Re: So what's null then if it's not nothing?
From: Alexandr Savinov <spam_at_conceptoriented.com>
Date: Fri, 18 Nov 2005 16:31:44 +0100
Message-ID: <437df3f1$1_at_news.fhg.de>
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> This is the practical answer to the question in the subjectline.
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> And IMHO this points in the right direction to proceed.
Date: Fri, 18 Nov 2005 16:31:44 +0100
Message-ID: <437df3f1$1_at_news.fhg.de>
mAsterdam schrieb:
> Alexandr Savinov wrote:
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>> JOG schrieb: >> >>> Alexandr Savinov wrote: >>> >> Because sometimes we have a slot for that and we must write some value >> into it.
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> This is the practical answer to the question in the subjectline.
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>> ...Because there are two parts of data modeling: >> >> - entity modeling, and >> - identitiy mdoeling >> >> They are completely different although exist together. When we are >> talking about existence then it is about identity modeling. When we >> are talking about properties (solour, size etc.) then it is all about >> entity modeling.
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> And IMHO this points in the right direction to proceed.
I am already there... In particulr, the structure of a data model should consist of two parts: one for identity modeling (hierarchical) and another for entity modeling (acyclic graph with top and bottom). Any element then has two flavors: one one hand it exhibit its physical existence as a whole, and on the other hand it is characterized by other elements of the model. And so on...
-- http://conceptoriented.comReceived on Fri Nov 18 2005 - 16:31:44 CET