基于JavaWeb的博客网站的设计与实现外文翻译.docx

基于JavaWeb的博客网站的设计与实现外文翻译.docx

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基于JavaWeb的博客网站的设计与实现外文翻译

外文原文

DatabaseDevelopmentProcess

Basedoninformationengineeringinformationsystemsplanningdatabaseisasourceofdevelopmentprojects.Thesenewdatabasedevelopmentprojectsisusuallyinordertomeetthestrategicneedsoforganizations,suchasimprovingcustomersupport,improveproductandinventorymanagement,oramoreaccuratesalesforecast.However，manymoredatabasedevelopmentprojectisthebottom—upapproachemerging，suchasinformationsystemuserneedsspecificinformationtocompletetheirwork,thusbeginningaprojectrequest,andasotherinformationsystemsexpertsfoundthatorganizationsneedtoimprovedatamanagementandbeginnewprojects.Bottom—upeveninthecircumstances,tosetupanenterprisedatamodelisalsonecessarytounderstandtheexistingdatabasecanprovidethenecessarydata，otherwise,thenewdatabase,dataentitiesandattributescanbeaddedtothecurrentdataresourcestotheorganization。

Boththestrategicneedsoroperationalinformationneedsofeachdatabasedevelopmentprojectsnormallyconcentratedinadatabase。

Someprojectsonlyconcentratedinthedatabasedefinition,designandimplementationofadatabase,asafollow-uptothebasisofthedevelopmentofinformationsystems。

However，inmostcases，thedatabaseandassociatedinformationprocessingfunctionasacompleteinformationsystemsdevelopmentprojectwaspartofthedevelopment。

one。

SystemDevelopmentLifeCycle

Guidemanagementinformationsystemdevelopmentprojectsisthetraditionalprocessofsystemdevelopmentlifecycle（SDLC）.SystemdevelopmentlifecycleisanorganizationofthedatabasedesignersandprogrammersinformationsystemcomposedofthePanelofExpertsdetaileddescription，development，maintenanceandreplacementoftheentireinformationsystemsteps.ThisprocessisbecauseWaterfallthanforeverystepintotheadjacentthenextstep，thatis,theinformationsystemisaspecificationdevelopedbyapieceofland,everypieceoftheoutputisunderaninput.Howevershowninthefigure，thesestepsarenotpurelylinear，eachofthestepsoverlapintime（andthuscanmanageparallelsteps），butwhentheneedtoreconsiderpreviousdecisions,butalsotorollbacksomestepsahead。

（Andthereforewatercanbeputbackinthewaterfall!

）

Thesystemdevelopmentlifecycleincludingeachstageanddatabasedevelopment—relatedactivities，therefore,thequestionofdatabasemanagementsystemsthroughouttheentiredevelopmentprocess。

InFigure5werepeatofthesystemdevelopmentlifecyclestageoftheseven，andoutlinesthecommondatabaseateachstageofdevelopmentactivities.Pleasenotethatthesystemsdevelopmentlifecyclestagesanddatabasedevelopmentstepsexistsbetweentherelationshipbetweentheconceptofmodelingdatainbothsystemsdevelopmentlifecyclestagesbetween.

1.1EnterpriseModeling

Databasedevelopmentprocessfromtheenterprisemodeling（systemdevelopmentlifecyclestageoftheprojectfeasibilitystudies，andtochooseapart）

Organizationssetthescopeandgeneraldatabasecontent。

Enterprisemodelingininformationsystemsplanningandotheractivities，theseactivitiesdeterminewhichpartofinformationsystemsneedtochangeandstrengthentheentireorganizationandoutlinesthescopeofdata.Inthisstep，checkthecurrentdatabaseandinformationsystems，developmentoftheprojectasthemainareasofthenatureofthebusiness,withaverygeneraldescriptionofeachterminthedevelopmentofinformationsystemswhenneededdata.Eachitemonlywhenitachievedtheexpectedgoalsoforganizationscanbewhenthenextstep.

1。

2ConceptualDataModeling

OnehasalreadybegunontheInformationSystemproject,theconceptofdatamodelingphaseoftheinformationsystemsneedsofallthedata。

Itisdividedintotwostages。

First,itbegantheprojectintheplanningstage。

Atthesametimeoutliningtheestablishmentofotherdocumentstotheexistingdatabasewithoutconsideringthecircumstancesspecificdevelopmentprojectsinthescopeoftherequireddata.Thiscategoryonlyincludeshigh-leveldata（entities）,andmaincontact。

Theninthesystemdevelopmentlife—cycleanalysisstagemusthaveamanagementinformationsystemsettheentireorganizationDetailsofthedatamodeldefinitionofalldataattributes，listingalldatatypesthatalldatainter-entitybusinesslinkages，definingdescriptionofthefulldataintegrityrules。

Intheanalysisphase，butalsotheconceptofinspectiondatamodel（alsocalledtheconceptbehindthemodel）andthegoalofinformationsystemsusedtoexplainotheraspectsofthemodelofconsistencycategories，suchasprocessingsteps,rulesanddataprocessingtimeoftiming.However,eveniftheconceptissuchdetaileddatamodelisonlypreliminary,becausefollow—upinformationsystemlifecycleactivitiesinthedesignofservices,statements,displayandinquiriesmayfindthatmissingelementormistakes。

Therefore,theconceptofdataoftensaidthatmodelingisatop—downmanner,itsareasofoperationfromthegeneralunderstandingofthedriver，ratherthanthespecificinformationprocessingactivitiesbythedriver.

