LINQ到SQL-更新分部类中的数据上下文对象

在我创建的这个局部方法中,我想更新一些其他对象。我似乎无法将更新持久化到数据库中。这是我删除预订的部分方法。

public partial class LawEnforcementDataContext
{

    partial void DeleteReservation(Reservation instance)
    {
        // Get ID's of those seated in course
        var roster = new Roster(this, instance.CourseID);
        var seated = from r in roster.All
                     where r.WaitingList == false
                     select r.ID;

        // delete the reservation
        this.ExecuteDynamicDelete(instance);

        // get seated id's not in original seated ids
        var newlySeated = from r in roster.All
                          where r.WaitingList == false && !seated.Contains(r.ID)
                          select r.ID;

        var reservations = this.Reservations.Where(r => newlySeated.Contains(r.ID));

        foreach (var r in reservations)
        {
            r.Confirmed = false;
            // Have tried doing nothing, thinking calling code's db.SubmitChanges() would do the trick
            //this.ExecuteDynamicUpdate(r); HAVE TRIED THIS
        }
        //this.SubmitChanges(); HAVE TRIED THIS
    }
}

正在进行删除,但未进行更新。最后几行中的注释是我尝试过的一些事情。

以下是我为解决这个问题所做的工作:

   public override void SubmitChanges(System.Data.Linq.ConflictMode failureMode)
{
    ChangeSet delta = GetChangeSet();

    foreach (var res in delta.Deletes.OfType<Reservation>())
    {
        // Get ID's of those seated in course
        var roster = new Roster(this, res.CourseID);
        var seated = from r in roster.All
                     where r.WaitingList == false
                     select r.ID;

        base.SubmitChanges(failureMode);

        // get seated id's not in original seated ids
        var newlySeated = from r in roster.All
                          where r.WaitingList == false && !seated.Contains(r.ID)
                          select r.ID;

        var reservations = this.Reservations.Where(r => newlySeated.Contains(r.ID));

        foreach (var r in reservations)
        {
            r.Confirmed = false;
        }
    }

    base.SubmitChanges(failureMode);
}