Re: Weird NOT IN condition in SELECT (PostgreSQL

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