Using mvc-mini-profiler database profiling with Entity Framework Code First

Question

I'm using the mvc-mini-profiler in my project built with ASP.Net MVC 3 and Entity Framework code-first.

Everything works great until I attempt to add database profiling by wrapping the connection in the ProfiledDbConnection as described in the documentation. Since I'm using a DbContext, the way I am attempting to provide the connection is through the constructor using a static factory method:

public class MyDbContext : DbContext
{                
    public MyDbContext() : base(GetProfilerConnection(), true)
    { }

    private static DbConnection GetProfilerConnection()
    {
        // Code below errors
        //return ProfiledDbConnection.Get(new SqlConnection(ConfigurationManager.ConnectionStrings["MyConnectionName"].ConnectionString));

        // Code below works fine...
        return new SqlConnection(ConfigurationManager.ConnectionStrings["MyConnectionName"].ConnectionString);
    }

    //...
}

When using the ProfiledDbConnection, I get the following error:

ProviderIncompatibleException: The provider did not return a ProviderManifestToken string.

Stack Trace:

[ArgumentException: The connection is not of type 'System.Data.SqlClient.SqlConnection'.]
   System.Data.SqlClient.SqlProviderUtilities.GetRequiredSqlConnection(DbConnection connection) +10486148
   System.Data.SqlClient.SqlProviderServices.GetDbProviderManifestToken(DbConnection connection) +77
   System.Data.Common.DbProviderServices.GetProviderManifestToken(DbConnection connection) +44

[ProviderIncompatibleException: The provider did not return a ProviderManifestToken string.]
System.Data.Common.DbProviderServices.GetProviderManifestToken(DbConnection connection) +11092901
   System.Data.Common.DbProviderServices.GetProviderManifestToken(DbConnection connection) +11092745
   System.Data.Entity.DbModelBuilder.Build(DbConnection providerConnection) +221
   System.Data.Entity.Internal.LazyInternalContext.CreateModel(LazyInternalContext internalContext) +61
   System.Data.Entity.Internal.RetryLazy`2.GetValue(TInput input) +1203482
   System.Data.Entity.Internal.LazyInternalContext.InitializeContext() +492
   System.Data.Entity.Internal.InternalContext.GetEntitySetAndBaseTypeForType(Type entityType) +26
   System.Data.Entity.Internal.Linq.InternalSet`1.Initialize() +89
   System.Data.Entity.Internal.Linq.InternalSet`1.get_InternalContext() +21
   System.Data.Entity.Infrastructure.DbQuery`1.System.Linq.IQueryable.get_Provider() +44
   System.Linq.Queryable.Where(IQueryable`1 source, Expression`1 predicate) +135

I have stepped through and the type returned by ProfiledDbConnection.Get is of type ProfiledDbConnection (Even if the current MiniProfiler is null).

The MiniProfiler.Start() method is called within the Global Application_BeginRequest() method before the DbContext is instantiated. I am also calling the Start method for every request regardless but calling stop if the user is not in the correct role:

    protected void Application_BeginRequest()
    {
        // We don't know who the user is at this stage so need to start for everyone
        MiniProfiler.Start();
    }

    protected void Application_AuthorizeRequest(Object sender, EventArgs e)
    {
        // Now stop the profiler if the user is not a developer
        if (!AuthorisationHelper.IsDeveloper())
        {
            MvcMiniProfiler.MiniProfiler.Stop(discardResults: true);
        }
    }

    protected void Application_EndRequest()
    {
        MiniProfiler.Stop();
    }

I'm not sure if this affects things but I'm also using StructureMap as IoC for the DbContext using the following initialiser:

For().Singleton().HybridHttpOrThreadLocalScoped();

I understand that there is a similar question on here with a good explanation of what's happening for that user, however it doesn't seem to solve my problem.

EDIT:

For clarity. I am attempting to pass the connection as ProfiledDbConnection in order to profile the generated sql from Entity Framework Code First.

Profiled Sql

The Entity Framework is expecting a connection with type SqlConnection which of course this isn't.

Here is an example of my connection string (notice the providerName)

I attempted to create my own version of the ProfiledDbConnection inheriting from SqlConnection but it is a sealed class.

If there is some way of telling Entity Framework about the custom connection type then perhaps this would work. I tried setting the providerName in the connection string to MvcMiniProfiler.Data.ProfiledDbConnection but that didn't work.

So. Perhaps an evolution of the question would be: How can you pass a custom connection type to Entity Framework Code First?

Using mvc-mini-profiler database profiling with Entity Framework Code First

3 Answers