Måltabellen kan inte uppdateras

Jag tror att din UPDATE syntax är felaktig. Se om detta fungerar:

UPDATE booked r
INNER JOIN (
   SELECT a.st_code as from_t
        , b.st_code as to_t 
   FROM `stops_at` a 
   CROSS JOIN `stops_at` b 
   WHERE (a.stop_no < b.stop_no) 
     and (a.train_no = b.train_no) 
     and (a.train_no = '11280')
   ) new 
ON r.st_from = new.from_t 
  and r.st_to = new.to_t
  and r.date = '2013-04-16' 

SET r.seat_ac = r.seat_ac-5