1.3LogicalDatabaseDesign

Logicaldatabasedesignfromtwoperspectivesdatabasedevelopment.First,theconceptofdatamodeltransformintorelationaldatabasetheorybasedonthecriteriathatmeans—between。

Then，asthedesignofinformationsystems，everycomputerprocedures（includingproceduresfortheinputandoutputformat），databasesupportservices,statements，andinquiriesrevealedthatadetailedexamination。

Inthisso-calledBottom-upanalysis,accurateverificationoftheneedtomaintainthedatabaseandthedataineachaffairs，statementsandsoontheneedsofthoseinthenatureofthedata。

Foreachseparatestatements,services,andsoontheanalysismusttakeintoaccountaspecific，limitedbutcompletedatabaseview。

Whenstatements，services，andotheranalysismightbenecessarytochangetheconceptofdatamodel.Especiallyinlarge-scaleprojects，thedifferentanalyticalsystemsdevelopmentstaffandtheteamcanworkindependentlyindifferentproceduresorinacentralized，thedetailsoftheirworkuntilallthelogicdesignstagemaybedisplayed。

Inthesecircumstances，logicdatabasedesignstagemustbetheoriginalconceptofdatamodelanduserviewtheseindependentormergedintoacomprehensivedesign.Inlogicdesigninformationsystemsalsoidentifyadditionalinformationprocessingneedsofthesenewdemandsatthistimemustbeintegratedintothelogicofearlieridentifiedinthedatabasedesign.Logicaldatabasedesignisbasedonthefinalstepfortheformationofgooddataspecificationsanddeterminetherules，thecombination,thedataafterconsultationspecificationsorconvertedintobasicatomicelement.Mostoftoday'sdatabase，theserulesfromtherelationaldatabasetheoryandtheprocessknownasstandardization,＃。

Thisstepistheresultofmanagementofthesedatahavenotcitedanydatabasemanagementsystemforacompletedescriptionofthedatabasemap.Logicaldatabasedesigncompleted，webegantoidentifyindetailthelogicofthecomputerprogramandmaintenance，thereportcontentsofthedatabaseforinquiries.

1.4Physicaldatabasedesignanddefinition

Physicaldatabasedesignanddefinitionphasedecisionscomputermemory（usuallydisk）databaseintheorganization,definitionofAccordingtothelibrarymanagementsystemforphysicalstructure，theproceduresoutlinedprocessingservices，producethedesiredmanagementinformationanddecisionsupportstatements。

Theobjectiveofthisstageistodesignaneffectiveandsafemanagementofalldata-processingdatabase，thephysicaldatabasedesigntocloselyintegratetheinformationsystemsofotherphysicalaspectsofthedesign,includingprocedures，computerhardware,operatingsystemsanddatacommunicationsnetworks。

1.5DatabaseImplementation

Thedatabasepreparedbytherealizationstage,testingandinstallationproceduresforhandlingdatabases.Designerscanusethestandardprogramminglanguage（suchasCOBOL，CorVisualBasic），thededicateddatabaseprocessinglanguages（suchasSQL），ortheprocessofthenon-exclusivelanguageprogramminginordertoproduceastatementofthefixedformat，theresultwillbedisplayed,andmayalsoincludecharts。

Inachievingstage，butalsothecompletionofallthedatabasefiles,trainingusersforinformationsystems（database）usersetupprogram.Thefinalstepistouseexistingsourcesofinformation（documentslegacyapplicationsanddatabasesandnowneedsnewdata）loadingdata。

Loadingdataisoftenthefirststepindatafromexistingfilesanddatabasestoanintermediateformat（suchasbinaryortextfiles）andthentoturnintermediateloadingdatatoanewdatabase。

Finally，runningdatabasesandrelatedapplicationsfortheactualusermaintenanceandretrievalofdata。

Inoperation，theregularbackupdatabaseandthedatabasewhendamagedoraffectedresumedatabase。

1.6Databasemaintenance

Duringthedatabaseintheprogressivedevelopmentofdatabasemaintenance。

Inthisstep，inordertomeetchangingbusinessconditions,inordertocorrecttheerroneousdatabasedesign，databaseapplicationsorprocessingspeedincrease，deleteorchangethestructureofthedatabase。

Whenaprocedureorfailureofthecomputerdatabaseaffectordamagethedatabasemayalsobereconstruction.Thisstepusuallyisthelongestinthedatabasedevelopmentprocessstep，asitcontinuedtodatabasesandrelatedapplicationsthroughoutthelifecycle，thedevelopmentofeachdatabasecanbeseenasabriefdatabasedevelopmentprocessanddatamodelingconceptsarise,logicalandphysi