How do I get the raw SQL underlying a LINQ query when using Entity Framework CTP 5 "code only"?

I've using Entity Framework CTP5 in "code only" mode. I'm running a LINQ query on a object that was return from the database, as the query is running really slowly. Is there any way in which I can get the SQL statement that is being generated from the query?

Topic currentTopic =
    (from x in Repository.Topics
     let isCurrent = (x.StoppedAt <= x.StartedAt || (x.StartedAt >= currentTopicsStartedAtOrAfter))
     where x.Meeting.Manager.User.Id == user.Id && isCurrent
     orderby x.StartedAt descending
     select x).FirstOrDefault();

The "Repository" property is a descendent of DbContext.

It's a lit开发者_如何学运维tle complicated, as EF can't use my helper methods on the objects, so I'm specifying the logic directly in the query.

So, is there any way I can dump the SQL that will be produced by that LINQ query (e.g. to my log4net repository)?

You can try using Entity Framework tracing provider as described here (but it is old post for CTP3).

Your other choices are:

• SQL Server Profiler - part of MS SQL Developer tools (in case your DB is SQL Server)
• Intelli trace - only in VS 2010 Ultimate but it doesn't show parameter values
• Hugati Query Profiler
• Entity framework profiler

In common EF you can also use ToTraceString as @Andy suggested but DbQuery in CodeFirst doesn't have this method (or I didn't find it).

Edit:

So DbQuery doesn't have ToTraceString because it is directly implemented as ToString.

This worked for me and it is free:

public static class DebugExtensions
{
    private static object GetPropertyValue(object o, string Name)
    {
        return o.GetType().GetProperties(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public).Where(x => x.Name == Name).First().GetValue(o, null);
    }
    public static string ToTraceString(this IQueryable query)
    {
        var oquery = (ObjectQuery)GetPropertyValue(GetPropertyValue(query, "InternalQuery"), "ObjectQuery");
        return oquery.ToTraceString();
    }
}

Usage:

   var rows = db.Forecasts.Take(1);
   System.Diagnostics.Debug.WriteLine(rows.ToTraceString());

I'd either use SQL Trace to grab the query running on the server directly, or use the Event Tracing for Windows (SQL Profiling) feature out of ANTS Performance Profiler.

Setting up logging is as easy as:

context.Database.Log = Console.WriteLine;

Original answer: https://stackoverflow.com/a/20757916/2183503

The extension method ToTraceString() might be what you're looking for:

http://msdn.microsoft.com/en-us/library/system.data.objects.objectquery.totracestring.aspx