Mysql hata

ip: xxx 
PHP Warning:  mysql_fetch_row(): supplied argument is not a valid MySQL result resource in /var/www/vhosts/xxx/httpdocs/xxx/-/db.php on line 56

Debug backtrace begin:
        at 0  /var/www/vhosts/xxx/httpdocs/xxx/-/options.php (line 53) -> getDebugBacktrace(
)
        at 1   (line ) -> hata(2,mysql_fetch_row(): supplied argument is not a valid MySQL result resource,/var/www/vhosts/xxx/httpdocs/xxx/-/db.php,56,Array)
        at 2   /var/www/vhosts/xxx/httpdocs/xxx/-/db.php (line 56) -> mysql_fetch_row()
        at 3  /var/www/vhosts/xxx/httpdocs/xxx/-/durum.php (line 115) -> readRow()
Debug backtrace end

<?php
class Database
{
	var $connection;

	function Database()
	{
		global $configuration;
		$this->connection = mysql_connect(
			$configuration["host"].':'.$configuration["port"],
			$configuration["user"],
			$configuration["pass"]);
		if ($this->connection) {
			if (!mysql_select_db($configuration["db"])) {
				//throw new Exception('Veritabanı bulunamadı');
				echo 'Veritabanı bulunamadı';
				exit();
			}
		} else {
			//throw new Exception('cannot connect');
			echo 'Veritabanına bağlanılamadı';
			exit();
		}
	}

	static function escape($param)
	{
		return $param;
	}

	static function connect()
	{
		static $database = null;
		if (!isset($database)) {
			$database = new Database();
		}
		return $database->connection;
	}

	static function reader($query, $connection)
	{
		$cursor = mysql_query($query, $connection);
		return $cursor;
	}

	static function read($cursor)
	{
		return mysql_fetch_assoc($cursor);
	}

	static function readRow($cursor)
	{
		return mysql_fetch_row($cursor);
	}

	static function nonQuery($query, $connection)
	{
		mysql_query($query, $connection);
		$result = mysql_affected_rows($connection);
		if ($result == -1) {
			return false;
		}
		return $result;

	}

	static function query($query, $connection)
	{
		$result = mysql_query($query, $connection);
		if ($result == FALSE)
			return 0;
		return mysql_num_rows($result);
	}

	static function insertOrUpdate($query, $connection)
	{
		$result = mysql_query($query, $connection);
		if ($result == FALSE)
			return 0;
		return intval(mysql_insert_id($connection));
	}
}
?>