我有一个附加的图形对象，我无法弄清楚如何更改记录上的外键。我的数据库中保存了一个加载记录。我通过id检索所述记录并跟踪。我
public partial class Load
{
[Key]
public virtual int Id {get;set;}
[Required]
public virtual int AccountId { get; set; }
public virtual Account Account { get; set; }
[Required]
public virtual int CustomerId { get; set; }
[ForeignKey("CustomerId")]
public virtual Customer Customer { get; set; }
}
然后我检索了我想要与加载记录关联的客户记录
public partial class Customer
{
[Key]
public virtual int Id {get;set;}
[Required]
[MaxLength(100)]
public virtual string Name { get; set; }
}
无论我做什么，我都会遇到某种异常。
var customer = context.Customers.Where(x => x.Id == customerId).SingleOrDefault();
load.Customer = customer;
load.CustomerId = customer.Id;
load.ModifiedByApplicationUserId = userId;
load.ModifiedDateTime = DateTime.Now;
context.Entry(load).State = EntityState.Modified;
context.SaveChanges();
在附加的图形对象上更改外键关系的正确方法是什么？
编辑。我添加了例外。
[InvalidOperationException：附加类型为＆＃39; Triton.Core.Models.Identity.ApplicationUser＆＃39;的实体。失败，因为同一类型的另一个实体已具有相同的主键值。使用＆＃39;附加＆＃39;方法或将实体的状态设置为“未更改”＃39;或者＆＃39;修改＆＃39;如果图中的任何实体具有冲突的键值。这可能是因为某些实体是新的并且尚未收到数据库生成的键值。在这种情况下，请使用＆＃39;添加＆＃39;方法或“添加”＃39;实体状态跟踪图形，然后将非新实体的状态设置为“未更改”。或者＆＃39;修改＆＃39;作为适当的。] System.Data.Entity.Core.Objects.ObjectContext.AttachSingleObject（IEntityWrapper wrappedEntity，EntitySet entitySet）+690 System.Data.Entity.Core.Objects.DataClasses.RelatedEnd.AddEntityToObjectStateManager（IEntityWrapper wrappedEntity，Boolean doAttach）+130 System.Data.Entity.Core.Objects.DataClasses.EntityReference.AddEntityToObjectStateManager（IEntityWrapper wrappedEntity，Boolean doAttach）+65 System.Data.Entity.Core.Objects.DataClasses.RelatedEnd.AddGraphToObjectStateManager（IEntityWrapper wrappedEntity，Boolean relationshipAlreadyExists，Boolean addRelationshipAsUnchanged，Boolean doAttach）+67 System.Data.Entity.Core.Objects.DataClasses.RelatedEnd.IncludeEntity（IEntityWrapper wrappedEntity，Boolean addRelationshipAsUnchanged，Boolean doAttach）+340 System.Data.Entity.Core.Objects.DataClasses.EntityReference
1.Include(Boolean addRelationshipAsUnchanged, Boolean doAttach) +209 System.Data.Entity.Core.Objects.DataClasses.RelationshipManager.AddRelatedEntitiesToObjectStateManager(Boolean doAttach) +164 System.Data.Entity.Core.Objects.ObjectContext.AttachTo(String entitySetName, Object entity) +510 System.Data.Entity.Internal.Linq.<>c__DisplayClassa.<Attach>b__9() +97 System.Data.Entity.Internal.Linq.InternalSet1.ActOnSet（Action action，EntityState newState，Object entity，String methodName）+354 System.Data.Entity.Internal.Linq.InternalSet1.Attach(Object entity) +200 System.Data.Entity.Internal.InternalEntityEntry.set_State(EntityState value) +357 System.Data.Entity.Infrastructure.DbEntityEntry1.set_State（EntityState value）+42 drit中的Triton.Service.LoadService.UpdateCustomer（Load load，Int32 customerId，Int32 userId）：BitBucket \ trunk \ Triton \ Triton.Service \ LoadService.cs：73 Triton.Web.Controllers.LoadsController.Customer（LoadViewModel模型）在d：\ BitBucket \ trunk \ Triton \ Triton.Web \ Controllers \ LoadsController.cs：138 lambda_method（Closure，ControllerBase，Object []）+180 System.Web.Mvc.ActionMethodDispatcher.Execute（ControllerBase controller，Object []参数）+59 System.Web.Mvc.ReflectedActionDescriptor.Execute（ControllerContext controllerContext，IDictionary2 parameters) +434 System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary2个参数）+60 System.Web.Mvc.Async.ActionInvocation.InvokeSynchronousActionMethod（）+76 System.Web.Mvc.Async.AsyncControllerActionInvoker.b__39（IAsyncResult asyncResult，ActionInvocation innerInvokeState）+36 System.Web.Mvc.Async.WrappedAsyncResult2.CallEndDelegate(IAsyncResult asyncResult) +73 System.Web.Mvc.Async.WrappedAsyncResultBase1.End（）+136 System.Web.Mvc.Async.AsyncResultWrapper.End（IAsyncResult