Re: postgresql vs mysql
От | Lincoln Yeoh |
---|---|
Тема | Re: postgresql vs mysql |
Дата | |
Msg-id | 200702221614.l1MGE7ue043348@smtp6.jaring.my обсуждение исходный текст |
Ответ на | Re: postgresql vs mysql (Tim Tassonis <timtas@cubic.ch>) |
Список | pgsql-general |
At 10:22 PM 2/22/2007, Tim Tassonis wrote: >Chris wrote: >>An empty string is a KNOWN value. You know exactly what that value >>is - it's an empty string. >>A NULL is UNKNOWN - it doesn't have a value at all. > >I do still think it is a bit of an oddity, the concept of the null >column. From my experience, it creates more problems than it >actually solves and generally forces you to code more rather than >less in order to achieve your goals. > >But as it is a fundamental, defined part of the sql standard, one >just has to live with it. Well it can be useful to have a column like: foo integer not null default null That means someone/something must specify a value for foo when doing an insert. They can't just hope for the best that there's a default... I think that works on postgresql but not on MySQL (see back on topic :) ). Have fun! Link.
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