Taking my very first babysteps with Entity Framework 5.0, I run into an exception with the very first Entity I create.
Please note that every table created after that works just fine. Also, do note that I've taken the usual steps of regenerating the database and/or restarting the Visual Studio IDE.
Using Model-First, I created a trivial table called Contacts
, defined as
<EntityType Name="Contacts">
<Key>
<PropertyRef Name="ContactID" />
</Key>
<Property Name="ContactID" Type="int" StoreGeneratedPattern="Identity" Nullable="false" />
<Property Name="Name" Type="nvarchar(max)" Nullable="false" />
</EntityType>
I then tried to run the following code (from the Page_Load of an ASP.NET page)
var contact = new DataContext.Contact { Name = aName };
context.Contacts.Add(contact);
context.SaveChanges();
(with aName != null)
Exception:
System.NullReferenceException was unhandled by user code
HResult=-2147467261
Message=Object reference not set to an instance of an object.
Source=System.Web
StackTrace:
at System.Web.UI.ParseChildrenAttribute.GetHashCode()
at System.Collections.Generic.ObjectEqualityComparer`1.GetHashCode(T obj)
at System.Collections.Generic.HashSet`1.InternalGetHashCode(T item)
at System.Collections.Generic.HashSet`1.AddIfNotPresent(T value)
at System.Collections.Generic.HashSet`1.UnionWith(IEnumerable`1 other)
at System.Collections.Generic.HashSet`1..ctor(IEnumerable`1 collection, IEqualityComparer`1 comparer)
at System.Collections.Generic.HashSet`1..ctor(IEnumerable`1 collection)
at System.Data.Entity.ModelConfiguration.Utilities.AttributeProvider.GetAttributes(Type type)
at System.Data.Entity.ModelConfiguration.Utilities.AttributeProvider.GetAttributes(PropertyInfo propertyInfo)
at System.Data.Entity.Internal.Validation.EntityValidatorBuilder.BuildPropertyValidator(PropertyInfo clrProperty)
at System.Data.Entity.Internal.Validation.EntityValidatorBuilder.BuildValidatorsForProperties(IEnumerable`1 clrProperties, IEnumerable`1 edmProperties, IEnumerable`1 navigationProperties)
at System.Data.Entity.Internal.Validation.EntityValidatorBuilder.BuildTypeValidator[T](Type clrType, IEnumerable`1 edmProperties, IEnumerable`1 navigationProperties, Func`3 validatorFactoryFunc)
at System.Data.Entity.Internal.Validation.EntityValidatorBuilder.BuildEntityValidator(InternalEntityEntry entityEntry)
at System.Data.Entity.Internal.Validation.ValidationProvider.GetEntityValidator(InternalEntityEntry entityEntry)
at System.Data.Entity.Internal.InternalEntityEntry.GetValidationResult(IDictionary`2 items)
at System.Data.Entity.DbContext.ValidateEntity(DbEntityEntry entityEntry, IDictionary`2 items)
at System.Data.Entity.DbContext.GetValidationErrors()
at System.Data.Entity.Internal.InternalContext.SaveChanges()
at System.Data.Entity.Internal.LazyInternalContext.SaveChanges()
at System.Data.Entity.DbContext.SaveChanges()
at Contactisch._Default.AddContact(String aName) in c:ProjectsContactischContactischContactischDefault.aspx.cs:line 32
at Contactisch._Default.Page_Load(Object sender, EventArgs e) in c:ProjectsContactischContactischContactischDefault.aspx.cs:line 14
at System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e)
at System.Web.UI.Control.OnLoad(EventArgs e)
at System.Web.UI.Control.LoadRecursive()
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
InnerException:
Can someone explain the cause of this exception ? Especially, what is that call to ParseChildrenAttribute.GetHashCode doing there?
I did find someone running into the same issue here, but no satisfactory explanation was given.
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