CREATE TABLE `Positionen` (
  `Id` int(11) NOT NULL auto_increment,
  `GpsProviderId` int(11) NOT NULL,
  `Mobilnummer` varchar(25) collate utf8_unicode_ci NOT NULL,
  `NaviId` varchar(10) collate utf8_unicode_ci NOT NULL,
  `Timestamp` timestamp NULL default '0000-00-00 00:00:00',
  `Longitude` decimal(10,6) NOT NULL,
  `Latitude` decimal(10,6) NOT NULL,
  `Hoehe` decimal(10,1) NOT NULL,
  `Geschwindigkeit` decimal(10,1) NOT NULL,
  `Richtung` int(11) NOT NULL default '0',
  `Sateliten` int(11) NOT NULL default '0',
  PRIMARY KEY  (`Id`),
  KEY `NaviId` (`NaviId`),
  KEY `Mobilnummer` (`Mobilnummer`)
) ENGINE=InnoDB;

SELECT Positionen.*
FROM Positionen
WHERE Timestamp=(
    SELECT MAX(Posits.Timestamp)
    FROM Positionen as Posits
    WHERE Positionen.NaviId=Posits.NaviId OR Positionen.Mobilnummer=Posits.Mobilnummer
)

SELECT *
FROM (
    SELECT *
    FROM Positionen
    ORDER BY Timestamp DESC
) as s
GROUP BY Mobilnummer