Bekomme Inner Joins nicht hin

[ibp]

Code:

SELECT
      id, Daten1, Daten2, MAX(changeTimestamp) changeTimestamp, changeComment
FROM Item a INNER JOIN (
       SELECT id AS fkey, MAX(changeTimestamp) changeTimestamp, changeComment
       FROM Item_Rev      
       GROUP BY id, changeComment
 ) b ON (a.rev = b.fkey)
 GROUP BY id, Daten1, Daten2, changeComment

vielleicht so:

Code:

SELECT
      a.rev, a.Daten1, a.Daten2, MAX(b.changeTimestamp) changeTimestamp, b.changeComment
FROM Item a 
INNER JOIN Item_Rev b ON (a.rev = b.id)
GROUP BY a.Daten1, a.Daten2, b.changeComment