Richard Huxton said: > Ferruccio Zamuner wrote: >> Hi, >> >> I've following select, and I expect to receive a single record as result >> from it: >> >> select c.id >> from copie as c >> where c.enum=46857 and >> c.condizio_prestito = 'A' and >> c.id not in (select id_copia from testi_fermi_prenotati) and >> c.id not in (select id_copia from prestiti); >> >> but it doesn't give me any records at all.
>> CREATE TABLE prestiti ( >> id_copia integer references copie(id) > >> CREATE TABLE testi_fermi_prenotati ( >> id_copia integer NOT NULL references copie(id), > > Are you sure you don't have any null values in prestiti.id_copia? Yes, there is a null value and it has not to be there. Thank you. Bye, \ferz ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html