I try this query
select a2.Email_account, o2.Numero_ordine, totale_ordine2.totale as totale_ordine, totale_ordine1.totale as totale_riferimento
from
account a1, account a2, ordine o1, ordine o2,
(
select o.Numero_ordine as ordine, SUM(b.Prezzo * b.Quantita) as totale
from biglietto b, ordine o
where
b.Numero_ordine = o.Numero_ordine
group by b.Numero_ordine
) totale_ordine1,
(
select o.Numero_ordine as ordine, SUM(b.Prezzo * b.Quantita) as totale from biglietto b, ordine o
where
b.Numero_ordine = o.Numero_ordine
group by b.Numero_ordine
) totale_ordine2
where
a1.Email_account ='[email protected]'
and a1.Email_account = o1.Email_account
and o2.Email_account = a2.Email_account
and o1.Numero_ordine = totale_ordine1.ordine
and o2.Numero_ordine = totale_ordine2.ordine
and totale_ordine2.totale > max(totale_ordine1.totale);
but i have the error ERROR 1111 (HY000): Invalid use of group function. I understand the problem is the sum and max function but i don't know how to resolve