How do you show underlying SQL query in EF Core?

Question

At 3:15 from the end of this ".NET Core 2.0 Released!" video, Diego Vega shows a demo of new features in Entity Framework Core 2.0. As part of that, a dump of the underlying SQL is shown in the console app.

I have seen many answers on Stack Overflow suggesting that people use an SQL profiler to view the underlying queries. But now I'm curious: how can you do what Diego Vega did, and get the query to show right there in the application?

Update for .NET 6: EF logging is enabled by default in development. See this GitHub issue

Update: Diego added "Microsoft.EntityFrameworkCore.Database.Command": "Information" to appsettings.Development.json. See How do you show underlying SQL query in EF Core? for more details.

Answer 1

Hi you can do something like following to display Entity Framework Core generated sql code in output window. In your DbContext class:

public static readonly Microsoft.Extensions.Logging.LoggerFactory _myLoggerFactory =      new LoggerFactory(new[] {          new Microsoft.Extensions.Logging.Debug.DebugLoggerProvider()      });  protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder) {     optionsBuilder.UseLoggerFactory(_myLoggerFactory); } 

The debug logger writes messages in the debug output window only when a debugger is attached.

You will have to do following:

• using Microsoft.Extensions.Logging;
• Install nuget package: Microsoft.Extensions.Logging.Debug