php - 根据相同的值将数组元素包装在 div 中

Question

从 mysql 中获取结果后，是否可以将 id_group 字段中具有相同值的数组元素分组，并将它们包装在 div 元素中。谁能给我一些建议？

这是我想要的输出:

 <div class="id_group_1"> 
   <div>comment from group 1</div>
   <div>comment from group 1</div>
   <div>comment from group 1</div>
 </div>

 <div class="id_group_2">
   <div>comment from group 2</div>
   <div>comment from group 2</div>
   <div>comment from group 2</div>
   <div>comment from group 2</div>
   <div>comment from group 2</div>
 </div>

PHP

  $id_group = $_POST["group"];
  $reply = $_POST["reply"];
  $sql = "SELECT a.comments,b.name,a.id_group from `reviews` a 
          INNER JOIN `users` b 
          ON a.app_id = b.id  
          WHERE a.post_name = ? 
          AND a.id_group IN ($in) 
          ORDER BY a.id_group";

  $users = $dbh->prepare($sql);
  $users->bindValue(1,$reply);
  $i = 3;
  foreach ($id_group as $id) {
    $users->bindValue($i++, $id);
  }
  $users->execute(array_merge(array($reply), $id_group));

  //*****Here*****//
  foreach($users as $row)
  {
    echo "<div>".$row["comments"]."<br>Written by ".$row["name"]."</div>";  
  }

Answer 1

$rows = $users->fetchAll(PDO::FETCH_ASSOC);
$arrayByGroup = array();

$id = null;
foreach ($rows as $r) {
  if($id != $r['id_group']) {
    if (!is_null($id)) {
      echo '</div>';
    }
    $id = $r['id_group'];
    echo '<div class="id_group_' . $id . '">';
  }
  echo "<div>".$r["comments"]."<br>Written by ".$r["name"]."</div>";

}
echo '</div>'

根据 Matt Barrett 的见解进行编辑。