Entity Framework Core 2.2.1 DbQuery error system.Data.SqlTypes.SqlNullValueException

Trying to work with DbQuery. I need to get non-entity type UserDetailDTO using raw sql. Added DbQuery to the context and call it from controller. But it's generate system.Data.SqlTypes.SqlNullValueException.

My context:

public class TrainingAppDbContext : DbContext
{
    public DbSet<User> Users { get; set; }
    public DbQuery<UserDetailDTO> UserDetailDTO { get; set; }

    public TrainingAppDbContext(DbContextOptions<TrainingAppDbContext> options)
    : base(options)
    {
        Database.EnsureCreated();
    }        
}

Controller:

public class AccountController : Controller
{
    private readonly TrainingAppDbContext ct;

    public AccountController(TrainingAppDbContext ct)
    {
        this.ct = ct;
    }

    public IActionResult Test()
    {
        var results = ct.UserDetailDTO.FromSql("SELECT * FROM users").ToList();
        return View();
    }
 }

When I calling my UserDetailDTO from context it's generates an error.

error picture