal,onlybeusedinthedeliveryofusertraining.Finally,onceconstructedanacceptableprototype,developers,anduserswillbethefinaldecisionofwhethertoprototypedeliveryandtheuseofthedatabase.Ifthesystem(includingdata

37、base)efficiencyisverylow,thenthesystemanddatabasewillbere-programmingandre-organizationinordertoachievethedesiredperformance.Alongwithvisualprogrammingtools(suchasVisualBasic,Java,VisualC+andfourthgenerationlanguage)increasinglypopularuseofvisualprogrammingtoolscaneasilychangetheuserinterfacewiththe

38、system,theprototypeisbecomingthechoiceofsystemdevelopmentmethodology.Customersusingtheprototypemethodstatementsandshowchangestothecontentandlayoutisquiteeasy.Intheprocess,thenewdatabaseneedswereidentified,soitisthedevelopmentoftheuseoftheexistingdatabaseshouldbeamended.Thereiseventhepossibilityofane

39、edforanewdatabasesystemprototypemethod,insuchcircumstances,whenthesystemdemandintheiterativeprocessofdevelopmentintheever-changingneedsaccesstosampledata,theconstructionorreconstructionofthedatabaseprototype.数据库开发过程基于信息工程的信息系统规划是数据库开发项目的一个来源。这些开发新数据库的项目通常是为了满足组织的战略需求，例如改善客户支持、提高产品和库存管理或进行更精确的销售预测。然而

40、许多数据库开发项目更多的是以自底向上的方式出现的，例如信息系统的用户需要特定的信息来完成他们的工作，从而请求开始一个项目，又如其他信息系统的专家发现组织需要改进数据管理而开始新的项目。即使在自底向上的情况下，建立企业数据模型也是必须的，以便理解现有的数据库是否可以提供所需的数据，否则，新的数据库、数据实体和属性都应该加到当前的组织数据资源中去。无论是战略需求还是操作信息的需求，每个数据库开发项目通常集中在一个数据库上。一些数据库项目仅仅集中在定义、设计和实现一个数据库，以作为后续信息系统开发的基础。然而在大多数情况下，数据库及其相关信息处理功能是作为一个完整的信息系统开发项目的一部分而被开发的

41、。一系统开发生命周期指导管理信息系统开发项目的传统过程是系统开发生命周期(SDLC)。系统开发生命周期是指一个组织中由数据库设计人员和程序员组成的信息系统专家小组详细说明、开发、维护和替换信息系统的全部步骤。这个过程比作瀑布是因为每一步都流到相邻的下一步，即信息系统的规格说明是一块一块地开发出来的，每一块的输出是下一块的输入。然而如图所示，这些步骤并不是纯线性的，每个步骤在时间上有所重叠（因此可以并行地管理步骤），而且当需要重新考虑先前的决策时，还可以回滚到前面某些步骤。（因而水可以在瀑布中倒流！）系统开发生命周期的每一阶段都包括与数据库开发相关的活动，所以，数据库管理的问题遍布整个系统开发过

42、程。请注意，系统开发生命周期的阶段和数据库开发步骤之间不存在一一对应的关系，概念数据建模发生在两个系统开发生命周期阶段之间。1.1企业建模数据库开发过程从企业建模（系统开发生命周期中项目论证和选择阶段的一部分）开始，设定组织数据库的范围和一般内容。企业建模发生在信息系统规划和其他活动期间，这些活动确定信息系统的哪个部分需要改变和加强并概述出全部组织数据的范围。在这一步中，检查当前数据库和信息系统，分析作为开发项目主体的业务领域的本质，用非常一般的术语描述每个信息系统在开发时所需要的数据。每个项目只有当它达到组织的预期目标时才可以进行下一步。1.2概念数据建模对一个已经开始的信息系统项目而言，概念数据建模阶段分析信息系统的全部数据需求。它分为两个阶段。首先，它在