'System.Data.Entity.ModelConfiguration.ModelValidationException' occurred in EntityFramework.dll but was not handled in user code

Question

I am now working on a MVC project on running the program I've got an error on trying to retrieve the data from my SqlServer Database.

Controller:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using Activity.Models;

namespace Activity.Controllers
{
     public class ProductsController : Controller
    {
        public ActionResult ProductDetails(int id)
        {
            ProductContext productsContext = new ProductContext();
            Products prod = productsContext.Product.Single(pru => pru.ProductKey == id);

            return View(prod);
        }

    }
}

Models: I have two classes(Products.cs and ProductContext.cs)

For ProductContext.cs

using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Web;

namespace Activity.Models
{
    public class ProductContext : DbContext
    {
        public DbSet<Products> Product { get; set; }
    }
}

For Products.cs

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations.Schema;
using System.Linq;
using System.Web;

namespace Activity.Models
{

    [Table("PruProductDetails")]
    public class Products
    {
        public int ProductKey { get; set; }
        public string ProductCode { get; set; }
        public string ProductName { get; set; }
        public double Price { get; set; }
        public string Discountable { get; set; }
        public string DateAdded { get; set; }
        public double Discount { get; set; }
        public int Quantity { get; set; }
        public int ReOrderLevel { get; set; }
        public int OrderLimit { get; set; }
    }
}

Web.Config

<connectionStrings>
    <add name="ProductContext"
         connectionString="server=(local); database=Exam; integrated security=SSPI"
          providerName="System.Data.SqlClient"/>
   </connectionStrings>

Global.asax

using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Web;
using System.Web.Http;
using System.Web.Mvc;
using System.Web.Routing;

namespace Activity
{

    public class MvcApplication : System.Web.HttpApplication
    {
        protected void Application_Start()
        {
            Database.SetInitializer<Activity.Models.ProductContext>(null);
            AreaRegistration.RegisterAllAreas();
            WebApiConfig.Register(GlobalConfiguration.Configuration);
            FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
            RouteConfig.RegisterRoutes(RouteTable.Routes);
        }
    }
 }

I hope someone can help me. I am only a beginner in MVC. Thank you

Answer 1

Try to modify your Products class like this - Adding Key attribute for ProductKey

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations.Schema;
using System.Linq;
using System.Web;

namespace Activity.Models
{

[Table("PruProductDetails")]
public class Products
{
    [Key]
    public int ProductKey { get; set; }
    public string ProductCode { get; set; }
    public string ProductName { get; set; }
    public double Price { get; set; }
    public string Discountable { get; set; }
    public string DateAdded { get; set; }
    public double Discount { get; set; }
    public int Quantity { get; set; }
    public int ReOrderLevel { get; set; }
    public int OrderLimit { get; set; }
}

}