How to update non-scalar entity properties in EF 4.0?
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by Mike
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Published on 2010-04-27T13:09:02Z
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2010/04/30
11:57 UTC
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At first I was using this as an extension method to update my detached entities...
Public Sub AttachUpdated(ByVal obj As ObjectContext, ByVal objectDetached As EntityObject)
If objectDetached.EntityState = EntityState.Detached Then
Dim original As Object = Nothing
If obj.TryGetObjectByKey(objectDetached.EntityKey, original) Then
obj.ApplyCurrentValues(objectDetached.EntityKey.EntitySetName, objectDetached)
Else
Throw New ObjectNotFoundException()
End If
End If
End Sub
Everything has been working great until I had to update non-scalar properties. Correct me if I am wrong but that is because "ApplyCurrentValues" only supports scalars. To get around this I was just saving the FK_ID field instead of the entity object relation. Now I am faced with a many to many relationship so its not that simple. I would like to do something like this...
Dim Resource = RelatedResource.GetByID(item.Value)
Condition.RelatedResources.Add(Resource)
But when I call SaveChanges the added Resources aren't saved. I started to play around with self-tracking entities (not sure if they will help solve my prob) but it seems they cannot be serialized to ViewState and this is a requirement for me.
I guess one solution would be to add the xRef table as an entity and add the fks myself but I would rather it just work how I expect it too.
I am open to any suggestions on how to either save my many to many relationships or serialize self-tracking entities (if self-trackingwould even solve my problem). Thanks!
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