Web数据库技术高晗张翠玲杨玲编著普通高等教育“十一五”国家级规划教材21高职高专新概念教材中国水利水电出版社第1章Web数据库概述 Web数据库的概念 几种常用Web数据库的特点 脚本程序与数据库连接的常用方法本章学习要点NSPIXPisstandforNetworkServiceProviderInternetexchangeprojectorpoint,LastPhastwomeanings-ProjectandPoint.NSPIXPisaresearchprojectonIX,operatedbyWIDEProjectsince1994.BeforedescribingNSPIXP,IwouldliketotalkaboutthenameNSPIXP.ThenameofNSPIXPisverydifficulttopronounce.Andeveryonesaid,“Whydidn’tyouassignamorefancynametotheproject?InWIDEProject,thenaminggodisJunMurai.Everyname,suchasaworkinggroupname,oraProjectname,isnamedbyJun.ButNSPIXPdoesnotfallunderJun’slaw.Intheyear1994inJapan,commercialISP’sstartedbusinesseswithnewcommunicationservices.TheJapanesegovernmentwantedtocontrolthenewISPbusinesses.InJapan,everyinterconnectionaroundthecommunicationbusinessesmustgetpermissionfromtheMPT(MinistryofPostandTelecommunication).Internetservicesisnotanexception.IfISPAandBwanttoconnecttheirnetworktoeachother,thoseISP’smustgetpermissionfromMPT.ThispolicydoesnotscaleonanInternetexchangepoint.Asaresult,if50ISP’sareconnectedatanIX,wehavetogetover2000permissionsfromMPT!SowestartedanInternetexchangetest-bed.WeassignedanamethatdidnotrepresentanIXsuchasJPIX,JIX,andsoon.ThisisthereasonwhywenamedourIXtest-bedNSPIXP.WeagreedthatifMPTchangedthepermissioncontrol,wewouldchangetoanewnamethatisagoodandfancyname,otherthanNSPIXP!Officiallytheinterconnectingpermissionpolicyisstillthere.ItisneededtogetpermissionfromMPTwhenconnectingtoanISP’snetwork.ButwedonothaveanyrequestaboutthepermissionfromMPT.MPTrecognizesWIDENSPIXPasamajorIXinJapan.I’minvitedtomanygovernmentmeetingsrelatedwithIXissues.WeguessthattheJapanesegovernmentisstillconfused.Theydonothaveananswerofhowtoapplyandtomodifythetraditionalgovernmentalcontrolsystemforcommunicationbusinesses,totheInternetbusinesses.1.1Web概述Web即万维网,就是通过使用通信设备和线路,将处在不同地理位置、操作上相对独立的多个计算机连接起来,再配置一定的系统软件和应用软件,在这些计算机上实现软硬件的资源共享和信息传递,由此而构成的计算机网络。OkIwouldliketotalkaboutpurposeofNSPIXP.Before1994,TherewereseveralNetworksinJapansuchasWIDEInternet,TISNthatwasanetworkforresearchersonaerospaceandhighenergyphysics,andSINETforUniversityresearchersfoundedbythegovernment.Thosenetworkswereinterconnectedatseveralpoints.At1994,commercialInternetserviceprovidersstartedtheirbusinesses.WewereworriedaboutinterconnectionbetweenthosecommercialnetworksandR&Dnetworks.TherewasnoIXinJapan.Andwedidnothaveanyagreementforinterconnection.SoWIDEProjectstartedanIXwithcommercialISP’sasatest-bed.AsaTest-bedisnotbusinesses,wecoulddiscusspeeringpolicy,technologiesandoperationalissueswithoutanygovernmentcontrol.AndalsowecouldmakeaninterconnectionbetweencommercialISPnetworksandR&Dnetworks.NSPIXPbecamearoundtablefornetworkoperators.WWW由联入互联网的Web服务器和浏览页面的客户机构成,这种工作模式通常称为浏览器/服务器模式(Browser/Server模式),简称B/S模式。