




版权说明:本文档由用户提供并上传,收益归属内容提供方,若内容存在侵权,请进行举报或认领
文档简介
UsingApplicationContextsObjectivesAftercompletingthislesson,youshouldbeabletodothefollowing:DescribehowanapplicationcontextisusedDescribethesourcesofapplicationcontextvaluesImplementalocalcontextImplementanapplicationcontextthatisaccessedgloballyApplicationContext:DescriptionAnapplicationcontextisamemorycontainerwithattributes:Thecontaineriscalledanamespace.Anamespacehasattributes.Eachnamespaceisindependentofothers.Thenamespaceispopulatedbyapackage.NamespaceUsetheCREATECONTEXTcommandto:CreateacontextinanamespaceAssociateapackagewiththecontextHRAPPCREATECONTEXThrappUSINGhr_context;UsetheSET_CONTEXTprocedureto:CreateattributesSetvaluesofattributesdbms_session.set_context('hrapp','emp_id',v_emp_id);UsingtheApplicationContextAnapplicationcontext:IsreadbyapplicationsCanbeusedto:AuthorizeusersLimitaccesstodata,calledFGACSetattributesusedintheapplicationSettingtheApplicationContextThecontextattributesaresetbyapackage,which:CreatesattributesinthecontextAssignsvaluestotheattributesofthecontextIsusuallycalledwhenauserconnectsEachapplicationcanuseoneormorecontexts.Acontextmaybeusedbymorethanoneapplication.USERENVisabuilt-incontextwithsessionpropertiesandisavailabletoallapplications.ApplicationContextDataSourcesThebuilt-inUSERENVcontextcontainssessionprimitivesasattributes. Example:ClientIPaddressAlocalcontextusesdatabaseobjects.Thedevelopersetstheseattributes. Example:TheEMPLOYEE_IDcolumnintheEMPLOYEEStableAnexternalizedcontextcangetvaluesfromanexternalsource,suchasOracleCall
Interface(OCI).Aglobalcontextusesvaluesfromthedirectory-entryattributes.ImplementingaLocalContext1. Createanapplicationcontext.2. CreateaPL/SQLpackagethatsetsthecontext.3. Callthepackagetosetthecontextattribute.4. Readthecontextattributeintheapplication.ApplicationcontextPL/SQLpackagePL/SQLprogramSetReadStep1:CreateanApplicationContextCreateauniquecontext:NamesthecontextHRAPPAssociatesitwithanHR_CONTEXTpackageYoucansetthecontextattributesonly:InthepackagenamedinCREATECONTEXTInthefunctionassociatedwithapolicyInthepackage,setattributesbycallingDBMS_SESSION.SET_CONTEXT.Alternatively,youcanuseOraclePolicyManagerGUI.CREATECONTEXThrappUSINGhr_context;Step2:CreateaPL/SQLPackage
ThatSetstheContextCreatetheHR_CONTEXT.SET_EMP_IDprocedure:UseSYS_CONTEXTtogetthesessionusername:sys_context('userenv','session_user');SELECTemployee_idINTOv_emp_idFROMemployees WHEREemail= sys_context('userenv','session_user');dbms_session.set_context('hrapp','emp_id',v_emp_id);UseSET_CONTEXTtosetacontextattribute:UsethesessionusernametogettheemployeeID:Step3:CallthePackage
CreatealogontriggerthatcallstheHR_CONTEXT.SET_EMP_IDprocedure:CREATEORREPLACETRIGGERhr_context_logonAFTERLOGONONphall.SCHEMABEGINhr_context.set_emp_id();END;/Step4:ReadtheContextAttribute
intheApplicationToreturnanattributevalue,use:Therearetwoarguments:NameofthecontextNameoftheattributeExampleinSELECT:sys_context('hrapp','emp_id')SELECT*FROMdepartmentsWHEREmanager_id=
sys_context('hrapp','emp_id');SYS_CONTEXTPL/SQLFunctionSYS_CONTEXTreturnscontextattributes: sys_context('context','attribute')ToreturntheclientIPaddressfromthebuilt-incontext,use:ToreturnEMP_IDfromtheHRAPPcontext,use:sys_context('userenv','ip_address')sys_context('hrapp','emp_id')ApplicationContextAccessedGloballySharesacontextacrosssessionsSimplifiesconnectionpoolingfromamiddletierUsesaclientidentifiertoidentifytheuserofasession
