using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var myDatabase = new

        {

            Persons = new DbPerson[]

            {

                new DbPerson { GivenName = "Alice", FamilyName = "Smith", AltGivenName = "AFoo" },

                new DbPerson { GivenName = "Bob", FamilyName = "Hancock", AltGivenName = "BBar" }

            }

        };

        var persons = myDatabase.Persons.Select(MappingHelper.ToPerson);

        var anonPersons = myDatabase.Persons.Select(MappingHelper.ToAnonymousPerson);

        Console.WriteLine(string.Join(", ", persons));

        Console.WriteLine(string.Join(", ", anonPersons));

    }

}

​

public static class MappingHelper

{

    public static Person ToPerson(this DbPerson dbPerson)

    {

        return new Person

        {

            GivenName = dbPerson.GivenName,

            FamilyName = dbPerson.FamilyName

        };

    }

    public static AnonymousPerson ToAnonymousPerson(this DbPerson dbPerson)

    {

        return new AnonymousPerson

        {

            Nickname = dbPerson.AltGivenName

        };

    }

}

​

public class DbPerson

{

    public string GivenName { get; set; }

    public string FamilyName { get; set; }

    public string AltGivenName { get; set; }

}

​

public class Person

{

    public string GivenName { get; set; }

    public string FamilyName { get; set; }

    public override string ToString() => $"{GivenName} {FamilyName}";

}

​

public class AnonymousPerson

{

    public string Nickname { get; set; }

    public override string ToString() => Nickname;

}