How to log queries using Entity Framework 7?

Question

I am using Entity Framework 7 on the nightly build channel (right now I\'m using version EntityFramework.7.0.0-beta2-11524) and I\'m trying to log the queries that EF genera

Answer 1

For those using EF7 none of the above worked for me. But this is how i got it working. (from @avi cherry's comment)

In your Startup.cs you proably have a Configure method with a bunch of configurations in it. It should look like below (in addition to your stuff).

    public void Configure(IApplicationBuilder app, ILoggerFactory loggerFactory)
    {
        //this is the magic line
        loggerFactory.AddDebug(LogLevel.Debug); // formerly LogLevel.Verbose

        //your other stuff

    }

Answer 2

As an alternative to the above answers, I found this answer by far the easiest solution for me to reason about:

private readonly ILoggerFactory loggerFactory;

// Using dependency injection
public FooContext(ILoggerFactory loggerFactor) {
    this.loggerFactory = loggerFactory;
}

protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder) {
    optionsBuilder.UseLoggerFactory(loggerFactory);    // Register logger in context
}

Answer 3

For those who just want SQL queries to be logged (using Entity Framework Core with .NET Core 2.0 or above), use the following code in your DbContext class:

public static readonly LoggerFactory MyLoggerFactory
    = new LoggerFactory(new[]
    {
        new ConsoleLoggerProvider((category, level)
            => category == DbLoggerCategory.Database.Command.Name
               && level == LogLevel.Information, true)
    });

protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    => optionsBuilder
        .UseLoggerFactory(MyLoggerFactory) // Warning: Do not create a new ILoggerFactory instance each time
        .UseSqlServer(
            @"Server=(localdb)\mssqllocaldb;Database=EFLogging;Trusted_Connection=True;ConnectRetryCount=0");

Reference: https://docs.microsoft.com/en-us/ef/core/miscellaneous/logging

Answer 4

This worked for me with EF7 rc2-16485:

"EntityFramework.MicrosoftSqlServer": "7.0.0-rc2-16485",
"Microsoft.Extensions.Logging.Console": "1.0.0-rc2-15888",

public static class DbContextExtensions
{
    public static void LogToConsole(this DbContext context)
    {
        var contextServices = ((IInfrastructure<IServiceProvider>) context).Instance;
        var loggerFactory = contextServices.GetRequiredService<ILoggerFactory>();
        loggerFactory.AddConsole(LogLevel.Verbose);
    }
}