strange behaviour

Поиск
Список
Период
Сортировка
От Mathieu Arnold
Тема strange behaviour
Дата
Msg-id 5.0.2.1.2.20010225133146.00a08080@wheresmymailserver.com
обсуждение исходный текст
Ответы Re: strange behaviour  (Peter Eisentraut <peter_e@gmx.net>)
Список pgsql-general
Hi

could someone explain this to me :

sympa=> select count(*) from subscriber_table;
  count
-------
  14029
sympa=> select count(*) from subscriber_table where bounce_subscriber =
NULL;
  count
-------
  14024
sympa=> select count(*) from subscriber_table where bounce_subscriber <> NULL;
  count
-------
      0
sympa=> select count(*) from subscriber_table where bounce_subscriber = '';
  count
-------
      0
sympa=> select count(*) from subscriber_table where bounce_subscriber <> '';
  count
-------
      5

I was thinking that "= NULL" and "<> NULL" were oposite and that "<> NULL"
would give me the result i had with "<> ''" or am I mistaken ?

--
Mathieu Arnold


В списке pgsql-general по дате отправления:

Предыдущее
От: Richard Huxton
Дата:
Сообщение: Re: Request for thoughts...
Следующее
От: Peter Eisentraut
Дата:
Сообщение: Re: strange behaviour