Website querys advanced - php

Question

I am building website like social network.
And i made 3 tables: users, posts, and friends.
How can I write code to display posts from me and from my friends:
Users: id, email, username, password, image
Posts: id, pid, pname, ppost, pimage
Friends: id, user1, user2, friends(yes or no)
So i need to check if user1 is $_SESSION[user] , than too check every row with friends as yes and than echo every post from user1(me) and other users who are friend of mine.
I made some code but it echo posts only from me and first user i marked as friend, i can't show posts from other users i marked as friend.
Users: id:1 email:email#email.com, username:test, password:xd , image:This is link
Users: id:2 , email: test#email.com, username:test2, password:xd, image:Link
Users: id:3 , email: test2#email.com, username:test3, password:xd, image:Link
Posts: id:1 , pid(this is publisher id):etc 1,2,3 , pname:Name of publisher , ppost:Text , pimage: image of publisher:
So just imagine i have 3 posts from 3 diferent users
Friends: id:(auto)1,2,3,4 , user1(user1 is session user) if i login to first user it will be 1, user2(id of other user like 2(test2)), friends(yes)
Friends: id:(auto)1,2,3,4 , user1(user1 is session user) if i login to first user it will be 1, user2(id of other user like 3(test3)), friends(yes)
So i need to echo posts from users(me) , and two others and every other user which have friends(yes) , and don't show posts from users which are marked no.
I made this so far: Querys:
`session_start();
$res=mysql_query("SELECT * FROM users WHERE id=".$_SESSION['user']);
$row=mysql_fetch_array($res);
$res2=mysql_query("SELECT * FROM posts WHERE pid=".$_SESSION['user']);
$row2=mysql_fetch_array($res2);
$res3=mysql_query("SELECT * FROM obavijesti");
$row3=mysql_fetch_array($res3);
$res5=mysql_query("SELECT user1, user2 FROM osobe WHERE friends='yes' AND user1='$_SESSION[user]' order by id limit 5000");
$row5=mysql_fetch_array($res5);
$user2=$row5['user2'];
$user1=$_SESSION['user'];
`
PHP script:
<?php $result = mysql_query("SELECT * FROM posts WHERE pid='$user1' OR pid='$user2' order by id desc limit 5000") ?>
<div class="publishcontent">
<link rel="stylesheet" type="text/css" href="testt.css">
<div class="posts">
<article class="post">
<header class="post-header"><span class="post-user-name"><?php echo $row4['pname']; ?></span><span class="post-header-posted">Objavljeno: Danas</span></header>
<div class="post-flex-container">
<aside class="post-user">
<image src="<?php echo $row4['pimage']; ?>" class="post-user-image"></image>
<div class="post-user-status is-online">TEST</div>
<div class="post-user-posts">Broj objava: x</div>
<div class="post-user-joined"><?php if($row['spol'] == "zensko" ) {
echo "Pridružila se";
}
else {
echo "Pridružio se";
} ?> : <?php echo $row['date']; ?></div>
</aside>
<section class="post-content">
<p>
<?php echo htmlspecialchars($row4['ppost']); ?>
</p>
</section>
</div>
</article>
</div>
</div>
<?php endwhile ?>
And it only displays posts from me and first person i marked as friend, but don't show posts from third person

Answer 1

I would go back to your mysql and refactor your database schema. Your Users table will need to have a one to many relationship with user_id in your Friends table. And your Users table will also need to have a one to many relationship with friend_id in the Friends table. (this allows you to store the user_id of the friend and the user_id of the befriended.) The users table will also have a one to many relationship with the Posts table. Then Change Your mysql to use an inner join query. The inner join query will allow you to query all the results from each table with one query. Here is a link to learn more about that. http://www.w3schools.com/sql/sql_join_inner.asp
SELECT users.*, friends.*, posts.* FROM users INNER JOIN friends ON users.id = friends.user_id INNER JOIN posts ON users.id = posts.user_id
Also you can add a WHERE clause at the end of the query to get related posts and friends for the current logged in user