Separate MySQL results into Divs using while loop - php

Question

Just beginning PHP to bear with me.
Results I'm trying to achiever:
I have a table of YouTube URL's and MetaData.
Trying to build this:
<div class="slide">
<iframe></iframe>
<iframe></iframe>
</div>
<div class="slide">
<iframe></iframe>
<iframe></iframe>
</div>
Two videos per slide, then I'm going to paginate through results using Deck.js.
I suspect I'm going about this completely the wrong way, not that experienced at programmin g logic;
while($data = mysql_fetch_array($result)) {
for ($counter = 1; $counter<=2; $counter++) {
echo "<div class=\"slide\">";
echo "<h3>" . $data['VIDEO_TITLE'] . "</h3>";
echo "<iframe width=\"560\" height=\"315\" src=\"" . $data['VIDEO_URL'] . "\" frameborder=\"0\" allowfullscreen></iframe>";
/* If Video 1, increment counter for 2nd video */
if ($counter == 1) {
$counter++;
}
/* If Video 2, close div and reset counter */
else if ($counter == 2) {
echo "</div>";
$counter = 1;
}
/* If error break out */
else {
echo "</div>";
break;
}
}
}
Basically trying to nest loops to keep track of how many videos per div and start a new one when a div has two.
I've tried a few different ways, this being the latest. Results in:
<div class="slide">
<iframe></iframe>
<div class="slide>
<iframe></iframe>
Hit the blank wall now, not sure what to try next. Willing to use/learn any method to accomplish the results, just not sure where to go at this point.
Cheers.

Answer 1

You could remove the second loop all together using the % operator (modulus). The idea is that a % b === 0 then the number a was evenly divisible by b. Using this, you can easily check for even or odd or every Nth row.
$k = 1;
echo "<div class=\"slide\">";
while($data = mysql_fetch_array($result)) { // you should really change to mysqli or PDO
if($k % 3 === 0){
echo "</div>";
echo "<div class=\"slide\">";
}
echo "<h3>" . $data['VIDEO_TITLE'] . "</h3>";
echo "<iframe width=\"560\" height=\"315\" src=\"" . $data['VIDEO_URL'] . "\" frameborder=\"0\" allowfullscreen></iframe>";
$k++;
}
echo "</div>";

Answer 2

Put the echo <div> before the for loop (still inside the while loop) and the </div> after the for loop

Answer 3

In your while loop you're retrieving just one row, but then you're iterating over it twice with a nested loop. Do away with the inner loop and just use a flip-flop variable to track left and right. I think this will do what you want:
$left=true; // track whether we're emitting HTML for left or right video
while($data = mysql_fetch_array($result)) {
if ($left) {
echo "<div class=\"slide\">";
echo "<h3>" . $data['VIDEO_TITLE'] . "</h3>";
}
echo "<iframe width=\"560\" height=\"315\" src=\"" . $data['VIDEO_URL'] . "\" frameborder=\"0\" allowfullscreen></iframe>";
if (!$left) {
echo "</div>";
}
$left = !$left; // invert $left to indicate we're emitting the right iFrame
}
// end of loop. If we had an odd number of
// videos, tidy up the HTML
if (!$left) {
echo "</div>";
}

Answer 4

PHPFiddle
<?php
$x = 10;
$counter = 0;
while($x > 0)
{
if($counter != 0 && $counter % 2 == 0)
{
echo "ENDOFSLIDE</br>";
}
if($counter == 0 || $counter % 2 == 0)
{
echo "SLIDE</br>";
}
echo "iframe => $x </br>";
$x--;
$counter++;
}
echo "ENDOFSLIDE";
?>

Answer 5

It won't work because the for loop is inside the fetch loop for the SQL data. The second iteration of the for loop does not have a new SQL row. A better solution would be to capture the common column that identifies the two videos (the title) and generate a new div whenever that value changes. Try something like this, which will work for any number of SQL rows with the same title. This will also give proper results if the SQL query returns no rows and will handle the potential of a title with only one URL - which could get ugly if you merely flip-flop and end up with URLs on the wrong title. Of course, as in your current solution, your SQL query must ORDER BY VIDEO_TITLE so the rows are adjacent. I didn't run it, but should be close.
$lastTitle = "";
$n = 0; //count SQL rows processed
while($data = mysql_fetch_array($result)) {
// See if the title changed from last
if( $data['VIDEO_TITLE'] != $lastTitle ) {
// if we processed any rows, must end the current div before starting a new one
if( $n > 0 )
echo "</div>";
echo "<div class=\"slide\">";
echo "<h3>" . $data['VIDEO_TITLE'] . "</h3>";
//save the title as last title
$lastTitle = $data['VIDEO_TITLE'];
}
$n++; //count the SQL row
echo "<iframe width=\"560\" height=\"315\" src=\"" . $data['VIDEO_URL'] . "\" frameborder=\"0\" allowfullscreen></iframe>";
}
if( $n > 0 )
echo "</div>";