update callingroute AS t1 INNER JOIN callingroute AS t2 SET t1.day = (select date FROM (select dayname(date) from callingroute where status = 'OK')AS X) WHERE t1.calling_route_id IS NOT NULL;
// Любая идея, почему я получаю эти ошибки
Во всяком случае, запрос должен быть сокращен до
update callingroute AS t1 SET t1.day = dayname(date) WHERE t1.calling_route_id IS NOT NULL AND status = 'OK';