LINQ to SQL – 更新部分类中的数据上下文对象

我创建了一个可扩展性方法来删除一个名为Reservation的Linq To Sql对象。

好吧，在我创建的这个部分方法中，我想更新一些其他对象。 我似乎无法将更新保留在数据库中。 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 } } 

删除正在进行，但更新不是。 在最后几行中评论了我尝试过的一些事情。

有任何想法吗？ 谢谢！

编辑

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()) { // 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); } 

Answer 1

我希望这里的问题是它已经调用了GetChangeSet() 。

我建议你在数据上下文中覆盖SubmitChanges() ，然后在那里应用这个逻辑……

 partial class LawEnforcementDataContext { public override void SubmitChanges( System.Data.Linq.ConflictMode failureMode) { ChangeSet delta = GetChangeSet(); foreach (var reservation in delta.Deletes.OfType()) { // etc } base.SubmitChanges(failureMode); } } 

Answer 2

以下是更新部分类中对象的解释和好方法： 实现linqtosql部分DataContext类 – 如何检查值之前/之后

我希望它有所帮助。