Getting NullReferenceException on object deletion.

Question

User949231861 posted

I'm getting a null reference exception when trying to delete items from both the Details or List pages. This seems to only happen for one of my tables. I've checked and it is not a foreign key constraint issue where another table is dependent on the key or is it a varchar key like another topic I found on this forum. This is something that only comes up once published and running on the server as it does not happen while running the site on my development machine. Here is the stack trace produced:

[NullReferenceException: Object reference not set to an instance of an object.] System.Data.Objects.Internal.ForeignKeyFactory.CreateConceptualNullKey(EntityKey originalKey) +16 System.Data.Objects.DataClasses.EntityReference.NullAllForeignKeys() +1111 System.Data.Objects.EntityEntry.NullAllForeignKeys() +275 System.Data.Objects.EntityEntry.Delete(Boolean doFixup) +95 System.Data.Objects.ObjectContext.DeleteObject(Object entity) +149 System.Web.UI.WebControls.EntityDataSourceView.ExecuteDelete(IDictionary keys, IDictionary oldValues) +140116 System.Web.UI.DataSourceView.Delete(IDictionary keys, IDictionary oldValues, DataSourceViewOperationCallback callback) +3702789 System.Web.UI.WebControls.FormView.HandleDelete(String commandArg) +872 System.Web.UI.WebControls.FormView.HandleEvent(EventArgs e, Boolean causesValidation, String validationGroup) +675 System.Web.UI.WebControls.FormViewRow.OnBubbleEvent(Object source, EventArgs e) +148 System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +52 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3707

Answer 1

User-330204900 posted

This is usually when deleting an entity that is still being referenced from another entity?

Answer 2

User949231861 posted

Happens with both referenced and unreferenced entities from just the one table. I actually found the error when adding an entity then trying to delete it right afterwards. Past that even, the referenced part should not be an issue since the database has it set to cascade the delete, and that functionality works when deleting from other tables set up the same way.

Answer 3

User3866881 posted

set to cascade the delete, and that functionality works when deleting from other tables set up the same way.

Hello,

Is your problem solved when setting the cascading key?

Answer 4

User-330204900 posted

Hi Cody, can you send me a screen shot of your data model showing the table and any related tables please (to my e-mail address)

Answer 5

User949231861 posted

Good news, the bug seems to have gone away after upgrading everything to using .net 4.5 and Entity Framework 5.0. I cannot replicate it on the deployment server.

Answer 6

User-330204900 posted

OK I know what the issue may be, I have had issues where I was using char(n) as the FK->PK relationship is that what you are doing as I know this is fixed in .Net 4.5

Answer 7

User949231861 posted

No the primary key was an integer identity key.

Answer 8

User3866881 posted

Good news, the bug seems to have gone away after upgrading everything to using .net 4.5 and Entity Framework 5.0. I cannot replicate it on the deployment server.

Hi,

I come here to close the issue. If you have futher information, you can continue by creating another new thread.