The ADO.NET provider 'Oracle.ManagedDataAccess.Client' is either not registered in the machine or application config file, or could not be loaded

Question

I am using .NET4.5.1 , MVC5 , EF6 , with Oracle.ManagedDataAccess 4.121.1.0 and Oracle.ManagedDataAccess.EntityFramework 6.121.2.0

I was able to generate Model from existing database (part of it adding table by table), application builds just fine.

However when I try run test query to see if it can get the data

 public ActionResult Cancellations()
    {
        var factoryClasses = System.Data.Common.DbProviderFactories.GetFactoryClasses();
        using (var db = new Entities())
        {
            var cancelationStatuses = new[] {3, 7, 9};
           var result = db.TRANSACTIONDETAIL.Where(o => cancelationStatuses.Contains(o.TRANSACTIONSTATUSID));
           return View(result);
        }
    }

it fails (on var result = ... ) with Unable to find the requested .Net Framework Data Provider. It may not be installed. Unable to find the requested .Net Framework Data Provider. It may not be installed.

When trying to look for DbProviderFactories indeed there is nothing in collection ( var factoryClasses = ).

However I do have installed 12c 4 (ODTwithODAC121024) and 11g (ODTwithODAC1120320_32bit), and have restarted machine.

Database is running on 11g and I can access it with PL/SQL developer

Web.config looks following:

<configuration>
<configSections>
<!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
 <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
 <section name="Oracle.ManagedDataAccess.Client" type="OracleInternal.Common.ODPMSectionHandler, Oracle.ManagedDataAccess, Version=4.121.2.0, Culture=neutral, PublicKeyToken=89b483f429c47342" />
</configSections>
.....
<connectionStrings>
.....
<add name="OracleDbContext" providerName="Oracle.ManagedDataAccess.Client" connectionString="User Id=oracle_user;Password=oracle_user_password;Data Source=oracle" />
 <add name="Entities" connectionString="metadata=res://*/OracleDb.csdl|res://*/OracleDb.ssdl|res://*/OracleDb.msl;provider=Oracle.ManagedDataAccess.Client;provider connection string='data source=******" providerName="System.Data.EntityClient" />           </connectionStrings>
......
<system.data>
<DbProviderFactories>
  <!-- Remove in case this is already defined in machine.config -->
  <add name="Oracle Data Provider for .NET" invariant="Oracle.ManagedDataAccess.Client" description="Oracle Data Provider for .NET" type="Oracle.ManagedDataAccess.Client.OracleClientFactory, Oracle.ManagedDataAccess, Version=4.121.1.0, Culture=neutral, PublicKeyToken=89b483f429c47342" />
  <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=4.121.2.0, Culture=neutral, PublicKeyToken=89b483f429c47342" />
</DbProviderFactories>

My assumption it's failing because Oracle is not being registered in DbProviderFactories or somewhere

How do I register Oracle in DbProviderFactories? Or if this is not the case what is wrong with my setup?

Answer 1

I encountered this error when i updated Visual Studio 2017. The error can be resolved by reinstalling ODT for VS 2017:

1) Close Visual Studio.

2) Uninstall the existing Oracle Developer Tools for Visual Studio 2017 from control Panel.

3) Install the latest one (ODTforVS2017_122011.exe) from the following link:

http://www.oracle.com/technetwork/topics/dotnet/downloads/odacmsidownloadvs2017-3806459.html

4) Open visual studio and build solution.The error should not generate now.

Answer 2

Figured it out.

In my machine.config there was already

<add name="Oracle Data Provider for .NET" invariant="Oracle.ManagedDataAccess.Client" description="Oracle Data Provider for .NET" type="Oracle.ManagedDataAccess.Client.OracleClientFactory, Oracle.ManagedDataAccess, Version=4.121.1.0, Culture=neutral, PublicKeyToken=89b483f429c47342" />

and then it was repeated in my web.config which would silently fail to give out any providers. So after taking out:

  <add name="Oracle Data Provider for .NET" invariant="Oracle.ManagedDataAccess.Client" description="Oracle Data Provider for .NET" type="Oracle.ManagedDataAccess.Client.OracleClientFactory, Oracle.ManagedDataAccess, Version=4.121.1.0, Culture=neutral, PublicKeyToken=89b483f429c47342" />
  <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=4.121.2.0, Culture=neutral, PublicKeyToken=89b483f429c47342" />

I got it running.

Answer 3

I resolved this by adding ODP.NET (Oracle.ManagedDataAccess.EntityFramework 12c) from NuGet. I'm running VS2015 with EF 6.2.0.

Answer 4

我刚刚通过安装Visual Studio 2013的Oracle Developer工具（我安装的VS版本）ODTforVS2013_121025.exe解决了这个错误