Implement "follow person, post" feature in asp.net mvc

In any social network, you can follow a person, a post or anything, everything you followed will be displayed in your wall, now I wanna implement the same feature in asp.net mvc, but I have problem on design table to query all following things of a user. This is tables I designed:

 [User(id,name,email,password)]
 [Following(id,personId,followingId,source)]
 [Post(id,title,description,authorId)]

So when a user followed other user,a new record will be pushed on Following table with followingId is userId, and source is "User" table, the same as with following a post with followingId is postId and source is "Post" table. The problem is when fetch data from what your following, the query join many tables to return result if user followed more things than a Post, and Other User (such as a Tag, a Topic...). this will be not good performance and query time to return data to user. Do you have any ide开发者_如何学运维a about this ? I'm very appreciate to hear your solution, thanks a lot!

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Your database design is flawed, instead of one "link" table with a string to identify where the "Followed thing" resides makes it hard to query effectively.

Instead you need one link table per thing linked. SO in your simplified example you might have

[User(id,name,email,password)]
[Post(id,title,description,authorId)]
[UserFollowingUser(id, userId, followedUserId]
[UserFollowPost(id,userId,postId)]

Therefore to get all users following a post, or all posts followed by a user, or get all users following a particular user, or get all users followed by a particular user is easy as pie.