Question

好吧，这就是我实际看到的错误：

An error occurred accessing the database. This usually means that the connection to the database failed. Check that the connection string is correct and that the appropriate DbContext constructor is being used to specify it or find it in the application's config file. See http://go.microsoft.com/fwlink/?LinkId=386386 for information on DbContext and connections. See the inner exception for details of the failure.

当我去Visual Studio并通过这个小工具打开我的远程服务器中的数据连接和添加时，我可以很好地连接到它。但是，我似乎无法通过我的应用程序与ConnectionStrings连接到它。这是连接时的完整错误日志。

Using StartUp project 'Chime System'.
Using NuGet project 'Chime System'.
Specify the '-Verbose' flag to view the SQL statements being applied to the target database.
System.Data.Entity.Core.ProviderIncompatibleException: An error occurred 
accessing the database. This usually means that the connection to the database failed. Check that the connection string is correct and that the appropriate DbContext constructor is being used to specify it or find it in the application's config file. See http://go.microsoft.com/fwlink/?LinkId=386386 for information on DbContext and connections. See the inner exception for details of the failure. ---> System.Data.Entity.Core.ProviderIncompatibleException: The provider did not return a ProviderManifestToken string. ---> Oracle.ManagedDataAccess.Client.OracleException: ORA-12154: TNS:could not resolve the connect identifier specified ---> OracleInternal.Network.NetworkException: ORA-12154: TNS:could not resolve the connect identifier specified
at OracleInternal.Network.AddressResolution..ctor(String TNSAlias, String instanceName)
at OracleInternal.Network.OracleCommunication.DoConnect(String tnsDescriptor)
at OracleInternal.Network.OracleCommunication.Connect(String tnsDescriptor, Boolean doNAHandshake, String IName)
at OracleInternal.ServiceObjects.OracleConnectionImpl.Connect(ConnectionString cs, Boolean bOpenEndUserSession, CriteriaCtx criteriaCtx, String instanceName)
--- End of inner exception stack trace ---
at OracleInternal.ConnectionPool.PoolManager`3.Get(ConnectionString csWithDiffOrNewPwd, Boolean bGetForApp, CriteriaCtx criteriaCtx, String affinityInstanceName, Boolean bForceMatch)
at OracleInternal.ConnectionPool.OraclePoolManager.Get(ConnectionString csWithNewPassword, Boolean bGetForApp, CriteriaCtx criteriaCtx, String affinityInstanceName, Boolean bForceMatch)
at OracleInternal.ConnectionPool.OracleConnectionDispenser`3.Get(ConnectionString cs, PM conPM, ConnectionString pmCS, SecureString securedPassword, SecureString securedProxyPassword, CriteriaCtx criteriaCtx)
at Oracle.ManagedDataAccess.Client.OracleConnection.Open()
at Oracle.ManagedDataAccess.EntityFramework.EFOracleProviderServices.GetDbProviderManifestToken(DbConnection connection)
at System.Data.Entity.Core.Common.DbProviderServices.GetProviderManifestToken(DbConnection connection)
--- End of inner exception stack trace ---
at System.Data.Entity.Core.Common.DbProviderServices.GetProviderManifestToken(DbConnection connection)
at System.Data.Entity.Utilities.DbProviderServicesExtensions.GetProviderManifestTokenChecked(DbProviderServices providerServices, DbConnection connection)
--- End of inner exception stack trace ---
at System.Data.Entity.Utilities.DbProviderServicesExtensions.GetProviderManifestTokenChecked(DbProviderServices providerServices, DbConnection connection)
at System.Data.Entity.Infrastructure.DefaultManifestTokenResolver.<>c__DisplayClass1.<ResolveManifestToken>b__0(Tuple`3 k)
at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
at System.Data.Entity.Infrastructure.DefaultManifestTokenResolver.ResolveManifestToken(DbConnection connection)
at System.Data.Entity.Utilities.DbConnectionExtensions.GetProviderInfo(DbConnection connection, DbProviderManifest& providerManifest)
at System.Data.Entity.DbModelBuilder.Build(DbConnection providerConnection)
at System.Data.Entity.Internal.LazyInternalContext.CreateModel(LazyInternalContext internalContext)
at System.Data.Entity.Internal.RetryLazy`2.GetValue(TInput input)
at System.Data.Entity.Internal.LazyInternalContext.InitializeContext()
at System.Data.Entity.Internal.LazyInternalContext.get_ModelBeingInitialized()
at System.Data.Entity.Infrastructure.EdmxWriter.WriteEdmx(DbContext context, XmlWriter writer)
at System.Data.Entity.Utilities.DbContextExtensions.<>c__DisplayClass1.<GetModel>b__0(XmlWriter w)
at System.Data.Entity.Utilities.DbContextExtensions.GetModel(Action`1 writeXml)
at System.Data.Entity.Utilities.DbContextExtensions.GetModel(DbContext context)
at System.Data.Entity.Migrations.DbMigrator..ctor(DbMigrationsConfiguration configuration, DbContext usersContext, DatabaseExistenceState existenceState, Boolean calledByCreateDatabase)
at System.Data.Entity.Migrations.DbMigrator..ctor(DbMigrationsConfiguration configuration)
at System.Data.Entity.Migrations.Design.ToolingFacade.BaseRunner.GetMigrator()
at System.Data.Entity.Migrations.Design.ToolingFacade.UpdateRunner.Run()
at System.AppDomain.DoCallBack(CrossAppDomainDelegate callBackDelegate)
at System.AppDomain.DoCallBack(CrossAppDomainDelegate callBackDelegate)
at System.Data.Entity.Migrations.Design.ToolingFacade.Run(BaseRunner runner)
at System.Data.Entity.Migrations.Design.ToolingFacade.Update(String targetMigration, Boolean force)
at System.Data.Entity.Migrations.UpdateDatabaseCommand.<>c__DisplayClass2.<.ctor>b__0()
at System.Data.Entity.Migrations.MigrationsDomainCommand.Execute(Action command)
An error occurred accessing the database. This usually means that the connection to the database failed. Check that the connection string is correct and that the appropriate DbContext constructor is being used to specify it or find it in the application's config file. See http://go.microsoft.com/fwlink/?LinkId=386386 for information on DbContext and connections. See the inner exception for details of the failure.

