Ошибка в SQL:

SELECT cat.id,cat.pid,cat.cid,cat.mid,cat.title,cat.note,cat.is_popular,cat.taitle,MIN(trip.start) as start,get_vacation_price(cat.id,start,end) as min FROM catalog as cat LEFT JOIN catalog_vacation_period as trip ON cat.id = trip.cid WHERE cat.active=1 AND cat.cid = 439 AND cat.pid = 78 GROUP BY cat.id ORDER BY MIN(trip.start) ASC LIMIT 0,5

Unknown column 'aug_jun' in 'order clause'