asyncResult，Object tag）+102 System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod（IAsyncResult asyncResult）+49 Castle.Proxies.AsyncControllerActionInvokerProxy.EndInvokeActionMethod_callback（IAsyncResult asyncResult）+42 Castle.Proxies.Invocations.AsyncControllerActionInvoker_EndInvokeActionMethod.InvokeMethodOnTarget（）+103 Castle.DynamicProxy.AbstractInvocation.Proceed（）+ 117 Glimpse.Core.Extensibility.CastleInvocationToAlternateMethodContextAdapter.Proceed（）+48 Glimpse.Mvc.AlternateType.EndInvokeActionMethod.NewImplementation（IAlternateMethodContext context）+152 Glimpse.Core.Extensibility.AlternateTypeToCastleInterceptorAdapter.Intercept（IInvocation invocation）+183 Castle.DynamicProxy.AbstractInvocation.Proceed（）+483 Castle.Proxies.AsyncControllerActionInvokerProxy.EndInvokeActionMethod（IAsyncResult asyncResult）+203 System.Web.Mvc.Async.AsyncInvocationWithFilters.b__3d（）+117 System.Web.Mvc.Async。＆lt;＆gt; c__DisplayClass46.b__3f（）+323 System.Web.Mvc.Async。＆lt;＆gt; c__DisplayClass46.b__3f（）+323 System.Web.Mvc.Async。＆lt;＆gt; c__DisplayClass33.b__32（IAsyncResult asyncResult）+44 System.Web.Mvc.Async.WrappedAsyncResult1.CallEndDelegate(IAsyncResult asyncResult) +47 System.Web.Mvc.Async.WrappedAsyncResultBase1.End（）+136 System.Web.Mvc.Async.AsyncResultWrapper.End（IAsyncResult asyncResult，Object tag）+102 System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters（IAsyncResult asyncResult）+50 System.Web.Mvc.Async。＆lt;＆gt; c__DisplayClass2b.b__1c（）+72 System.Web.Mvc.Async。＆lt;＆gt; c__DisplayClass21.b__1e（IAsyncResult asyncResult）+184 System.Web.Mvc.Async.WrappedAsyncResult1.CallEndDelegate(IAsyncResult asyncResult) +42 System.Web.Mvc.Async.WrappedAsyncResultBase1.End（）+133 System.Web.Mvc.Async.AsyncResultWrapper.End（IAsyncResult asyncResult，Object tag）+56 System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction（IAsyncResult asyncResult）+40 System.Web.Mvc.Controller.b__1d（IAsyncResult asyncResult，ExecuteCoreState innerState）+34 System.Web.Mvc.Async.WrappedAsyncVoid1.CallEndDelegate(IAsyncResult asyncResult) +70 System.Web.Mvc.Async.WrappedAsyncResultBase1.End（）+139 System.Web.Mvc.Async.AsyncResultWrapper.End（IAsyncResult asyncResult，Object tag）+59 System.Web.Mvc.Async.AsyncResultWrapper.End（IAsyncResult asyncResult，Object tag）+40 System.Web.Mvc.Controller.EndExecuteCore（IAsyncResult asyncResult）+44 System.Web.Mvc.Controller.b__15（IAsyncResult asyncResult，Controller controller）+39 System.Web.Mvc.Async.WrappedAsyncVoid1.CallEndDelegate(IAsyncResult asyncResult) +62 System.Web.Mvc.Async.WrappedAsyncResultBase1.End（）+139 System.Web.Mvc.Async.AsyncResultWrapper.End（IAsyncResult asyncResult，Object tag）+59 System.Web.Mvc.Async.AsyncResultWrapper.End（IAsyncResult asyncResult，Object tag）+40 System.Web.Mvc.Controller.EndExecute（IAsyncResult asyncResult）+39 System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute（IAsyncResult asyncResult）+39 System.Web.Mvc.MvcHandler.b__5（IAsyncResult asyncResult，ProcessRequestState innerState）+39 System.Web.Mvc.Async.WrappedAsyncVoid1.CallEndDelegate(IAsyncResult asyncResult) +70 System.Web.Mvc.Async.WrappedAsyncResultBase1.End（）+139 System.Web.Mvc.Async.AsyncResultWrapper.End（IAsyncResult asyncResult，Object tag）+59 System.Web.Mvc.Async.AsyncResultWrapper.End（IAsyncResult asyncResult，Object tag）+40 System.Web.Mvc.MvcHandler.EndProcessRequest（IAsyncResult asyncResult）+40 System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest（IAsyncResult result）+38 System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute（）+9651688 System.Web.HttpApplication.ExecuteStep（IExecutionStep step，Boolean＆amp; completedSynchronously）+155
答案 0 :(得分：0)
事实证明我在一个被引用的子类中有一个对象，所以EF试图将它添加到图形中。一旦我使该对象无效，一切都正常。