mysqli version of David Walsh's PHP MySQL backup script

mysql_backup.php

/* backup the db OR just a table
 * See original: https://davidwalsh.name/backup-mysql-database-php
 */
 
function backup_tables($host,$user,$pass,$name,$tables = '*')
{
    $link = mysqli_connect($host,$user,$pass,$name);
    
    //get all of the tables
    if($tables == '*')
    {
        $tables = array();
        $result = $link->query('SHOW TABLES');
        while($row = $result->fetch_row())
        {
            $tables[] = $row[0];
        }
    }
    else
    {
        $tables = is_array($tables) ? $tables : explode(',',$tables);
    }
    
    //cycle through
    foreach($tables as $table)
    {
        $result = $link->query('SELECT * FROM '.$table);
        $num_fields = $result->field_count;
        
        $return.= 'DROP TABLE '.$table.';';
        $row2 = $link->query('SHOW CREATE TABLE '.$table);
        $row2 = $row2->fetch_array();
        $return.= "\n\n".$row2[1].";\n\n";
        
        for ($i = 0; $i < $num_fields; $i++) 
        {
            while($row = $result->fetch_array())
            {
                $return.= 'INSERT INTO '.$table.' VALUES(';
                for($j=0; $j < $num_fields; $j++) 
                {
                    $row[$j] = addslashes($row[$j]);
                    $row[$j] = ereg_replace("\n","\\n",$row[$j]);
                    if (isset($row[$j])) { $return.= '"'.$row[$j].'"' ; } else { $return.= '""'; }
                    if ($j < ($num_fields-1)) { $return.= ','; }
                }
                $return.= ");\n";
            }
        }
        $return.="\n\n\n";
    }
    
    //save file
    $handle = fopen('db-backup-'.time().'-'.(md5(implode(',',$tables))).'.sql','w+');
    fwrite($handle,$return);
    fclose($handle);
}