mAsterdam schrieb:
> Alexandr Savinov wrote:
>
>> JOG schrieb:
>>
>>> Alexandr Savinov wrote:
>>>
>> Because sometimes we have a slot for that and we must write some value
>> into it.
>
>
> This is the practical answer to the question in the subjectline.
>
>> ...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.
>
>
> 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.com
Received on Fri Nov 18 2005 - 09:31:44 CST
