为什么没有“UpdateOnSubmit”方法？ [英] Why is there no "UpdateOnSubmit" method?

问题描述

我可以通过"UpdateOnSubmit"排队一系列插入内容。在"SubmitChanges"上进行交易的方法，如果有任何失败，则使用事务回滚。但是，我对如何管理更新感到困惑，因为似乎没有一个平等的"UpdateOnSubmit"。这可以包含在SubmitChanges集合中。

I can queue up a series of Inserts via the "UpdateOnSubmit" method that are transacted on "SubmitChanges", with a transaction rollback if any fail. However, I am confused on how updates are managed as there does not seem to be an equilivent "UpdateOnSubmit" that can be included in the SubmitChanges collection.

我似乎在这里缺少一些基本的东西。有人可以解释我会怎样做：

I seem to be missing something basic here. Can someone explain how I would do something like:

dctx.customer.InsertOnSubmit（cust）;
dctx.vehicle.UpdateOnSubmit（veh）;
dctx.stock.InserOnSubmit （股票）;

dctx.customer.InsertOnSubmit(cust);
dctx.vehicle.UpdateOnSubmit(veh);
dctx.stock.InserOnSubmit(stock);

dctx.SubmitChanges（ConflictMode.ContinueOnConflict）;

dctx.SubmitChanges(ConflictMode.ContinueOnConflict);

推荐答案

LINQ to SQL执行自动更改跟踪，因此它已经知道您对通过DataContext检索的对象所做的更改。隐含了在SubmitChanges期间更新对象的请求。它还知道您何时创建了对象的新实例并将其与已经跟踪的对象（通过关系属性）相关联，因此在这些情况下您甚至不需要调用InsertOnSubmit。

LINQ to SQL does automatic change tracking, so it is already aware of changes you've made to objects you've retrieved via the DataContext. A request to update the object during SubmitChanges is implied. It also knows when you've created a new instance of an object and associated it with an object that it is already tracking (via a relationship property), so in those cases you don't even need to call InsertOnSubmit. 

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