我正在使用代碼優先的POCO與EF4,CTP5。我有一張桌子上有很多列(超過100)。我想將表格拆分成多種類型(又稱「表格拆分」),這樣我就不必每次都需要獲取一些基本信息時獲取所有數據。如何首先在EF4代碼中將表分成多個類型?
我似乎無法找到任何有關此使用谷歌的文檔。我發現了「Table Splitting」這個概念的引用,並且我也看到了如何使用EDMX文件來完成它,但是沒有用於代碼優先的樣本。
我希望這將是作爲定義另一個實體類型並與他們就像任何其他的導航屬性是這樣的...
public class User
{
public int UserID { get; set; }
public string UserName { get; set; }
[ForeignKey("UserID")]
public virtual UserDetails Details { get; set; }
}
public class UserDetails
{
public int UserID { get; set; }
public string MoreData { get; set; }
[ForeignKey("UserID")]
public virtual User User { get; set; } // nice to have, but not required
}
我這樣稱呼它簡單...
return (from u in Context.Users // <-- error occurs here
where u.UserID == userID
select u).FirstOrDefault();
不幸的是,這似乎並沒有工作。我收到以下錯誤當我這樣做......
[IndexOutOfRangeException: Index was outside the bounds of the array.]
System.Data.Entity.ModelConfiguration.Conventions.Edm.PropertyMaxLengthConvention.System.Data.Entity.ModelConfiguration.Conventions.Edm.IEdmConvention<System.Data.Edm.EdmAssociationType>.Apply(EdmAssociationType associationType, EdmModel model) +598
System.Data.Entity.ModelConfiguration.Configuration.EdmConventionDispatcher.Dispatch(TEdmDataModelItem item) +100
System.Data.Entity.ModelConfiguration.Configuration.EdmConventionDispatcher.VisitEdmAssociationType(EdmAssociationType item) +22
System.Data.Entity.ModelConfiguration.Edm.Services.DataModelItemVisitor.VisitCollection(IEnumerable`1 collection, Action`1 visitMethod) +267
System.Data.Entity.ModelConfiguration.Edm.Services.EdmModelVisitor.VisitAssociationTypes(EdmNamespace edmNamespace, IEnumerable`1 associationTypes) +75
System.Data.Entity.ModelConfiguration.Edm.Services.EdmModelVisitor.VisitEdmNamespace(EdmNamespace item) +91
System.Data.Entity.ModelConfiguration.Configuration.EdmConventionDispatcher.VisitEdmNamespace(EdmNamespace item) +32
System.Data.Entity.ModelConfiguration.Edm.Services.DataModelItemVisitor.VisitCollection(IEnumerable`1 collection, Action`1 visitMethod) +267
System.Data.Entity.ModelConfiguration.Edm.Services.EdmModelVisitor.VisitNamespaces(EdmModel model, IEnumerable`1 namespaces) +75
System.Data.Entity.ModelConfiguration.Edm.Services.EdmModelVisitor.VisitEdmModel(EdmModel item) +47
System.Data.Entity.ModelConfiguration.Configuration.EdmConventionDispatcher.VisitEdmModel(EdmModel item) +45
System.Data.Entity.ModelConfiguration.Configuration.ConventionsConfiguration.ApplyModel(EdmModel model) +254
System.Data.Entity.ModelConfiguration.ModelBuilder.Build(DbProviderManifest providerManifest, DbProviderInfo providerInfo, Boolean validateModel) +257
System.Data.Entity.ModelConfiguration.ModelBuilder.Build(DbConnection providerConnection) +172
System.Data.Entity.Internal.LazyInternalContext.CreateModel() +62
System.Lazy`1.CreateValue() +361
System.Lazy`1.LazyInitValue() +104
System.Lazy`1.get_Value() +89
System.Data.Entity.Internal.LazyInternalContext.InitializeContext() +358
System.Data.Entity.Internal.InternalContext.Initialize() +16
System.Data.Entity.Internal.InternalContext.GetEntitySetAndBaseTypeForType(Type entityType) +16
System.Data.Entity.Internal.Linq.InternalSet`1.Initialize() +61
System.Data.Entity.Internal.Linq.InternalSet`1.get_Provider() +15
System.Data.Entity.Infrastructure.DbQuery`1.System.Linq.IQueryable.get_Provider() +13
System.Linq.Queryable.Where(IQueryable`1 source, Expression`1 predicate) +63
TourFactory.Web.AgentWebsite.Models.Websites.WebsiteRepository.GetUser(Int32 userID) in C:\Code\hdtf\TF4\Web\AgentWebsite\Models\Websites\WebsiteRepository.cs:28
TourFactory.Web.AgentWebsite.Controllers.WebsiteController.get_Agent() in C:\Code\hdtf\TF4\Web\AgentWebsite\Controllers\WebsiteController.cs:42
TourFactory.Web.AgentWebsite.Controllers.WebsiteController.OnActionExecuting(ActionExecutingContext filterContext) in C:\Code\hdtf\TF4\Web\AgentWebsite\Controllers\WebsiteController.cs:55
System.Web.Mvc.Controller.System.Web.Mvc.IActionFilter.OnActionExecuting(ActionExecutingContext filterContext) +39
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +81
System.Web.Mvc.<>c__DisplayClass17.<InvokeActionMethodWithFilters>b__14() +61
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodWithFilters(ControllerContext controllerContext, IList`1 filters, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +305
System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName) +830
System.Web.Mvc.Controller.ExecuteCore() +136
System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext) +232
System.Web.Mvc.ControllerBase.System.Web.Mvc.IController.Execute(RequestContext requestContext) +39
System.Web.Mvc.<>c__DisplayClassb.<BeginProcessRequest>b__5() +68
System.Web.Mvc.Async.<>c__DisplayClass1.<MakeVoidDelegate>b__0() +44
System.Web.Mvc.Async.<>c__DisplayClass8`1.<BeginSynchronous>b__7(IAsyncResult _) +42
System.Web.Mvc.Async.WrappedAsyncResult`1.End() +141
System.Web.Mvc.Async.AsyncResultWrapper.End(IAsyncResult asyncResult, Object tag) +54
System.Web.Mvc.Async.AsyncResultWrapper.End(IAsyncResult asyncResult, Object tag) +40
System.Web.Mvc.<>c__DisplayClasse.<EndProcessRequest>b__d() +61
System.Web.Mvc.SecurityUtil.<GetCallInAppTrustThunk>b__0(Action f) +31
System.Web.Mvc.SecurityUtil.ProcessInApplicationTrust(Action action) +56
System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +110
System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +38
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +8841105
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +184
卸下User.Details特性使錯誤消失,但後來我不能使用EF4的漂亮的導航功能。
感謝。我希望的是更好的解決方案。我開始懷疑我是否需要切換到NHibernate的支持我們的傳統數據庫。 – Brian 2011-01-19 21:19:30