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POEF-Code First: Unable to create a constant value of type ''. Only primitive types ('such as Int32, String, and Guid') are supported in this context
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  1. POEF-Code First: Unable to create a constant value of type ''. Only primitive types ('such as Int32, String, and Guid') are supported in this context
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    copied!<p>I am currently having trouble with some some linq using EF code first. My current code works fine: </p> <p>My database model</p> <pre><code>public class MyDatabase : DbContext { public DbSet&lt;Person&gt; People { get; set; } public DbSet&lt;Role&gt; Roles { get; set; } public DbSet&lt;Visit&gt; Visits { get; set; } } public class Person { public int PersonId { get; set; } public string Forename { get; set; } public string Surname { get; set; } } public class Visit { public int VisitId { get; set; } public string Name {get; set;} public int PersonId { get; set; } public string VisitStatus { get; set; } public virtual Person People { get; set; } //There is a one to many relationship to person } public class Role { public Role() { People = new HashSet&lt;Person&gt;(); } [Key] public int RoleId { get; set; } public string Name { get; set; } public virtual ICollection&lt;Person&gt; People { get; set; } //There is a many to many relationship to person } </code></pre> <p>My query</p> <pre><code>public IEnumerable&lt;VisitDetails&gt; GetGuestVisiterList() { using (var db = new MyDatabase()) { return (from p in db.People where p.Roles.Any(a =&gt; a.Name == "Guest") select new GuestVisitDetails { PersonId = p.PersonId, Forename = p.Forename, Surname = p.Surname, NumberOfVisits = db.Visits.Count(v =&gt; v.PersonId == p.PersonId &amp;&amp; v.VisitStatus != "Complete") }).ToList(); } } </code></pre> <p>My View model</p> <pre><code>public class GuestVisitDetails { public int PersonId { get; set; } public string Forename { get; set; } public string Surname { get; set; } public int NumberOfVisits { get; set; } } </code></pre> <p>But when I try to use an interface for my database model so I can unit test, it get the following error:</p> <pre><code>Unable to create a constant value of type 'MyVisits.Data.Model.Visit'. Only primitive types ('such as Int32, String, and Guid') are supported in this context </code></pre> <p>My Datebase interface</p> <pre><code>public class MyDatabase : DbContext, IDolphinDatabase { public IDbSet&lt;Person&gt; People { get; set; } public IDbSet&lt;Role&gt; Roles { get; set; } public IDbSet&lt;Visit&gt; Visits { get; set; } } public interface IMyDatabase : IDisposable { public IDbSet&lt;Person&gt; People { get; set; } public IDbSet&lt;Role&gt; Roles { get; set; } public IDbSet&lt;Visit&gt; Visits { get; set; } } </code></pre> <p>My new Query, I created a dbFactory to just get the IMyDatabase</p> <pre><code>public IEnumerable&lt;VisitDetails&gt; GetGuestVisiterList(int paperId) { using (var db = _dbFactory.GetDatabase()) { return (from p in db.People where p.Roles.Any(a =&gt; a.Name == "Guest") select new GuestVisitDetails { PersonId = p.PersonId, Forename = p.Forename, Surname = p.Surname, NumberOfVisits = db.Visits.Count(v =&gt; v.PersonId == p.PersonId &amp;&amp; v.VisitStatus != "Complete") }).ToList(); } } </code></pre> <p>I've found out that it is the 'NumberOfVisits' that is causing the problem but am unsure why or how to fix it.</p> <p>As requested the stack trace</p> <pre><code>[NotSupportedException: Unable to create a constant value of type 'MyVisits.Data.Model.Visit'. Only primitive types ('such as Int32, String, and Guid') are supported in this context.] System.Data.Objects.ELinq.ConstantTranslator.TypedTranslate(ExpressionConverter parent, ConstantExpression linq) +902 System.Data.Objects.ELinq.TypedTranslator`1.Translate(ExpressionConverter parent, Expression linq) +54 System.Data.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq) +110 System.Data.Objects.ELinq.&lt;&gt;c__DisplayClass77.&lt;TypedTranslate&gt;b__75(Expression e) +11 System.Linq.WhereSelectEnumerableIterator`2.MoveNext() +151 System.Data.Common.CommandTrees.ExpressionBuilder.Internal.EnumerableValidator`3.Validate(IEnumerable`1 argument, String argumentName, Int32 expectedElementCount, Boolean allowEmpty, Func`3 map, Func`2 collect, Func`3 deriveName) +237 System.Data.Common.CommandTrees.ExpressionBuilder.Internal.EnumerableValidator`3.Validate() +46 System.Data.Common.CommandTrees.ExpressionBuilder.Internal.ArgumentValidation.CreateExpressionList(IEnumerable`1 arguments, String argumentName, Boolean allowEmpty, Action`2 validationCallback) +142 System.Data.Common.CommandTrees.ExpressionBuilder.Internal.ArgumentValidation.ValidateNewCollection(IEnumerable`1 elements, DbExpressionList&amp; validElements) +72 System.Data.Objects.ELinq.NewArrayInitTranslator.TypedTranslate(ExpressionConverter parent, NewArrayExpression linq) +121 System.Data.Objects.ELinq.TypedTranslator`1.Translate(ExpressionConverter parent, Expression linq) +54 System.Data.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq) +110 System.Data.Objects.ELinq.ConstantTranslator.TypedTranslate(ExpressionConverter parent, ConstantExpression linq) +520 System.Data.Objects.ELinq.TypedTranslator`1.Translate(ExpressionConverter parent, Expression linq) +54 System.Data.