Simple MySQL database dump lib

dump.php

<?php

class Dump
{
    public static function from( $host, $username, $password, $database, $charset = 'utf8' )
    {
        $o = new self;
        $o->host = $host;
        $o->username = $username;
        $o->password = $password;
        $o->database = $database;
        $o->charset = $charset;

        return $o;
    }

    public $host;
    public $username;
    public $password;
    public $database;
    public $charset;

    public function save( $filename )
    {
        if( file_exists( $filename ) )
        {
            throw new Exception('File arleady exists.');
        }

        $file = new SplFileObject( $filename, 'w' );//fopen( $filename, 'w' );

        $mysql = mysql_connect( $this->host, $this->username, $this->password );
        mysql_select_db( $this->database, $mysql );
        mysql_set_charset( $this->charset, $mysql );

        $tables = array();
        $result = mysql_query('SHOW TABLES');

        while( $row = mysql_fetch_row( $result ) )
        {
            $tables[] = $row[0];
        }

        foreach( $tables as $table )
        {
            $result = mysql_fetch_row( mysql_query("SHOW CREATE TABLE $table;") );

            $file->fwrite( "DROP TABLE IF EXISTS $table;" . PHP_EOL . PHP_EOL );
            $file->fwrite( $result[1] . ";" . PHP_EOL . PHP_EOL );

            $offset = 0;

            while( true )
            {
                $result = mysql_query("SELECT * FROM $table LIMIT $offset, 50;");
                $count = mysql_num_rows( $result );

                while( $row = mysql_fetch_row($result) )
                {
                    $file->fwrite("INSERT INTO $table VALUES(");

                    foreach( $row as $k => $v )
                    {
                        $v = str_replace("\n", "\\n", addslashes( $v ));
                        $file->fwrite("'$v'");
                        if( $k < count($row)-1 ) $file->fwrite(',');
                    }

                    $file->fwrite(");" . PHP_EOL);
                }

                if( $count < 50 ) break;

                $offset += 50;
            }

            $file->fwrite(PHP_EOL . PHP_EOL);
        }
    }
}