我如何正确设置在实体框架4 Entitydesigner两个对象之间的关联？ [英] How do I correctly set an association between two objects in the Entity Framework 4 Entitydesigner?

问题描述

有关一个新的项目，我想先创建我的商业课程，后来创建真正的数据库表。因此，我使用的是实体框架4设计。 A创建一个新的ADO.Net实体数据模型的文件，扩展的.edmx。

For a new project I'm trying to create my business classes first and create the real database tables later. Therefore I'm using the Entity Framework 4 Designer. A created a new "ADO.Net Entity Data model" file, with the extension .edmx.

我创建了两个实体：结果

I created two Entities:

我要添加产品之间的1到NC关系 - >组。如果我创建了MSSQL数据库首先，​​我会加入一列IDGroup到表产品和参考Product.IDGroup到Group.IDGroup。据我所看到的，我不能在设计中添加这种关联，如果我添加一个名为IDGroup新属性的产品实体

I want to add a 1 to nc relation between Product -> Group. If I'd created the MSSQL database first, I would have added a column IDGroup to the Table Product and referenced Product.IDGroup to Group.IDGroup. As far as I can see, I can't add such association in the designer if I add a new Property called IDGroup to the Product Entity

这是我怎么加的映射：

This is how I add the mapping:

这会导致：结果

Which results in:

现在的部分是什么这个问题大概是：如果我从一个现有的MSSQL数据库的EDMX文件中添加两个表，我会得到编译错误：

Now the part what this question is about: If I add two tables from an existing MSSQL database to the edmx file, I'll get the compile error:

Error 3027: No mapping specified for the following EntitySet/AssociationSet - GroupSet, ProductSet

这是什么意思的错误和我必须做什么来解决这个问题？
如果我删除这两个表，我会收到一个警告而不是：

What does that error mean and what must I do to fix this? If I delete those two tables, I'll receive a warning instead:

Error 2062: No mapping specified for instances of the EntitySet and AssociationSet in the EntityContainer myContainer.

有个声音告诉我，我做的这一切错误的，这仅仅是基本的东西。我该怎么办呢吧？

Something tells me, I'm doing this all wrong and this is just basic stuff. How can I do it right?

推荐答案

我只是碰到了这个自己＆放大器;当我GOOGLE了它（我打你的问题）。

I just ran into this myself & when I Googled it (I hit your question).

我能够双击设计器中的线（关联线）。在属性填写那里，我得到它的工作。

I was able to double click on the line (association line) in the designer. Fill in the properties there and I got it working.

我也不得不关闭VS和重新打开它得到一些报告的错误中去了......

I also had to close VS and re-open it to get some of the errors reported to go away...

不能说这是正确的答案 - 只是摸索周围，并似乎得到的结果。

Can't say this is the correct answer - just fumbling around and seeming to get results.

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