Carousel not displaying cards right after getting data from mysql

You're closing 2 </div> inside the while loop, but they are being opened before the while loop, you need to add them to the beginning of the while loop.

Added a condition to check if it's the first element in the carousel, and if it is, add the active class as required per the documentation.

Initial active element required The .active class needs to be added to one of the slides. Otherwise, the carousel will not be visible.

The code I suggest as an answer makes it a lot more readable, this makes it a lot easier to prevent problems of this nature. Indentation goes a long way to help you see clearly where a block/loop starts and where it ends.

Working minimal fiddle here.

Replace:

<div class="container p-t-0 m-t-2 carousel-inner">
         <div class="row row-equal carousel-item active m-t-0">
             <div class="col-md-4">
    <?php

      $sql = "SELECT * FROM users;";
      $results = mysqli_query($conn, $sql);
      $resultCheck = mysqli_num_rows($results);

      if ($resultCheck > 0){
        while ($row = mysqli_fetch_assoc($results)) {


          //echo '<tr><th scope="row">'.$row['user_id'].'</th><td>'.$row['user_last']."</td><td>".$row['user_uid']."</td></tr>";
          /*echo '<div class="card" style="width: 18rem;">';
          echo '<img class="card-img-top" src="'.$row['avatar'].'" alt="Card image cap">';
          echo '<div class="card-body">';
          echo '<h5 class="card-title">'.$row['user_first'].' '.$row['user_last'].'</h5>';
          echo '<p class="card-text">'.$row['card_text_profil'].'</p>';
          echo '<a href="'.$row['profil_link'].'" class="btn btn-primary">Profil site</a>';
          echo '</div>';
          echo '</div>';*/
          echo '<div class="card" style="width: 18rem;">';
          echo '<div class="card-img-top">';
          echo '<img class="img-fluid" src="'.$row['avatar'].'" alt="Carousel">';
          echo'</div>';
          echo '<div class="card-body">';
          echo '<h5 class="card-title">'.$row['user_first'].' '.$row['user_last'].'</h5>';
          echo '<p class="card-text">'.$row['card_text_profil'].'</p>';
          echo '<a href="'.$row['profil_link'].'" class="btn btn-primary">Profil site</a>';
          echo '</div>';
          echo '</div>';
          echo '</div>';
          echo '</div>';




        }
      }
    ?>





     </div>

With:

<div class="container p-t-0 m-t-2 carousel-inner">
  <?php
  $sql = "SELECT * FROM users;";
  $i = 1;
  $results = mysqli_query($conn, $sql);
  $resultCheck = mysqli_num_rows($results);
  if ($resultCheck > 0){
    while ($row = mysqli_fetch_assoc($results)) { ?>
      <?php if($i % 2 != 0): //add new slider every odd row ?>
          <div class="row row-equal carousel-item <?php echo ($i == 1) ? "active" : ""; ?> m-t-0">
      <?php endif; ?>
        <div class="col-md-4">
          <div class="card" style="width: 18rem;">
            <div class="card-img-top">
              <img class="img-fluid" src="<?php echo $row['avatar']; ?>" alt="Carousel">
            </div>
            <div class="card-body">
              <h5 class="card-title"><?php echo $row['user_first'].' '.$row['user_last']; ?></h5>
              <p><?php echo $row['card_text_profil']; ?></p>
              <a href="<?php echo $row['profil_link']; ?>" class="btn btn-primary">Profil site</a>
            </div>
          </div>
        </div>
          <?php if($i % 2 != 0): //add new slider every odd row ?>
            </div>
          <?php endif; ?>
    <?php $i++; } ?>
  <?php } ?>
</div>