How to log Entity Framework SQL

Question

I'd like to be able to log all the SQL queries executed by the Entity Framework to log4net. What's the best way to do this?

Answer 1

As far as I know, there is no simple solution to do it automatically. However you can easily get the SQL command for a query using the ToTraceString method :

var query = from p in context.Products
            where p.Price < 10.0
            select p;

Log(((ObjectQuery)query).ToTraceString());

To make it easier, you can create an extension to perform the cast to ObjectQuery :

public static string ToTraceString(this IQueryable query)
{
    ObjectQuery objectQuery = (ObjectQuery)query;
    if (objectQuery != null)
    {
        return objectQuery.ToTraceString();
    }
    return null;
}

Log(query.ToTraceString());

Answer 2

As Thomas wrote, there is no simple way (at least in VS2008), but I found a solution on MSDN and described an implementation on my blog. You only need to replace my file logging method with a call to log4net.

Answer 3

You could use SQL Profiler as well.