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How do I first split a table into several types in EF4 code?

I am using code POCO with EF4, CTP5. I have a table with a lot of columns (over 100). I want to split a table into several types (aka "Splitting a table"), so I don’t need to retrieve all the data every time I need some basic information.

I can not find documentation on this issue using Google. I found links to the concept of "Partitioning Tables", and I also saw how to do this using the EDMX file, but without samples for the first code.

I was hoping it would be as simple as defining another type of object and linking them in the same way as any other navigation property, for example ...

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
}

And I call it that ...

return (from u in Context.Users  // <-- error occurs here
        where u.UserID == userID
        select u).FirstOrDefault();

Unfortunately this does not work. I get the following error when I do this ...

[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

User.Details , EF4.

+3
3

- . Code First ( EF ) / . , EF , :

public class User
{
    public int UserID { get; set; }
    public string UserName { get; set; }
    public UserDetails Details { get; set; }
}

[ComplexType]
public class UserDetails
{
    public string MoreData { get; set; }
}

- , "--", .

EF Code First CTP . :
EF CTP5: 1 -

+4

, , EF Code First .

:

[Table("UserTable")]
public class User
{
    [Key, ForeignKey("Details")]
    public int UserID { get; set; }
    public string UserName { get; set; }
    public virtual  UserDetails Details { get; set; }
}

[Table("UserTable")]
public class UserDetails
{

    [Key, ForeignKey("User")]
    public int UserID { get; set; }
    public string MoreData { get; set; }
    public virtual User User { get; set; }
}

( ) , .

, ,

  • 1 1
0

, . , , . . -, , [ComplexType] - .

Use the second one either in the Fluent API or from the book of Julia Lerman (breaking the table "People" into objects Person and PersonPhoto.

   modelBuilder.Entity<Person>().ToTable("People");
   modelBuilder.Entity<PersonPhoto>().ToTable("People");
0
source

Source: https://habr.com/ru/post/1786477/

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