实体框架 - 添加导航属性手动 [英] Entity Framework - Add Navigation Property Manually

问题描述

我从数据库中生成一个实体框架模型（4.0）。我没有设计的数据库，并没有对架构的任何控制，但有没有外键约束定义的几桌，但有定义的隐含关系。

I generated an Entity Framework Model (4.0) from my database. I did not design the database and do not have any control over the schema, but there are a few tables that do not have foreign key constraints defined, but there is an implicit relationship defined.

例如：

我有以下几列的表中调用的人：
GenderID
RaceID

I have a table called People that has the following columns: GenderID RaceID

有两个性别和种族的表，但没有在人民表中没有外键。

There are tables for both Gender and Race but there is no foreign key in the People table.

当我导入模型并没有添加导航属性这些关系。我尝试手动添加它，但是从作用和角色都被禁止。我不知道如何添加关系喽。我该怎么做呢？

When I imported the model it did not add Navigation Properties for these relationships. I tried to add it manually but From Role and To Role are disabled. I'm not sure how to add the relationship myself. How do I do this?

推荐答案

是的 - 它不是那么简单。

Yup - it's not that straightforward.

下面就是你要做的：

1 - 右键单击​​设计师，添加 - > 协会

1 - Right click on the designer, Add -> Association

2 - 设置的关联和基数（人民*。1性别，人民*。1赛）

2 - Setup the association and cardinalities (People *..1 Gender, People *..1 Race)

3 - 走进在模型浏览器 - > 协会

3 - Go into the Model Browser -> Associations

4 - 鼠标右键点击你新建的关联，点击属性

4 - Right click on your newly created associations, click Properties

5 - 在这里你需要设置的关键和级联选择的端点。确保你得到了正确的终点。您还可以设置一个参照约束在这里为您导航隐含属性。

5 - Here you need to setup the endpoints for the key and cascade options. Make sure you get the endpoints correct. You can also setup a referential constraint here for your implicit navigational property.

6 - 导航属性相关的表/字段映射

6 - Map the navigational property to the relevant tables/fields.

7 - 验证模型，手指交叉

7 - Validate your model, cross your fingers.

希望这有助于。

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