Entity Framework Core: Show Parameter Values in Logging

Back in October, I did a post on Entity Framework Core: Logging which covers enabling logging for Entity Framework Core. This post is going to expand on that previous post and show you how to get the parameter values used in the queries in addition to the SQL statements being used.

Review

This post will not be covering how to set up a logger please see this previous post for those details. The following is the kind of information you get in the log based on the previous post.

Microsoft.EntityFrameworkCore.Database.Command[20101]
Executed DbCommand (41ms) [Parameters=[@__id_0='?' (DbType = Int32)], CommandType='Text', CommandTimeout='30']
SELECT TOP(2) [m].[Id], [m].[Address], [m].[City], [m].[Email], [m].[Name], [m].[Phone], [m].[PostalCode], [m].[State]
FROM [Contact] AS [m]
WHERE [m].[Id] = @__id_0

This is helpful when you need to verify the queries Entity Framework is producing, but if you are trying to track down a data related problem not knowing what parameters values are being used can be a pain.

Enable Parameter Values in Logging

Entity Framework Core provides an option to enable sensitive data logging. To enable this option open the Startup class and in the ConfigureServices function make the following change to the AddDbContext call for the DbContext you want the option on for.

Before:
services
  .AddDbContext<ContactsContext>(options => 
     options.UseSqlServer(Configuration["Data:ContactsContext:ConnectionString"]));

After:
services
  .AddDbContext<ContactsContext>(options =>
  {                         
     options.UseSqlServer(Configuration["Data:ContactsContext:ConnectionString"]);
     options.EnableSensitiveDataLogging();
  });

Now running the same query as above you will see the following output.

Microsoft.EntityFrameworkCore.Database.Command[20100]
Executing DbCommand [Parameters=[@__id_0='1' (Nullable = true)], CommandType='Text', CommandTimeout='30']
SELECT TOP(2) [m].[Id], [m].[Address], [m].[City], [m].[Email], [m].[Name], [m].[Phone], [m].[PostalCode], [m].[State]
FROM [Contact] AS [m]
WHERE [m].[Id] = @__id_0

As you can see with enable sensitive data logging we get the value of the ID parameter instead of a question mark.

Before: [Parameters=[@__id_0='?' (DbType = Int32)]
After:  [Parameters=[@__id_0='1' (DbType = Int32)]

Wrapping Up

This is a handy option when you need it. Just use it with care as it could expose data that should be kept private.