DELETE upt FROM #__mycomponent_user_posts AS upt WHERE upt.posts=0 AND upt.owner=0 AND upt.favorite=0 AND upt.subscribed=0 AND upt.params='' 
     
DELETE FROM #__mycomponent_user_posts AS upt WHERE upt.posts=0 AND upt.owner=0 AND upt.favorite=0 AND upt.subscribed=0 AND upt.params=''