MVC Viewmodel to display only model data - asp.net-mvc

Question

This question is similar to this link:
ViewModel to display partial information
I am hoping for an example however. I've created my model, it looks like this:
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
namespace GuestListTemplate.Models
{
public class Guest
{
public int ID { get; set; }
[Required]
[Display(Name = "First Name:")]
public string FirstName { get; set; }
[Display(Name = "Last Name:")]
public string LastName { get; set; }
[DataType(DataType.EmailAddress)]
[Display(Name = "e-Mail:")]
public string eMail { get; set; }
[DataType(DataType.PhoneNumber)]
[Display(Name = "Phone #:")]
public string phone { get; set; }
public Boolean OptIn { get; set; }
[Display(Name = "Guest Last Name:")]
public string GuestLastName { get; set; }
[Display(Name = "Guest First Name:")]
public string GuestFirstName { get; set; }
[DataType(DataType.Currency)]
public decimal Donation { get; set; }
public int? Attended { get; set; }
}
}
All of this information is not neccesary for some views. I want to make a viewmodel to display only the first name, last name, donation and perhaps join the First and Last name. I am trying to do something like this but it doesn't work:
namespace GuestListTemplate.ModelViewModels
{
public class GuestViewModel
{
public string FirstName { get; set; }
public string LastName { get; set; }
public decimal Donation {get; set;}
[Display(Name = "Full Name")]
public string FullName
{
get { return FirstName + " " + LastName;}
}
}
}
How do I tell MVC to use the GUEST model as the source of data for this viewmodel, or how do I bind them together? (The purpose for this is I thought it might help performance of my application, Will it actually help performance??). I understand how to use Viewmodels to display data from multiple tables and pull in ALL data but in this case I want to pull only certain data from one table. Last, Is this better accomplished in the controller?
I hope this question makes sense. Would it be better to use a LINQ query such as
var Guests = db.Guest.Include(g => g.firstname, g.lastname, g.donation);
return (Guests.ToList());
(I understand the above command might not be exact syntax bbut you get the idea). If this is a better way to do it can someone demonstrate a basic way of doing this with the entire viewmodel code. I am pretty good with LINQ, so if someone offers a basic example I should be able to make it work for my purposes.
EDIT:
This worked for me (as well the interfaces outlined in the answer below):
ViewModel is the same as above.
Here is what I do in the controller:
var viewmodel = db.Guests.Select(g => new GuestListIndexData
{
ID = g.ID,
FirstName = g.FirstName,
LastName = g.LastName,
Donation = g.Donation,
Attended = g.Attended
}).OrderBy(g => g.FirstName);
return View(viewmodel.ToList());
My view is essentially the same as what I listed above as well. This works, but i'm not sure how much faster performance I am actually getting out of it so I probably won't use it until I am working with very large databases.

Answer 1

I was able to achieve this with interfaces, such as this:
public interface INameEntity
{
string FirstName { get; set; }
string LastName { get; set; }
}
And add this to Guest:
public class Guest : INameEntity
And use INameEntity in the partial:
#model INameEntity
#Html.TextBoxFor(i => i.FirstName)
This is the technique I use and it works great if Guest is your direct model in the parent view. If there is a parent model class, it's doable but a little more complex setup.