I have three tables (user, friends, posts) and two users (user1 and user2).

When user1 adds user2 as friend then user1 can see the posts of user2 just like on Facebook. But only the posts after the date when user1 added user2 as friend. My query is like this:

$sql = mysql_query("SELECT * FROM posts p JOIN friends f ON 
        p.currentuserid = f.friendid AND p.time >= f.friend_since OR 
        p.currentuserid='user1id' WHERE f.myid='user1id' 
        ORDER BY p.postid DESC LIMIT 20");

it is working all the way fine but with a little problem.....!! it displays user2, user3 (all the users as friends of user1) posts for single time but shows user1 posts multiple.......i.e

user2. hi
user1. userssfsfsfsfsdf
user1. userssfsfsfsfsdf
user3. dddddddd
user1. sdfsdsdfsdsfsf
user1. sdfsdsdfsdsfsf

but i in database it is single entry/post why it is happening........!!

How can I fix it?