entity framework 4 - See SQL From EntityFramework with Collection-like Queries

Question

I do not have 'full' the version of MS SQL (SQL Express 2008) so I do not have the profiler tool.

I want to see the SQL generated by my Entity Framework code, but all of the examples I find use the

var x = from u in table
        select u;

type of syntax; But most of my queries are more like ..

var x = context.Users.Single(n => n.Name == "Steven");

type of syntax. What can I do to see the SQL generated, from this manner of coding? Any ideas?

Answer 1

check out this link... it has a tracing provider for EF4.

I'll try to give an example based on how I'm using this in a unit test.

Step 1: Register the provider

There are a couple ways to configure the provider. For my unit tests I configured the provider in code by calling the static method RegisterProvider();

[AssemblyInitialize()]
public static void AssemblyInit(TestContext context) {
    EFTracingProviderConfiguration.RegisterProvider();
}

Step 2: Create a sub-class of your entity model to provide the tracing extensions

public partial class ExtendedNorthwindEntities : NorthwindEntities {
    private TextWriter logOutput;

    public ExtendedNorthwindEntities(string connectionString)
        : base(EntityConnectionWrapperUtils.CreateEntityConnectionWithWrappers(
                connectionString,
                "EFTracingProvider")) {
    }

    #region Tracing Extensions

    private EFTracingConnection TracingConnection {
        get { return this.UnwrapConnection<EFTracingConnection>(); }
    }

    public event EventHandler<CommandExecutionEventArgs> CommandExecuting {
        add { this.TracingConnection.CommandExecuting += value; }
        remove { this.TracingConnection.CommandExecuting -= value; }
    }

    public event EventHandler<CommandExecutionEventArgs> CommandFinished {
        add { this.TracingConnection.CommandFinished += value; }
        remove { this.TracingConnection.CommandFinished -= value; }
    }

    public event EventHandler<CommandExecutionEventArgs> CommandFailed {
        add { this.TracingConnection.CommandFailed += value; }
        remove { this.TracingConnection.CommandFailed -= value; }
    }

    private void AppendToLog(object sender, CommandExecutionEventArgs e) {
        if (this.logOutput != null) {
            this.logOutput.WriteLine(e.ToTraceString().TrimEnd());
            this.logOutput.WriteLine();
        }
    }

    public TextWriter Log {
        get { return this.logOutput; }
        set {
            if ((this.logOutput != null) != (value != null)) {
                if (value == null) {
                    CommandExecuting -= AppendToLog;
                }
                else {
                    CommandExecuting += AppendToLog;
                }
            }

            this.logOutput = value;
        }
    }

    #endregion
}

Step 3: Attach to the Log property

var context = new ExtendedNorthwindEntities("name="NorthwindEntities"");

context.Log = System.Console.Out;