ASP.Net MVC 3 EF4.1 code first - Multiple object sets per type are not supported

Question

I wanted to use a EF 4.1 code first pattern that was unit testable. I followed the code sample illustrated in an answer to This Post. But now I am getting an error that states "Multiple object sets per type are not supported". I am using the latest Structure Map for IoC as well. I am not sure how to trouble shoot this issue.

Multiple object sets per type are not supported. The object sets 'MemberTypes' and 'MemberTypes' can both contain instances of type 'SocialSite.Model.Entities.MemberType'.

Line 82: public virtual IEnumerable<T> FindAll()
Line 83: {
Line 84:     return _dbSet.ToList();
Line 85: }
Line 86: 

[InvalidOperationException: Multiple object sets per type are not supported. The     object sets 'MemberTypes' and 'MemberTypes' can both contain instances of type     'SocialSite.Model.Entities.MemberType'.]
   System.Data.Entity.Internal.DbSetDiscoveryService.RegisterSets(DbModelBuilder     modelBuilder) +336
   System.Data.Entity.Internal.LazyInternalContext.CreateModelBuilder() +393
   System.Data.Entity.Internal.LazyInternalContext.CreateModel(LazyInternalContext     internalContext) +22
   System.Data.Entity.Internal.RetryLazy`2.GetValue(TInput input) +117
   System.Data.Entity.Internal.LazyInternalContext.InitializeContext() +407
   System.Data.Entity.Internal.InternalContext.GetEntitySetAndBaseTypeForType(Type entityType) +17
   System.Data.Entity.Internal.Linq.InternalSet`1.Initialize() +62
   System.Data.Entity.Internal.Linq.InternalSet`1.GetEnumerator() +15
   System.Data.Entity.Infrastructure.DbQuery`1.System.Collections.Generic.IEnumerable<TResult>.GetEnumerator() +40
   System.Collections.Generic.List`1..ctor(IEnumerable`1 collection) +315
   System.Linq.Enumerable.ToList(IEnumerable`1 source) +58
   SocialSite.Data.Repositories.Impl.Repository`1.FindAll() in D:\Visual Studio 2010\SocialSite\SocialSite.Data\Repositories\Impl\Repository.cs:84
   SocialSite.Service.Impl.MemberTypesService.GetMemberTypes() in D:\Visual Studio 2010\SocialSite\SocialSite.Components\Impl\MemberTypesService.cs:23
   SocialSite.Web.Areas.Admin.Controllers.MemberTypesController.ListMemberTypes() in D:\Visual Studio 2010\SocialSite\SocialSite\Areas\Admin\Controllers\MemberTypesController.cs:44
   lambda_method(Closure , ControllerBase , Object[] ) +62
   System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters) +17
   System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +208
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +27
   System.Web.Mvc.<>c__DisplayClass15.<InvokeActionMethodWithFilters>b__12() +55
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +263
   System.Web.Mvc.<>c__DisplayClass17.<InvokeActionMethodWithFilters>b__14() +19
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodWithFilters(ControllerContext controllerContext, IList`1 filters, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +191
   System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName) +343
   System.Web.Mvc.Controller.ExecuteCore() +116
   System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext) +97
   System.Web.Mvc.ControllerBase.System.Web.Mvc.IController.Execute(RequestContext requestContext) +10
   System.Web.Mvc.<>c__DisplayClassb.<BeginProcessRequest>b__5() +37
   System.Web.Mvc.Async.<>c__DisplayClass1.<MakeVoidDelegate>b__0() +21
   System.Web.Mvc.Async.<>c__DisplayClass8`1.<BeginSynchronous>b__7(IAsyncResult _) +12
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +62
   System.Web.Mvc.<>c__DisplayClasse.<EndProcessRequest>b__d() +50
   System.Web.Mvc.SecurityUtil.<GetCallInAppTrustThunk>b__0(Action f) +7
   System.Web.Mvc.SecurityUtil.ProcessInApplicationTrust(Action action) +22
   System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +60
   System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +8862381
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +184

not sure how to format the stack trace any bertter than that.

here is the model in question.

public class MemberType
{
    [Key]
    public virtual int Id { get; set; }

    [StringLengthAttribute(65, ErrorMessage = "Maximum length 65 characters")]
    public virtual string Name { get; set; }

    public virtual string Description { get; set; }

    public virtual bool Registration { get; set; }

    public virtual bool Enabled { get; set; }

    [TimestampAttribute]
    public virtual byte[] Timestamp { get; set; }

    public virtual bool Activation { get; set; }

    public virtual Guid RoleId { get; set; } // TODO: this should be a complex type of aspnet_Role or atleaset a foriegn key

    public virtual bool Searchable { get; set; }

    public virtual ICollection<MemberTypeProfileFieldGroup> MemberTypeProfileFieldGroups { get; set; }
}

Could you format your question better, and provide the code for your models? — Yngve B-Nilsen, May 09 '11 at 15:34

score 12 · Answer 1 · answered May 09 '11 at 21:17

The exception says that your DbContext (or perhaps some class referenced from your context defines DbSet<MemberType> MemberType twice. Each type can have only one defined DbSet. Code you posted has absolutely no relation to the exception. The exception is thrown when EF code first explores DbContext and creates model metadata from available DbSets

ASP.Net MVC 3 EF4.1 code first - Multiple object sets per type are not supported

1 Answers1