Microsoft.AspNetCore.Mvc.Rendering.SelectListGroup 'требует определения первичного ключа

Question

Я не могу пройти эту ошибку. Я просто пытаюсь получить список товаров в выпадающем списке. Использование: Asp.Net Core 1.0 Ядро EntityFramework. MVC Образцовый шаблон.

Я пробовал все, что у меня есть. У меня есть [Key] атрибут над моим Guid/Oid PK. (Является ли это проблемой GUID?) Я добавил HasKey() в свой класс DBContext для Entity/ViewModel, который я использую. он у меня отображается в таблицу исходной модели/ТН (это правильно ??)

я сделал БД Сначала к существующей БД с помощью Microsoft реверса инженера в Entity Framework: https://docs.efproject.net/en/latest/platforms/aspnetcore/existing-db.html#reverse-engineer-your-model

На данный момент, я даже не уверен, что я подключаюсь к моей БД. Я не видел никаких данных.

У меня полная потеря. Помощь приветствуется.

Вот мой пуск класс:

public class Startup 
{ 
    public Startup(IHostingEnvironment env) 
    { 
     var builder = new ConfigurationBuilder() 
      .SetBasePath(env.ContentRootPath) 
      .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true) 
      .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true) 
      .AddEnvironmentVariables(); 

     if (env.IsDevelopment()) 
     { 
      // This will push telemetry data through Application Insights pipeline faster, allowing you to view results immediately. 
      builder.AddApplicationInsightsSettings(developerMode: true); 
     } 
     Configuration = builder.Build(); 
    } 

    public IConfigurationRoot Configuration { get; } 

    // This method gets called by the runtime. Use this method to add services to the container. 
    public void ConfigureServices(IServiceCollection services) 
    { 

     // Add framework services. 
     services.AddApplicationInsightsTelemetry(Configuration); 

     services.AddDbContext<ltgwarehouseContext>(options => options.UseSqlServer(Configuration["DefaultConnection:ConnectionString"])); 
     services.AddMvc(); 
     services.AddSingleton<ICommodityRepository, CommodityRepository>(); 


    } 
} 

Это мой DbContext Класс:

 public partial class ltgwarehouseContext : DbContext 
    { 
//  protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder) 
//  { 
////#warning// To protect potentially sensitive information in your connection string, you should move it out of source code. See http://go.microsoft.com/fwlink/?LinkId=723263 for guidance on storing connection strings. 
//   optionsBuilder.UseSqlServer(@"Server=.;Database=ltgwarehouse;Trusted_Connection=True;"); 
//  } 
     public ltgwarehouseContext(DbContextOptions<ltgwarehouseContext> options) 
      : base(options) 
     { } 


     //public ltgwarehouseContext() 
     //{ 
     //} 
     public DbSet<CommodityViewModel> CommoditiesList { get; set; } 

     public DbSet<Commodity> Commodities { get; set; } 



     protected override void OnModelCreating(ModelBuilder modelBuilder) 
     { 
      modelBuilder.Entity<CommodityViewModel>(entity => 
      { 
       modelBuilder.Entity<CommodityViewModel>().ToTable("Commodity"); 
       modelBuilder.Entity<CommodityViewModel>().HasKey(c => c.Oid); 
       //.HasName("PK_Commodity"); 
      }); 
    } 
    } 

Мой ViewModel:

public partial class CommodityViewModel 
    { 
     public CommodityViewModel() 
     { 

     } 

     public IEnumerable<SelectListItem> CommoditiesList { get; set; } 
     [Key] 
     public Guid Oid { get; set; } 

     public string Code { get; set; } 

     public string Description { get; set;} 
} 

Мой Интерфейс:

public interface ICommodityRepository 
{ 

    IEnumerable<CommodityViewModel> GetCommodities(); 

} 

Мой Repository (Это где ошибка выкинут при отладке)

public class CommodityRepository : ICommodityRepository 
{  
    private readonly ltgwarehouseContext _context; 


    public CommodityRepository(ltgwarehouseContext context) 
    { 
     _context = context; 
    } 

    public IEnumerable<CommodityViewModel> GetCommodities() 
    { 
     return _context.CommoditiesList.ToList(); 
    } 

} 

трассировки стека: Действие

System.InvalidOperationException was unhandled by user code 
    HResult=-2146233079 
    Message=The entity type 'Microsoft.AspNetCore.Mvc.Rendering.SelectListGroup' requires a primary key to be defined. 
    Source=Microsoft.EntityFrameworkCore 
    StackTrace: 
     at Microsoft.EntityFrameworkCore.Internal.ModelValidator.ShowError(String message) 
     at Microsoft.EntityFrameworkCore.Internal.ModelValidator.Validate(IModel model) 
     at Microsoft.EntityFrameworkCore.Internal.RelationalModelValidator.Validate(IModel model) 
     at Microsoft.EntityFrameworkCore.Infrastructure.ModelSource.CreateModel(DbContext context, IConventionSetBuilder conventionSetBuilder, IModelValidator validator) 
     at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory) 
     at Microsoft.EntityFrameworkCore.Internal.DbContextServices.CreateModel() 
     at Microsoft.EntityFrameworkCore.Internal.LazyRef`1.get_Value() 
     at Microsoft.Extensions.DependencyInjection.ServiceProvider.ScopedCallSite.Invoke(ServiceProvider provider) 
     at Microsoft.Extensions.DependencyInjection.ServiceLookup.ConstructorCallSite.Invoke(ServiceProvider provider) 
     at Microsoft.Extensions.DependencyInjection.ServiceProvider.ScopedCallSite.Invoke(ServiceProvider provider) 
     at Microsoft.Extensions.DependencyInjection.ServiceLookup.ConstructorCallSite.Invoke(ServiceProvider provider) 
     at Microsoft.Extensions.DependencyInjection.ServiceProvider.ScopedCallSite.Invoke(ServiceProvider provider) 
     at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider provider, Type serviceType) 
     at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService[T](IServiceProvider provider) 
     at Microsoft.Extensions.DependencyInjection.ServiceProvider.ScopedCallSite.Invoke(ServiceProvider provider) 
     at Microsoft.Extensions.DependencyInjection.ServiceLookup.ConstructorCallSite.Invoke(ServiceProvider provider) 
     at Microsoft.Extensions.DependencyInjection.ServiceProvider.ScopedCallSite.Invoke(ServiceProvider provider) 
     at Microsoft.Extensions.DependencyInjection.ServiceLookup.ConstructorCallSite.Invoke(ServiceProvider provider) 
     at Microsoft.Extensions.DependencyInjection.ServiceProvider.ScopedCallSite.Invoke(ServiceProvider provider) 
     at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetService[T](IServiceProvider provider) 
     at Microsoft.EntityFrameworkCore.Infrastructure.AccessorExtensions.GetService[TService](IInfrastructure`1 accessor) 
     at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.<.ctor>b__2_0() 
     at Microsoft.EntityFrameworkCore.Internal.LazyRef`1.get_Value() 
     at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.System.Collections.Generic.IEnumerable<TEntity>.GetEnumerator() 
     at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection) 
     at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source) 
     at Lansing.BasisMap.Domain.CommodityRepository.GetCommodities() in C:\LTG Projects\Basis Map\Lansing.Geo\Lansing.BasisMap.Domain\Models\Repositories\CommodityRepository.cs:line 52 
     at Lansing.BasisMap.Controllers.HomeController.Index() in C:\LTG Projects\Basis Map\Lansing.Geo\Lansing.BasisMap\Controllers\HomeController.cs:line 30 
     at lambda_method(Closure , Object , Object[]) 
     at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.<InvokeActionFilterAsync>d__28.MoveNext() 
    InnerException: 

My Controller:

public IActionResult Index() 
{ 
    ViewBag.Commodities = _commoditiyRepository.GetCommodities().Select(c => new SelectListItem() { Text = c.Code, Value = c.Oid.ToString() }).Cast<CommodityViewModel>().ToList(); 
    return View(); 
} 

И, наконец, мой взгляд:

@model MyCompany.BasisMap.Domain.Models.CommodityViewModel 
         @if (ViewBag.Commodities == null) 
         { 
          throw new Exception("No Data!"); 

         } 
         else 
         { 
          foreach (var commoditiy in ViewBag.Commodities) 
          { 
           <li> 
            @commoditiy.code 
           </li> 
          } 

         } 

Answer 1

Вы должны удалить CommodityViewModel.CommoditiesList или по крайней мере игнорировать:

modelBuilder.Entity<CommodityViewModel>().Ignore(c => c.CommoditiesList); 

Или игнорировать типам себя:

modelBuilder.Ignore<SelectListItem>(); 
modelBuilder.Ignore<SelectListGroup>();