当外键不存在时禁用关联 [英] Disable associations when a foreign key do not exist

问题描述

我已经为我的数据库创建了一个edmx。在其中Entity框架删除了一个表，而是在两个表之间创建了一个关联，因为它将列名与另一个表中的主键相匹配。

我不想要因为这些表之间没有真正的关联。例如：

> SomeTable

• Id int pk

MiddleTable

• SomeTableId int fk


• SomeCode int

其他表

• SomeCode int pk

这是 MiddleTable ，没有得到

解决方案

• 从edmx中删除一个表，例如。


• 从数据库更新模型，并添加 MiddleTable 。


• 从数据库更新模型，并添加 OtherTable 。

当我用类似的模型这样做时，我最终得到一个 SomeTable 和 MiddleTable 和一个未关联的 OtherTable 。现在您可以根据需要手动添加/删除关联。

正常的EF行为不是为中间表创建一个类。这是一种所谓的 c c> SomeTable 和 OtherTable 之间的许多由两个集合属性建模：

SomeTable.OtherTables

OtherTable.SomeTables

中间表，连接表并不是真的必要。

对我来说有点令人惊讶，你说两个表之间没有关联，虽然显然在数据库中有外键。从技术上讲，它是一对多的关联。

I've created an edmx for my database. In it Entity framework removed a table and instead created an association between two tables because it matches a column name with the primary key in the other table.

I do not want that as there is no real association between those tables. How can I remove that association and get a class for the middle table instead?

Example:

SomeTable

• Id int pk

MiddleTable

• SomeTableId int fk
• SomeCode int

OtherTable

• SomeCode int pk

It's the MiddleTable which do not get a class.

解决方案

• Remove one table from the edmx, e.g. OtherTable.
• Update model from database and add MiddleTable.
• Update model from database and add OtherTable.

When I do this with a similar model I end up with an association between SomeTable and MiddleTable and an unassociated OtherTable. Now you can add/remove associations manually as you wish.

It's normal EF behavior not to create a class for the middle table. This is a so-called many to many association between SomeTable and OtherTable which can be modelled by two collection properties:

SomeTable.OtherTables
OtherTable.SomeTables

The middle table, the junction table, is not really necessary.

It's a bit surprising to me that you say that there is no association between the two tables although, apparently, in the database there are foreign keys. Technically, it is a many to many association.

这篇关于当外键不存在时禁用关联的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！