Exclude Property on Update in Entity Framework

Question

Exclude Property on Update in Entity Framework

asp.net-mvc c# entity-framework

Question

I've been looking for a proper way to mark a property to NOT be changed when updating a model in MVC.

For example, let's take this small model:

class Model
{
    [Key]
    public Guid Id {get; set;}
    public Guid Token {get; set;}

    //... lots of properties here ...
}

then the edit method MVC creates looks like this:

[HttpPost]
public ActionResult Edit(Model model)
{
    if (ModelState.IsValid)
    {
        db.Entry(model).State = EntityState.Modified;
        db.SaveChanges();
        return RedirectToAction("Index");
    }
    return View(model);
}

now if my View does not contain the Token, it will be nullified through that edit.

I'm looking for something like this:

db.Entry(model).State = EntityState.Modified;
db.Entry(model).Property(x => x.Token).State = PropertyState.Unmodified;
db.SaveChanges();

The best way so far I found is to be inclusive and set all properties I want included by hand, but I really only want to say which ones to be excluded.

Manuel Schweigert

Popular Answer

Create new model that will have limited set of properties that you want to update.

I.e. if your entity model is:

public class User
{
    public int Id {get;set;}
    public string Name {get;set;}
    public bool Enabled {get;set;}
}

You can create custom view model that will allow user to change Name, but not Enabled flag:

public class UserProfileModel
{
   public int Id {get;set;}
   public string Name {get;set;}
}

When you want to do database update, you do the following:

YourUpdateMethod(UserProfileModel model)
{
    using(YourContext ctx = new YourContext())
    { 
        User user = new User { Id = model.Id } ;   /// stub model, only has Id
        ctx.Users.Attach(user); /// track your stub model
        ctx.Entry(user).CurrentValues.SetValues(model); /// reflection
        ctx.SaveChanges();
    }
}

When you call this method, you will update the Name, but Enabled property will remain unchanged. I used simple models, but I think you'll get the picture how to use it.

Admir TuzoviÄ‡

View more on Stack Overflow

Nitin Dominic · Accepted Answer · 12/17/2015 6:13:33 PM

Accepted Answer

we can use like this

 db.Entry(model).State = EntityState.Modified;
 db.Entry(model).Property(x => x.Token).IsModified = false;
 db.SaveChanges();

it will update but without Token property

Nitin Dominic

Exclude Property on Update in Entity Framework

Question

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Accepted Answer

Popular Answer

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