CODEWITHSUNDEEP
c#asp.net-mvc-3entity-framework
Jason La
Jason La

Reputation: 1081

MVC3 + Entity Framework, updating selective fields in an entity

Assume I have Entity Framework setup correctly, and the POCO classes are have the proper relationships, etc.

<!-- language: c# -->
public class Person
{
    public int Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string SomeFieldIDontWantUsersToEdit { get; set; } // there are a lot of these
    public IList<Address> Addresses { get; set; }
}

public class Address
{
    public string EntireAdressInOneLine { get; set; }
}

When I display things to the user, I only want to show FirstName and LastName, and the addresses. That works and the view is functioning properly.

This is my view:

<!-- language: c# -->
@using (Html.BeginForm(actionName: null, controllerName: null, method: FormMethod.Post))
{
    @Html.TextBoxFor(model => Model.Person.FirstName)
    @Html.TextBoxFor(model => Model.Person.LastName)
    @Html.HiddenFor(model => Model.Person.Id)
}

But when it comes time to Update this entry, I'm lost. If this is the action for update:

<!-- language: c# -->
[HttpPost]
public ActionResult UpdatePerson(int personId, Person updatedPerson)
{
    if (ModelState.IsValid)
    {

    }
}

When I submit the form, the model binder will pickup that I want a Person object. Cool, that works. Of course, SomeFieldIDontWantUsersToEdit will be null since it wasn't included in the view -- I understand that part.

My question is, is there some way to tell EF that I only want to update certain properties in this entity, and use whatever value was there already for all other properties.

I want the original values of SomeFieldIDontWantUsersToEdit to say the same, but want to allow the user to edit First and Last name. If it were only 1 or 2 fields, sure, I can do it manually, but it's a lot more fields in the actual code.

Maybe a better question is, what is the proper/recommended way of doing this?

Upvotes: 2

Views: 570

Answers (2)

Pablo Romeo
Pablo Romeo

Reputation: 11396

Why not actually create a ViewModel, such as:

public class PersonalInfoModel
{
    public int Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
}

And just have your Action receive that type:

[HttpPost]
public ActionResult UpdatePerson(PersonalInfoModel updatedPerson)
{
    if (ModelState.IsValid)
    {

    }
}

In this scenario, you should go to your context, load the real entity using PersonalInfoModel.Id, and just update the two properties you want to update.

It isn't mandatory that you use your real entities as Models, you can create your own representations of information (in several cases even recommended, instead of using the actual entities).

Upvotes: 1

Kyle Nunery
Kyle Nunery

Reputation: 2049

Use Automapper if you don't want to do the "mapping" by hand.

Upvotes: 1

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