I have been trying to figure out how to do this, and even with looking at other examples, I can't get it figured out, so maybe I can get some personalized help.
I've got two tables, users_status and friendships.
In the users_status table I have a field userid, and several others.
In the friendships table, I have the fields request_to,request_from, and friendship_status.
Basically what I want to do is get all of the status posts by the current user AND those who are friends of the current user (which I can specify in my PHP using a $userid variable).
Here's an example of the friendships table structure. When a friend request is sent, the userid of the sender and receiver are placed in the table, with a friendship_status of 0. When the request is accepted, the friendship_status is set to 1 and those two are now friends.
friendship_id request_from request_to friendship_status
1 111248 111249 1
2 111209 111249 1
3 111209 111248 0
11 111209 111259 1
5 111252 111209 1
12 111261 111209 1
I realize this may not even be the best structure for determining friendships, especially since the site is relationship based and having to check for friendship connections will be a frequently used thing.
Would it perhaps be better to have two separate tables for friend_requests and friendships? If so, how would I structure/manage the friendships table?
You can use a table join (e.g. http://dev.mysql.com/doc/refman/5.0/en/join.html) to find all of the requests.
Actually you can use a subquery here:
SELECT * FROM users_status WHERE userid = "$userid"
OR userid in (SELECT request_to FROM friendships where request_from = "$userid" AND friendship_status = 1)
OR userid in (SELECT request_from FROM friendships where request_to = "$userid" AND friendship_status = 1)
replace $userid with your user id