Re: Nulls get converted to 0 problem
От | terry@greatgulfhomes.com |
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Тема | Re: Nulls get converted to 0 problem |
Дата | |
Msg-id | 002401c32c1e$c32c3080$2766f30a@development.greatgulfhomes.com обсуждение исходный текст |
Ответ на | Re: Nulls get converted to 0 problem (Jon Earle <je_pgsql@kronos.honk.org>) |
Список | pgsql-general |
One good reason not interpret the empty string as NULL is because the empty string could violate a foreign key constraint, whereas a NULL says "don't evaluate the fkey constraint, there is no value here for this row" Terry Fielder Manager Software Development and Deployment Great Gulf Homes / Ashton Woods Homes terry@greatgulfhomes.com Fax: (416) 441-9085 > -----Original Message----- > From: pgsql-general-owner@postgresql.org > [mailto:pgsql-general-owner@postgresql.org]On Behalf Of Jon Earle > Sent: Thursday, June 05, 2003 9:39 AM > To: pgsql-general@postgresql.org > Subject: Re: [GENERAL] Nulls get converted to 0 problem > > > On Wed, 4 Jun 2003 terry@ashtonwoodshomes.com wrote: > > > Oracle *incorrectly* interprets blank (empty) strings as > NULL. They are NOT > > the same. A string of zero characters is a string > nonetheless. A NULL is > > "the absence of value", which equals nothing (theoretically > not even another > > NULL). > > If you're testing a value, you're testing to see if there's > something in > there or not - what difference does it make if the variable > contains 0, "" > or NULL? > > Why not adhere to the practices inherent (and thus anticipated by > developers) in other languages (C comes to mind) where 0, > NULL and "" are > equivalent? > > Cheers! > > -- > Jon Earle > > SAVE FARSCAPE http://www.savefarscape.com/ > > ---------------------------(end of > broadcast)--------------------------- > TIP 6: Have you searched our list archives? > > http://archives.postgresql.org >
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