How Do I Solve My Problem In Deleting From My Database In Entity Framework

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im working on a content management system with visual studio 2012 and entity framework.
as i run this part:

C#

protected void grdResults_RowDeleting(object sender, GridViewDeleteEventArgs e)
{

    int w = int.Parse(grdResults.Rows[e.RowIndex].Cells[0].Text);
    NewsDbModel.NewsDbEntities db = new NewsDbModel.NewsDbEntities();
   
    var x = (from NewsTable in db.Tables where NewsTable.Id == w select NewsTable);
    db.DeleteObject(x); 
      
    db.SaveChanges();

}

i face this error:
"The object cannot be deleted because it was not found in the ObjectStateManager."

pls help me in solving this problem.
thanks alot

Posted 6-Sep-14 22:09pm

f.bateni

Updated 9-Sep-14 9:46am

v3

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f.bateni 7-Sep-14 10:34am

thanks dear George Jonsson
i did what u said. x hasnt null value so it inter the if but again faced the same error:"The object cannot be deleted because it was not found in the ObjectStateManager.
how can i make ObjectStateManager finds var x?
thanks again

George Jonsson 9-Sep-14 21:03pm

I didn't see your comment coz you put it in the wrong place.
See below.

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George Jonsson · Answer 1 · 2014-09-06T22:43:00

Solution 1

Well, you try to delete the same object twice. That should be an issue.
Also add a check for your x variable so it actually contains a value.

C#

protected void grdResults_RowDeleting(object sender, GridViewDeleteEventArgs e)
{

    int w = int.Parse(grdResults.Rows[e.RowIndex].Cells[0].Text);
    NewsDbModel.NewsDbEntities db = new NewsDbModel.NewsDbEntities();

    var x = (from NewsTable in db.Tables where NewsTable.Id == w select NewsTable);
    if (x != null)    // Set a break point here and debug.
        db.DeleteObject(x);
    db.DeleteObject(x);

    db.SaveChanges();

}

Posted 6-Sep-14 22:43pm

George Jonsson

Comments

Nelek 9-Sep-14 18:38pm

The OP got the wrong "have a question or comment" widget and reply you in the question-comments. Have a look.

George Jonsson 9-Sep-14 21:00pm

Thanks for the notice.

Nelek 10-Sep-14 4:07am

You are welcome :)

George Jonsson 9-Sep-14 21:32pm

Have you checked the value of 'w'?
Or first, check the value of grdResults.Rows[e.RowIndex].Cells[0].Text

f.bateni 10-Sep-14 11:31am

yeah i checked it. it get correct id of my table
also value of grdResults.Rows[e.RowIndex].Cells[0].Text is true & x get value of the correct row of table.
i also sent it to another gridViwe to check it. but as it faced to db.DeletObject(x) it stopped and has run time error