Question

When i use foreign keys in the entity framework the foreign key object is null when i do a POST. I am using MVC3 and EF 4.1. I have two tables, Product and Product Details. I am exposing them using the HTML helpers in a Razor view. When the GET happens, the product details are shown. But when i do a form Submit and post to the server, the Product Details collection is null. I lose all my changes.

Any ideas what i am doing wrong?

Thanks for your help!

The Code (i shortened it because it is fairly lengthy):

Database:

Table Product
{
  int Id
  varchar Name
}

Table ProductDetails
{
  int id,
  int ProductId, <- foreign key SQL 2008 to Product Table
  varchar Details
}


View:
@model WebSite.Models.Product
@{
    ViewBag.Title = "MyLifeSaverStoreInfo";
}

@Html.TextBoxFor(m => m.Product.Name)
@Html.TextBoxFor(m => m.Product.ProductDetails.FirstOrDefault().Description)

Controller:
public ActionResult EditProduct(int productId)
{
  var Product = _productRepository.GetProduct(productId);
  return View(product);
}


[HttpPost]
public ActionResult EditProduct(Product model)
{
   string name = model.Name; <- this update comes through
   string description = model.ProductDetails.FirstorDefault().Description;
}

Thanks

Answer 1

Got it!

Instead of creating the “Product” entity on the POST EditProduct method, i use a Form Collection and then set each product detail according to that form collection and then save. I don’t understand why it doesn’t work the first way. I am manually updating the foreign reference. Maybe i am missing something?

[HttpPost]
public ActionResult EditProduct(int id, FormCollection formCollection)
{
    var model = new MyLSstoreInfoViewModel{
                                  StoreCurrent = _profileRepository.GetProduct(Id)
                                          };
    var productDetails = model.Product.ProductDetails.Where(p => p.productId == id).Single();


            productDetaisl.Details = formCollection["details"];
            if (TryUpdateModel(model.StoreCurrent))
            {

                _profileRepository.Save();

            }
}