还有一种模式为客户机/服务器模式(Client/Server模式),简称为C/S模式,它是通过在服务器和客户机上分别安装相应的程序,从而达到使客户机能够与服务器进行通信的目的。客户机/服务器结构(C/S) 由两部分组成,即客户应用程序和数据库服务器程序; 服务器被启动,就随时等待响应客户程序发来的请求; 当需要对数据库中的数据进行任何操作时,客户程序就自动地寻找服务器程序,并向其发出请求,服务器程序根据预定的规则作出应答,送回结果。������������������������������������������������������������HereisbriefoverviewoftheNSPIXPtest-bed.WehavebeenoperatingfourIX’sinJapan.ThefirstIXtest-bedwasNSPIXP-1startedin1994.WeinstalledasingleEthernetHubatWIDETokyoNetworkOperationCenter.IIJ,JENSandInfoWebbroughttheirrouterswith192Kbpsdedicatedleasedlines.WestartedasaLayer3IXlikeaCIXinUS.WIDEroutertransitedalltrafficamongtheISPs.BeforethestartingIX,wediscussedpeeringpolicy.In1994,thepriceofadedicatedleasedline,especiallycrossingthePacificOcean,wasveryexpensive.ISP’sworriedabouttrafficfromIX.TrafficfromIXusedtheISP’sresourcesfreely.SofirstpeeringpolicyofNSPIXP-1wasL3IX,everyISProuterhadtopeertheWIDErouter.AndeveryISPannouncedonlyinternaldomesticroutinginformation.ThismeansthatNSPIXP-1exchangeddomesticroutinginformationonlyatstartingpoint.AndthebandwidthbetweenISP’snetworkandNSPIXP-1hadalimitationuptoT.1.((((ISP’scoulddecidethebandwidthbetweentheISPnetworkandWIDETokyonetworkoperationcenter.Thislinewaslikeafuseofthenetwork.IfanISParrow??(allow??borrow??意味不明回線を借りる?)the128KbpsbandwidthfromIX,theycouldassignthe128Kbpsontheline.WeagreedtosetthelimitationofthebandwidthasT1.)))↑この辺の文法は直したが、もと意味は私にはよくわからないです。Butasyouknow,thispolicyandoperationcausesdisasterssoon!ThislimitationcausedmanypacketlossatIX.SomemagazineswrotethatNSPIXP-1madeeverypacketlossinJapan.SowestartedNSPIXP-2asthenextstep.NSPIXP-2startedin1996.WeselectedtheKDDIcollocationspacefortheNSPIXP-2.NSPIXP-2wasdesignedforhighbandwidth–areliableandscalableIX.ThereasonwhyweselectedtheKDDIcollocationspacewasreliability.WeusedtwoDECGigaSwitches.Andin1998,weexpandedtofour.DualhomingofFDDIspecificationwasveryusefulforreliableoperations.Butasyouknow,FDDImeansthat100MbpsisnotenoughforrecentIXtraffic.Wehadtochangetonewtechnology,GigabitEthernettechnologyfromFDDIin2000.ThecurrentNSPIXP-2hasinstalledfourGigabitEthernetSwitches,andover60networksareinterconnected.浏览器/服务器结构(B/S) 客户层(browser)用户接口和用户请求的发出地,典型应用是网络浏览器; 服务器层(webserver)典型应用是Web服务器和运行业务代码的应用程序服务器 数据层(datatier)典型应用是关系型数据库和其他后端(back-end)数据资源,如Oracle和LDAP等。�������WEB������/�����������DB/LDAP�����TCP/IP����������API������������������������在浏览网页时,服务器上的WWW服务允许用鼠标点击“超级链接”,要涉及两个不同的程序: WWW客户机程序 Web服务器程序Andthisisthesamegraphasbefore,theYaxisisexponential.NSPIXP-2trafficshowsexponentialgrowth.