Re: XOR logical operator

Поиск
Список
Период
Сортировка
От Pavel Stehule
Тема Re: XOR logical operator
Дата
Msg-id Pine.LNX.4.44.0310171009030.10282-100000@kix.fsv.cvut.cz
обсуждение исходный текст
Ответ на XOR logical operator  (Nagib Abi Fadel <nagib_postgres@yahoo.com>)
Список pgsql-general
Hello,

PostgreSQL hasn't logical operator XOR. But You can find it in cookbook
http://www.brasileiro.net/postgres/cookbook/view-recipes.adp?section_id=41&format=long

Regards
Pavel



On Fri, 17 Oct 2003, Nagib Abi Fadel wrote:

> Is there a XOR logical operator in Postgresql, or a
> function for XOR ??
>
> I only found in the docs a Binary XOR (#).
>
> I need to do the following checkup:
> (field1 is NULL XOR field2 is NULL XOR filed3 is NULL)
>
> i can't right it like this:
> (
> (field1 is NUll or field2 is NUll)
> and (field1 is NUll or field3 is NUll)
> and (field2 is NUll or field3 is NUll)
> )
>
> But if i have alot of fields :
> field1,field2,...,field5
> ... this will take a hell of a time
> I can write a function F1 that does the following:
> if a field is NULL it will return 1
> else it will return 0
>
> then i can do:
> (F1(field1) # F1(field2) # F1(field3) ...)
>
>
> but i just wanted to see if XOR already exists ...
>
>
>
> __________________________________
> Do you Yahoo!?
> The New Yahoo! Shopping - with improved product search
> http://shopping.yahoo.com
>
> ---------------------------(end of broadcast)---------------------------
> TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org
>


В списке pgsql-general по дате отправления:

Предыдущее
От: Nagib Abi Fadel
Дата:
Сообщение: XOR logical operator
Следующее
От: Nick Burrett
Дата:
Сообщение: Re: ShmemAlloc errors