Question

The Model as below:

public class User
{
    public int Id
    public virtual ICollection<Tag> FollowingTags {get;set;}
}

public class Tag
{
    public int Id
    public virtual ICollection<User> Followers {get;set;}
    public virtual ICollection<Post> Posts {get;set;}
}

public class Post    {
    public int Id
    public virtual ICollection<Tag> Tags {get;set;}
}

That means there are two many-to-many from User to Post, perhaps it can be called a M:M:M relationship.

Now, if I want to find all posts with tags that followed by a certain User. I wonder what is the best practice with EF 4.1?

If use ADO.NET, I think joining two joint tables is effective way, but joint tables are hidden in EF, then how to do it ? I know some solutions, but the performance is not good, because the generated SQL not good enough. so I ask for a good query to get good performance.

Thank you!

Answer 1

(from p in db.Posts
from t in p.Tags
from f in t.Followers
where f.Id == id
select p).Distinct()