// @nuget: EntityFramework

​

using System;

using System.Data.Entity;

using System.Linq;

using System.Collections.Generic;

using System.ComponentModel.DataAnnotations.Schema;

using System.ComponentModel.DataAnnotations;

using System.Data.Entity.Validation;

public class Program

{

    public static void Main()

    {

        using (var context = new EntityContext())

        {

            try

            {

                var blog = new Blog()

                {

                    Name = ".NET Framework Blog",

                    Url = "https://blogs.msdn.microsoft.com/dotnet/"

                };

​

                context.Blogs.Add(blog);

                context.SaveChanges();

                FiddleHelper.WriteTable(context.Blogs.ToList());

            }

            catch (DbEntityValidationException e)

            {

                foreach (var eve in e.EntityValidationErrors)

                {

                    Console.WriteLine("Entity of type \"{0}\" in the state \"{1}\" has the following validation errors:",

                        eve.Entry.Entity.GetType().Name, eve.Entry.State);

                    foreach (var ve in eve.ValidationErrors)

                    {

                        Console.WriteLine("- Property: \"{0}\", Error: \"{1}\"",

                            ve.PropertyName, ve.ErrorMessage);

                    }

​

                    foreach (var ve in eve.ValidationErrors)

                    {

                        Console.WriteLine("- Property: \"{0}\", Value: \"{1}\", Error: \"{2}\"",

                            ve.PropertyName,

                            eve.Entry.CurrentValues.GetValue<object>(ve.PropertyName),

                            ve.ErrorMessage);

                    }

                }

            }

        }

    }

    public class EntityContext : DbContext

    {

        public EntityContext() : base(FiddleHelper.GetConnectionStringSqlServer())

        {

​

        }

        public DbSet<Blog> Blogs { get; set; }

​

    }

    public class Blog

    {

        public int BlogId { get; set; }

        [StringLength(10)]

        public string Name { get; set; }

        public string Url { get; set; }

    }

}