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq) +110 System.Data.Objects.ELinq.AggregateTranslator.Translate(ExpressionConverter parent, MethodCallExpression call) +86 System.Data.Objects.ELinq.SequenceMethodTranslator.Translate(ExpressionConverter parent, MethodCallExpression call, SequenceMethod sequenceMethod) +14 System.Data.Objects.ELinq.MethodCallTranslator.TypedTranslate(ExpressionConverter parent, MethodCallExpression linq) +102 System.Data.Objects.ELinq.TypedTranslator`1.Translate(ExpressionConverter parent, Expression linq) +54 System.Data.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq) +110 System.Data.Objects.ELinq.MemberInitTranslator.TypedTranslate(ExpressionConverter parent, MemberInitExpression linq) +310 System.Data.Objects.ELinq.TypedTranslator`1.Translate(ExpressionConverter parent, Expression linq) +54 System.Data.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq) +110 System.Data.Objects.ELinq.ExpressionConverter.TranslateLambda(LambdaExpression lambda, DbExpression input) +80 System.Data.Objects.ELinq.ExpressionConverter.TranslateLambda(LambdaExpression lambda, DbExpression input, DbExpressionBinding&amp; binding) +88 System.Data.Objects.ELinq.OneLambdaTranslator.Translate(ExpressionConverter parent, MethodCallExpression call, DbExpression&amp; source, DbExpressionBinding&amp; sourceBinding, DbExpression&amp; lambda) +85 System.Data.Objects.ELinq.SelectTranslator.Translate(ExpressionConverter parent, MethodCallExpression call) +37 System.Data.Objects.ELinq.SequenceMethodTranslator.Translate(ExpressionConverter parent, MethodCallExpression call, SequenceMethod sequenceMethod) +14 System.Data.Objects.ELinq.MethodCallTranslator.TypedTranslate(ExpressionConverter parent, MethodCallExpression linq) +102 System.Data.Objects.ELinq.TypedTranslator`1.Translate(ExpressionConverter parent, Expression linq) +54 System.Data.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq) +110 System.Data.Objects.ELinq.ExpressionConverter.Convert() +16 System.Data.Objects.ELinq.ELinqQueryState.GetExecutionPlan(Nullable`1 forMergeOption) +110 System.Data.Objects.ObjectQuery`1.GetResults(Nullable`1 forMergeOption) +149 System.Data.Objects.ObjectQuery`1.System.Collections.Generic.IEnumerable&lt;T&gt;.GetEnumerator() +44 System.Data.Entity.Internal.Linq.InternalQuery`1.GetEnumerator() +40 System.Data.Entity.Infrastructure.DbQuery`1.System.Collections.Generic.IEnumerable&lt;TResult&gt;.GetEnumerator() +40 System.Collections.Generic.List`1..ctor(IEnumerable`1 collection) +315 System.Linq.Enumerable.ToList(IEnumerable`1 source) +58 MyVisits.Business.&lt;GetGuestVisiterList&gt;c__Binding.Invoke(Object&amp; instance, Arguments arguments, Object aspectArgs) in E:\Visual Studio\Projects\MyVisits_current\MyVisits.Business\VisitService.cs:459 PostSharp.Aspects.Internals.MethodInterceptionArgsImpl`1.Proceed() +23 MvcMiniProfiler.Aop.MiniProfilerAttribute.OnInvoke(MethodInterceptionArgs args) in E:\Visual Studio\Projects\MyVisits_current\MvcMiniProfiler.Aop\MiniProfilerAttribute.cs:17 MyVisits.Business.VisitService.GetGuestVisiterList() in :0 MyVisits.Web.Areas.RegionalAdministrator.Controllers.VisitController.EditVisitor() in E:\Visual Studio\Projects\MyVisits_current\MyVisits.Web\Areas\RegionalAdministrator\Controllers\VisitController.cs:85 lambda_method(Closure , ControllerBase , Object[] ) +101 System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters) +17 System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +208 Castle.Proxies.ControllerActionInvokerProxy.InvokeActionMethod_callback(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +27 Castle.Proxies.Invocations.ControllerActionInvoker_InvokeActionMethod.InvokeMethodOnTarget() +154 Castle.DynamicProxy.AbstractInvocation.Proceed() +56 Glimpse.Mvc3.Interceptor.InvokeActionMethodInterceptor.Intercept(IInvocation invocation) +336 Castle.DynamicProxy.AbstractInvocation.Proceed() +94 Castle.Proxies.ControllerActionInvokerProxy.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +214 System.Web.Mvc.&lt;&gt;c__DisplayClass15.&lt;InvokeActionMethodWithFilters&gt;b__12() +55 System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +263 System.Web.Mvc.&lt;&gt;c__DisplayClass17.&lt;InvokeActionMethodWithFilters&gt;b__14() +19 System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +263 System.Web.Mvc.&lt;&gt;c__DisplayClass17.&lt;InvokeActionMethodWithFilters&gt;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.&lt;&gt;c__DisplayClassb.&lt;BeginProcessRequest&gt;b__5() +37 System.Web.Mvc.Async.&lt;&gt;c__DisplayClass1.&lt;MakeVoidDelegate&gt;b__0() +21 System.Web.Mvc.Async.&lt;&gt;c__DisplayClass8`1.&lt;BeginSynchronous&gt;b__7(IAsyncResult _) +12 System.Web.Mvc.Async.WrappedAsyncResult`1.End() +62 System.Web.Mvc.&lt;&gt;c__DisplayClasse.&lt;EndProcessRequest&gt;b__d() +50 System.Web.Mvc.SecurityUtil.&lt;GetCallInAppTrustThunk&gt;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() +8920029 System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean&amp; completedSynchronously) +184 </code></pre> <p>Any help would be great </p>
 

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