这里是App的连接字符串信息：

<section name="oracle.manageddataaccess.client" type="OracleInternal.Common.ODPMSectionHandler, Oracle.ManagedDataAccess, Version=4.122.1.0, Culture=neutral, PublicKeyToken=89b483f429c47342" /> 

<connectionStrings>
 <add name="defaultConnection" connectionString="Data Source=myServer;Persist Security Info=True;User ID=myUserID;Password=***********;" providerName="Oracle.ManagedDataAccess.Client"/>
</connectionStrings>

<oracle.manageddataaccess.client>
 <version number="*">
  <dataSources>
    <dataSource alias="SampleDataSource" descriptor="(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=myServer)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=ORCL)))" />
  </dataSources>
 </version>
</oracle.manageddataaccess.client>

这里是来自数据连接工具

的ConnectionString

connectionString = Data Source=myServer;Persist Security Info=True;User ID=myUserID;Password=***********;Unicode=True
provider = .NET Framework Data Provider for Oracle

所以我的问题是我到底做错了什么？我的应用程序中的ConnectionStrings是否有问题？我也不认为它是我的防火墙，尽管我会仔细检查这个。您可以提供的任何帮助或建议都会有所帮助。

Answer 1

该错误消息的重要部分如下：

ORA-12154：TNS：无法解析指定的连接标识符

您正尝试使用端口1521连接到主机myServer上名为ORCL的服务。

第一个问题：你能ping那台服务器吗？（即：DNS工作吗？你真的可以与服务器建立网络连接吗？）我猜你可以。

第二个问题：Oracle侦听器是否在该服务器上运行？

您可以通过让数据库服务器上的oracle用户运行以下命令来找到它： lsnrctl status该命令的输出应显示服务器上找到的服务的名称以及运行侦听器的端口号。如果它没有提供任何服务，那么它就不会运行而且需要运行。 lsnrctl start作为oracle用户将使其运行，lsnrctl status将告诉您可用的端口和服务。

如果我不得不猜测我会说你的监听器在数据库服务器上运行并且正在侦听端口1521，但是你正在尝试访问一个不被监听的服务名称（即：你该服务器上没有ORCL服务。）

连接到远程Oracle Server Visual Studio 2015时出现问题

1 个答案: