Deleting records in LINQ with foreign keys - invalid cast exception

Question

I have a simple database:

ARTICLE
----------
ArticleId (PK),
ArticleTitle
..other stuff...

USER-ARTICLE
------------
ArchiveId (PK),
UserId,
ArticleId
..other stuff...

The articleId's are foreign keys.

I want to be able to delete a user article row by UserArticleId using the following code,

UserArticle myobjtodelete = PersonalArchiveDb.UserArticles.Single(ua => ua.ArchiveId == 3);
PersonalArchiveDb.UserArticles.DeleteOnSubmit(myobjtodelete);
PersonalArchiveDb.SubmitChanges();

^{(Yes I'm aware I can do the statement inside the delete rather than retrieving the object, it was for debugging purposes to make sure the object definitely exists - it does.)}

When the debugger hits the SubmitChanges() line, I get a runtime error:

Specified cast is not valid.

Here is the stack trace,

at System.Data.Linq.IdentityManager .StandardIdentityManager .SingleKeyManager`2.TryCreateKeyFromValues(Object[] values, V& v) at System.Data.Linq.IdentityManager.StandardIdentityManager.IdentityCache`2.Find(Object[] keyValues) at System.Data.Linq.IdentityManager.StandardIdentityManager.Find(MetaType type, Object[] keyValues) at System.Data.Linq.CommonDataServices.GetCachedObject(MetaType type, Object[] keyValues) at System.Data.Linq.ChangeProcessor.GetOtherItem(MetaAssociation assoc, Object instance) at System.Data.Linq.ChangeProcessor.BuildEdgeMaps() at System.Data.Linq.ChangeProcessor.SubmitChanges(ConflictMode failureMode) at System.Data.Linq.DataContext.SubmitChanges(ConflictMode failureMode)
at System.Data.Linq.DataContext.SubmitChanges() at Driver_SOC_ASO.Controls.PersonalArchive.ArchiveListing.grdArchive_RowDeleting(Object sender, GridViewDeleteEventArgs e) in C:\work\Driver.Net\Driver-SOC-ASO\Driver-SOC-ASO\Controls\PersonalArchive\ArchiveListing.ascx.cs:line 78 at System.Web.UI.WebControls.GridView.OnRowDeleting(GridViewDeleteEventArgs e) at System.Web.UI.WebControls.GridView.HandleDelete(GridViewRow row, Int32 rowIndex) at System.Web.UI.WebControls.GridView.HandleEvent(EventArgs e, Boolean causesValidation, String validationGroup) at System.Web.UI.WebControls.GridView.RaisePostBackEvent(String eventArgument) at System.Web.UI.WebControls.GridView.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

I am at a loss, any ideas?

Your sample code uses "ArchiveId" rather than "ArticleId" - in your original description, do you mean "Archive" instead of "Article"? — Jon Skeet, Nov 05 '08 at 11:17
Yeah sorry, there UserArticleId == ArchiveId, poor naming i know Will edit — Chris James, Nov 05 '08 at 11:23

score 1 · Answer 1 · answered Jun 04 '09 at 00:01

1

This may be an example of this bug, which Microsoft says is fixed in .NET 4.0.

answered Jun 04 '09 at 00:01

Jim Counts

12,535
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score 0 · Answer 2 · answered Mar 10 '10 at 21:46

0

In your dbml, check to see if there is incorrect an association b/w Article and UserArticle.

answered Mar 10 '10 at 21:46

DotNetWala

6,574
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score 0 · Answer 3 · answered Apr 05 '09 at 03:39

0

try setting ON CASCADE DELETE for ArticleId

answered Apr 05 '09 at 03:39

Rony

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Deleting records in LINQ with foreign keys - invalid cast exception

3 Answers3