Don't repeat values in loop

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.