gistfile1.cs

protected override void DataPortal_Update()
{
    RaiseListChangedEvents = false;
    using (SqlConnection cn = new SqlConnection(Database.LocalConnection))
    {
        cn.Open();
        // loop through each deleted child object
        // foreach (Sales deletedChild in DeletedList)
        //   // deletedChild.DeleteSelf(cn);
        // DeletedList.Clear();
        // loop through each non-deleted child object
        foreach (Sales child in this)
        {
            // child.Update(cn);
        }
    }
    RaiseListChangedEvents = true;
}