(でいいか?)1.2Web数据库数据库是指按照一定的结构和规则组织起来的相关数据的集合,是存放数据的“仓库”。将网络数据库定义为以后台数据库为基础的,加上一定的前台程序,通过浏览器完成数据存储、查询等操作的系统。一个Web数据库就是用户利用浏览器作为输入接口,输入所需要的数据,浏览器将这些数据传送给网站,而网站再对这些数据进行处理。Ok,backtothetable.NSPIXP-3wasstartedat1997,oneyearafterNSPIXP-2.ThelocationofNSPIXP-2isdowntownTokyo.TheKDDIBuildingsarestrongbuildings…butwehadtoconsiderearthquakes.SowesetuptheIXintheOsakaareaforbackupoftheNSPIXP-2.AndnowwearestartingthedistributionoftheNSPIXP-2calledasNSPXIP-2+inthetable.MostofthecurrentinternettrafficisfromDataCenters.WemustcarrytrafficfromDataCenterstotheISPssmoothly.SoweareconnectingseveralDataCenterwithfiber.ThisisNSPIXP-2+,DistributedNSPIXP-2,DIX?.....Sorry,NSPIXPdoesnothaveanofficialname!?SoNSPIXP-2+isalsotemporaryname.!WeareusingIEEE802.3adastrunkingmechanismandusingFastSTPbetweenthelocations.Nowwearetestingfromendoflastyear.IwouldliketostarttheoperationbyAprilthisyear.几种常用Web数据库的比较1.SQLServer微软公司从Sysbase获得基本部件的使用许可后开发出的一种关系型数据库。目前最新的版本是SQLServer2005,但SQLServer2000和SQLServer7.0仍在广泛使用。如果用户使用的是Windows操作系统,那么IIS、SQLServer就应该是最佳的选择。2.MySQL当今Unix或Linux类服务器上广泛使用MySQL作为Web数据库系统。由于它不支持事务处理,MySQL的速度比一些商业数据库快2~3倍,并且MySQL还针对很多操作平台做了优化,完全支持多CPU系统的多线程方式。在编程方面,MySQL也提供了C、C++、Java、Perl、Python等API接口,而且有MyODBC接口,任何可以使用ODBC接口的语言都可以使用它。MySQL的源代码是公开的,可以免费使用。ThisisamapofdistributedNSPIXP-2.NTTOtemachibuilding,@TokyoPower.comariake,WorldcomRoppongiMINDatNishioiAndLevel3atToranomon,Wehaveanewlocation,AboveNetdatacenterisalsoconnectedasthedistributedNSPIXP-2.3.Oracle一种面向网络计算机并支持对象关系模型的数据库产品。它之所以备受用户喜爱是因为它具有以下突出的特点:(1)支持大型数据库、多用户和高性能的事务处理。(2)Oracle遵守数据库存取语言、操作系统、用户接口和网络通信
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。(3)实施安全性控制和完整性控制。(4)支持分布式数据库和分布式处理。表1-13种数据库的性价比HerearetrafficstatisticsforNSPIXP-3Therecenttrafficisover500Mbps.1.3脚本程序与数据库的接口在脚本程序中连接数据库一般都需要相应的接口来完成。连接数据库的常用方法有: ODBC(OpenDatabaseConnectivity,即开放式数据库连接) DAO(DataAccessObjects,即数据库访问对象) RDO(RemoteDataObjects,即远程数据对象) ADO(ActivteXDataObjects,即ActivteX数据对象)1.4应用开发平台(1)ASPASP(ActivexServerPages)是由微软创建的Web应用开发标准,ASP服务器已经包含在IIS服务器中。ASP服务器将Web请求转入解释器中,解释器对所有ASP中的脚本进行分析,然后执行。ASP还可以创建COM对象以完成更多的功能。ASP中的脚本是Vbscript。(2)PHPPHP由于其良好的性能和免费的特点,是互联网中应用较为流行的一种应用开发平台。(3)JSPJSP(JavaServerPages)是由SunMicrosystems公司倡导、许多公司参与一起建立的一种动态网页技术标准。JSP技术有点类似ASP技术,它是在传统的网页HTML文件(*.htm,*.html)中插入Java程序段(Scriptlet)和JSP标记(tag),从而形成JSP文件(*.jsp)。本章主要介绍了Web数据库的概念,分析与比较了几种常用的Web数据库的功能及特点,对脚本程序与数据库的接口技术也进行了简要的介绍。通过本章的学习,读者对Web数据库有了初步的了解。