online.php

<?php  

	include('db.php');
	$online_sql=mysqli_query($conn,"SELECT online_user.*,user.name,user.photo FROM online_user INNER JOIN user ON online_user.user_id=user.id GROUP BY online_user.user_id"); //groud by function to make group
	$data="";
	$data.='<li class="list-group-item"><i class="fas fa-circle text-danger" style="font-size:12px;"></i> <b>Active Users</b> <span class="badge badge-info">'.mysqli_num_rows($online_sql).'</span></li>';
	while ($online=mysqli_fetch_assoc($online_sql)) 
	{
		$data.='<li class="list-group-item border-top-0 border-bottom-0"><img src="img/'.$online['photo'].'" class="rounded-circle" width="35px" > '.$online['name'].'</li>';

	}
	echo $data;
	
?>