Deleting Row from Database C# WPF Linq

Question

I want to delete a row from the Database on a selected row in my Datagrid I already got how to select a row in my Datagrid, but when I delete it on button_click it only deletes it in my Datagrid but not in my actual Database

I'm using the following code to delete my Rows:

private void btnDeleteUser_Click(object sender, RoutedEventArgs e)
    {
        DialogResult dr = System.Windows.Forms.MessageBox.Show("Do You Want to Delete this User?", "", MessageBoxButtons.YesNo, MessageBoxIcon.Warning);

        if (dr == DialogResult.Yes)
        {
            var query =
                from t in db.tbl_Users
                where t.Name == name
                select t;

            foreach (var t in query)
            {
                db.tbl_Users.DeleteOnSubmit(t);
            }

            db.SubmitChanges();

            var refresh =
                        (from q in db.tbl_Users
                         select new { Name = q.Name, Rights = q.Rights, Operatortag = q.Operatortag, Active = q.Active, Cardcode = q.CardCode }).ToList();

            dgUsers.ItemsSource = refresh;
        }
    }

My Database-property is set on Copy If Newer and I already tried to set in to Copy Always but that wouldn't help either.

Does someone know the answer to my problem?

Answer 1

You have to call .ToList() hope it will help

var items = query.ToList();

foreach (var item in items)
{
    db.tbl_Users.DeleteOnSubmit(item);
}

or you can use DataContext

List<GroupMember> removeFromGroup = (from gm in dataContext.GroupMembers
                                 where (gm.memberID == memberid))
                                 select gm).ToList();

dataContext.GroupMembers.DeleteAllOnSubmit(removeFromGroup);
dataContext.SubmitChanges();