本章小结NSPIXPisstandforNetworkServiceProviderInternetexchangeprojectorpoint,LastPhastwomeanings-ProjectandPoint.NSPIXPisaresearchprojectonIX,operatedbyWIDEProjectsince1994.BeforedescribingNSPIXP,IwouldliketotalkaboutthenameNSPIXP.ThenameofNSPIXPisverydifficulttopronounce.Andeveryonesaid,“Whydidn’tyouassignamorefancynametotheproject?InWIDEProject,thenaminggodisJunMurai.Everyname,suchasaworkinggroupname,oraProjectname,isnamedbyJun.ButNSPIXPdoesnotfallunderJun’slaw.Intheyear1994inJapan,commercialISP’sstartedbusinesseswithnewcommunicationservices.TheJapanesegovernmentwantedtocontrolthenewISPbusinesses.InJapan,everyinterconnectionaroundthecommunicationbusinessesmustgetpermissionfromtheMPT(MinistryofPostandTelecommunication).Internetservicesisnotanexception.IfISPAandBwanttoconnecttheirnetworktoeachother,thoseISP’smustgetpermissionfromMPT.ThispolicydoesnotscaleonanInternetexchangepoint.Asaresult,if50ISP’sareconnectedatanIX,wehavetogetover2000permissionsfromMPT!SowestartedanInternetexchangetest-bed.WeassignedanamethatdidnotrepresentanIXsuchasJPIX,JIX,andsoon.ThisisthereasonwhywenamedourIXtest-bedNSPIXP.WeagreedthatifMPTchangedthepermissioncontrol,wewouldchangetoanewnamethatisagoodandfancyname,otherthanNSPIXP!Officiallytheinterconnectingpermissionpolicyisstillthere.ItisneededtogetpermissionfromMPTwhenconnectingtoanISP’snetwork.ButwedonothaveanyrequestaboutthepermissionfromMPT.MPTrecognizesWIDENSPIXPasamajorIXinJapan.I’minvitedtomanygovernmentmeetingsrelatedwithIXissues.WeguessthattheJapanesegovernmentisstillconfused.Theydonothaveananswerofhowtoapplyandtomodifythetraditionalgovernmentalcontrolsystemforcommunicationbusinesses,totheInternetbusinesses.OkIwouldliketotalkaboutpurposeofNSPIXP.Before1994,TherewereseveralNetworksinJapansuchasWIDEInternet,TISNthatwasanetworkforresearchersonaerospaceandhighenergyphysics,andSINETforUniversityresearchersfoundedbythegovernment.Thosenetworkswereinterconnectedatseveralpoints.At1994,commercialInternetserviceprovidersstartedtheirbusinesses.WewereworriedaboutinterconnectionbetweenthosecommercialnetworksandR&Dnetworks.TherewasnoIXinJapan.Andwedidnothaveanyagreementforinterconnection.SoWIDEProjectstartedanIXwithcommercialISP’sasatest-bed.AsaTest-bedisnotbusinesses,wecoulddiscusspeeringpolicy,technologiesandoperationalissueswithoutanygovernmentcontrol.AndalsowecouldmakeaninterconnectionbetweencommercialISPnetworksandR&Dnetworks.NSPIXPbecamearoundtablefornetworkoperators.HereisbriefoverviewoftheNSPIXPtest-bed.WehavebeenoperatingfourIX’sinJapan.ThefirstIXtest-bedwasNSPIXP-1startedin1994.WeinstalledasingleEthernetHubatWIDETokyoNetworkOperationCenter.IIJ,JENSandInfoWebbroughttheirrouterswith192Kbpsdedicatedleasedlines.WestartedasaLayer3IXlikeaCIXinUS.WIDEroutertransitedalltrafficamongtheISPs.BeforethestartingIX,wediscussedpeeringpolicy.In1994,thepriceofadedicatedleasedline,especiallycrossingthePacificOcean,wasveryexpensive.ISP’sworriedabouttrafficfromIX.TrafficfromIXusedtheISP’sresourcesfreely.SofirstpeeringpolicyofNSPIXP-1wasL3IX,everyISProuterhadtopeertheWIDErouter.AndeveryISPannouncedonlyinternaldomesticroutinginformation.ThismeansthatNSPIXP-1exchangeddomesticroutinginformationonlyatstartingpoint.AndthebandwidthbetweenISP’snetworkandNSPIXP-1hadalimitationuptoT.1.((((ISP’scoulddecidethebandwidthbetweentheISPnetworkandWIDETokyonetworkoperationcenter.Thislinewaslikeafuseofthenetwork.IfanISParrow??(allow??borrow??意味不明回線を借りる?)the128KbpsbandwidthfromIX,theycouldassignthe128Kbpsontheline.WeagreedtosetthelimitationofthebandwidthasT1.)))↑この辺の文法は直したが、もと意味は私にはよくわからないです。Butasyouknow,thispolicyandoperationcausesdisasterssoon!ThislimitationcausedmanypacketlossatIX.SomemagazineswrotethatNSPIXP-1madeeverypacketlossinJapan.SowestartedNSPIXP-2asthenextstep.NSPIXP-2startedin1996.WeselectedtheKDDIcollocationspacefortheNSPIXP-2.NSPIXP-2wasdesignedforhighbandwidth–areliableandscalableIX.ThereasonwhyweselectedtheKDDIcollocationspacewasreliability.WeusedtwoDECGigaSwitches.Andin1998,weexpandedtofour.DualhomingofFDDIspecificationwasveryusefulforreliableoperations.Butasyouknow,FDDImeansthat100MbpsisnotenoughforrecentIXtraffic.Wehadtochangetonewtechnology,GigabitEthernettechnologyfromFDDIin2000.ThecurrentNSPIXP-2hasinstalledfourGigabitEthernetSwitches,andover60networksareinterconnected.Andthisisthesamegraphasbefore,theYaxisisexponential.NSPIXP-2trafficshowsexponentialgrowth.(でいいか?)Ok,backtothetable.NSPIXP-3wasstartedat1997,oneyearafterNSPIXP-2.ThelocationofNSPIXP-2isdowntownTokyo.TheKDDIBuildingsarestrongbuildings…butwehadtoconsiderearthquakes.SowesetuptheIXintheOsakaareaforbackupoftheNSPIXP-2.AndnowwearestartingthedistributionoftheNSPIXP-2calledasNSPXIP-2+inthetable.MostofthecurrentinternettrafficisfromDataCenters.WemustcarrytrafficfromDataCenterstotheISPssmoothly.SoweareconnectingseveralDataCenterwithfiber.ThisisNSPIXP-2+,DistributedNSPIXP-2,DIX?.....Sorry,NSPIXPdoesnothaveanofficialname!?SoNSPIXP-2+isalsotemporaryname.!WeareusingIEEE802.3adastrunkingmechanismandusingFastSTPbetweenthelocations.Nowwearetestingfromendoflastyear.IwouldliketostarttheoperationbyAprilthisyear.ThisisamapofdistributedNSPIXP-2.NTTOtemachibuilding,@TokyoPower.comariake,WorldcomRoppongiMINDatNishioiAndLevel3atToranomon,Wehaveanewlocation,AboveNetdatacenterisalsoconnectedasthedistributedNSPIXP-2.HerearetrafficstatisticsforNSPIXP-3Therecenttrafficisover500Mbps.