using System;

using System.Collections.Generic;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        var type = typeof(Item);

        var properties = type.GetProperties().ToList();

        var props = new List<string>();

        foreach (var item in properties)

        {

            var nullable = false;

            var name = item.Name;

            var t = item.PropertyType.Name;

            var test = Nullable.GetUnderlyingType(item.PropertyType);

            if (test != null)

            {

                t = test.Name;

                nullable = true;

            }

​

            var nullSymbol = nullable ? "NULL" : "NOT NULL";

            var dbType = Types(t);

            if (dbType != null)

            {

                props.Add($"{name} {dbType} {nullSymbol}");

            }

        }

​

        Console.WriteLine($"CREATE TABLE {type.Name} (");

        foreach (var item in props)

        {

            var index = props.IndexOf(item);

            if((props.Count() - 1) == index){

                Console.WriteLine($"    {item}");

            } else {

                Console.WriteLine($"    {item},");

            }

        }

​

        Console.WriteLine(")");

    }

​

    public static string? Types(string type)

    {

        string? returnValue = null;

        switch (type)

        {

            case nameof(Int32):

                returnValue = "INT";

                break;

            case nameof(Int64):

                returnValue = "BIGINT";

                break;

            case "decimal":

                returnValue = "DECIMAL(10,20)";

                break;

            case "string":

                returnValue = "NVARCHAR(255)";

                break;

            case nameof(Guid):

                returnValue = "UNIQUEIDENTIFIER";

                break;

            default:

                returnValue = null;

                break;

        }

​

        return returnValue;

    }

}

​

public class Item

{

    public int Id { get; set; }

​

    public long? id2 { get; set; }

​

    public Guid Test { get; set; }

}