PHP code to be checked - php

Question

I have the following code. What I have labelled block 1 and block 2 don't seem to work together but one does if i get rid of the other; when checking using print_r. I am fairly new to php and was wondering if somebody could point out where I went wrong. I had it working somewhere else before but lost the file. Many thanks in advance.
P.S: I am aware it is a good idea to get into PDO and mysqli sooner rather than later. But I just want to get to grips with the basics first.
<?php
//Connect to database
$connect = mysql_connect ("localhost","root","password");
$db = mysql_select_db("project");
//Find top 100 most popular images
$pop = mysql_query("
SELECT * FROM users ORDER BY pop DESC LIMIT 2
");
//Define local variables for images to show
//block 1//
$images = array();
while ($row = mysql_fetch_array($pop)) {
$images[] = $row['image'];
}
//block2//
$links = array ();
while ($row = mysql_fetch_array($pop)){
$links[] = $row['username'];
}
?>

Answer 1

mysql_data_seek will work:
$images = array();
while ($row = mysql_fetch_array($pop)) {
$images[] = $row['image'];
}
mysql_data_seek( $pop, 0 );
$links = array ();
while ($row = mysql_fetch_array($pop)){
$links[] = $row['username'];
}
However, a better / cleaner solution to your problem would be to put both values into their respective arrays during the first loop:
$links = array();
$images = array();
while ($row = mysql_fetch_assoc($pop)) {
$images[] = $row['image'];
$links[] = $row['username'];
}
Or, even cleaner - add an array to your array:
$avatars = array();
while ($row = mysql_fetch_assoc($pop)) {
array_push(
$avatars,
array('image' => $row['image'], 'username' => $row['username'])
);
}
var_dump($avatars);

Answer 2

First off, Please, don't use mysql_* functions in new code. They are no longer maintained and the deprecation process has begun on it. See the red box? Learn about prepared statements instead, and use PDO, or MySQLi - this article will help you decide which. If you choose PDO, here is a good tutorial.
Try with mysql_data_seek($pop, 0) between the two while loops or replace your code with this:
$images = array();
$links = array();
while ($row = mysql_fetch_array($pop)) {
$images[] = $row['image'];
$links[] = $row['username'];
}

Answer 3

You've already iterated over the entire result set in the first block, you need to re-seek the pointer to the begining of the the result set between the two blocks of code by doing:
mysql_data_seek($pop, 0);

Answer 4

Wrong syntax.
while ($row = mysql_fetch_array($pop, MYSQL_ASSOC))