Changing class for subsequent rows - php

Question

I have this piece of code regarding a carousel. I need the first card to have the "active" class but not the following ones or the carousel wont slide. How can i do that?
Here's my code...
$sql = "select wine.wine_name, wine.id, wine.wine_img,
region.region_name, winetype.winetype_name from wine, region, winetype
where wine.region_id = region.id and wine.winetype_id = winetype.id
and sponsored = 1;";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
// output data of each row
while($row = $result->fetch_assoc()) {
echo '<div class="carousel-item col-md-4 active">
<div class="card align-items-center">
<img class="card-img-top img-fluid " src='.$row["wine_img"].' alt="Card image cap">
<div class="card-body">
<h4 class="card-title">'.$row["wine_name"].'</h4>
<p class="card-text">'.$row["winetype_name"].' - '.$row["region_name"].'</p>
</div>
</div>
</div>';
}
} else {
echo "ERRO!";
}

Answer 1

you can use a counter to set the active class.
$result = $conn->query($sql);
if ($result->num_rows > 0) {
// output data of each row
$count_results = 0;
while($row = $result->fetch_assoc()) {
echo '<div class="carousel-item col-md-4 ' . ($count_results == 0 ? 'active' : '') . '">
<div class="card align-items-center">
<img class="card-img-top img-fluid " src='.$row["wine_img"].' alt="Card image cap">
<div class="card-body">
<h4 class="card-title">'.$row["wine_name"].'</h4>
<p class="card-text">'.$row["winetype_name"].' - '.$row["region_name"].'</p>
</div>
</div>
</div>';
$count_results++;
}
} else {
echo "ERRO!";
}

Answer 2

You could just have a field with the extra class part set to active and then reset it at the end of the loop...
// output data of each row
$class = ' active';
while($row = $result->fetch_assoc()) {
echo '<div class="carousel-item col-md-4' .$class. '">
<div class="card align-items-center">
<img class="card-img-top img-fluid " src='.$row["wine_img"].' alt="Card image cap">
<div class="card-body">
<h4 class="card-title">'.$row["wine_name"].'</h4>
<p class="card-text">'.$row["winetype_name"].' - '.$row["region_name"].'</p>
</div>
</div>
</div>';
$class = '';
}

Answer 3

This should do the trick:
while($row = $result->fetch_assoc()) {
$active = isset($active) ? '' : 'active';
echo '<div class="carousel-item col-md-4 ' . $active . '">
...
}
The variable $active will only be unset (undefined or null) on the first iteration. Then, on the other iterations, the variable will be defined and not null (since it's an empty string) so then we simply set it as an empty string again.

Answer 4

I would make a counter and simply check if you need to add the class. Of course, since you only need it once, you can use a boolean.
<?php
$sql = "select wine.wine_name, wine.id, wine.wine_img,
region.region_name, winetype.winetype_name from wine, region, winetype
where wine.region_id = region.id and wine.winetype_id = winetype.id
and sponsored = 1;";
$result = $conn->query($sql);
?>
<?php if ($result->num_rows > 0): ?>
<?php $first = true; ?>
<?php while ($row = $result->fetch_assoc()): ?>
<div class="carousel-item col-md-4 <?= $first ? 'active' : '' ?>">
<div class="card align-items-center">
<img class="card-img-top img-fluid " src=<?= $row["wine_img"] ?> alt="Card image cap">
<div class="card-body">
<h4 class="card-title"><?= $row["wine_name"] ?></h4>
<p class="card-text"><?= $row["winetype_name"] ?> - <?= $row["region_name"] ?></p>
</div>
</div>
</div>
<?php $first = false; ?>
<? endwhile; ?>
<?php else: ?>
<span>Error!</span>
<?php endif; ?>
I've also taken the liberty of taking all of your HTML out of the single echo. This is much cleaner :)