PL/SQLprogramAPL/SQLprogramBUserDatabaseSession2UserDatabaseSession1SGAApplicationcontextisEMPID=101HowtheApplicationContextAccessedGloballyWorks2. Logsin6. Makesanotherrequest8. Logsout1. Buildsconnectionpool3. Establishessession4. Processesrequest5. Completesrequest7. Processessecondrequest9. ClearscontextPHALLApplicationServerOracle9iPL/SQLPackagesandProceduresDBMS_SESSIONmanages:Contexts:Globalidentifiers:dbms_session.set_context ('hrapp','emp_id',v_emp_id);dbms_session.set_identifier(12345);set_context(context,attribute,value);dbms_session.set_identifier(client_id);ImplementingtheApplicationContextAccessedGlobally1. Createtheapplicationcontextaccessedglobally.2. Modifytheprogramthatestablishesasession:Settheapplicationcontext.Setthesessionclientidentifier.Cleartheclientidentifierwhentherequestends.3. Modifytheapplicationserverprogramthathandlessubsequentrequestsinthesamesession:Setthesessionclientidentifierfromthissession.Cleartheclientidentifierwhentherequestends.4. Createormodifytheapplicationserverprogramthatendsasessiontoclearthecontext.Step1:CreatetheApplicationContextAccessedGloballyCreatethecontextbyusing:TheACCESSED
GLOBALLYclauseindicatesthatthecontextcanbeaccessedfrommultiplesessions.CREATECONTEXThrappUSINGhr_contextACCESSEDGLOBALLY;Step2:EstablishaSession1. Getauniquevaluetouseasaclientidentifier.2. Settheapplicationcontext:3. Setthesessionclientidentifier:4. Savetheclientidentifierinacookie.dbms_session.set_context('hrapp','id','phall','APPSMGR',12345);dbms_session.set_context('hrapp','dept','sales','APPSMGR',12345);dbms_session.set_identifier(12345);dbms_session.set_context(context,attr,value,username,client_id);Step3:HandleSubsequentRequests1. Gettheclientidentifierfromthecookie.2. Settheclientidentifierforthissession:3. Cleartheclientidentifierwhentherequestends:dbms_session.set_identifier(12345);dbms_session.clear_identifier();Step4:EndaSession1. Gettheclientidentifierfromthecookie.2. Clearthecontext:EXECdbms_session.clear_context('HRAPP','12345');DataDictionaryViewsSQL>CREATECONTEXThrappUSINGhr_context;Contextcreated.SQL>SELECT*2FROMdba_con
温馨提示
- 1. 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
- 2. 本站的文档不包含任何第三方提供的附件图纸等,如果需要附件,请联系上传者。文件的所有权益归上传用户所有。
- 3. 本站RAR压缩包中若带图纸,网页内容里面会有图纸预览,若没有图纸预览就没有图纸。
- 4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
- 5. 人人文库网仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对用户上传分享的文档内容本身不做任何修改或编辑,并不能对任何下载内容负责。
- 6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
- 7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。
最新文档
- 软件升级及维护合同
- 交通协管员聘用合同协议书
- 家禽购销合同
- 货品抵款结算协议书
- 应对市场变化的解决方案研究
- 兰州房屋租赁合同
- 机械租赁协议合同
- 第19课 治学须有疑无疑不成学-《怀疑与学问》(教学设计)九年级语文上册同步高效课堂(统编版)
- 第一单元学习任务《如何阐述自己的观点》教学设计 2023-2024学年统编版高中语文必修下册
- Unit 4 Fun with numbers 第二课时(教学设计)-2024-2025学年外研版(三起)(2024)英语三年级上册
- 幼儿园食品安全教育课件
- (中级)航空油料特设维修员(四级)理论考试题库-下(判断题)
- 《中国心力衰竭诊断和治疗指南2024》解读
- TJSJCXH 4-2023 先张法预应力超高强混凝土管桩
- DB37-T 4384-2021 混凝土桥梁有效预应力无损检测技术规程
- 大学物理英语词汇
- 汽车悬挂系统结构原理详细图解
- GB/T 13305-2024不锈钢中α-相含量测定法
- 2024年高中英语衡水体书法练字字帖
- 垃圾清运管理制度12篇
- 人教版二年级下册口算题天天练1000道可打印带答案
评论
0/150
提交评论