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CSharp · Console

/Program.cs

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;
}