Don't repeat values in loop - php

Question

I've the following query
As you see jigsaw repeats twice because the movie has two categories
but i would like to echo both categories but not twice the movie..
<?php
while ($mInfo = $testquery->fetch(PDO::FETCH_ASSOC)) {
?>
<div class="col-xs-6 col-sm-4 col-md-3">
<a href="movie.php?title=<?php echo $mInfo['titleEN']; ?>&m=<?php echo $mInfo['imdbID']; ?>" title="<?php echo $mInfo['titleEN']; ?>" alt="<?php echo $mInfo['titleEN']; ?>" target="_self">
<div class="movie-info">
<img src="assets/images/poster/<?php echo $mInfo['poster']; ?>.jpg" alt="<?php echo $mInfo['titleEN']; ?>">
</div>
<div class="movieinformation">
<div class="movie-title"><?php echo $mInfo['titleEN']; ?></div>
<div class="movie-categories">I WOULD LIKE TO ECHO THE CATEGORIES HERE</div>
</div>
</a>
</div>
<?php
}
?>
So far i just could do it, could anyone help me with that?

Answer 1

Here's a concept for such tasks. I kept it with general names and left out html on purpose.
$oldMainId = null; // Initialize to null to start with. This will be needed later.
while ($item = $result->fetch()) { // get your items (movies in your case)
if($oldMain != $item['mainId']) {
// only show title if you haven't yet
echo $item['mainTitle'];
}
// always show the category though
echo $item['sub'];
// re-set the 'old' variable.
$oldMainId = $item['mainId'];
}

Answer 2

I would use
OPTION 1
$res = $stmt->fetchAll(PDO::FETCH_GROUP);
Then it will group on the first column, assuming that is movie ID, or something unique to the movie you would get multiple rows in a nested array for that movie.
Then when you iterate thorough them you can loop over the nested array for the genre stuff
OPTION 2
Another option is to use GROUP_CONCAT and group by the movie id,
SELECT GROUP_CONCAT(genre) AS genre, ... WHERE ... GROUP BY movieID
But be aware that GROUP_CONCAT does have a setting for max length and it will silently truncate your data if it exceeds it.
OPTION 3
You can build the structure yourself (same as fetch group does)
$data = [];
while ($mInfo = $testquery->fetch(PDO::FETCH_ASSOC)) {
$key = $mInfo['movieid']
if(!isset($data[$key])) $data[$key] = [];
$data[$key][] = $mInfo;
}
Then go through that and do your html by using a second foreach($data as ...) It has to be done after organizing the data as the order of the result is unknown.