@viewModel DotvvmDemo.CalculatorViewModel, Dotvvm
    
<p>
    Enter the first number: 
    <dot:TextBox Text="{value: Number1}" />
</p>
<p>
    Enter the second number: 
    <dot:TextBox Text="{value: Number2}" />
</p>
<p>
    <dot:Button Text="Calculate" Click="{command: Calculate()}" />
</p>
<p>
    The result is: {{value: Result}}
</p>

using System;
    
namespace DotvvmDemo 
{
    public class CalculatorViewModel 
    {
            
        public int Number1 { get; set; }
            
        public int Number2 { get; set; }
            
        public int Result { get; set; }
            
        public void Calculate() 
        {
            Result = Number1 + Number2;
        }
    }
}

using System.Collections.Generic;

namespace EF_Sample08.DomainClasses
{
    public class Doctor
    {
        public int Id { set; get; }
        public string Name { set; get; }

        public virtual ICollection<Patient> Patients { set; get; }
    }
}

namespace EF_Sample08.DomainClasses
{
    public class Patient
    {
        public int Id { set; get; }
        public string Name { set; get; }

        public virtual Doctor Doctor { set; get; }
    }
}

using System.Data.Entity;
using EF_Sample08.DomainClasses;

namespace EF_Sample08.DataLayer.Context
{
    public class Sample08Context : DbContext
    {
        public DbSet<Doctor> Doctors { set; get; }
        public DbSet<Patient> Patients { set; get; }
    }
}

using System.Data.Entity.Migrations;
using EF_Sample08.DomainClasses;
using System.Collections.Generic;

namespace EF_Sample08.DataLayer.Context
{
    public class Configuration : DbMigrationsConfiguration<Sample08Context>
    {
        public Configuration()
        {
            AutomaticMigrationsEnabled = true;
            AutomaticMigrationDataLossAllowed = true;
        }

        protected override void Seed(Sample08Context context)
        {
            addData(context);
            addSP(context);
            addFn(context);
            base.Seed(context);
        }

        private static void addData(Sample08Context context)
        {
            var patient1 = new Patient { Name = "p1" };
            var patient2 = new Patient { Name = "p2" };
            var doctor1 = new Doctor { Name = "doc1", Patients = new List<Patient> { patient1, patient2 } };
            context.Doctors.Add(doctor1);
        }

        private static void addFn(Sample08Context context)
        {
            context.Database.ExecuteSqlCommand(
                @"IF  EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[FindDoctorPatientsCount]') 
                   AND type in (N'FN', N'IF', N'TF', N'FS', N'FT'))
                      DROP FUNCTION [dbo].[FindDoctorPatientsCount]");
            context.Database.ExecuteSqlCommand(
                @"CREATE FUNCTION FindDoctorPatientsCount(@Doctor_Id INT)
                    RETURNS INT
                    BEGIN
                     RETURN 
                     (
                         SELECT COUNT(*)
                         FROM   Patients
                         WHERE  Doctor_Id = @Doctor_Id
                     );
                    END");
        }

        private static void addSP(Sample08Context context)
        {
            context.Database.ExecuteSqlCommand(
                @"IF  EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[FindDoctorsStartWith]')
                  AND type in (N'P', N'PC'))
                       DROP PROCEDURE [dbo].[FindDoctorsStartWith]
                 ");
            context.Database.ExecuteSqlCommand(
                @"CREATE PROCEDURE FindDoctorsStartWith(@name NVARCHAR(400))
                  AS
                 SELECT *
                 FROM   Doctors
                 WHERE  [Name] LIKE @name + '%'");
        }
    }
}

using System;
using System.Data;
using System.Data.Entity;
using System.Data.Objects.SqlClient;
using System.Data.SqlClient;
using System.Linq;
using EF_Sample08.DataLayer.Context;
using EF_Sample08.DomainClasses;

namespace EF_Sample08
{
    class Program
    {
        static void Main(string[] args)
        {
            Database.SetInitializer(new MigrateDatabaseToLatestVersion<Sample08Context, Configuration>());

            using (var db = new Sample08Context())
            {
                runSp(db);
                runFn(db);
                usingSqlFunctions(db);
            }
        }

        private static void usingSqlFunctions(Sample08Context db)
        {
            var doctorsWithNumericNameList = db.Doctors.Where(x => SqlFunctions.IsNumeric(x.Name) == 1).ToList();
            if (doctorsWithNumericNameList.Any())
            {
                //do something
            }
        }

