我在ASP.NET Webforms项目上使用VS 15 Pro。我想创建一个与Oracle数据库的小型数据库连接。我安装了NuGet包＆＃39; Oracle.ManagedDataAccess＆＃39;。在启动项目时，它会向我抛出错误，即“oracle.manageddataaccess.client”部分＆＃39; oracle.manageddataaccess.client＆＃39;据说定义了两次，即使它只在web.config中定义一次。我在machine.config中找到了它，但是当我删除它时甚至无法启动VS.当我从web.config中取出它时，在使用OracleConnection.Open();时会引发错误。据推测，TNS尚未定义，但它位于tnsnames.ora中，连接字符串可用于其他项目和程序。有趣的是，使用SQL数据源ASP Web控件工作正常。
它有效，现在我把TNS的定义放在连接字符串中就像这样
<connectionStrings>
<add name="val" connectionString="Data Source=(DESCRIPTION =(ADDRESS = (PROTOCOL = TCP)(HOST = myHost)(PORT = 1521))(LOAD_BALANCE = yes)(CONNECT_DATA = (SERVER = DEDICATED)(SERVICE_NAME = myServiceName)));User ID=val;Password=xxxx;" providerName="System.Data.OracleClient"/>
</connectionStrings>
<?xml version="1.0"?>
<!--
For more information on how to configure your ASP.NET application, please visit
http://go.microsoft.com/fwlink/?LinkId=169433
-->
<configuration>
<configSections>
<section name="oracle.manageddataaccess.client"
type="OracleInternal.Common.ODPMSectionHandler, Oracle.ManagedDataAccess, Version=4.122.1.0, Culture=neutral, PublicKeyToken=89b483f429c47342"/>
</configSections>
<connectionStrings>
<add name="val" connectionString="correct connection string" providerName="System.Data.OracleClient"/>
</connectionStrings>
<system.web>
<authentication mode="Windows"/>
<compilation debug="true" targetFramework="4.5"/>
<httpRuntime/>
<pages controlRenderingCompatibilityVersion="4.0"/>
</system.web>
<system.codedom>
<compilers>
<compiler language="c#;cs;csharp" extension=".cs" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.CSharpCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:6 /nowarn:1659;1699;1701"/>
<compiler language="vb;vbs;visualbasic;vbscript" extension=".vb" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.VBCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:14 /nowarn:41008 /define:_MYTYPE=\"Web\" /optionInfer+"/>
</compilers>
</system.codedom>
<system.data>
<DbProviderFactories>
<remove invariant="Oracle.ManagedDataAccess.Client"/>
<add name="ODP.NET, Managed Driver" invariant="Oracle.ManagedDataAccess.Client" description="Oracle Data Provider for .NET, Managed Driver" type="Oracle.ManagedDataAccess.Client.OracleClientFactory, Oracle.ManagedDataAccess, Version=4.122.1.0, Culture=neutral, PublicKeyToken=89b483f429c47342"/>
</DbProviderFactories>
</system.data>
<runtime>
<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
<dependentAssembly>
<publisherPolicy apply="no"/>
<assemblyIdentity name="Oracle.ManagedDataAccess" publicKeyToken="89b483f429c47342" culture="neutral"/>
</dependentAssembly>
</assemblyBinding>
</runtime>
<oracle.manageddataaccess.client>
<version number="*">
<dataSources>
<dataSource alias="SampleDataSource" descriptor="(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=localhost)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=ORCL))) "/>
</dataSources>
</version>
</oracle.manageddataaccess.client>
</configuration>
OracleConnection.Open()错误Serverfehler in der Anwendung /.
ORA-12154: TNS: Angegebener Connect Identifier konnte nicht aufgelöst werden
Beschreibung: Unbehandelte Ausnahme beim Ausführen der aktuellen Webanforderung. Überprüfen Sie die Stapelüberwachung, um weitere Informationen über diesen Fehler anzuzeigen und festzustellen, wo der Fehler im Code verursacht wurde.
Ausnahmedetails: OracleInternal.Network.NetworkException: ORA-12154: TNS: Angegebener Connect Identifier konnte nicht aufgelöst werden
Quellfehler:
Zeile 111: using (OracleConnection oc = new OracleConnection(ConfigurationManager.ConnectionStrings["val"].ConnectionString))
Zeile 112: {
Zeile 113: oc.Open();
Zeile 114:
Zeile 115: OracleCommand cmd = new OracleCommand(string.Format("select berechtigung from dim_sql_ausgeben_user where name = '{0}'", user), oc);
Quelldatei: C:\Users\Mschloesser\Documents\Visual Studio 2015\Projects\plain_sql_executer\plain_sql_executer\default.aspx.cs Zeile: 113
Stapelüberwachung:
[NetworkException (0x2f7a): ORA-12154: TNS: Angegebener Connect Identifier konnte nicht aufgelöst werden]
OracleInternal.Network.AddressResolution..ctor(String TNSAlias, String instanceName) +126
OracleInternal.Network.OracleCommunication.DoConnect(String tnsDescriptor) +68
OracleInternal.Network.OracleCommunication.Connect(String tnsDescriptor, Boolean doNAHandshake, String IName) +29
OracleInternal.ServiceObjects.OracleConnectionImpl.Connect(ConnectionString cs, Boolean bOpenEndUserSession, CriteriaCtx criteriaCtx, String instanceName) +4760
[OracleException (0x80004005): ORA-12154: TNS: Angegebener Connect Identifier konnte nicht aufgelöst werden]
OracleInternal.ConnectionPool.PoolManager`3.Get(ConnectionString csWithDiffOrNewPwd, Boolean bGetForApp, CriteriaCtx criteriaCtx, String affinityInstanceName, Boolean bForceMatch) +10583
OracleInternal.ConnectionPool.OraclePoolManager.Get(ConnectionString csWithNewPassword, Boolean bGetForApp, CriteriaCtx criteriaCtx, String affinityInstanceName, Boolean bForceMatch) +951
OracleInternal.ConnectionPool.OracleConnectionDispenser`3.Get(ConnectionString cs, PM conPM, ConnectionString pmCS, SecureString securedPassword, SecureString securedProxyPassword, CriteriaCtx criteriaCtx) +1024
Oracle.ManagedDataAccess.Client.OracleConnection.Open() +3273
plain_sql_executer._default.check_authority() in C:\Users\Mschloesser\Documents\Visual Studio 2015\Projects\plain_sql_executer\plain_sql_executer\default.aspx.cs:113
plain_sql_executer._default.Page_Load(Object sender, EventArgs e) in C:\Users\Mschloesser\Documents\Visual Studio 2015\Projects\plain_sql_executer\plain_sql_executer\default.aspx.cs:17
System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +51
System.Web.UI.Control.OnLoad(EventArgs e) +95
System.Web.UI.Control.LoadRecursive() +59
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +678