添加/删除许多在实体框架许多联想 [英] Add/Remove many to many associations in Entity Framework
问题描述
我在我的示例数据库三个表：
I have three tables in my sample database:
- ID
- 用户名
- 密码
- ID
- 名称
- 说明
- 用户名
- RoleID
UserRoles是一个查找表来模拟一个多对多的关系。添加记录到该表允许一个记录用户和角色联系起来。我的问题是，在实体框架是正确的跨$ P $点这是一个多对多的关系和摘要走的查找表。由此产生的实体和关系是这样的：
UserRoles is a lookup table to simulate a many to many relationship. Adding records to this table allows one to associate records in Users and Roles. My problem is that in Entity Framework it correctly interprets this as a many to many relationship and abstracts away that lookup table. The resulting entities and relationship look like this:
这伟大工程的大部分时间，但我不知道做什么，当我想从查找表中添加/删除条目。我可以删除角色或用户，但实际删除的对象不只是与对方的联系。
This works great most of the time, but I'm not sure what to do when I want to add/delete entries from that lookup table. I can delete roles or users but that actually deletes the objects not just their association with each other.
我知道的一个选项，以一个虚拟列添加到UserRoles查找表。这将迫使实体框架打开查找表成一个成熟的实体，让我能够添加和删除它们作为唯一的目标。但我有没有必要为一个虚拟列，这似乎是一个黑客。我在寻找更好的建议。
I do know of one option to add a dummy column to the UserRoles lookup table. That will force Entity Framework to turn the lookup table into a full-blown entity, allowing me to add and remove them as lone objects. But I have no need for a dummy column and this seems like a hack. I am looking for better suggestions.
任何帮助是AP preciated。
Any help is appreciated.
推荐答案
这应该是这个样子：
user.Roles.Remove(existingRoleEntity);
要添加关系
user.Roles.Add(existingRoleEntity);
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