PHP Bereken records

$sql = mysql_query("SELECT * FROM leden_rekenen");
while($db = mysql_fetch_assoc($sql))
{
  if(!empty($db['user']))
  {
    echo $db['user']."<br />";
  }
}

<?php
$sql = mysql_query("SELECT DISTINCT * FROM leden_rekenen"); 

while( $db = mysql_fetch_assoc( $sql ) ) 
{ 

  $sub_query = mysql_query( "SELECT * FROM leden_rekenen WHERE user = '" . $db['user'] . "'" );
  $num_rows = mysql_num_rows( $sub_query );
  
  echo htmlspecialchars($db['user']) . ' ' . $num_rows . 'x<br />'; 
  
} 
?>

<?php
$query = mysql_query("SELECT * FROM leden_rekenen GROUP BY user");
while($db = mysql_fetch_assoc($query)) {
 echo $db['user']." (".mysql_num_rows(mysql_query("SELECT user FROM leden_rekenen WHERE user='".$db['user']."'"))."x)<br />";
}
?>

<?php 
$query = mysql_query("SELECT COUNT(*) as `amount` FROM `leden_rekenen` GROUP BY `user`"); 
while($db = mysql_fetch_assoc($query)) { 
 echo $db['user']." (".$db['amount']."x)<br />"; 
} 
?>

<?php 
$query = mysql_query("SELECT user,COUNT(*) as amount FROM leden_rekenen GROUP BY user"); 
while($db = mysql_fetch_assoc($query)) { 
 echo $db['user']." (".$db['amount']."x)<br />"; 
} 
?>