Faire un dump des tables SQL en PHP

<?php
include 'config.php';
include 'opendb.php';

$backupFile = $dbname . date("Y-m-d-H-i-s") . '.gz';
$command = "mysqldump --opt -h $dbhost -u $dbuser -p$dbpass $dbname | gzip > $backupFile";
system($command);
include 'closedb.php';
?> 

 <?php  
 include 'config.php';  
 include 'opendb.php';  
   
 $tableName  = 'mypet';  
 $backupFile = 'backup/mypet.sql';  
 $query      = "SELECT * INTO OUTFILE '$backupFile' FROM $tableName";  
 $result = mysql_query($query);  
   
 include 'closedb.php';  
 ?>