Unable to find the requested .Net Framework Data Provider. It may not be installed

Hi guys, I was on my holidays and enjoying something different so I was away for some time. However right now I am back and working on a Sliver light project. In that project I found an interesting situation which I would like to share with you. I was using Enterprise Library 5.0 for my connection string and I was using Oracle.DataAccess for my connection.

Here was the line on which I was getting error:-
dbase = DatabaseFactory.CreateDatabase("MyDB");

After spending some time I checked that every thing seems OK and there is no issue with my web.config file. I tried to replace CreateDatabase and use another way to create database connection in Enterprise Library:-
DbProviderFactory providerFactory =
DbProviderFactories.GetFactory("Oracle.DataAccess.Client");
dbase = new Microsoft.Practices.EnterpriseLibrary.Data
.GenericDatabase("data source=xxx;User id=xxx;Password=xxx;",providerFactory);

Above also did not solved my problem and I started to get another error :-

I checked that either I have installed ODP or not but It was installed in my GAC folder (usually at C:\Windows\assembly). Here is how my GAC folder looks like:-

Now finally I had a clue that what happened. My system have multiple versions of Oracle.DataAccess installed and .net can not decide that which version should be used. So, to Resolve this I have to add a DbProviderFactory in my web.config file. So here is how I added it:-
 <system.data>
    <DbProviderFactories>
    <add name="Oracle Data Provider for .NET"
            invariant="Oracle.DataAccess.Client"
            description="Oracle Data Provider for .NET"
            type="Oracle.DataAccess.Client.OracleClientFactory,
                  Oracle.DataAccess,
                  Version=2.112.1.2,
                  Culture=neutral,
                  PublicKeyToken=89b483f429c47342" />
</DbProviderFactories>

Now last thing, I know that I have to use Oracle.DataAccess but how did I get other information i.e. Version, Culture and PublicKeyToken. To do this simply right click on the Assembly and take it properties. Here is the page that will appear through which you can get all the details:-

Finally my application started working and it connected to database perfectly. Hopefully this will also be useful for you . Do share your comments with me. Happy coding !!!