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.

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.