CREATE TABLE `mod_nl_recipients` (
  `nlrID` int(11) NOT NULL auto_increment,
  `nlrMail` varchar(120) NOT NULL default ''
## hier gibts noch weitere felder die nicht relevant sind
  PRIMARY KEY  (`nlrID`),
  KEY `nlrID` (`nlrID`)
) TYPE=MyISAM AUTO_INCREMENT=1 ;

CREATE TABLE `mod_nl_recipient_groups` (
  `nlrgID` int(11) NOT NULL auto_increment,
  `nlrgRID` int(11) NOT NULL default '0',
  `nlrgGID` int(11) NOT NULL default '0',
  PRIMARY KEY  (`nlrgID`),
  KEY `nlrgGID` (`nlrgGID`),
  KEY `nlrgID` (`nlrgID`),
  KEY `nlrgRID` (`nlrgRID`)
) TYPE=MyISAM AUTO_INCREMENT=1 ;

SELECT 
    nlrMail,COUNT(*) AS Count 
FROM 
    `mod_nl_recipients` 
GROUP BY 
    nlrMail 
HAVING 
    Count  > 1

SELECT 
	t1.nlrMail,COUNT(*) AS Count 
FROM 
	mod_nl_recipients AS t1
LEFT JOIN
	mod_nl_recipient_groups AS t2
ON 
	t1.nlrID = t2.nlrgRID
GROUP BY 
	t1.nlrMail
HAVING
	Count  > 1
WHERE
    	t2.nlrgGID = 3
[/quote]
das problem in diesem fall ist das WHERE, sobald ich das drin hab, bekomme ich nur noch einen fehler.
dachte dann man könnte das mit ins ON packen, das hatte aber keinerlei effekt:

[quote]
SELECT 
	t1.nlrMail,COUNT(*) AS Count 
FROM 
	mod_nl_recipients AS t1
LEFT JOIN
	mod_nl_recipient_groups AS t2
ON 
	t1.nlrID = t2.nlrgRID AND
	t2.nlrgGID = 3
GROUP BY 
	t1.nlrMail
HAVING
	Count  > 1

SELECT
   t1.nlrMail,COUNT(*) AS Count
FROM
   mod_nl_recipients AS t1
LEFT JOIN
   mod_nl_recipient_groups AS t2
ON
   t1.nlrID = t2.nlrgRID AND
   t2.nlrgGID = 3
WHERE
   t2.nlrgGID IS NOT NULL /* <<<<<<<<<<<<<<<<<<<<<<< */
GROUP BY
   t1.nlrMail
HAVING
   Count  > 1