代码优先实体框架C＃，多对多映射，创建连接表，但未在对象上填充列表属性

Question

Many Users can Send Many Message Requests to Many Other Users

USERS

Id

Name

Age

MESSAGE REQUESTS

Id

Message

FromUserID

ToUserID

ICollection<User> RequestUsers

I am trying to set up my class for this using code first. I have managed to get code first and EF to create the junction table but this is no good as the MessageRequest junction table is only used by the database. I am looking for a way to add it to part of the context so I can work with it in code.

I want to be able to get a list of all users that have had a message request sent to them based on the Message Request ID.

Even though code first created the junction table, when I debug the application and inspect RequestUsers property it is null and I want it to be populated automatically to work with in code.

I have tried all kinds of mappings but can't get it to work.

Can someone please explain how to layout the two classes for code first in ER and how I can get the RequestUsers Property to be populated automatically with the list of related users?

Answer 1

Any time you're talking about EF classes, you should post the class definitions. It's nearly impossible to answer a question like this otherwise. That said, I can take a guess that you neglected to add the virtual keyword to your collection, ie:

public virtual ICollection<User> RequestUsers { get; set; }

Without virtual EF will not load the relationship.