        private static void runFn(Sample08Context db)
        {
            var doctorIdParameter = new SqlParameter
            {
                ParameterName = "@doctor_id",
                Value = 1,
                SqlDbType = SqlDbType.Int
            };
            var patientsCount = db.Database.SqlQuery<int>("select dbo.FindDoctorPatientsCount(@doctor_id)", doctorIdParameter).FirstOrDefault();
            Console.WriteLine(patientsCount);
        }

        private static void runSp(Sample08Context db)
        {
            var nameParameter = new SqlParameter
            {
                ParameterName = "@name",
                Value = "doc",
                Direction = ParameterDirection.Input,
                SqlDbType = SqlDbType.NVarChar
            };
            var doctors = db.Database.SqlQuery<Doctor>("exec FindDoctorsStartWith @name", nameParameter).ToList();
            if (doctors.Any())
            {
                foreach (var item in doctors)
                {
                    Console.WriteLine(item.Name);
                }
            }
        }
    }
}

db.Database.SqlQuery<Doctor>("exec FindDoctorsStartWith "+ txtName.Text, nameParameter).ToList()

public class CustomPasswordValidator : PasswordValidator
{
    public override async Task<IdentityResult> ValidateAsync(string pass)
    {
            IdentityResult result = await base.ValidateAsync(pass);
            if (pass.Contains("12345"))
           {
            var errors = result.Errors.ToList();
            errors.Add("Passwords cannot contain numeric sequences");
            result = new IdentityResult(errors);
           }
           return result;
    }
}

public IActionResult ConfirmOrder(Order order)
{
    using (Serilog.Context.LogContext.PushProperty("OrderId", order.Id))
    {
        _logger.LogInformation("Check order validation");
        //DoSomething
        _logger.LogInformation("Order validation successfully");
        //DoSomething
        _orderService.ConfirmOrder(order);
        _logger.LogInformation("Order confirmed successfully");
    }
    return Ok();
}

{
   "Timestamp":"2020-10-20T23:01:01.0492132+03:30",
   "Level":"Information",
   "MessageTemplate":"Order Confirmed successfully",
   "Properties":{
      "SourceContext":"SerilogExamlpe.WebApplication.Controllers.WeatherForecastController",
      "ActionId":"870582be-312f-4065-88eb-5675e2df4928",
      "ActionName":"SerilogExamlpe.WebApplication.Controllers.WeatherForecastController.Get (SerilogExamlpe.WebApplication)",
      "RequestId":"0HM3L5QM34E6K:00000001",
      "RequestPath":"/weatherforecast",
      "SpanId":"|da92fcac-4169ab4e937de2ae.",
      "TraceId":"da92fcac-4169ab4e937de2ae",
      "ParentId":"",
      "OrderId":12345,//<-- NOTE THIS
      "MachineName":"FARHAD-PC",
      "Environment":"Development"
   }
}

using (_logger.BeginScope("OrderId : {orderId}", 12345))

app.Use(async (httpContext, next) =>
{
    //Get username  
    var username = httpContext.User.Identity.IsAuthenticated ? httpContext.User.Identity.Name : "anonymous";
    LogContext.PushProperty("User", username);

    //Get remote IP address  
    var ip = httpContext.Connection.RemoteIpAddress.ToString();
    LogContext.PushProperty("IP", !String.IsNullOrWhiteSpace(ip) ? ip : "unknown");

    await next.Invoke();
});

[ResponseCache(Duration = 0, Location = ResponseCacheLocation.None, NoStore = true)]
        public IActionResult Error(int? id)
        {
            string ErrorText = "";
            ErrorText = (id.Value == 401 || id.Value == 403) ? "Access Denied"
            : (id.Value == 404 ? "Not Found" : "Error Occured");

            return View(new ErrorViewModel
            {
                RequestId = Activity.Current?.Id ?? HttpContext.TraceIdentifier,
                ErrorId = id,
                ErrorText = ErrorText
            });
        }

<h1 class="text-danger">@Model.ErrorId : @Model.ErrorText</h1>

public class ErrorViewModel
    {
        public string RequestId { get; set; }

        public bool ShowRequestId => !string.IsNullOrEmpty(RequestId);

        public int? ErrorId { get; set; }

        public string ErrorText { get; set; }
    }