LINQ的问题，插入有对现有记录的引用新行 [英] Linq problem with inserting new rows that have references to existing records

问题描述

（我相信这是同样的问题的这个，但没有答案，我想我可以更好地在这里表达的问题...）

(I believe this is the same problem as this one, but there's no answer there, and I think I can express the problem better here...)

我有两个LINQ到SQL类，国家和县，其中县有FK到国家。下面是一些测试代码：

I have two Linq-to-SQL classes, State and County, where County has a FK to State. Here's some test code:

State s = State.GetState("NY"); // here I do a load of a State class via the Linq DataContext
County c = new County();
c.Name = "Rockland";
c.State = s;
MyDataContext.GetTable<County>().InsertOnSubmit(c);
MyDataContext.SubmitChanges(); // throws an exception

引发的异常是PRIMARY KEY约束违反PK_State'。不能插入对象dbo.State'重复键。

在换句话说，这似乎在这里发生的是尽管已经载入我的取值为现有的记录，当我试图插入 C ，LINQ的是假设所有相关的对象，国家在内，还需要插入！

In other words, what appears to be happening here is that despite my having loaded s as an existing record, when I attempt to insert c, Linq is assuming that all related objects, State included, also need to be inserted!

这是完全荒谬的，我不认为微软会作出如此巨大的错误 - 所以它必须在某个地方我自己的理解是错误的。

This is completely absurd, and I cannot believe that Microsoft would have made such a huge blunder - so it must be that somewhere my own understanding is faulty.

任何人都可以请解释什么，我做错了，什么正确的方法这里是？

Can anyone please explain what I am doing wrong, and what the correct approach here is?

谢谢！

推荐答案

是 State.GetState（...）使用相同的datacontext为 MyDataContext.GetTable< 功能;县及GT;（）？

Is the State.GetState(...) function using the same datacontext as MyDataContext.GetTable<County>()?

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